Outer coding methods for broadcast/multicast content and related apparatus

Priority claim under 35 U.SC § 119 This patent application is a provisional application No. 60 / 497,457 entitled Method and MFP for Seamless Delivery of Broadcast and Multicast Content Across Cell Borders and / or Between Different Transmission Schemes filed on August 21, 2003, and August 2003. It demands priority over Provisional Application No. 60 / 497,456 entitled "L2 Design for Outer Coding Scheme" filed on the 21st, both of which are assigned to this assignee and are specifically incorporated herein by reference.

Field The present invention generally relates to communication systems, and in particular to the delivery of broadcast and multicast content.

Wireless communication systems have traditionally been used to carry voice traffic and low data transmission rate non-voice traffic. Today, wireless communication systems that carry high data transfer rate (HDR) multimedia traffic such as video, data, and other types of traffic are being implemented. Multimedia broadcast and multicast service (MBMS) channels are based on audio, audio and video data sources such as radio broadcasts, television broadcasts, movies, and other formats of audio or video content. Used to transmit the Ming application. Streaming data sources are sometimes intermittent and generally compressed, so delays and some loss or bit error can be tolerated. Therefore, the data transmission rate of the transmission arriving in the radio access network (RAN) fluctuates greatly. Since application buffers are generally finite, an MBMS transmission mechanism corresponding to fluctuating source data transmission rates is required.

Base stations generally provide such multimedia traffic services to subscriber stations by transmitting information signals that are usually grouped into multiple packets. A packet is a set of bytes containing data (pay load) and control elements, which are arranged in a particular format. Control elements include preambles and quality metrics, including, for example, cyclic redundancy checks (CRCs), parity bits, and other forms of metrics. Packets are usually formatted during a message according to the communication channel structure. The message travels between the transmitting terminal and the target terminal and is affected by the characteristics of the communication channel such as signal-to-noise ratio, time variation, and other such characteristics. Such characteristics affect the modulated signal differently in different communication channels. Another consideration is that the transmission of the modulated information signal over the radio communication channel requires the selection of an appropriate method of protecting the information in the modulated signal. Such methods include, for example, coding, symbol repetition, and other methods known to those of skill in the art. However, these methods increase overhead. Therefore, a technical compromise must be made between the reliability of message delivery and the amount of overhead.

Operators are generally point-to-point (PTP) on a cell by cell criteria depending on the number of subscriber stations or user devices (UEs) interested in receiving MBMS content. ) Select either a connection or a point-to-multipoint (PTM) connection.

Two-point (PTP) transmission uses dedicated channels to service selective users in the reception area. The "dedicated" channel carries information from / to a single subscriber station. In two-point (PTP) transmission, separate channels are used for transmission to each mobile station. Dedicated user traffic for one user service in the forward or downlink direction is, for example, sent through a logical channel called a Dedicated Traffic Channel (DTCH). Two-point (PTP) communication services are generally most efficient unless, for example, there are sufficient users to require specific multimedia broadcasts and multicast services (MBMS) in the receiving area. is there. In such cases, two-point (PTP) transmission is used, in which the service is transmitted only to the specific user for which the base station has requested the service. For example, in a W-CDMA system, it is more efficient to use dedicated channel or two-point (PTP) transmission up to a certain number of mobile stations.

"Broadcast communication" or "one-point to multi-point (PTM) communication" is communication on a common communication channel to a plurality of mobile stations. A "common" channel carries information to / from a large number of subscriber stations and is used simultaneously by several terminals. In a one-point-to-multipoint (PTM) communication service, for example, if the number of users requesting the service exceeds a predetermined limit within the reception area of the base station, the cell base station is a common channel. Broadcast multimedia traffic services above. In CDMA2000 systems, PtM wireless carrier (radio) Broadcasting or one-point-to-multipoint (PTM) transmission is commonly used as an alternative to PtP transmission, as bearer) is almost as efficient as PtP radio carriers. Common channel transmissions from a particular base station are not always synchronized with common channel transmissions from other base stations. In a typical broadcast system, one or more central stations serve content to (user's broadcast net). The central station transmits information to either all subscribers or a group of specific subscriber stations. Each subscriber station interested in broadcast services monitors common forward line signals. One-point to multi-point (PTM) transmissions are sent over downlinks or forward common channels. This common broadcast forward line signal is a common traffic that generally exists in the forward line or "downline" direction. Broadcast on one-way channels such as channels (CTCH). Since this channel is unidirectional, allowing all subscriber units to reply to the base station would overload the communication system and the subscriber station would generally not communicate with the base station. In this way, in the one-point to multi-point (PTM) communication service, when the information received by the subscriber station is incorrect, the subscriber station cannot reply to the base station. Therefore, other means of information protection are desired.

In a CDMA2000 system, subscriber stations are loosely coupled in one-point-to-multipoint (PTM) transmission. Even when measures are taken to protect the information signal, the state of the communication channel deteriorates to the point where the destination station cannot decrypt some packets forwarded on the dedicated channel. In such cases, one strategy is to simply retransmit the undecrypted packet to the originating (base) station using an automatic retransmission reQuest (ARQ) created by the intended (subscriber) station. is there. Retransmission helps ensure the delivery of data packets. If the data cannot be delivered correctly, the RLC user on the transmission side will be notified.

Subscriber stations generally undergo transitions in some scenarios. These transitions fall into a variety of ways. For example, transitions are classified as "cross transitions" and "direct transitions". Migrations are also classified as "inter-cell" transitions and "intra-cell" transitions.

The transition between cell or transmission methods has unfavorable service interruption consequences for the user. When a subscriber station or user device (UE) moves from one cell to another, or the delivery of multimedia broadcasting and multicast service (MBMS) content is one mode in the service cell. -A problem arises when changing from one mode to another. Transmissions from neighboring cells are time-shifted by the amount Δt1 with respect to each other. In addition, a further delay is introduced during the transition because the mobile station needs to determine the system information in the target cell, which requires a certain amount of processing time Δt2. Data streams transmitted from different cells (or different transmission channel formats: two-point (PTP) / one-point to multi-point (PTM)) are offset relative to each other. Therefore, during multipoint (PTM) transmission from different cells, the mobile station may receive blocks of the same content twice, or some blocks of content may be lost, which is the Quality of Service. Service) is not preferable. The transition between cell-to-cell and / or two-point (PTP) transmission and one-point to multi-point (PTM) transmission is interrupted in service due to the duration of the transition and delays or misalignments between transmissions. cause.

Therefore, a service cell that provides service continuity and is caused by a transition that occurs when the user device (UE) moves from one cell to another, or the delivery of content is the same. Transmission techniques are needed in the art to reduce the interruptions in content delivery caused by the transition that occurs when changing from a two-point (PTP) connection to a one-point to multipoint (PTM) connection in. Such transmission techniques would preferably allow seamless delivery across cell boundaries and / or between different transmission methods such as one-point-to-multipoint (PTM) and two-point (PTP). Let's go. A mechanism for adjusting different streams so that the data is not lost during the transition and playing the content from each data block during such a transition is also desirable. It is also desirable to provide a mechanism for rearranging the data during decoding at the receiving terminal.

<figref num="1">It is a figure of a communication system.</figref><figref num="2">It is a block diagram of the UMTS signaling protocol stack.</figref><figref num="3">It is a block diagram of the packet switching user plane of the UMTS protocol stack.</figref><figref num="4">It is a block diagram of the access hierarchy part of the UMTS signal protocol stack.</figref><figref num="5A">It is a block diagram of the data transfer mode used in the radio link control (RLC) layer of the UMTS signal protocol stack, and the various channels used in each layer.</figref><figref num="5B">It is a block diagram which shows the architecture of the radio line control (RLC) layer including various RLC data transfer modes.</figref><figref num="5C">It is a block diagram which shows the entity which performs the radio line control (RLC) acknowledgment mode (AM).</figref><figref num="6">FIG. 5 is a diagram of a modified UMTS protocol stack with a forward error correction layer.</figref><figref num="7A">An embodiment of the protocol structure of the access layer including the forward error correction (FEC) layer is shown.</figref><figref num="7B">Another embodiment of the protocol structure of the access layer, including the forward error correction (FEC) layer, is shown.</figref><figref num="8">It is a figure of the information block and the external code block corresponding to the information block.</figref><figref num="9A">It is a figure which shows the external code block structure applicable to multimedia broadcasting and multicast service (MBMS) data.</figref><figref num="9B">It is a figure which shows the external code block structure of FIG. 9A in which a large number of lines are sent for each Transmission Time Interval (TTI).</figref><figref num="9C">It is a figure which shows the external code block structure of FIG. 9A where each row is sent by a multi-dimensional TTI.</figref><figref num="10A">It is a figure which shows the external code block generated by the forward error correction layer.</figref><figref num="10B">It is a figure which shows the external code block generated by the forward error correction layer.</figref><figref num="11">An embodiment of the forward error correction (FEC) layer used in the RLC UM + entity.</figref><figref num="12A">The coding process for generating an external code block from a data unit in which the row size of the external code block is fixed is shown.</figref><figref num="12B">An example of the information in FIG. 12A sent in the air is shown.</figref><figref num="13">The coding process for generating the external code block having various row sizes is shown.</figref><figref num="14">FIG. 5 is a diagram of an embodiment of a forward error correction (FEC) header format.</figref><figref num="15">An algorithm that allows a mobile station to delay decoding by a time offset between different logical streams.</figref><figref num="16">External code block received by a mobile station when the mobile station transitions while receiving one-point-to-multipoint (PTM) transmission from cell A and another one-point to multipoint (PTM) transmission from cell B. It is a figure which shows the time relationship between.</figref><figref num="17">FIG. 5 shows the time relationship between external code blocks received by a mobile station when a transition occurs between one-point-to-multipoint (PTM) transmission and two-point (PTP) transmission.</figref><figref num="18">Move during transition or relocation between two-point (PTP) transmission from wireless network controller (RNC) A and other two-point (PTP) transmission from wireless network controller (RNC) B It is a figure which shows the time relationship between the external code blocks received by a station.</figref>

The term "exemplary" here means "useful as an example, case, or example." The embodiment shown herein as "typical" is not always construed as favorable or advantageous over other embodiments.

The term "mobile station" is used here as the term "destination station", "subscriber station", "subscriber unit", "terminal" and "user-". Compatible with "User Equipment (UE)" and used here to refer to hardware such as base stations with which access networks such as UMTS terrestrial radio connections (UTRAN) communicate. .. In a UMTS system, a user device (UE) allows a user to access a UMTS network service, and more preferably on a device containing USIM that contains all user reservation information. is there. Mobile stations are mobile or stationary and generally include, for example, communication devices, data devices or terminals that communicate over wireless or wired channels using fiber optics or coaxial cables. Mobile stations are embodied in devices including, but not limited to, PC cards, CompactFlash, external or internal modems, or wireless or wired telephones.

The term "connection setup state" refers to the state in which a mobile station is in the process of establishing an operational traffic channel connection with a base station.

The term "traffic state" refers to the state in which a mobile station has established an operating traffic channel connection with a base station.

The term "communication channel" is used here to mean a physical or logical channel depending on the context.

The term "physical channel" is used herein to refer to a channel that carries user data or control information over an aerial interface. A physical channel is a "transmission medium" that provides a wireless platform on which information is actually transferred and is useful for carrying communications and user data over wireless lines. Physical channels generally include a combination of frequency scrambled and channelized codes. In the uplink direction, relative phase is also included. Several different physical channels are used in the uplink direction based on what the mobile station is trying to do. In UMTS systems, the term "physical channel" refers to different types of bandwidth allocated for different purposes on the Uu interface. The physical channel forms the physical presence of the Uu interface between the user device (UE) area and the network connection area. Physical channels are defined by the physical maps and attributes used to transfer data over the air interface.

The term "transport channel" is used herein to refer to a communication route for data transport between peer physical layer entities. The transport channel relates to the way information is transmitted. There are two types of transport channels, commonly known as Common Transport Channels and Dedicated Transport Channels. The transport channel uses, for example, either dedicated or common physical channels, or logical channel multiplexing, and how and what characteristic data is transferred to the physical layer over the aerial interface. Defined by logic. The transport channel acts as a service access point (SAP) for the physical layer. In UMTS systems, transport channels describe how logical channels are transferred and the flow of this information is mapped to physical channels. The transport channel is Medium Access Used to carry signals and user data between the Control: MAC) layer and the physical layer (LI). The Radio Network Controller (RNC) looks at the carrier channel. Information is passed from the MAC layer to the physical layer on any one of several transport channels mapped to the physical channel.

The term "logical channel" is used herein to refer to an information stream or wireless interface dedicated to the transfer of certain forms of information. Logical channels relate to the information being transmitted. A logical channel is defined by what form of information is transferred, eg, communication or user data, and is understood as a different task that the network and terminals should perform at different times. The logical channel is mapped to a carrier channel that actually transfers information between the mobile station area and the access area. Information is passed via a logical channel that is mapped via a transport channel that is mapped to a physical channel.

The term "dedicated channel" is generally a channel that is dedicated or provided for a particular user and that carries information from or to a particular mobile station, subscriber unit, or user facility. Used here to refer to. Dedicated channels typically carry information for certain users and contain data for actual services as well as higher layer control information. Dedicated channels are identified by a sign at a frequency. Dedicated channels are bidirectional to potentially enable feedback.

The term "common channel" is used herein to refer to a carrier channel that carries information from / to a large number of mobile stations. On a common channel, information is shared among all mobile stations. The common channel is distributed among all users or users in a group of cells.

The term "Point-to-Point (PTP) communication" is used here to mean communication transmitted to a single mobile station on a dedicated physical communication channel.

The term "broadcast communication" or "Point-to-Multipoint (PTM) communication" is used here to refer to communication to multiple mobile stations on a common communication channel. ..

The term "reverse link" or "uplink channel" is used herein to refer to a communication channel / line in which a mobile station sends a signal to a base station in a wireless network. This channel is also used to transmit signals from mobile station to mobile station or from mobile station to base station.

The term "forward link" or "downlink channel" is used herein to mean a communication channel / line through which a wireless network sends a signal to a mobile station.

The term "Transmission Timing Interval (TTI)" is used here to refer to how often data arrives from the higher layers to the physical layer. The transmission time interval (TTI) is the arrival time interval of the Transport Block Set (TBS), which is approximately equal to the period at which TBS is transferred by the physical layer on the wireless interface. The data sent over the transport channel during the TTI is encoded and interleaved together. TTI is a multiple of the minimum interlacing period across many radio frames. The TTI start positions for different transport channels that are multiplexed together for a single connection are time aligned. TTIs have a common starting point. Media access control delivers a set of transport blocks to the physical layer for each TTI. Different transport channels mapped on the same physical channel have different transmission time interval (TTI) durations. Many PDUs are sent in one TTI.

The term "packet" is used herein to mean a group of bits and includes data or payloads and control elements arranged in a particular format. Control elements include, for example, preambles, quality metrics, and others known to those of skill in the art. Quality metrics include, for example, Cyclic Redundancy Checks (CRCs), parity bits and others known to those of skill in the art.

The term "access network" is used here to mean the equipment needed to access the network. The network includes a collection of base stations (BS) and a network and one or more base station controllers (BSCs). The network carries data packets between a large number of subscriber stations. The network is also connected to additional networks outside the network, such as a corporate intranet or internet, and carries data packets between the access terminal and such an outer network. In UMTS systems, the connection network is called the UMTS Terrestrial Radio Access Network (UTRAN).

The term "core network" is used for public switched telephone networks (PSTN) for circuit-switched calls in the circuit-switched (CS) area and packets for packet-switched calls in the packet-switched (PS) area. Used here to refer to switching and routing capabilities for connecting to any of the data networks (PSDN). The term "core network" also refers to mobility and subscriber location management, and the ability to allocate routes for authentication services. The core network contains the network elements necessary for exchange and subscriber control.

The term "base station" is used herein to refer to an "origination station" that includes hardware with which a mobile station communicates. In UMTS systems, the term "Node B" is used interchangeably with the term "base station". Base stations are fixed or mobile.

The term "cell" is used herein to refer to either hardware or a geographical coverage area, depending on the context in which the term is used.

The term "Service Data Unit (SDU)" is used herein to refer to a data unit that is exchanged for a protocol above the protocol of interest.

The term "Payload Data Unit (PDU)" is used here to refer to a data unit that is exchanged for a protocol below the protocol of interest. Of the protocol of interest. If the identity is ambiguous, certain mentions will be made in the name, for example, the FEC-PDU is a FEC layer PDU.

The term "soft handoff" is used here to mean communication between a subscriber station and two or more sectors, where each sector belongs to a different cell. Reverse line communication is received by both sectors, and forward line communication is carried simultaneously on the forward lines of two or more sectors.

The term "softer handoff" is used here to mean communication between a subscriber station and two or more sectors, where each sector belongs to the same cell. Reverse line communication is received by both sectors, and forward line communication is carried simultaneously by one of the forward lines of two or more sectors.

The term "erasure" is used here to mean the unsuccessful recognition of a message, and to refer to a set of bits that are missed during decryption.

The term "cross transition" is defined as the transition from two-point (PTP) transmission to one-point-to-multi-point (PTM) transmission, and so on. The reverse is also true. From two-point (PTP) transmission in cell A to one-point to multipoint (PTM) transmission in cell B, from one-point to multipoint (PTM) transmission in cell A to two-point (PTP) transmission in cell B. From two-point (PTP) transmission in cell A to one-point to multipoint (PTM) transmission in cell A, and from one-point to multipoint (PTM) transmission in cell A to two-point (PTP) transmission in cell A There are four possible crossover transitions.

The term "direct transition" is defined as the transition from one two-point transmission to another two-point transmission and from one-point-to-multipoint transmission to one-point-to-multipoint transmission. From two-point (PTP) transmission in cell A to two-point (PTP) transmission in cell B, and from one-point to multipoint (PTM) transmission in cell A to one-point to multipoint (PTM) transmission in cell B There are two possible direct transitions.

The term "inter-cell transition" is used to refer to a transition that crosses cell boundaries. From two-point (PTP) transmission in cell A to two-point (PTP) transmission in cell B, from one-point to multipoint (PTM) transmission in cell A to one-point to multipoint (PTM) transmission in cell B. From two-point (PTP) transmission in cell A to one-point to multipoint (PTM) transmission in cell B, and from one-point to multipoint (PTM) transmission in cell A to two-point (PTP) transmission in cell B There are four possible cell-to-cell transitions. In general, the most frequent transition is one-point-to-multipoint (PTM) transmission to one-point-to-multipoint (PTM) transmission across cell boundaries.

The term "intra-cell transition" is used to refer to an intra-cell transition from one mode to another. From two-point (PTP) transmission in cell A to one-point to multipoint (PTM) transmission in cell A, and from one-point to multipoint (PTM) transmission in cell A to two-point (PTP) transmission in cell A There are two possible intra-cell migrations.

The term "radio bearer" is provided by Layer 2 for the transfer of user data between the user device (UE) and the UMTS Terrestrial Radio Connection Network (UTRAN). Used to refer to services.

Examples of the present invention in which the above embodiments are implemented in a W-CDMA or UMTS communication system will be discussed below. Figures 1-5C illustrate some forms of conventional UMTS or W-CDMA systems in which the forms of the invention described herein are presented for purposes of illustration and limitation. The embodiments of the present invention are also applicable to other systems that carry both voice and data, such as GSM stems and CDMA2000 systems that comply with the "3rd Generation Partnership Project (3GPP)". Document numbers 3G TS25.211, 3G TS25.212, 3G TS25.213, and 3G TS25.214 (W-CDMA standard), or "TR-45.5 cdma2000 Spectral Spread System" (IS2000 standard), and TS04.08 (moving) What can be embodied in a set of documents including GSM specifications such as wireless interface layer 3 specifications), TS05.08 (wireless subsystem line control), and TS05.01 (physical layer on wireless path (general description)) Should be recognized.

For example, although the description states that the wireless network 20 will instead be implemented using the All-Ground Radio Service (UTRAN) aerial interface in the GSM / GPRS system, the wireless network 20 Is a GSM / EDGE wireless network (GERAN), which in the case of a interconnect includes cells of the UTRAN aerial interface and cells of the GSM / EDGE aerial interface.

<u style="single">UMTS Network Topology-</u> Figure 1 is a block diagram of a communication system based on the UMTS network topology. The UMTS system includes a user device (UE) 10, a connection network 20, and a core network 30. UE10 is connected to the connection network connected to the core network 30 connected to the external network.

UE10 includes a mobile device 12 containing user reservation information and a Universal Subscriber Identity Module (USIM) 14. The Cu interface (not shown) is the electrical interface between the USIM 14 and the mobile device 12. UE10 is generally a device that allows users to access USIM network services. UE10 is a mobile such as a mobile phone, fixed station, or other data terminal. A mobile device is, for example, a wireless terminal used for wireless communication over an aerial interface (Uu). The Uu interface is an interface where the UE accesses a fixed part of the system. USIM is an application that resides in a "smart card" or other logical card, generally including a microprocessor. The smart card holds the subscriber certificate, executes the authentication algorithm, and stores the authentication in the encryption key and subscription information required by the terminal.

The connection network 20 includes a wireless device for accessing the network. In a W-CDMA system, the connection network 20 is a Universal Terrestrial Radio Access Network (UTRAN) aerial interface. The UTRAN includes at least one base station connected to at least one radio network controller (RNC) 24 or at least one radio network subsystem (RNS) including "node B" 22.

RNC controls UTRAN's radio resources. The RNC24 of the connection network 20 communicates with the core network 30 via the Iu interface. The Uu interface, Iu interface 25, Iub interface, and Iur interface allow interconnection between devices from different supply manufacturers and are specified in the 3GPP standard. Implementations of wireless network controllers (RNCs) vary by supply manufacturer and will therefore be presented as a general theory below.

The radio network controller (RNC) 24 serves as a switch and control element for the UMTS Terrestrial Radio Connection Network (UTRAN) and is located between the Iub interface and the Iu interface 25. The RNC acts as a service access point for managing connections to all services UTRAN provides to the core network 30, for example user devices. The Iub interface 23 connects to the throat B22 and the radio network controller (RNC) 24. The Iu interface connects UTRAN to the core network. The radio network controller (RNC) is an Iu carrier (Iu) Provides a switching point between bearer) and the base station. The user device (UE) 10 has several radio carriers between itself and the radio network controller (RNC). A radio carrier is a set of definitions required by Iub to provide a common and dedicated connection between a user device (UE) and a radio network controller (RNC). (UE) It has something to do with the context. Each RNC24 communicates with each other on any Iur interface that allows soft handover between cells connected to different nodes 22. The Iur interface thus enables RNC-to-RNC connections. In such cases, the service RNC maintains the Iu connection 25 to the core network 30 and performs selector and external loop power control functions, while the idle RNC is via one or more base stations 22. Transfer the frame that can be exchanged on the Iur interface to mobile station 10.

The RNC that controls one node B is called the node B control RNC, because of the new radio line that controls the load and congestion of its own cells and also to be established in those cells. Approval control and code assignment of.

The RNC and base station (or throat B) are connected via the Iub interface 23 and communicate on it. The RNC controls the use of radio resources by each base station 22 connected to a particular RNC 24. Each base station 22 controls one or more cells and provides a wireless line to the mobile station 10. The base station performs interface processing such as channel coding and interleaving, transmission rate adaptation and spreading. Base stations also perform basic radio resource management operations such as loop-to-loop power control. Base station 22 converts the data flow between Iub and Uu interfaces 23, 26. Base station 22 is also involved in radio resource management. The aerial interface Uu26 connects each base station 22 to the mobile station 10. The base station is involved in radio transmission in one or more cells to mobile station 10 and radio reception in one or more cells from mobile station 10.

The core network 30 should be connected to either (1) PSDN42 if there is a circuit exchange call, or packet data network (PDN) if there is a packet exchange call, (2) mobility and subscriber location management, and (3) Includes all switching and routing capabilities for authentication services. The core network 30 has a fixed position register (HLR) 32, a mobile exchange service center- / visitor-position register (MSC / VLR) 34, a gateway mobile exchange center- (GMSC) 36, and a general service packet. Includes wireless service support node (SGSN) 38 and gateway GPRS support node (GGSN) 40.

Core network 30 is connected to an external circuit-switched (CS) network 42 that provides circuit-switched connections such as the Public Switched Telephone Network (PTSN) or ISDN if there is a packet-switched call, or packet if there is a packet-switched call. -Connected to a PS network 44, such as the Internet, which provides data service connections.

<u style="single">UMTS signal protocol stack</u> FIG. 2 is a block diagram of the UMTS signal protocol stack 110. The UMTS signal protocol stack 110 includes an access hierarchy and a non-access hierarchy (NAS).

The access layer generally includes a physical layer 120, a layer 2 (130) including a media access control (MAC) layer 140 and a radio line control (RLC) layer 150, and a radio resource control (RRC) layer 160. The various layers of the access hierarchy are described in more detail below.

The UMTS non-access layer is essentially the same as the GSM upper layer and is divided into a circuit switching part 170 and a packet switching part 180. The circuit exchange part 170 includes a connection management (CM) layer 172 and a mobility management (MM) layer 178. CM layer 172 handles circuit exchange calls and includes various sublayers. The call control (CC) lower layer 174 performs functions such as establish and release. Auxiliary service (SS) lower layer 176 performs functions such as call transfer and three-way calling. Short Message Service (SMS) The lower layer 177 performs a short message service. MM layer 178 handles location update and circuit exchange call authentication. The packet switching part 180 includes a session management (SM) lower layer 182 and a GPRS mobility management (GMM) lower layer 184. The session management (SM) lower layer 182 handles packet-switched calls by performing functions such as build and release, and also includes a short message service (SMS) section 183. GMM lower layer 184 handles location update and packet switching call authentication.

Figure 3 is a block diagram of the packet-switched user plane of the UMTS protocol stack. The stack includes an access hierarchy (AS) layer and a non-access hierarchy (NAS) layer. The NAS layer includes an application layer 80 and a packet data protocol (PDP) layer 90. The application layer 80 is provided between the user device (UE) 10 and the remote user-42. PDP layer 90, such as IP or PPP, is provided between the GGSN 40 and the user device (UE) 10. Low Layer Packet Protocol (LLPP) 39 is provided between the remote user-42 and SGSN 38. The Iu interface protocol 25 is provided between the radio network controller (RNC) 24 and SGSN38, and the Iub interface protocol is provided between the radio network controller (RNC) 24 and the node B22. Will be done. Other parts of the AS layer are shown below.

<u style="single">Access Hierarchy (AS) Layer</u> Figure 4 is a block diagram of the access hierarchy portion of the UMTS signal protocol stack. Traditional access layers are Physical Layer (L1) 120, Media Access Control (MAC) Layer 140, Wireless Line Control (RLC) Layer 150, Packet Data Convergence Protocol (PDCP) Layer 156, Broadcast / Multicast Control (BMC) ) Includes a data line layer (L2) 130 having a lower layer including layer 158, and a radio resource control (RRC) layer 160. These layers are further described below.

The wireless carrier carries the user data 163 between the application layer and layer 2 (L2) 130. The control plane signal 161 is used for all UMTS specific control signals and includes the application protocol as a signal carrier for carrying the application protocol message. The application protocol is used to set the carrier on UE10. The user plane carries all user plane information 163 sent and received by the user, such as a coded voice in a voice call or a packet in an internet connection. The user plane information 163 carries the data stream and the data carrier related to these data streams. Each data stream is characterized by one or more frame protocols specified for that interface.

The radio resource control (RRC) layer 160 functions as an overall control of the access hierarchy and constitutes all other layers in the access hierarchy. RRC layer 160 includes wireless line control unit 152, physical layer (L1) 120, media access control (MAC) layer 140, wireless line control (RLC) layer 150, packet data convergence protocol (PDCP) layer 156, and Generates a control plane signal 161 that controls broadcast / multicast control (BMC) layer 158. Radio Resource Control (RRC) Layer 160 determines the form of measurement to be made and reports those measurements. The RRC layer 160 also serves as a control and signal interface for the non-access layer.

In particular, the RRC layer 160 broadcasts a system information message, including both access and non-access layers, to all user devices (UEs) 10. RRC layer 160 establishes, maintains, and disconnects a radio resource control (RRC) connection between UTRAN 20 and UE 10. UE RRC requests a connection, while UTRAN RRC sets up and disconnects a connection. The RRC layer 160 also establishes, reconstructs, and disengages the radio carrier between the UTRAN 20 and the UE 10 by the UTRAN 20 that initiates these operations.

The RRC layer 160 also handles various forms of mobility of the user device (UE) 10. These procedures depend on the UE state, that is, whether the call is a circuit exchange call or a package exchange call, and the new cell wireless connection technology (RAT). RRC layer 160 also pages UE10. UTRAN RRC pages the UE regardless of whether the UE is listening to the paging channel or the paging indicator channel. UE's RRC notifies the upper layers of Core Network (CN) 30.

Data line layer (L2) 130 is media access control (MAC) lower layer 40, wireless line control (RLC) lower layer 150, packet data convergence protocol (PDCP) lower layer 156, and broadcast / multicast control. (BMC) Includes lower layer 158.

The Broadcast and Multicast Control Protocol (BMC) 158 provides a message on the wireless interface that originates from the cell broadcast center by adapting the broadcast / multicast service that originates from the broadcast area on the wireless interface. Transport. BMC protocol 158 is "a radio It provides a service called "bearer)" and exists on the user plane. BMC Protocol 158 and RNC store cell broadcast messages received on the CBC-RNC for scheduled transmission. On the UTRAN side, the BMC158 calculates the transmission rate required for the cell broadcast service based on the message received on the CBC-RNC interface (not shown) and the appropriate CTCH from the RRC. / FACH Request resources. BMC Protocol 158 also receives scheduling information with each cell broadcast message on the CBC-RNC interface. Based on this scheduling information, the BMC on the UTRAN side generates a scheduled message, and therefore a scheduled BMC message. On the user-device side, the BMC estimates the planning message and presents the planning parameters to the RRC used by the RRC to form the lower layer for discontinuous reception. The BMC also transmits the schedule and cell broadcast messages according to the schedule. The undamaged cell broadcast message is delivered to the upper layer. Part of the control signal between UE10 and UTRAN20 is radio resource control that carries all the parameters needed to configure, modify, and release Layer 2 Protocol 130 and Layer 1 Protocol 120 entities. RRC) 160 messages. The RRC message carries all high-level signals in their payroads. Radio resource control (RRC) controls the mobility of the user device in the connection mode by signals such as measurement, takeover and cell update.

The Packet Data Convergence Protocol (PDCP) 156 resides in the user plane for services from the PS region. The services provided by PDCP are called wireless carriers. The Packet Data Convergence Protocol (PDCP) provides a header-compression service. Packet Data Convergence Protocol (PDCP) 156 includes a compression method that provides better spectral efficiency for services that transmit IP packets over the air. Several header-compression algorithms can be used. PDCP compresses redundant protocol information in the transmitting entity and decompresses it in the receiving entity. He header - particular network layer compression method, a combination of the transport layer or higher layer protocols, for example, specific to the TCP / IP and RTP / UDP / IP. PDCP also transfers the user data it receives in the form of PDCP service data units (SDUs) from the non-access layer and sends them to the RLC entity. The reverse is also true. PDCP also provides support for lossless SRNS relocation. PDCP acknowledged Mode: AM) When using RLC in sequence delivery, the PDCP entity configured to assist in loss RSRNS relocation-has a protocol data unit (PDU) sequence number, which is re-identified with unconfirmed PDCP packets. Sent to new SRNC during deployment.

The RLC layer 150 is used by the higher layer protocol on the UE side and services to the higher layer (eg, non-access layer) via the service access point (SAP) used by the IURNAP protocol on the UTRAN side. I will provide a. The service access point (SAP) describes how the RLC layer handles data packets. All high-level signals such as mobility management, call control, session management, etc. are encapsulated in RLC messages for transmission of wireless interfaces. RLC layer 150 includes various radio line control entities-152 connected to MAC layer 140 via logical channels that carry signal information and user data.

On control plane 161 the RLC service is used by the RLC layer for signal delivery. On the user plane 163, the RLC service is used by either the service specific protocol layer PDCP or BMC, or any other higher layer user plane function. The RLC service is called the signal radio carrier on the control plane 161 and the radio carrier on the user plane 163 for PDCP156 and services that do not utilize the user plane protocol. In other words, the RLC layer 150 provides a service called a signal radio carrier (SRB) on the control plane 161 and a radio carrier (RB) on the user plane 163 if PDCP and BMC are not used by that service. ) Provides a service called. In other cases, the RB service is provided by PDCP layer 156 or BMC layer 158.

The wireless line control (RLC) layer 150 performs a framing function on the user and control data, which includes segmentation / concatenation and padding functions. .. The RLC layer 150 is generally divided and connected to the radio resource control (RRC) layer for the control data on the control plane 161 and to the application layer for the user data on the user plane 163. -Provide bis. The RLC layer typically performs segmentation / reconstruction of variable length higher layer protocol data units (PDUs) from / to smaller RLC protocol data units (PDUs). One Radio Line Control (RLC) Protocol Data Unit (PDU) generally has one PDU. The size of the wireless line control (RLC) PDU is set according to the minimum possible bit rate of the service using, for example, wireless line control (RLC). As discussed below, for variable bit rate services, some radio line control (RLC) PDUs are during one transmission time interval (TTI) when any bit rate is higher than the lowest one used. Is transmitted to. The RLC transmission entity-also performs the concatenation. If the contents of the wireless line control (RLC) service data unit (SDU) do not satisfy an integer number of wireless line control (RLC) PDUs, the first segment of the next wireless line control (RLC) SDU is Concatenated with the last segment of the previous RLC SDU and placed in a radio line control (RLC) PDU. The RLC transmission entity also performs the jamming function. If the remaining data to be transmitted does not satisfy the entire radio line control (RLC) PDU of a certain size, the rest of the data field is filled with the jamming bits. Techniques for reducing or removing the amount of clogging utilized are provided, for example, according to the embodiments of the invention discussed below with reference to FIGS. 11-13.

The RLC receiving entity-detects duplicate received wireless line control (RLC) PDUs and ensures that the results in the higher layer PDUs are delivered to the higher layers. The RLC layer also controls the transmission rate at which the PRLC transmitting entity-sends information to the RLC receiving entity.

Figure 5A illustrates the data transfer mode used in the wireless line control (RLC) layer of the UMTS signal protocol stack and is a block diagram showing possible mappings of logical, transport and physical UMTS channels with respect to the access hierarchy. is there. Those skilled in the art will appreciate that not all maps are necessarily defined for a user device (UE) at the same time, and that multiple instantiations of several maps occur simultaneously. For example, a voice call would use three dedicated traffic channel (DTCH) logical channels mapped to three dedicated channel (DCH) transport channels. In addition, some channels shown in Figure 5, such as CPICH, SCH, DPCCH, AICH and PICH, exist in the physical layer context and do not carry upper layer signals and user data. .. The content of these channels is defined at physical layer 120 (L1).

Each RLC instance in the wireless line control (RLC) layer operates in one of three modes: transparent mode (TM), negative response mode (UM), or acknowledgment mode (AM). It consists of a radio resource control (RRC) layer, which is described in detail below with reference to Figure 5B. The three data transfer modes indicate the mode in which wireless line control (RLC) is configured for logical channels. Transparent and negative response mode RLC entities-are defined as unidirectional, while acknowledgment mode entities-are bidirectional. Normally, for all RLC modes, CRC error detection is performed on the physical layer, and the results of the CRC inspection are delivered to RLC together with the actual data. Depending on the specific requirements of each mode, these modes perform some or all of the functions of RLC150, which are segmentation, reconfiguration, concatenation, jamming, re-transmission control, flow control, duplication. Includes detection, discontinuous delivery, error correction and encryption. These functions are described in more detail below with reference to FIGS. 5B and 5C. A new radio line control (RLC) data transfer mode is provided according to the embodiments of the invention discussed herein.

The MAC layer 140 provides services to the RLC layer 150 by means of logical channels whose characteristics are determined by the type of data transmitted. The media access control (MAC) layer 140 maps and multiplexes logical channels to transport channels. MAC layer 140 identifies a user device (UE) on a common channel. MAC layer 140 also multiplexes / demultiplexes higher layer PDUs from / to transport blocks that deliver higher layer PDUs to / from common transport channels. MAC handles a service that multiplexes for a common transport channel because it is not done at the physical layer. The media access control (MAC) header-contains the identification of the UE when the common transport channel transports data from the dedicated logical channel. The MAC layer also multiplexes / demultiplexes higher layer PDUs from / to the transport block set delivered to or from the physical layer on a dedicated channel.

MAC layer 140 receives an RLC PDU with state information about the amount of data in the RLC transmission buffer. The MAC layer 140 compares the amount of data corresponding to the transport channel with the threshold set by the RRC layer 160. If the amount of data is too high or too low, the MAC will send a measurement report on the traffic state to the RRC. RRC layer 160 also requires MAC layer 140 to transmit these measurements on a regular basis. RRC layer 160 uses these reports to initiate the reconstitution of radio carriers and / or transport channels.

The MAC layer selects the appropriate transport format (TF) for each transport channel according to the instantaneous source rates of the logical channels. The MAC layer 140 gives priority to the data flow by selecting a "high bit rate" and a "low bit rate" transport format (TF) for different data streams. Packet-switched (PS) data is spontaneous in nature, so the amount of available data to send varies from frame to frame. When more data is available, MAC layer 140 chooses one of the higher data rates, however, when both signal and user data are available. , MAC layer 140 chooses between them to maximize the amount of data sent from the higher priority channels. The transport format (TF) is selected for each connection with respect to the transport format combination (TFC) defined by the approval control.

The media access control (MAC) layer also performs encryption. Each radio carrier is encrypted separately. Details of the encryption are given in 3GPP TS 33.102.

In systems such as W-CDMA, there are three types of transport channels used to send packet data. These channels are known as common transport channels, dedicated transport channels, and shared transport channels. On the downlink, the carrier channel packet data is selected by the packet scheduling algorithm. On the uplink, the carrier channel is selected by the mobile station 10 based on the parameters set by the packet scheduling algorithm.

The common channel is, for example, the random access channel RACH on the uplink and the forward access channel FACH on the downlink. Both carry signal data and user data. The common channel has a low set time. Since the common channel is used for communication before the connection is set up, the common channel is used to send packets immediately rather than a long set time. Generally there are several RACHs or FACHs per sector. Common channels do not have feedback channels and therefore generally use open loop power control and fixed power. In addition, the common channel cannot use soft handover. As described above, the line level performance of the common channel is worse than that of the dedicated channel, and more interference occurs than that of the dedicated channel. Therefore, the common channel is more suitable for sending small individual packets. The applications used in the common channel will be applications such as short message services and short text emails. Sending a single request to a web page also fits well with the concept of common channels, however, with higher data volumes, common channels suffer from poor radio performance.

Dedicated channels can use soft handover characteristics that improve high-speed power control and radio performance, and generally produce less interference than common channels. However, setting up a dedicated channel takes more time than accessing a common channel. Dedicated channels have variable bit rates from a few kilobytes per second to 2 megabytes per second. Since the bit rate changes during transmission, the downlink orthogonal code must be assigned according to the highest bit rate. Therefore, a dedicated channel with a variable bit rate consumes an expensive downlink orthogonal code space.

The physical layer (L1) 120 couples to the MAC layer 140 via a carrier channel that carries signal information and user data. The physical layer 120 provides services to the MAC layer via a transport channel whose characteristics are determined by how and with what characteristics the data is transferred.

The physical layer (L1) 120 receives signals and user data on the wireless line via the physical channel. The physical layer (L1) generally includes other physical layer procedures such as acquisition, access, pagination, and wireless line establishment / failure, as well as multiplexing and channel coding, including CRC calculations, forward error correction (FEC). ), Transmission rate adjustment, transport channel data interleaving, and transport channel data multiplexing. The physical layer (L1) is also responsible for diffusion and scrambling, modulation, measurement, transmission diversity, power weighting, handover, compression mode and power control.

FIG. 5B is a block diagram showing the architecture of the wireless line control (RLC) layer. As mentioned above, each RLC entity in wireless line control (RLC) layer 150-or instance 152 is one of three data movement modes by wireless resource control (RRC) layer: transparent mode (transparent mode). It consists of a radio resource control (RRC) layer that operates in TM), negative response mode (UM), or acknowledgment mode (AM). The data transfer mode for user data is controlled by quality of service (QoS) settings.

TM is unidirectional and includes transmit TM entity-152A and receive TM entity-152B. In transparent mode, protocol order is not added to higher layer data. The erroneous protocol data unit (PDU) is either discarded or marked as erroneous. In special cases, streaming transmission is generally used in which high-level data is not segmented, although limited segmentation / reconstruction is achieved. When segmentation / reconstruction is used, it is negotiated in the radio carrier setup procedure.

The UM is also one-way and includes the sending UM entity-152C and the receiving UM entity-152D. The UM RLC entity-is defined as one-way because no association between the uplink and downlink is required. Data delivery is not guaranteed by UM. For example, UM is used for certain RRC signaling procedures where acknowledgment and retransmission are not part of the RRC procedure. Examples of user services that utilize the negative response mode RLC are cell broadcasting services and voice on IP. Received error data is marked or discarded depending on the configuration. Timer without explicit signaling function-RLC with reference discard applied and thus not sent within the specified time PDUs are simply removed from the transmit buffer. In the negative response data transfer mode, the PDU structure includes the sequence number and the sequence number check is performed. Series number checking helps ensure the integrity of reconstructed PDUs, and when they are rebuilt into a radio line control (RLC) SDU, the broken radio by checking the series number in the radio line control (RLC) PDU. Provides a means of detecting line control (RLC) SDU. Any corrupted radio line control (RLC) SDU is discarded. Segmentation and concatenation is also done in the negative response mode (UM).

In the acknowledgment mode, the RLC AM entity is bidirectional and can conjugate line condition instructions in the opposite direction to the user data. FIG. 5C is a block diagram showing an entity that implements the Radio Line Control (RLC) Acknowledgment Mode (AM) entity-and how an AM PDU is constructed. Data packets (RLC SDU) received from higher layers via AM-SAP are segmented and / or concatenated into fixed length protocol data units (PDUs) (514). The length of the protocol data unit is a semi-static value determined on the configured radio carrier and can be changed by the RRC radio carrier reconstruction procedure. For concatenation or packing purposes, a bit with length and extension information is inserted at the beginning of the last protocol data unit, or data from the SDU is included. If several SDUs fit into one PDU, they are linked to the appropriate length index (LI) and inserted at the beginning of the PDU. The PDU is then placed in transmission buffer 520, which is also responsible for retransmission management.

A PDU is constructed by taking one PDU from the transmit buffer 520 and adding a header for it, and if the data in the PDU does not fill all RLC PDUs, it is in a padding field or bound state. A message is added. The conjugation state message is issued from the receiving side or the transmitting side to instruct the RLC SDU to be discarded. The header-is the RLC PDU sequence number (SN), the pole bit (P) (which is used to request the status from the peer entity), and the concatenation of the SDU, jammed, or conjugated PDU is RLC. Optionally include a length indicator (LI) used if done in the PDU.

Acknowledgment mode (AM) is commonly used for packet-type services such as internet browsing and email downloads. In the acknowledgment mode, the automatic repeat request (ARQ) mechanism is used for error correction. Any received packet with an error will be retransmitted. The quality vs. delay performance of RLC is controlled by RLC through several retransmission configurations provided by RLC. If the RLC does not deliver the data correctly, for example, if the maximum number of retransmissions arrives or the transmission time is exceeded, the upper layer will not be notified and the wireless line control (RLC) SDU will be discarded. Will be done. The peer entity is also notified of the SDU discard operation by sending a mobile receive window command during the status message, so that the receiver removes all PDUs belonging to the discarded Radio Line Control (RLC) SDU.

RLC consists of both in-sequence and out-of-sequence deliveries. In-line delivery maintains the order of the higher layers of PDUs, while out-of-line delivery forwards higher layer PDUs as soon as they are fully received. The RLC layer provides intra-series delivery of higher layer PDUs. This feature maintains the order of the higher layer PDUs presented for transfer by RLC. If this feature is not used, out-of-line delivery will occur. In addition to data PDU delivery, state and reset control procedures are communicated between peer RLC entities. The control procedure, of course, uses separate logical channels, thus one AM RLC entity-using either one or two logical channels.

Encryption is performed at the RLC layer for acknowledgment and negative response RLC modes. In Figure 5C, the AM RLC PDU is encrypted excluding the first two bits, including the PDU sequence number and the pole bit (540). The PDU sequence number is an input parameter to the encryption algorithm and must be readable by the peer entity for encryption. The 3GPP specification TS33.102 states encryption.

The PDU is then sent to the MAC layer 140 via the logical channel. In Figure 5C, a special logical channel (DCCH / DTCH) is indicated by a dashed line, exemplifying that one RLC entity-is configured to send control and data PDUs using different logical channels. To do. The receiving side 530 of the AM entity-receives the RLC AM PDU from the MAC layer through one of the logical channels. Errors are checked by the physical layer CRC, which is calculated on all RLC PDUs. The actual CRC check is done at the physical layer, the RLC entity-after decoding all the headers-receives the result of the CRC check with the data, and possible conjugation state information is extracted from the RLC PDU. If the PDU received was a strong message, or the status information is AM When combined with the PDU, the control information (status message) is passed to the sender that inspects the retransmit buffer for the received status information. The PDU number from the RLC header-is used for decryption (550) and when storing the encrypted PDU in the receive buffer. Once all PDUs belonging to the complete SDU are in the receive buffer, the SDU is rebuilt. Although not shown, intra-series delivery and duplicate detection occur before the RLC SDU is delivered to the higher layers.

The RLC entity-152 is reinitialized when the user-device (UE) or mobile station moves (or changes cells) between PTM and two-point (PTP) transmissions. This has the undesired consequence of losing any data in the wireless line control (RLC) buffer. As mentioned above, when a mobile station moves from one cell to another, or from two-point (PTP) transmission of multimedia broadcast and multicast service (MBMS) content in a service cell. Problems arise when switching to one-point to multi-point (PTM) transmission.

Multimedia broadcasts and between transitions between two-point (PTP) transmissions and one-point-to-multipoint (PTM) transmissions, or between transitions that occur between different cells (eg, handover). It is desirable to maintain a multicast service (MBMS) and avoid presenting duplicate information. In order to maintain the continuity of the MBMS service and avoid the presentation of duplicate information, Layer 2 (150) must be able to reorganize the data coming from the two streams. This synchronization cannot be performed by the physical layer because the network terminal points are different in each mode. As with 3GPP2, if forward error correction (FEC) is performed below RLC layer 150, the data will be any transition between one-point-to-multipoint (PTM) and two-point (PTP) transmissions. Lost during. The reverse is also true. In addition, this will require physical layer synchronization and sharing of the same media access control (MAC) between multiple cells (eg, having a common schedule). Therefore, this would cause problems in 3GPP2 where such assumptions do not apply.

<u style="single">Two-point (PTP) transmission</u> Assuming that the application has a valid delay tolerance, the most efficient data transfer mode for two-point (PTP) transmission is the wireless line control (RLC) acknowledgment mode (AM). is there. For example, the RLC acknowledgment mode (AM) is commonly used for packet-switched data forwarding on dedicated logical channels. RLC operates in acknowledgment mode (AM) on a dedicated logical channel. As shown in Figure 5A, a dedicated user traffic for one user service in the downlink direction is sent through a logical channel known as a dedicated traffic channel (DTCH).

In the acknowledgment mode (AM), if the data is incorrect, the reverse line can be used for the retransmission request. The RLC transmits the service data unit (SDU) and retransmits it to ensure delivery to its peer entity. If the RLC does not deliver the data correctly, the sender's RLC user will be notified. Operations in RLC AM are generally more power efficient at the expense of added delay.

<u style="single">One-point to multi-point (PTM) transmission</u> A common traffic channel is a one-way channel that exists in the downlink direction and is used when transmitting information to either all terminals or a specific group of terminals. Both of these data transfer modes use a one-way common channel that does not have a configured reverse line channel.

It would be desirable to provide architecture that allows MBMS services to be transparently switched between two-point (PTP) and one-point-to-multi-point (PTM) transmission modes. Allows interchange between different radio line control (RLC) modes for good performance when migrating between two-point (PTP) and one-point-to-multipoint (PTM) transmission modes It would also be desirable to provide an architecture to do. This helps, for example, to reduce the required power.

Embodiments of the present invention will now be described with reference to the examples shown and described with reference to FIGS. 6-19. These features, among other things, help maintain service continuity during such transitions by using a new forward error correction (FEC) layer.

FIG. 6 is a diagram of an improved UMTS protocol stack with forward error correction (FEC) layers that can operate in forward error correction (FECd) mode and forward error correction (FECc) mode. When the user device (UE) changes from two-point (PTP) transmission to one-point to multi-point (PTM) transmission while maintaining service continuity, there is one forward error correction (FEC) layer. Allows you to change the underlying radio line control (RLC) entity-152 from a radio line control (RLC) data transfer mode to another radio line control (RLC) data transfer mode. According to this example, the FEC layer operates in the first mode (FECc) or the second mode (FECd). In one implementation, the first mode (FECc) utilizes the parity block and the second mode (FECd) operates without the parity block. The effect of changing between FECd and FECc modes is much lower than that of transitions between RLC modes and can be seamless so that data loss does not occur during the transition.

The forward error correction (FECc) mode uses external coding technology to protect the user data. This is especially useful on common channels. Forward error correction (FECc) mode is a function found in negative response mode (UM), such as framing (segmentation and concatenation) and sequence number addition that occurs above the wireless line control (RLC) layer. And so on. As a result, the traditional negative response mode (UM) is performed in the forward error correction (FEC) layer, so that the wireless line control (RLC) layer is a transparent mode for two-point (PTP) transmission. TM) is used. This feature overlaps in the radio line control (RLC) acknowledgment mode (AM), but the gain from the ARQ compensates for this duplication.

By placing a forward error correction (FEC) or external coding layer on top of the radio line control (RLC) layer, the sequence number is added to a layer unrelated to the radio line control (RLC) layer. Due to negative response transmission, the use of additional overheads such as sequence numbers is used during asynchronous transmission of MBMS data for Encoder Packets (EPs) and Protocol Data Units (PDUs). Allows reorganization. Since the sequence number is added to the layer above wireless line control (RLC), the sequence number is common to both two-point (PTP) transmission and one-point to multi-point (PTM) transmission, and thus one-point to pair. Series number continuity is maintained when the transition from multipoint (PTM) transmission to bipoint (PTP) transmission occurs. This allows the data to be reorganized to avoid duplication of data and / or missed data.

External coding is used in two-point (PTP) transmission, which potentially provides some power benefit to the system and / or reduces re-transmission delay. Multimedia broadcasting and multicast service (MBMS) data are fairly delay tolerant. For two-point (PTP) transmission, a feedback route is provided. It uses a more efficient radio line control (RLC) acknowledgment mode (AM) by using ARQ retransmission, which is generally more efficient than the FEC method, where additional parity blocks are always sent when needed. Therefore, the addition of a parity block to MBMS pay-road data is unnecessary on a dedicated logical channel, eg, between two points (PTP).

Figures 7A and 7B show examples of access layer protocol structures including forward error correction (FEC) layer 157 located above wireless line control (RLC) layer 150. The forward error correction (FEC) layer is described with reference to FIG.

Forward error correction (FEC) layer 157 receives user-plane information 163 directly on the user-plane radio carrier. The forward error correction (FEC) layer is located above the wireless line control (RLC) layer, so the FEC protocol data unit (PDU) corresponds to the RLC service data unit (SDU). To do. The FEC layer is preferably any SDU size (constrained to multiples of 8 bits), variable rate sources, out-of-series reception of packets from the lower layers, and reception of duplicate packets from the lower layers. Corresponds to. FEC PDU size is constrained to multiples of 8 bits.

As described in more detail below with reference to FIG. 9A, FEC layer 157 segments and connects high-level blocks of user data such as SDU. Each line is also referred to as an internal block. Each protocol data unit (PDU) contains an overhead. The overhead is a protocol data unit (PDU) in which data from a specific block of user data, such as a service data unit (SDU), is located. Includes a length indicator (LI) that indicates the beginning of. A collection of PDUs includes an encoder packet (EP) or an "encoder matrix". The number of PDUs contained in a encoder packet (EP) depends, among other things, on the external code used. Packing each encoder "matrix" row into independent or separate transmission time intervals (TTIs) enhances physical layer performance. A short transmission time interval (TTI) duration is used to reduce the buffer load.

The coder packet (EP) then passes through an external code coder to generate a parity line. As described in more detail below with reference to FIG. 9A, FEC layer 157 is externally coded by providing the functionality of a Reed-Solomon (RS) encoder in UMTS Terrestrial Radio Connection Network (UTRAN) 20. Performs conversion and performs external coding by providing the functionality of a Reed-Solomon encoder within User Device (UE) 10.

The parity lines generated by the external encoder are added to the encoder packet (EP) and placed in the transmission buffer as a group of internal blocks. Each internal block has information added to it to create a protocol data unit (PDU). Then, the PDU group is transmitted.

FEC layer 157 also allows playback of data belonging to one EP, even if different internal blocks are received from different cells. This is achieved through the transmission of the sequence number (SN) in the header of each protocol data unit (PDU). In one embodiment, the system frame number (SFN), which helps maintain data alignment for coded packets (EP). Series numbers are discussed in more detail in this document with reference to, for example, Figures 10A and 10B.

FEC layer 157 also performs jamming and reconfiguration, transfer of user data, and forward delivery of higher layer PDUs, duplicate detection, and sequence number checking.

In the examples shown in FIGS. 6-7A, the forward error correction (FEC) layer 157 is between the packet data convergence protocol (PDCP) layer 156 and the radio line control (RLC) layer 150 (eg, (eg, It is shown at the same level as the BMC) layer and below the Packet Data Convergence Protocol (PDCP) layer). The internal block size matches the "gold" packet size of packets sent wirelessly, so by placing forward error correction (FEC) layer 157 just above wireless line control (RLC) layer 150. External code performance is optimized. Nevertheless, it should be understood that the forward error correction (FEC) layer is shown here for illustrative purposes only and is unrestricted. Packet Data Convergence Protocol (PDCP) Layer 156 is used at the top of Forward Error Correction (FEC) Layer 157 because of its header-compression capacity. It should be noted that currently Packet Data Convergence Protocol (PDCP) Layer 156 is defined for two-point (PTP) transmission using dedicated logical channels. As shown in FIG. 7, the forward error correction (FEC) layer is provided anywhere in the access layer above the wireless line control (RLC) layer or in the application layer. The forward error correction (FEC) layer may be below or above the packet data convergence protocol (PDCP) layer. If FEC is performed at application layer 80, even if the "golden" packet size differs for the two, it can be applied equally to GSM and W-CDMA.

<u style="single">External code design</u> The new forward error correction (FEC) layer performs external coding based on user-plane information. FIG. 8 is a diagram showing an information block 91 and an external code block 95 to illustrate the concept of the external code structure. FIG. 9A is a diagram showing an example in which the external code block structure is applied to multimedia broadcasting and multicast service (MBMS) data 91. External coding improves physical layer performance when broadcasting delay-tolerant content over the entire cell. The external code causes, for example, data loss during cell-to-cell transitions and between two-point (PTP) transmission mode and one-point-to-multipoint (PTM) transmission mode. Helps avoid.

The external code block 95 is represented in the form of k protocol data block 91 and Nk parity line 93. In external block coding, by segmenting, concatenating, and packing data (including inserting overheads into the internal block), and added to the information block 91 that makes the external code block 95. By encoding the resulting information block 91 to generate the Nk parity line 93, the user data can be systematized into a k-paid line to output to a large coder packet or information block 91. -Tas are assembled. Parity block 93 adds redundancy information to information block 91. The individual lines of the external code block are then eventually transmitted during one or more transmission time intervals (TTIs). Redundancy information about a collection of protocol data units (PDUs) allows the original information to be reconstructed, even if some PDUs are lost during transmission.

Figure 9A shows a typical external code structure known as the Lead Solomon (RS) block code. The Reed-Solomon (RS) code is used to detect and correct channel errors. The external code shown in Figure 9A is a systematic (n, k) block code, where each Reed-Solomon (RS) code symbol is 1-byte information defined by rows and columns. Is. Each column contains a lead Solomon (RS) codeword. At least n parity blocks are required for n lost blocks to be restored. Therefore, as the number of parity blocks increases, the amount of memory required increases. In Reed-Solomon (RS) coding, Nk parity symbols are added to k-systemic symbols to generate codewords. In other words, the Reed-Solomon (RS) code [N, k] has k information or a "systematic" symbol and an Nk parity symbol. N is the length of the sign and k is the dimension of the sign. For each k information byte, the code creates an n-coded symbol, the first k of which is the same as the information symbol. Each line is "inner It is called "block)" and represents the pay load for each transmission time interval (TTI). In a typical W-CDMA system, transmission occurs, for example, on a basic W-CDMA structure with a 20 ms frame (TTI). The parity symbol is the generation matrix G defined below._{k × N}Obtained from systematic symbols using: m_{1 × k} G_{k × N}= c_{1 × k} (Equation 1) m_{1 × k}= Information word = [m₀ m₁ M_k-1] (Equation 2) c_{1 × N}= Codeword = [c₀ c₁ C_N-1] (Equation 3) Where m_i, c_iBelongs to any Galois field. For example, if the Reed-Solomon (RS) codeword symbol is 1 bit, a dimensional 2 (GF (2)) Galois field would be used to describe the decoding operation. In one embodiment, if the symbol is an octagon, a Galois field of dimension 256 GF (256) is used to describe the decoding operation. In this case, each information column consists of 1 byte per row. Each sequence of information is coded on a Galois field on dimension 256 GF (256) using the [N, k] Reed-Solomon (RS) code. If there are M-bytes per row, the external block is coded M times. Therefore, there are N * M bytes per external block 95.

<u style="single">Erase decryption</u> The external code structure allows for erasure correction. If the decoder knows which symbol is wrong, reconstructing the wrong systematic symbol requires a relatively small amount of calculation. A coder packet (EP) or matrix refers to the complete set of data at the output of the external coder. Redundancy information is taken column by column from each row, and each row transmitted has a CRC attached to it that must be inspected to ensure that the data was sent correctly. In the case of MBMS transmission, a CRC is used in each transport channel block to indicate if the internal block 91 is incorrect, and if the CRC fails, all symbols in the block are presumed to be incorrect. In the embodiment, if there is an error in an internal block 97, all the bits of that block are erased. The term "erasure" refers to each symbol belonging to the error block in which the CRC failed. Symbols that are not erased are considered correct. Ignoring the CRC undetected error probability, each Nx1 column contains the correct erased symbols.

The receive vector r is written as: r_{1 × N}= [c₀eec₃c₄ec₆c₈ C_N-1] (Equation 4) Here, e identifies the erasure.

Erase decoding allows even Nk error symbols to be corrected. Since non-erasable symbols are considered correct, the error correction characteristics of RS codes are generally much better than those of common RS codes. The size of the CRC used in each internal block must be large enough to ensure that the undetected error probabilities do not exceed the remaining external block probabilities. For example, if a 16-bit CRC is used in the internal block, the remaining external block error rate low limit is 2^-16=1.5×10^-5Will. If the first k internal block is correct, the systematic symbol is the same as the information symbol, so RS decoding is not necessary.

It is noteworthy that as soon as a k block with a good CRC is received, the decryption of the external block is performed without waiting for the reception of all the blocks inside N. Modified generation matrix Ω for erasure decoding_{k × k} Is generated by erasing or removing all columns corresponding to unnecessary blocks Matrix G_{k × N}Obtained from, for example, the first good k-received symbol is used to identify the modified generation matrix. The original information word m is restored as:<maths num="1"><img file="JP5054170B2_D0001.tif" /></maths>

The complexity of erasure decoding is reduced to the complexity of k × k matrix inversion. Thus, the use of RS erasure decoding greatly simplifies the computational complexity of RS decoding.

<u style="single">Effect of data clogging on external coding performance</u> As discussed below with reference to Figures 11-13, external coding is very large if the amount of jamming and overhead sent over the air is limited by a particular external coding technique. -Used with variable transmission rate data sources without reducing to the bar head. In the external coding technique discussed above, the data is packed into blocks of a certain size and the shortened Reed-Solomon code is executed across the blocks. The coder packet data is packed into the TTI in at least two different ways as described with reference to Figures 9A and 9B.

FIG. 9B is a diagram showing the external code block structure of FIG. 9A in which a large number of rows are sent per transmission time interval (TTI). According to another embodiment of the invention, data from one line is transmitted in one TTI. In another embodiment, data from one coded packet (EP) line is put into one TTI such that each TTI contains data from that coded packet (EP) line. Therefore, each row is transmitted in a separate W-CDMA frame or transmission time interval (TTI). Sending each row in one TTI will provide good performance. In Figure 9B, both k and n are separated by the number of rows per TTI, and the errors in the rows are fully correlated. When looking at EP error rate vs. TTI error rate, this makes a considerable difference.

FIG. 9C is a diagram showing the external block structure of FIG. 9A where each row is sent in a large number of TTIs. Figure 9C illustrates sending each line of a coder packet over four TTIs (TTI0 to TTI3), but it is understood that in practice each line is sent over any number of TTIs. It should be. Since each column is a codeword of an external code, each of the four obvious transmission "phases" (TTI0 to TTI3) is equal to an independent external code. It would be necessary for all of these independent external codes to be correctly decoded in order for the entire packet to be restored.

10A and 10B are diagrams showing external code blocks generated by the forward error correction layer.

The FECc mode is used on a common or one-point-to-multipoint (PTM) logical channel to build an external code block 95 by adding a parity row or block 93 to the MBMS Payrod data 91. To. Each outer block 95 includes a plurality of inner blocks 91, 93. Identifying the sequence of internal blocks and their position with respect to the coded packet allows each available internal block to be placed in the correct position so that external decoding can be performed correctly. In one embodiment, each internal block includes a header-94 that identifies the internal blocks by the number of internal blocks m and the number of external blocks n. For example, the external block n includes a data portion 91 with an internal multimedia broadcast and multicast service (MBMS) pay load block and a redundant portion 93 with an M- (m + 1) internal parity block. .. According to this example, the sequence number space is optimized for MBMS and is defined by some explicit sequence numbers, eg 0-127. The sequence number space is the reception where the same sequence number is caused by any kind of migration. gap) Must be large enough so that it does not appear later. The receiving UE must be able to determine the order of the internal blocks, even if some internal blocks are lost. If the UE loses more internal blocks that can be identified by the entire sequence number space, the UE will not be able to reorder the internal blocks correctly. The series number of the same internal block is the same across the FECd block and the FECc block. The FECd block does not include the redundant part 93 used in the FECc block. The FECd entity-and the FECc entity-use the same bitrate wirelessly.

<u style="single">Sender</u> Transmission Forward Error Correction (FEC) Entity-410 Receives SDU Service Data Unit (SDU) Buffer 412, Segmentation and Concatenation Unit 414, Reed-Solomon (RS) Encoding It includes an external encoder 416, a sequence number generator 418 that adds a sequence number to the coded PDU, a transmit buffer 420 that transmits the PDU over logical channel 406, and a scheduling unit 422.

The service data unit (SDU) buffer 412 receives the user data in the form of a service data unit on the radio carrier 402 as indicated by the arrow. Memorize FEC SDU from higher layers. The receive buffer 412 communicates how much data is transmitted to the scheduling unit 422.

As mentioned above, since the source data-rate generally varies, the amount of time it takes to fill a coder packet (EP) generally varies. As explained with reference to FIG. 13, frame filling efficiency is improved by having flexibility in determining when to start packing data. The amount of clogging introduced is reduced by delaying EP production as much as possible based on the jitter-tolerance of the receiving FEC entity-430.

Scheduling entity-422 determines when to start coding. The scheduler 422 preferably determines how long it is possible to wait before a packet needs to be sent, based on the QoS characteristics (profile) for that particular service. Once the scheduler 422 proves that sufficient data has been accumulated or that the maximum acceptable packet transmission delay has been exhausted, it initiates the creation of coder packets (EPs). To do. The segmentation and concatenation unit 414 divides the service data unit (SDU) into various rows to generate a length indicator (LI).

The scheduling unit 422 preferably determines the optimal size of the EP or protocol data unit (PDU) so that the SDU exactly fits the number of rows (eg, 12). Instead, the scheduler 422 selects the FEC PDU size from those composed of RRCs that will result in the least possible jamming, and the segmentation and concatenation function 414 sizes the SDU (PDU size-FEC header-. Request to format k blocks of size). This format changes. Examples of different forms of formatting are discussed below with reference to Figures 12 and 13. The total amount of possible data will include overheads that will be incorporated by the concatenation and segmentation function 414. To generate a encoder packet (EP), the scheduler 422 requires the concatenation and segment function 414 to create a kPDU of that size. This size contains rebuild information. In one embodiment, the PDU has a size that is a multiple of 8 bits, and the data of consecutive PDUs corresponds to different symbols in the codeword.

The kPDU block is then executed via an external encoder 416 that performs Reed-Solomon (RS) coding. The external coder 416 encodes the data in the coder packet (EP) matrix by generating and adding redundancy or parity information to the coder packet (EP) matrix to create the external code block. The encoder encodes k rows of information of equal length and delivers the same size n-protocol data unit (PDU) to the lower sublayer. The first k block is the same as what it receives, and the next nk block corresponds to the parity information.

The scheduler 422 also monitors the time sequence or relative timing of the PTM stream and transmits to adjust the sequence of different logical streams. For example, during the reconstruction, the time sequence between the PTP and the PTM logic stream is adjusted to benefit service continuity. Best performance is obtained when the streams are perfectly synchronized.

Different base stations (or different transmission modes: PTP, PTM) transmit the same content stream, but there is a gap between them. However, if the coder packet (EP) format of the data stream is the same, the information about each stream is exactly the same. Since the user device (UE) knows the relationship between the two streams, the user device (UE) combines the two streams by adding the sequence number to each external block. It becomes possible.

The sequence number generator 418 appends a sequence number to the front of each block in the same sequence used in the encoder 416 to create the PDU. In an embodiment, the sequence number generator adds an 8-bit sequence number to the front of each external code block, for example, to generate a PDU. Additional overhead information is also added to the external code block. The sequence number space must be large enough to accommodate the bad time difference between the streams. Therefore, in another embodiment, 20 sequence number spaces are used and at least 5 bits are provided in each header for sequence numbers. This header-is added to the external code block after Reed-Solomon (RS) coding is done, so this "outer" header-is not protected by the external code. Series numbers are also added, preferably for parity blocks, even if they are not sent. In one embodiment, the sequence number phase is aligned with the encoder packet boundary. A roll-over of sequence numbers will correspond to the reception of new coder packets.

<u style="single">Forward Error Correction (FEC) Header-Format</u> As mentioned above, data stream synchronization is achieved by introducing sequence numbers that contain information related to PDU ordering. In addition to reordering and duplicate detection, sequence numbers allow the data from each source contained in the coded package to be rearranged. This sequence number clearly identifies the order in which each packet should be considered. This sequence number can form a "FEC header-" that is added to both the information pay load unit (PDU) and the parity block after being encoded. The sequence number will not be protected by an external code as it is needed for decryption.

FIG. 14 is a diagram of an example of a forward error correction (FEC) header format. To facilitate alignment of the data with the coded packet (EP), the sequence number is the pending part (R) 402, the coded packet (EP) part 404 that identifies the EP (EPSN), and the coded packet. (IEPSN) Divided to include an internal encoder packet that identifies the location of a particular internal block within 406.

It is desirable for the FEC layer 400 to be able to interact with the wireless line control (RLC) mode. Both wireless line control (RLC) AM and wireless line control (RLC) UM require a service data unit (SDU) that is sized in multiples of 8 bits, so FEC Layer 400 also requires this. It would be desirable to stick to. Since the external code for FEC layer 400 works by increasing the byte size of the data, the row size of the encoder packet (EP) will also need to be an integer byte. Therefore, the FEC header-size 401 must also be a multiple of 8 bits for the FEC protocol data unit (PDU) in order to be acceptable for radio line control (RLC). In one embodiment where the forward error correction (FEC) header-401 is 1 byte, it includes a pending portion (R) containing a single bit, an EP (EPSN) 404 identifying portion containing 3 bits, and 4 bits. It has an IPE part that identifies the location of the PDU in the coder packet (IEPSN) 406. In this embodiment, one PDU is sent per TTI, and the transmission timings of different cells are not expected to fluctuate by more than 100 ms, so an 8-bit sequence number is used.

The transmission buffer 420 stores the PDU until the data frame is accumulated. When the PDU is requested, the transmission buffer 420 sequentially transmits the frames to the MAC layer on the wireless interface (Uu) via the logical channel. Then, the MAC layer communicates the PDU to the physical layer through which the PDU is eventually communicated with the UE 10 via the transport channel.

<u style="single">Receiver</u> Still referring to Figure 11, the receive forward error correction (FEC) entity-430 is a receive buffer / reorder / duplicate detection unit 438, a sequence number removal unit 436, an external decoder 434 that performs lead Solomon decoding, and Rebuild Unit / Service Data Unit (SDU) Includes transmission buffer 432.

The information line of the EP matrix corresponds to the PDU. To assist with external coding, the forward forward error correction (FEC) entity-430 accumulates several PDUs before initiating external coding. While decoding, the user device (UE) receives incoming protocol data units (PDUs), even though it is necessary to decode the coded packets to achieve continuous reception. Buffer.

Receive buffer 438 accumulates PDUs until all coded packets (EPs) are received or until the scheduling unit (not shown) is convinced that there are no more coded packet (EPs) retransmits. Once it is determined that no more data has been received for a coder packet, the missing PDU is identified as erasure. In other words, PDUs that do not pass the CRC check will be replaced with erasure in the decryption process.

The Receive Forward Error Correction (FEC) entity-430 is potentially a receive buffer / because some blocks can be lost during transmission, or different data streams have different delays. Reordering / Duplicate detection unit 438 detects and reorders received blocks. The sequence number is used in each FEC protocol data unit (PDU) to assist in reordering / duplication detection. The sequence number is used in receive buffer 438 to reorder the data received separately. Once the PDUs are reordered, the duplicate detection unit detects the PDUs in the coded packet (EP) based on their sequence number and removes any duplicates.

Then, the series number is removed. Since the sequence number is not part of the block sent to the Lead Solomon (RS) decoder, the sequence number removal unit 436 removes the sequence number from the coder packet (EP).

The data is then passed to the external decryption function 434 to recover the missing information. The external decoder 434 receives the encoder packet (EP) and, if necessary, the lead Solomon (RS) decoder uses the parity information to reproduce the incorrect or missing line. Decrypts a coder packet (EP) with. For example, if all protocol data units (PDUs) containing information are not received correctly, or if less than k are correctly received from nPDUs, then the protocol data units up to the size of the parity PDU. (PDU), external decryption is done to restore the missing information PDU. At least one parity PDU will be available at the receiver whenever external decryption takes place. Decryption is not necessary if all protocol data units (PDUs) containing information are correctly received, or if less than k are correctly received from nPDUs. The information protocol data unit (PDU) is then delivered to the rebuild function 432.

The information line is then delivered to the rebuild unit / function 432, regardless of whether the external decryption was successful. Reconstruction unit 432 reconstructs or reconstructs the SDU from the information rows of the coder packet (EP) matrix using the length index (LI). Once the SDUs have been successfully collected, the service data unit (SDU) transmission buffer 432 provides the service data unit (SDU) on the wireless carrier 440 to deliver the SDU to higher layers. To transmit.

In forward error correction (FEC) entity-430, allowing the UE to delay decoding by a time offset between different logical streams is due to the system lacking synchronization between the logical streams. Allows full use of potential out-of-line reception of data. This facilitates service during handoffs as well as transitions between PTPs and PTMs. The algorithm that allows the UE to delay decoding by time offset between different logical streams is discussed with reference to Figure 15.

<u style="single">Coder Packet (EP) Choices: Fixed or Variable Line Size</u> The protocol data unit (PDU) does not have to be sent continuously at every transmission time interval (TTI), so the FEC or external code entity-is constructed with the protocol data unit (PDU). There is flexibility when it comes to. This will result in good frame filling efficiency and less jamming overhead.

If desired, the external code entity-can generate a pay load at each transmission time interval (TTI). Since the service data unit (SDU) is received from the higher layers, the protocol data unit (PDU) is constructed in real time. If there is not enough data to build the protocol data unit (PDU), RLC adds the jam.

<u style="single">Fixed line size encoder packet (EP)</u> When encoding SDU201-204, it is desirable to reduce the amount of clogging transmitted as much as possible.

In one embodiment, the row size of the encoder packet (EP) matrix 205 is fixed. The speculative knowledge of the row size of the coder packet (EP) matrix 205 allows the data to be aligned to their original configuration. Since the line size of SDU201-204 that will be sent internally is known in advance, transmission should start as soon as the data is received without waiting for how much data will be sent. Can be done.

FIG. 12A shows an example of the coding process for creating the external code block 214 from the data units 201 to 204 in which the row size of the external code block 214 is fixed. In this example, the user data takes the form of multiple service data blocks (SDU) 201-204, including bits of any size block, the size of which is a particular appliqué. -Depends on the input (video, audio, etc.).

Segmentation, concatenation and packing is done at the FEC level to allow transmission of any size FEC SDU. Concatenation is not absolutely necessary, but without it it would result in a significant reduction in high-level data processing.

Higher layers SDU201-204 are first formatted to this fixed PDU size. In this embodiment, the segmentation / concatenation function produces a fixed size internal block directed by the subscriber unit. At step 220, the group of internal blocks is the service data unit by showing the internal blocks, the required degree of packing 208, and how many SDUs end in one line of the EP. (SDU) Segmented and concatenated to be part of the encoder packet matrix 205, including the length indicator (LI) 206 used to point to the end of 201-204. The external encoders discussed below use these internal blocks to create redundant blocks.

In wireless line control (RLC), the length index (LI) is identified by comparing it to the protocol data unit (PDU) rather than the service data unit (SDU). Indicates the end of the bis data unit (SDU). This helps reduce overheads, as the PDU size is generally smaller than that of service data units (SDUs). For example, the length index (LI) indicates the last octet at the end of each FEC service data unit (SDU) in a paid data unit (PDU). Used for. The "length index" is set to the number of octal numbers between the end of the FEC header-and the last octal number of the FEC SDU segment. The length indicator (LI) is preferably included in the PDU referenced by the length indicator (LI). In other words, the length indicator (LI) preferably refers to the same paid data unit (PDU) and is preferably in the same order as the FEC SDU referenced by the length indicator (LI).

When an external block is received, information such as length index (LI) tells the receiver where the service data unit (SDU) and / or jamming starts and ends. Used for.

Since the bits in the FEC header-cannot be used to indicate the presence of the length indicator (LI), the FEC header-adds a fixed header in the payrod indicating the presence of the length indicator (LI). Internal header-or LI provides all the information needed to build SDU201-204. The LI is included in the PLC-PDU it references. The presence of the first LI is indicated by a flag contained in the PLC-PDU sequence number header. The bits in each LI are used to indicate the extension. A 1-byte length index (LI) that indicates that the previous SDU was insufficient to meet the last PDU to allow the length of the length index (LI) to be exchanged for the FEC PDU size. ) Is introduced with a new specific value. The length indicator (LI) existence bits are implemented in various ways, two of which are discussed below.

In one embodiment, the length indicator (LI) presence bits are provided in each protocol data unit (PDU). For example, one byte is added to the beginning of each coder packet (EP) line, and the bits in the byte indicate the presence of LI. The entire first byte of each protocol data unit (PDU) is reserved for this "presence bit". To accommodate this existing bit, the length index is shortened by one bit. Providing an existing bit in each packet unit (PDU) allows the SDU to be decrypted if EP decryption fails, even if the first PDU is missing. This results in a low residual error rate. Providing existing bits in each PDU allows real-time concatenation / segmentation.

In another embodiment, the length indicator (LI) presence bit is provided in the first PDU. Instead of adding an overhead at the beginning of each PDU, the presence bits of all k information PDUs are added at the beginning of the first PDU of the EP. Providing present bits at the beginning of a coder packet (EP) results in less overhead when having a large SDU and / or small PDU.

After segmentation and concatenation, EP205 contains several rows occupied by multiple service data units (SDU) 201-204 and at least one of the packing blocks. The row size of the external block is a peak data for each row. It is designed to be transmitted during the transmission time interval (TTI) at rate). The service data unit (SDU) is generally not coordinated with the amount of data sent during the transmission time interval (TTI). Thus, as shown in FIG. 12A, the second and fourth SDU 202, 204 do not meet the transmission time interval (TTI) of the first and second rows of the EP, respectively. In this example, the EP has 12 lines available for data, and 4SDU201-204 are packed into the first three lines of these 12 lines. The remaining rows of EP205 are occupied by jam block 208. Thus, in the second SDU202, the first part of the second service data unit (SDU) 202 starts in the first line of the "information block" and the second part of the second SDU202 It is split so that it ends on the second line. Similarly, in the third SDU, the first part of the third service data unit (SDU) 203 starts in the second line, and the second part of the third SDU 203 starts in the third line. Must be split to end. The fourth service data unit (SDU) 204 fits within the third row and the rest of the third row is filled with packing block 208. In this example, the encoder packet (EP) 213 is usually composed of a jam 208.

The encoder uses EP to generate redundancy or parity information. At step 240, the encoder encodes the intermediate packet matrix 205, which is encoded by adding the external parity block 214 to generate the external code block 213, which is 16 blocks in length. The encoder extracts 8-bit data from each column of each block to create the resulting data 210. The Reed-Solomon (RS) encoder encodes the resulting data 210 to obtain four lines of redundancy or parity information 212. The parity information 212 is used to generate the external parity block 214 that is added to the EP matrix 205 to generate the 16 blocks of external code block 213.

FIG. 12B shows an example of information transmitted wirelessly in the example discussed above. In step 260, after adding an additional overhead containing the sequence number to each column of EP205, 16 blocks of external code block 213 are transmitted wirelessly as protocol data unit (PDU) 214. .. Sufficient or entire coded packet (EP) 213 matrix is not transmitted by protocol data unit (PDU) 214 sent over the downlink. Rather, the protocol data unit (PDU) contains information bits 201-204 and the length index (LI) 206 of the coder packet (EP) matrix 213. Since the coder packet (EP) matrix 213 rows size is fixed and therefore known to the receiver, it is not necessary to actually send the jamming 208 wirelessly. Since the jamming value is known, the jamming information 208 is not transmitted on the downlink, so there is no need to transmit the jamming information 208. For example, if the jam consists of a series of known bits, such as all 0s, all 1s, or alternating patterns of 0s and 1s, the receiver is nominally a protocol packet (EP) up to 213 line lengths. -Data unit (PDU) 214 can be packed. Therefore, instead of choosing a PDU size equal to the EP row size during transmission, the minimum available EP size that carries all the information bits 201-204 and the rebuild overhead (eg, LI) is It will be used.

Although the row size of the encoder matrix is fixed, the FEC PDU size is selected from a set in each transmission so that each contains all the information parts of one encoder matrix row (excluding clogging). Will be. When receiving a PDU smaller than the row size of the encoder matrix, the UE can pack up to that size with a known bit sequence. This allows the internal block size to remain fixed without increasing the load on the aerial interface. Using a fixed line size, the coder packet (EP) 213 eliminates the need to wait until all the data is available before starting to transmit the protocol data unit (PDU), and also jams. Eliminate the need to send packets.

If the above algorithm is implemented to handle variable rate transmission, a transmission rate equalization technique is used in which all coder packet matrices have a constant size. Smaller PDUs will be used when jamming forms part of a PDU. The jam consists of a specific bit sequence and is located at the end of the data. In the receiver, the size of the block received from the lower layer is equalized to the base-line size by adding a jam at the end.

If a given bit sequence is used for packing, this packing will not be transmitted wirelessly. The receiver does not need to know the actual coder packet line size unless the receiver needs to perform external decryption. Basic SDU reconstruction does not require knowing the amount of jamming at the end of the PDU. External decoding is not required if all PDUs containing information from the first k-coder packet (EP) line are received. In contrast, if at least one PDU containing information from the first k-code packet (EP) line is missing, then at least one PDU containing data from the parity line is required. To. Parity lines are generally uncluttered, so the size is used as a reference for the actual coder packet size that needs to be assumed.

<u style="single">Variable line size encoder packet (EP)</u> FIG. 13 shows a coding process for creating an external code block 313 with a variable row size.

This form of the invention relates to flexible external block coding of data sent over an aerial interface. This coding process results in less clogging being sent so that the frame filling efficiency is increased. Lines of coder packet (EP) 305 are variable size, and differently sized external blocks are sent for each transmission time interval (TTI). Preferably, the row size of the encoder packet (EP) 305 varies so that the SDU exactly fits the number of rows in the encoder packet (EP) matrix 305 (eg, 12). In this example The FEC layer must wait for all available data before making the EP so that the FEC layer can determine the optimum row size. The row size is selected from several different sizes based on the amount of data available to limit jamming. The row size of a coder packet (EP) is associated with the set of PDU sizes configured for S-CCPCH. Depending on the amount of data available when the encoder packet 305 needs to be generated, the line size with the least packing is chosen. By reducing the size of the external block 313 so that the block size is smaller at each frame, less data is sent over the same TTI period, so the data is sent at a reduced transmission rate. .. Using the variable row size of the coder packet (EP) 305 stabilizes the required power over the entire transmission of the coder packet (EP) and also takes advantage of the less parity overhead 314. Useful. This embodiment works well for one-point-to-multipoint (PTM) transmission in systems such as W-CDMA where the size of the transport block sent at each transmission time interval (TTI) varies with the intrinsic radio protocol.

In step 320, multiple service data units (SDU) 201-204 have a length index (LI) 206 pointing to the end of the service data unit (SDU) 201-204. Segmented and concatenated to generate the encoder packet (EP) matrix 305 used for. The length index (LI) is included in the last column where each service data unit (SDU) ends.

In step 330, redundancy or parity information is generated column-based by extracting 8-bit data from each data block, and the resulting data 310 is reed to obtain parity information 312. -Sent to the de Solomon (RS) encoder. Since the rows of the encoder packet (EP) matrix 305 are smaller, less redundancy information is generated.

In step 340, the parity information 312 produces an external parity block 314 that is attached to the 12-block coder packet (EP) matrix 305, thereby producing an external code block that is 16 blocks long in this example. The encoding continues as it is used for. Since the entire external code block 313 is occupied by either the SDU, the length index (LI) 206, and / or the redundancy information 314, this embodiment avoids jamming transmissions that improve transmission efficiency. In this particular example, no jamming was required. However, it should be understood that some packing is required despite the reduced amount of packing, as the number of PDU configuration sizes is limited in some cases. This results in high frame filling efficiency and also allows constant power to be maintained throughout the entire coder packet (EP). This is desirable in CDMA systems that utilize power control techniques.

Although not shown, the transmission of PDUs over the air occurs similar to what was discussed above for step 260 in Figure 12.

FIG. 11 is an example of forward error correction (FEC) layer 400 with RLC negative response mode (UM) + entity- (RLC UM +) provided over external coding or wireless line control (RLC). is there. In general, wireless line control (RLC) provides framing for higher layers. Here, the FEC layer above the wireless line control (RLC) layer is framed.

External coding layer 400 includes transmission forward error correction (FEC) entity-410 communicating with receive forward error correction (FEC) entity-430 on wireless interface (Uu) 404 via logical channel 408. ..

<u style="single">Reordering / Duplicate detection</u> FIG. 15 is a reordering protocol or algorithm that allows mobile station 10 to delay decoding by a time offset between different logical streams.

Forward Error Correction (FEC) entity-430 uses a sequence number to locate a PDU in the EP matrix. For example, part of the sequence number (PSN) identifies the location of the encoder packet (EP).

This algorithm, at best, assumes that data from two coder packets (EPs) is received before decoding begins. In the description below, the coder packet (EPd) is the next coder packet (EP) in the sequence to be decoded, and the coder packet (EPb) is the coder packet (EP) being buffered. The encoder packet (EPb) follows the encoder packet (EPd). UE implementations that require full coder packet transmission time to perform RS decoding will need to be double buffered to be able to decode series packets. Therefore, the UE stores at least the maximum size rows n + k of the code matrix (k and n are the total number of rows including the number of information rows and parity, respectively). UEs with faster decoding engines are lower than n + 1 but can reduce this requirement. For example, if the UE has a certain amount of buffer space (XtraBffr) beyond the amount required to receive sequence packets based on its decryption capabilities, and a 64kbps stream is assumed. If so, delaying decoding by 100 ms without increasing the computational demand would require an 800 byte increase in buffer size.

At block 1410, it is determined whether a new forward error correction (FEC) protocol data unit (PDU) has been received. If no new forward error correction (FEC) protocol data unit (PDU) is received, processing resumes at block 1410. If a new forward error correction (FEC) protocol data unit (PDU) is received, block 1420 decodes the new forward error correction (FEC) protocol data unit (PDU). Whether or not it belongs to the series is determined.

If the forward error correction (FEC) protocol data unit (PDU) does not belong to the sequence to be decoded, then in block 1421 a new forward error correction (FEC) protocol data unit (PDU) is installed. It is determined whether or not it belongs to the coder packet (EPb) that is being buffered. If the forward error correction (FEC) protocol data unit (PDU) does not belong to the buffered coded packet (EPb), the protocol data unit (PDU) is dropped in block 1440. .. If the forward error correction (FEC) protocol data unit (PDU) belongs to a buffered encoder packet (EPb), then the protocol data unit (PDU) is relevant in block 1423. Added to the EPb buffer at position. At block 1425, it is determined whether the amount of data related to EPb exceeds XtraBffr. If it is determined in block 1425 that the amount of data related to EPb does not exceed XtraBffr, processing resumes in block 1410. If the amount of data for EPb exceeds XtraBffr, in block 1428 the transmission entity-attempts to deliver the full SDU from EPd. Then, at block 1430, the remaining EPd is cleared from the buffer, and at block 1434 EPb is set to EPd.

If forward error correction (FEC) protocol data unit (PDU) belongs to EPd in block 1420, then in block 1422, protocol data unit (PDU) buffers EPd at the relevant location. Is added to. At block 1424, it is determined whether the buffer has individual PDUs for k with respect to EPd. If the buffer does not have k individual PDUs for EPd, processing resumes at block 1410. If the buffer has k individual PDUs for EPd, at block 1427, the decoder will perform an external decryption for EPd, and at block 1428, the transmission entity will deliver the full SDU from EPd. Try. Then, at block 1430, the remaining EPd is cleared from the buffer, and at block 1434, EPb is set to EPd.

Figure 16 shows the time relationship between the external code blocks received by the mobile station for one-point-to-multipoint (PTM) transmission from cell A (98) and another one-point to multipoint (99) from cell B (99). It is a figure which shows as a mobile station transition between receiving (PTM) transmission. Some forms of FIG. 16 are Grilli et al. US patent US-2004-0037245-A1 filed August 21, 2002, and Willengger et al. US patent US-2003-0207696 filed May 6, 2002. -Discussed further in A1 and they are incorporated here by reference throughout them.

The scenario depicted assumes the requirements of a UMTS Terrestrial Wireless Network (UTRAN) 20 and User Device (UE) 10. For example, if UTRAN20 sends content across cells using the same external block coding, the same numbering must be used for blocks carrying the same data or payroads in adjacent cells. External blocks with the same number are transmitted in a relatively time-aligned manner. The largest misalignment of PTM transmission across cells is controlled by the Radio Network Controller (RNC) 24. UTRAN20 controls delay jitter due to point-to-multipoint (PTM) transmission across cells. UE10 must be able to decrypt the external block when the next block is being received. Therefore, the buffer space in the UE should preferably be adapted to at least two external blocks 95A-95C, as the memory of one external block is needed to accumulate the current external blocks. Memory must also be able to accumulate internal blocks of "rows" in order for external blocks to cross base station 22 during lead Solomon (RS) decoding to compensate for inaccuracies in time alignment. Must be.

In cell A (98), during the transmission of the external block n (95A), the transition occurs between the transmission of the second internal multimedia broadcast and the multicast service (MBMS) paid block. The slope of arrow 96, which illustrates the transition of user device (UE) 10 from cell A (98) to cell B (99), is not horizontal, as some time elapses during the transition. .. By the time user device (UE) 10 reaches cell B (99), the fifth block of multimedia broadcasting and multicast service (MBMS) paid blocks is being transmitted. Therefore, the user device (UE) 10 lacks the second to fourth blocks from the time elapsed between the time misalignment and transition of each transmission. If enough blocks are received in cell B (99), the external block n (95A) is still decoded because the parity block is used to reconstruct the missing block.

Then, during the transmission of external block n + 2 (95C), user device (UE) 10 undergoes another transition from cell B (99) to cell A (98), which is external block n +. 2 (95C) 5th internal multimedia broadcast and multicast service (MBMS) paid block. In this situation, a few internal blocks are lost during the migration and the external blocks are still regenerated.

The use of external code blocks helps reduce the likelihood of any service interruption. To ensure that error recovery works, the same block must be sent on each transmission line, which means that the parity block should be constructed in the same way on each transmission line. (Since it is broadcast transmission, multimedia broadcasting and multicast service (MBMS) paid block are always the same for each transmission line.) Forward error correction (FEC) at the upper application layer 80 What is done is to ensure that the parity blocks are the same on each transmission line because the coding is done on the forward error correction (FEC) layer 157 and is therefore the same for each external block. In contrast, if the coding is done in the lower layers, for example, in the individual radio line control (RLC) entity-152, some adjustment is required as the parity block is different in each transmission line. ..

<u style="single">Transition from one-point to multi-point (PTM) to two-point (PTP)</u> FIG. 17 is a diagram showing the time relationship between external code blocks received by mobile station 10 when a transition occurs between one-point to multipoint (PTM) transmission and two-point (PTP) transmission. The technique shown in FIG. 17 applies to systems that utilize two-point (PTP) transmission, such as W-CDMA and GSM systems.

The embodiments of the present invention relate to forward error correction by adding parity information or blocks to the internal MBMS "pay load" or data block during PTM transmission. Each external code block transmitted in PTM transmission includes at least one read block and at least one internal parity block. The error correction capability of the external code block is, for example, when the UE moves from one cell to another, or when the delivery of MBMS content changes from a PTM connection to a PTP connection in the same service cell. To significantly reduce and eliminate the loss of MBMS content or "pay load" during the transition.

As mentioned above, some cells transmit to subscriber 10 using either PTP or PTM transmission techniques. For example, if the demand in the cell for the service falls below a certain threshold, the cell transmitting the broadcast service in the normal PTM transmission mode sets up a dedicated channel and sets the PTP mode. Choose to transmit (only to one subscriber 10). Similarly, a cell that normally transmits content to individual subscribers on a dedicated channel (PTP) decides to broadcast the content to a large number of users on a common channel. In addition, one cell will transmit content in PTP transmission mode, while another cell will transmit the same content in PTM transmission mode. A transition occurs when the mobile station 10 moves from one cell to another, or when the number of subscribers in the cell changes from PTP to PTM, or vice versa. The reverse is also true.

During the two-point (PTP) transmission of the external block n (95A), the transition occurs between the transmission of the fourth internal multimedia broadcast and the multicast service (MBMS) payroad block. The slope of arrow 101, which illustrates the user-device (UE) transition from one-point to multipoint (PTM) transmission to two-point (PTP) transmission, is horizontal because some time elapses during the transition. is not it. When the transition from PTM101 to PTP occurs, the radio transmission bit rate remains approximately the same. Two-point (PTP) transmissions generally have a bit error rate of 1 percent or less (eg, there is an error of 1 or less for every 100 pay load blocks during transmission). In contrast, one-point-to-multi-point (PTM) transmissions assume higher bit error rates. For example, in one embodiment, the base station generates external blocks once every 16 transmission time intervals (TTIs), of which 12 TTIs are occupied by paid blocks and 4 TTIs are occupied by parity blocks. .. The maximum number of block errors allowed must be 4 internal blocks out of 16 (12 basic blocks + 4 parity blocks). Therefore, the maximum permissible block error rate would be 1/4.

When a mobile station transitions from one-point to multipoint (PTM) transmission to two-point (PTP) transmission (101), some internal blocks are lost. On average, the percentage of retransmit blocks is generally high, assuming that one-point-to-multipoint (PTM) and two-point (PTP) transmissions have approximately the same bit rate at the physical layer (LI). Since it is less than or equal to the parity block ratio, PTP transmission allows MBMS paid blocks to be sent faster than PTM transmission. In other words, statistically speaking, the number of parity blocks is much higher than the number of wireless line control (RLC) re-transmissions (Re-Tx), so two-point (PTP) transmission is one-point to many-point (PTP) transmission. Generally much faster than PTM) transmission. Since migration 101 is from one-point to multipoint (PTM) transmission to generally much faster two-point (PTP) transmission, when user device 10 transitions to two-point (PTP) transmission, it is multicast. The first block of media broadcast and multicast service (MBMS) paid data is being transmitted. Therefore, no block is lost in the time misalignment of each transmission or the time elapsed during the transition 101. Therefore, when transitioning from one-point-to-multipoint (PTM) transmission to two-point (PTP) transmission, the lost pay road block is outside the current one once the PTP line is established on the target cell. Created by simply resuming from the beginning of the block. The network compensates by initiating PTP transmission at the beginning of the same external block, i.e. the first internal block. The network then recovers from the delay introduced by the migration with fast delivery of complete external blocks. Reducing data loss during the migration reduces the interruptions in the delivery of MBMS content caused by such migrations.

Then, during the PTP transmission of the external block n + 2, the user device (UE) 10 undergoes another transition 103 to the one-point to multi-point (PTM) transmission mode. In Figure 12, this transition from two-point (PTP) to one-point to multi-point (PTM) 103 is the last internal multimedia broadcast and multicast service (MBMS) pay-road block of external block n + 2. Occurs in. In this situation, many internal multimedia broadcast and multicast service (MBMS) paid blocks in external block n + 2 have already been sent except for the last internal block. FEC is generally used in situations where feedback is not available. The use of FEC does not seem to be beneficial, as PTP transmission utilizes a dedicated channel and therefore has the ability to feed back over the reverse line. To minimize or eliminate data loss in cross-transition, UMTS Terrestrial Radio Connection Network (UTRAN) 20 preferably regenerates all internal blocks that would be lost during the transition to PTM transmission. It depends on the low residual block error rate of the RLC acknowledgment mode (AM) in PTP transmission. In other words, standard layer 2 retransmissions are used to retransmit any packet for which an error is detected in the original transmission. Therefore, as shown in FIG. 17, parity blocks are not required for PTP transmission. If the error is present in the pay road block during the two-point (PTP) transmission, the wireless line control (RLC) layer requires the retransmission of any error block, so the external block is still decoded. That is, when there is an error during PTP transmission, mobile station 10 requests retransmission (re-TX), or when all blocks are correct, retransmission is not performed and transport format 0 (TF0) It will be used. External coding is preferably done at layer 2 of the protocol stack so that the size of each internal block 97 fits exactly one transmission time interval (TTI), as this increases coding efficiency.

If forward error correction (FEC) external coding is done at an upper layer of the protocol stack, such as the application layer, then the parity block is a transmission technique (two-point (PTP) or one-point-to-multi-point (PTM)). )) Will be sent regardless. Therefore, a parity block will also be added to the point-to-point (PTP) transmission.

As mentioned above, the use of parity blocks in PTP transmission is not necessary, as more efficient re-transmission techniques are used instead of forward error correction. Parity blocks are preferably not transmitted in PTP transmission, so delivery of a complete external block is on average faster than PTM, assuming the same bit rate wirelessly. Since two-point (PTP) transmission is expected for one-point to multi-point (PTM) transmission, this allows the UE to compensate for the interruption caused by the transition of PTM to PTP. The user-device (UE) uses (1) the internal block received in either the two-point (PTP) transmission in the new cell or after the transition, and (2) the one-point pair in the old cell or before the transition. Regenerate the external block by combining it with the internal block received in multipoint (PTM) transmission. The user device (UE) combines the internal blocks received before the migration and the internal blocks received after the migration that belong to the same external block. For example, User Device (UE) 10 is an internal multimedia broadcast and multicast service (MBMS) paid block in external block n + 2 received via two-point (PTP) transmission. Is combined with the internal multimedia broadcasting and multicast service (MBMS) paid block in the external block n + 2 and parity block received via one-point to multi-point (PTM) transmission. UMTS Terrestrial Wireless Network (UTRAN) 20 facilitates this process by slightly "anticipating" the transmission of external blocks to all users receiving MBMS content from the PTP line for transmission over the PTM line. To do.

Since UTRAN anticipates the transmission of external blocks for PTM transmission, a "seamless" transition from PTP to PTM is possible. As a result, delivery of MBMS content across cell boundaries and / or between different transmission methods such as PTP and PTM is also "seamless". This "time anticipation" is represented by the number of internal blocks. When the user-device (UE) 10 transitions to PTM transmission, the user-device (UE) 10 compromises the QoS of MBMS reception, even if the communication line does not exist during the transition time. It wastes up to the "time forecast" of the internal block. Once the UE initiates MBMS reception directly in PTP, UTRAN20 slowly transmits external blocks by avoiding empty internal blocks (TF0) until the expected number of internal blocks "time expected" is reached. UTRAN will apply the "time forecast" immediately at the beginning of the PTP transmission. From that point on, UTRAN keeps the "time forecast" constant.

For one-point-to-multi-point (PTM) transmission, the UE-specific feedback information available in the radio line controller (RNC) is unreliable. For point-to-point (PTP) transmission, UE10 will inform the RNC of the number of last external blocks correctly received prior to migration. This will apply to any transition to PTP (from PTM or from PTP). If this feedback is not considered acceptable, the UTRAN 20 estimates the last external block that was probably received by the user device (UE) 10 before the state transition. This estimate is based on knowledge of the greatest predictable time inaccuracy during obvious cell transmissions, and on external blocks that are currently being sent or will be sent soon in the target cell. Let's go.

Forward error correction (FEC) is performed so that any blocks lost during the transition are regenerated. This results in a "seamless" migration by reducing the likelihood that content will be lost during the migration. This technique causes a transition from two-point (PTP) to one-point to multi-point (PTM) transmission when the same external block is being transmitted from each source, which is generally the duration of the external block. It is assumed that it will occur if there is a period.

The amount of memory in UE10 is an antinomy with the accuracy of time alignment of PTM transmissions across adjacent cells. By relaxing the memory requirements in the user device (UE) 10, the time accuracy of PTM UTRAN transmission is increased.

Figure 18 shows during the transition or relocation between two-point (PTP) transmission from wireless network controller (RNC) A and two-point (PTP) transmission from wireless network controller (RNC) B. It is a figure which shows the time relationship between the external code blocks received by a mobile station. The term "RNC" is used interchangeably with the term "base station controller (BSC)". During the "relocation", the user device (UE) 10 is from the second point-to-point (PTP) transmission of the content stream in the region controlled by the first RNC A (124). Transition to two-point (PTP) transmission of the content stream in the region controlled by RNC B (224). Retransmission (re-Tx) is used to compensate for any missing MBMS paid blocks. The direct transition from two-point (PTP) transmission between cells to two-point (PTP) transmission is similar to release '99 soft handover or hard handover. Goal RNC without cooperation between two RNCs A and B A (124) must calculate the last total external block received by UE10. This estimate will be based on the timing of the MBMS content received by RNC24 on the Iu interface 25. When using PTP transmission, the RNC24 creates an initial delay and no part of the MBMS content will be lost without the need for lossless SRNS relocation.

Although the float diagrams are drawn in sequence for understanding, one of ordinary skill in the art will appreciate that certain steps are performed in parallel in actual implementation. Unless otherwise indicated, method steps can be replaced without departing from the scope of the invention.

Those skilled in the art will appreciate that information and signals are represented using a variety of different techniques and techniques. For example, the data, instructions, instructions, information, signals, bits, symbols, and chips cited throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Represented by.

The various exemplary logical blocks, modules, circuits, and algorithmic steps described in connection with the examples disclosed herein are as electronic hardware, computer software, or a combination of both. Those skilled in the art will further understand that it can be done. To articulate the compatibility of this hardware and software, various exemplary components, blocks, modules, circuits, and steps have generally been described above with respect to their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and design constraints imposed on the overall system. A skilled technician may be able to perform the functionality described in various ways for each particular application, but decisions of such practice should not be construed as departing from the scope of the invention.

The various exemplary logical blocks, modules, and circuits described in connection with the embodiments disclosed herein are general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), and field programs. -Lord programmable gate array (FPGA) or other programmable logic device, individual gate or transistor logic, individual hardware components, or any of them designed to perform the functions described herein. Implemented or executed by combination. The general purpose processor may be a microprocessor, but instead it may be any conventional processor, controller, microprocessor, or state machine. Processors are also implemented as a combination of computing devices, such as a combination of DSP and microprocessor, multiple microprocessors, one or more microprocessors connected to a DSP core, or any other configuration thereof.

The operations of the methods or algorithms described in connection with the embodiments disclosed herein are incorporated directly in hardware, in software modules executed by a processor, or in a combination of the two. Software modules are RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, replaceable disks, CD-ROMs, or other types of storage media known in the art. Resident in. A typical storage medium is connected to the processor so that the processor can read information from the storage medium and write the information to the storage medium. Alternatively, the storage medium may be integrated with the processor. The processor and storage medium may reside in the ASIC. The ASIC may be stationed at the user terminal. Alternatively, the processor and storage medium may reside as separate components in the user terminal.

The previous description of the disclosed examples is provided to allow one of ordinary skill in the art to make or use the present invention. Various changes to these embodiments will be immediately apparent to those skilled in the art and the general principles defined herein can be applied to other embodiments without departing from the spirit or scope of the invention. For example, the wireless connection network 20 is implemented in a GSM / GPRS system using a general-purpose terrestrial wireless connection network (UTRAN) aerial interface instead, while the access network is GSM / EDGE (GERAN). Or, in the case of an interface, it includes cells in the UTRAN aerial interface and cells in the GSM / EDGE aerial interface. As such, the invention is not intended to be limited to the examples presented herein, but should be given the broadest scope compatible with the principles and novel features disclosed herein.

Part of the disclosure of this patent document includes material subject to copyright protection. Because patent documents are published in patent files or records from the Patent and Trademark Office, the copyright owner does not object to facsimile reproduction of either the patent document or the patent specification, but in all other cases all copyrights. Withhold rights.<u style="single"> The inventions that describe the scope of the initial claims of the application of the present application are described below.</u><u style="single">[1]</u><u style="single"> Destination stations including receivers, and</u><u style="single"> An externally coded entity provided on the wireless line control (RLC) layer that comprises a transmitter that includes a transmitter that communicates with a receiver on the wireless interface via a common logical channel.</u><u style="single">[2]</u><u style="single"> The transmitter is</u><u style="single"> User-The first buffer to store a row of information,</u><u style="single"> Determine the maximum duration before the external code block needs to be transmitted so that the unfilled portion of the information block is reduced based on the user information stored in the first buffer. A planning unit that determines the optimal size of the information block that allows the user-information line to occupy the information block, and generates a request to start encoding the user-information line.</u><u style="single"> At the request of the scheduling unit, each piece of information that splits the user-information line to fit the optimally sized information block and indicates the end of the user-information line for that information block. Segmented and connected units that generate length indicators within blocks, and</u><u style="single"> The external coding entity according to [1], comprising an external coding device that uses the information block to generate a redundant block that is added to the information block to create the external code block.</u><u style="single">[3]</u><u style="single"> User-The external coding entity described in [2], where the planning unit begins coding when the amount of planar information accumulates.</u><u style="single">[4]</u><u style="single"> The external coding entity described in [2], wherein the scheduling unit begins coding when the packet transmission delay time ends.</u><u style="single">[5]</u><u style="single"> The transmitter further comprises a sequence number generator that adds a header-outside each information block, which contains a sequence number that identifies the order in which each information block should be considered, the external coding described in [2]. entity-.</u><u style="single">[6]</u><u style="single"> The external coding entity according to [5], wherein the series number includes a part that identifies an external code block and a part that identifies the position of each information block within the external code block.</u><u style="single">[7]</u><u style="single"> The externally encoded entity according to [5], wherein the transmitter further stores an information block and comprises a transmission buffer that transmits the information block to the MAC layer on a wireless interface via a common logical channel.</u><u style="single">[8]</u><u style="single"> The information block that carries user information in the first logical stream from the first source and the information block that carries the same user information in the second logical stream from the second source are the same. Has a sequence number, and</u><u style="single"> The scheduling unit monitors the sequence number of the first logical stream of the information block and the sequence number of the second logical stream of the information block so that the first and second streams are time aligned. The externally coded entity described in [5], which adjusts the relative time alignment of the first logical stream of the information block with respect to the second logical stream of the information block.</u><u style="single">[9]</u><u style="single"> User-The row size of the row of information varies based on the application, the externally coded entity described in [2].</u><u style="single">[10]</u><u style="single"> The scheduling unit determines the row size of the external code block where each row is fixed to be transmitted at the highest data rate during one transmission time interval (TTI) and receives all user information. The externally coded entity described in [2], which previously initiates the transmission of information blocks and length indicators.</u><u style="single">[11]</u><u style="single"> Segmentation and concatenation splits the user-information line to fit within a fixed-size external code block line, and places the user-information line in the external code block line to generate an information block. Fill an empty external code block with packing information and in each external code block line to indicate that the user information or packing line ends within the external code block line occupied by that information block. The externally coded entity described in [10], which adds at least one length index.</u><u style="single">[12]</u><u style="single"> The coder packet contains information blocks, jam information and length indicators, and the external coder extracts a portion of each coder packet to obtain the extract information and the extract information to generate a row of redundant information. The external coding entity according to [11], wherein a row of redundant information is added to the encoder packet to encode and generate an external code block with a fixed line size.</u><u style="single">[13]</u><u style="single"> The row size of the external code block is variable, and once all rows of user information have been received, the scheduling unit will use the amount of user information received for the rows of the external code block. The external coded entity according to [2], which determines the variable line size, and the size of the external code block transmitted during the transmission time interval varies based on the external code block line size.</u><u style="single">[14]</u><u style="single"> Segmentation and concatenation divides the user-information line to fit within a variable-sized external code block line so that the user-information line completely occupies multiple lines of the external code block. Place the user-information line in the external code block line to generate the information block, and each external to indicate that the user-information line ends within the external code block line occupied by the information block. An externally coded entity as described in [13], which adds at least one length index to a code block line.</u><u style="single">[15]</u><u style="single"> The coder packet contains an information block and a length indicator, and the external coder extracts a portion of each coder packet to obtain the extract information and encodes the extract information to generate a row of redundant information. The externally encoded entity according to [13], which adds a row of redundant information to the encoder packet to generate an externally coded block with a variable row size.</u><u style="single">[16]</u><u style="single"> The scheduling unit is based on the amount of user information received once it has been determined that all rows of user information should be received or an external code block should be generated. Some predetermined external code block lines that allow some of the external code blocks occupied by non-user information to be minimized, thereby reducing the user-information transmission rate. The external coded entity described in [2], which determines the variable external code block line size from the size.</u><u style="single">[17]</u><u style="single"> In the scheduling unit, once all rows of user information have been received, the rows of user information completely occupy the coder packet based on the amount of user information received. The external coding according to [2], wherein the variable external code block line size is determined, and the size of the external code block transmitted during the transmission time interval varies based on the external code block line size. entity-.</u><u style="single">[18]</u><u style="single"> The receiver is</u><u style="single"> A receive buffer that accumulates information blocks until the conditions are met,</u><u style="single"> Here, the series number identifies the external code block to which each information block belongs and the position of the information block in the external code block.</u><u style="single"> A reordering unit that utilizes the sequence number in each information block to reorder any information blocks received in no particular order, and</u><u style="single"> Once the information blocks are reordered, a duplicate detection unit that uses the sequence number in each information block to detect duplicate information blocks and excludes any duplicate information blocks is provided.</u><u style="single"> The external code according to [1], wherein when the condition is satisfied for a certain external code block, the duplicate detection unit replaces any information block that does not pass the cyclic redundancy check by erasure and generates a request to start external decoding. Transformed entity-.</u><u style="single">[19]</u><u style="single"> The condition is that the entire external code block is received, the external coded entity described in [18].</u><u style="single">[20]</u><u style="single"> The condition is that there is no longer retransmission for the external code block, the external coded entity described in [18].</u><u style="single">[21]</u><u style="single"> A series number removal unit that removes the series number from each information block of the external code block, and</u><u style="single"> [18] Further comprises an external decoder that receives an external code block and, if necessary, decodes any erasure in the external code block by using a redundant block to regenerate the missing information block. Externally coded entity-.</u><u style="single">[22]</u><u style="single"> User-Reconstruction units that use information blocks and length indicators to reconstruct rows of information, and</u><u style="single"> The externally coded entity according to [21], comprising a user-a transmit buffer that carries the user-a row of information on a wireless carrier to deliver the row of information to a higher layer.</u><u style="single">[23]</u><u style="single"> The receive buffer stores other incoming information blocks being received when the previously received information block is being decrypted to allow continuous reception of the information block during decoding, [21]. Externally coded entity-.</u><u style="single">[24]</u><u style="single"> The reordering unit delays decoding by a time offset between the first and second logical streams and waits for two external code blocks received before decoding begins, the external described in [18]. Coding entity-.</u><u style="single">[25]</u><u style="single"> The receive buffer receives an external code block containing multiple rows of information blocks, each row information block contains at least part of a row of user information, the size of each row of the information block is fixed, and one. The externally encoded entity described in [18] that occupies one transmission time interval (TTI).</u><u style="single">[26]</u><u style="single"> The external decoder decodes the external code block using a line of redundant information to generate a complete coded packet containing the information block and length index, and the information block is error-free, external as described in [21]. Coding entity-.</u><u style="single">[27]</u><u style="single"> The rebuilding unit ends each line of user-information within the external code block line occupied by that information block, and each information block divides the information block into user-information lines. The externally encoded entity described in [22], which uses at least one length indicator in.</u><u style="single">[28]</u><u style="single"> The receive buffer receives an external code block containing multiple rows of information blocks, each row information block contains at least a portion of the rows of user information, the size of each row of the information block is variable, and the user The-A row of information completely occupies multiple rows of information blocks, the externally encoded entity described in [18].</u><u style="single">[29]</u><u style="single"> User-The first buffer to store a row of information,</u><u style="single"> Determine the maximum duration before the external code block needs to be transmitted so that the unfilled portion of the information block is reduced based on the user information stored in the first buffer. A planning unit that determines the optimal size of the information block that allows the user-information line to occupy the information block, and generates a request to start encoding the user-information line.</u><u style="single"> At the request of the scheduling unit, each piece of information that splits the user-information line to fit the optimally sized information block and indicates the end of the user-information line for that information block. Segmented and connected units that generate length indicators within blocks, and</u><u style="single"> A transmitting station that receives an information block before the wireless line control (RLC) layer and has an external encoder that uses the information block to generate a redundant block that is added to the information block to create the external code block.</u><u style="single">[30]</u><u style="single"> The transmitting station according to [29], wherein the planning unit begins coding when the amount of user-planar information is accumulated.</u><u style="single">[31]</u><u style="single"> The transmitting station according to [29], wherein the scheduling unit begins coding when the packet transmission delay time ends.</u><u style="single">[32]</u><u style="single"> The transmitter according to [29] further comprises a sequence number generator that adds a header-outside each information block, the header-containing a sequence number that identifies the order in which each information block should be considered.</u><u style="single">[33]</u><u style="single"> The transmitting station according to [32], wherein the sequence number includes a part that identifies an external code block and a part that identifies the position of each information block within the external code block.</u><u style="single">[34]</u><u style="single"> The transmitting station according to [32], wherein the transmitter further includes a transmission buffer that stores an information block and transmits the information block on a wireless interface via a common logical channel.</u><u style="single">[35]</u><u style="single"> The information block that carries user information in the first logical stream from the first source and the information block that carries the same user information in the second logical stream from the second source are the same. Has a sequence number, and</u><u style="single"> The planning unit monitors the sequence number of the first logical stream of the information block and the sequence number of the second logical stream of the information block so that the first and second streams are time-aligned. The transmitting station described in [32], which adjusts the relative time alignment of the first logical stream of the information block with respect to the second logical stream of the information block.</u><u style="single">[36]</u><u style="single"> User-The line size of the information line changes based on the application, the originator described in [29].</u><u style="single">[37]</u><u style="single"> The scheduling unit determines the row size of the external code block where each row is fixed to be transmitted at the highest data rate during one transmission time interval (TTI) and receives all user information. The transmitting station according to [29], which previously initiates transmission of information blocks and length indicators.</u><u style="single">[38]</u><u style="single"> The segmentation and concatenation unit splits the user-information line to fit within a fixed-size external code block line and places the user-information line in the external code block line to generate an information block. , Fills an empty external code block with packing information, and each external code block line to indicate that the user information line or packing ends within the external code block line occupied by that information block. The calling station described in [37], which adds at least one length indicator to.</u><u style="single">[39]</u><u style="single"> The coder packet contains information blocks, jam information and length indicators, and the external coder extracts a portion of each coder packet to obtain the extract information and the extract information to generate a row of redundant information. [38] The transmitting station according to [38], wherein a line of redundant information is added to a coder packet to encode an external code block having a fixed line size.</u><u style="single">[40]</u><u style="single"> The row size of the external code block is variable, and once all rows of user information have been received, the scheduling unit will use the amount of user information received for the rows of the external code block. The transmitting station according to [29], wherein the variable line size is determined, and the size of the external code block transmitted during the transmission time interval varies based on the external code block line size.</u><u style="single">[41]</u><u style="single"> The segmentation and concatenation unit divides the user-information line to fit within a variable-sized external code block line so that the user-information line completely occupies multiple external code block lines. Place the user-information line in the external code block line to generate the information block, and each to indicate that the user-information line ends within the external code block line occupied by the information block. The transmitting station according to [40], which adds at least one length index to the external code block line.</u><u style="single">[42]</u><u style="single"> The coder packet contains an information block and a length indicator, and the external coder extracts a portion of each coder packet to obtain the extract information and encodes the extract information to generate a row of redundant information. The transmitting station according to [40], which adds a line of redundant information to the coder packet to generate an external code block having a variable line size.</u><u style="single">[43]</u><u style="single"> The scheduling unit is based on the amount of user information received once it has been determined that all rows of user information should be received or an external code block should be generated. Some predetermined external code block lines that allow some of the external code blocks occupied by non-user information to be minimized, thereby reducing the user-information transmission rate. The transmitting station described in [29], which determines the variable external code block line size from the size.</u><u style="single">[44]</u><u style="single"> In the scheduling unit, once all rows of user information have been received, the rows of user information completely occupy the coder packet based on the amount of user information received. The originator according to [29], wherein the variable external code block line size is determined, and the size of the external code block transmitted during the transmission time interval varies based on the external code block line size.</u><u style="single">[45]</u><u style="single"> A receive buffer that accumulates information blocks until the conditions are met,</u><u style="single"> Here, the series number identifies the external code block to which each information block belongs and the position of each information block in the external code block.</u><u style="single"> A reordering unit that utilizes the sequence number in each information block to reorder any information blocks received in no particular order, and</u><u style="single"> Once the information blocks are reordered, it comprises a duplicate detection unit that detects duplicate information blocks and excludes any duplicate information blocks using the sequence number in each information block.</u><u style="single"> When the condition is satisfied for a certain external code block, the duplicate detection unit replaces any information block that does not pass the cyclic redundancy check by erasure and generates a request to start external decoding.</u><u style="single">[46]</u><u style="single"> The condition is that the entire external code block is received, the destination station described in [45].</u><u style="single">[47]</u><u style="single"> Conditions outer code blanking is that there is no retransmission longer Lock, [45] the target station according.</u><u style="single">[48]</u><u style="single"> A series number removal unit that removes the series number from each information block of the external code block, and</u><u style="single"> External that receives the external code block before it reaches the wireless line control layer and, if necessary, decodes any erasure in the external code block by using redundant blocks to regenerate the missing information block. The destination station according to [45], further comprising a decoder.</u><u style="single">[49]</u><u style="single"> User-Reconstruction units that use information blocks and length indicators to reconstruct rows of information, and</u><u style="single"> The destination station according to [48], comprising a transmit buffer that transmits the user-information line on a wireless carrier to deliver the user-information line to a higher layer.</u><u style="single">[50]</u><u style="single"> The receive buffer stores other incoming information blocks being received when the previously received information block is being decrypted to allow continuous reception of the information block during decoding, [48]. Destination station.</u><u style="single">[51]</u><u style="single"> The destination station according to [45], wherein the reordering unit delays decoding by a time offset between the first and second logical streams and waits for two external code blocks to be received before decoding begins. ..</u><u style="single">[52]</u><u style="single"> The receive buffer receives an external code block containing multiple rows of information blocks, each row information block contains at least part of a row of user information, the size of each row of the information block is fixed, and one. The destination station according to [45] that occupies one transmission time interval (TTI).</u><u style="single">[53]</u><u style="single"> The external decoder decodes the external code block using a line of redundant information to generate a complete coder packet containing the information block and the length index, and the information block is error-free, the object described in [48]. Station.</u><u style="single">[54]</u><u style="single"> The rebuilding unit uses at least one length indicator in each information block to determine which line of user information ends within the external code block line occupied by that information block, and also uses the information block. User-The destination station described in [49], which is split into lines of information.</u><u style="single">[55]</u><u style="single"> The receive buffer receives an external code block containing multiple rows of information blocks, each row information block contains at least a portion of the user information rows, the size of each row of the information block is variable, and the user The-A line of information completely occupies multiple lines of an information block, the destination station described in [45].</u><u style="single">[56]</u><u style="single"> A method of creating a fixed line size external code block with multiple lines.</u><u style="single"> The user information is received on the wireless carrier, where the size of the user information line changes based on the application,</u><u style="single"> Based on the channel conditions, determine the fixed external code block line size that allows each line to be transmitted at the highest data rate during one transmission time interval (TTI).</u><u style="single"> Segment and concatenate user-information lines to fit within fixed-size external code block lines,</u><u style="single"> A user-information line is placed on the external code block line to generate an information block, where any empty external code block line is filled with jamming information.</u><u style="single"> To indicate that the user-information line or jam ends within the external code block line occupied by that information block, add at least one length index to each external code block line, where the encoder packet is Includes information blocks, jamming information and length indicators</u><u style="single"> Start transmitting information blocks and length indicators before receiving all user information,</u><u style="single"> Extract a part of each encoder packet to obtain the extraction information,</u><u style="single"> Encode the extracted information to generate a row of redundant information, and</u><u style="single"> A method involving adding a line of redundant information to a coder packet to generate an external code block with a fixed line size.</u><u style="single">[57]</u><u style="single"> A method of creating a variable row size external code block with multiple rows.</u><u style="single"> The user information is received on the wireless carrier, where the size of the user information line changes based on the application,</u><u style="single"> Once all lines of user information have been received, the variable external code block line size has been determined based on the amount of user information received, where it was transmitted during the transmission time interval. The size of the external code block varies based on the external code block line size,</u><u style="single"> Segment and concatenate user-information lines to fit within variable-sized external code block lines,</u><u style="single"> Place the user-information line in the external code block line to generate the information block,</u><u style="single"> Add at least one length index to each external code block line to indicate that the user information line ends within the external code block line occupied by that information block, where the user information line is It completely occupies multiple lines of external code blocks, and the coder packet contains information blocks and length indicators.</u><u style="single"> Extract a part of each encoder packet to obtain the extraction information,</u><u style="single"> Encode the extracted information to generate a row of redundant information</u><u style="single"> Add redundant information lines to the coder packet to generate an external code block with variable line size, and</u><u style="single"> A method that involves transmitting a encoder packet.</u><u style="single">[58]</u><u style="single"> Determining the variable external code block line size based on the amount of user information received is</u><u style="single"> Once it is decided that all rows of user information should be received or external code blocks should be generated, non-users are not based on the amount of user information received. -The-Variable external from some predetermined external code block line size that allows the information to minimize some of the external code blocks occupied by the information, thereby reducing the user-information transmission rate. [57] The method according to [57], which comprises determining the code block line size.</u><u style="single">[59]</u><u style="single"> Determining the variable external code block line size based on the amount of user information received is</u><u style="single"> Once all lines of user information have been received, it allows the lines of user information to completely occupy the coder packet, based on the amount of user information received. The method according to [57], wherein the size of the external code block transmitted during the transmission time interval varies based on the external code block line size, including determining the variable external code block line size.</u><u style="single">[60]</u><u style="single"> It receives an external code block containing multiple lines of information block, where each line information block contains at least part of the user-information line, the size of each line of the information block is fixed, and one transmission time interval. Occupy (TTI) and</u><u style="single"> Decrypt the external code block using a line of redundant information to generate a complete coder packet containing the information block and length index, where the information block is error-free and</u><u style="single"> User-Use at least one length indicator in each information block to determine where in the line of external code block occupied by that information block, and use the information block. A method of receiving user-information, including splitting it into lines of information.</u><u style="single">[61]</u><u style="single"> It receives an external code block containing multiple lines of information block, where each line information block contains at least part of the user-information line, the size of each line of the information block is variable, and the user- A row of information completely occupies multiple rows of information blocks</u><u style="single"> Decrypt the external code block using a line of redundant information to generate a complete coder packet containing the information block and length index, where the information block is error-free and</u><u style="single"> Use at least one length indicator in each information block to determine where a row of user information ends within the external code block row occupied by that information block, and</u><u style="single"> A method of receiving user information that involves splitting an information block into rows of user information.</u><u style="single">[62]</u><u style="single"> A one-point-to-multipoint (PTM) transmission system that enables segmentation and concatenation of variable-rate transmission, out-of-series reception, and one-point-to-multipoint (PTM) transmission of variable transmission rate sources.</u><u style="single"> A receiver buffer that stores forward error correction (FEC) service data unit (SDU),</u><u style="single"> Segmentation and concatenation entities that segment and concatenate the FEC SDU into rows of the encoder matrix containing the first number of information rows, where each row of the encoder matrix occupies an independent transmission time interval.</u><u style="single"> Once a predetermined amount of data has been received to reduce the clogging that is added to each line of the encoder packet during coding, the planning entity that generates the start instruction to start the coding. ,</u><u style="single"> An asynchronous external encoder that generates a encoder packet in response to the start instruction, where each encoder packet is at the first number of information lines, the second number of parity lines, and at the end of the encoder packet. Including jamming</u><u style="single"> After the external coding is done, a sequencer that adds an external header containing the sequence number to each line of the encoder packet, and</u><u style="single"> A transmission buffer that receives the encoder packets, formats them into synthetic code blocks, and transmits the synthetic code blocks on a wireless interface.</u><u style="single">A system that includes a network.</u><u style="single">[63]</u><u style="single"> A receiving unit that accumulates the lines of the encoder packet and delays decoding by delayed decoding with a time offset between different logical streams, where the receiving unit responds to the sequence number and in each order. Forward error correction (FEC) Each forward error correction in the coder packet so that the receiving unit uses the sequence number to detect and reorder the coded packet to which the PDU belongs and the receive block. FEC) Determine the location of the PDU and</u><u style="single"> The removal unit that removes the series number and</u><u style="single"> An external decoder that decodes the information line, and</u><u style="single"> With a send buffer that reconstructs the information line</u><u style="single">[62] The system according to [62], further comprising a terminal for receiving the synthetic code block comprising the above.</u><u style="single">[64]</u><u style="single"> The sequencer adds an internal header-providing information for reconstructing the SDU, which header-is encoded into a length index (LI) contained in the RLC-PDU it references, said the first. The system according to [63], wherein the presence of one LI is indicated by a flag in the sequence number header of the RLC-PDU.</u><u style="single">[65]</u><u style="single"> The system according to [64], wherein the internal header-is added only at the beginning of the EP.</u><u style="single">[66]</u><u style="single"> The system according to [65], wherein the internal header-is added to the beginning of each coder packet line.</u><u style="single">[67]</u><u style="single"> The system according to [62], wherein each coded packet line contains a forward error correction (FEC) protocol data unit (PDU), a parity block and / or jam.</u><u style="single">[68]</u><u style="single"> The system according to [62], wherein the line size of the encoder packet is variable.</u><u style="single">[69]</u><u style="single"> The system according to [62], wherein the line size of the encoder packet has a constant size.</u><u style="single">[70]</u><u style="single"> The system according to [62], wherein the sequence number identifies the particular coder packet (EP) and the PDU within the EP.</u>