Method and apparatus for data packet transport in a wireless communication system using an internet protocol

Method and device for data packet transmission in wireless communication system using internet protocol

[0001] This application is a subdivision of an invention patent application whose application date is October 2, 2002, application number is 02823879.6, and the invention title is "Method and Device for Data Packet Transmission in a Wireless Communication System Using Internet Protocol". Case application.

Technical field

[0002] The present invention generally relates to a wireless communication system, and more particularly to a method and device for message compression in preparation for transmission in a wireless communication system.

Background technique

[0003] There is an increasing demand for packet data services through wireless communication systems. Traditional wireless communication systems are involved in voice communication, and the expansion of supporting data services introduces many challenges. For most designers, saving bandwidth is a very important issue to consider. In unidirectional transmission, such as broadcast transmission, a single broadcast content is provided to multiple users. The user is identified by a unique identifier, which is then included in the address information. In this system, multiple infrastructure elements are required to replicate broadcast packets in order to identify each of multiple prospective receivers. The replication of the transmission signal uses valuable bandwidth, thereby reducing the efficiency of the communication system, and also increasing the processing requirements of intermediate infrastructure components. Especially for broadcast services, the number of target receivers can be very large, resulting in resource allocation and loss of available bandwidth.

[0004] Therefore, there is a need for an effective and accurate method for transmitting data to multiple receivers in a wireless communication system. Furthermore, there is a need for a method of routing broadcast data to multiple users, where each user is independently identified as a target recipient.

Summary of the invention

[0005] The embodiments disclosed herein satisfy the aforementioned needs by providing a method for routing IP packets in a wireless communication system, in which multicast addresses are used to route the packets to the access network.

[0006] In one aspect, a communication path for processing broadcast messages in a wireless communication system includes a first multicast tree part, in which the broadcast message is sent addressed to a multicast Internet Protocol address, a second multicast tree part, in which the broadcast The message is sent addressed to a multicast Internet Protocol address, and the third part, where the broadcast message is sent addressed to at least one unicast address.

[0007] On the other hand, in a wireless communication system supporting broadcast transmission, the system has a broadcast source node and at least one terminal node, at least one router coupled between the source node and at least one terminal node, and a router for establishing The method of transmission path includes determining the transmission range of broadcast transmission in this system, establishing a multicast tree from the first terminal node to the broadcast source node (this multicast tree includes at least one route), and sending through the multicast tree on the transmission range Broadcast news.

[0008] In another aspect, in a wireless transmission system that supports broadcast transmission, an infrastructure element is used to generate Internet protocol packets, and this infrastructure element includes a device for determining the broadcast transmission range and a device for generating Internet protocol packets. (This Internet Protocol packet has a multicast address), and a device for sending Internet Protocol packets.

Description of the drawings

[0009] FIG. 1 is a diagram of a spread spectrum communication system supporting several users.

[0010] FIG. 2 is a block diagram of a communication system supporting broadcast transmission.

[0011] FIG. 3 is a model of the protocol stack corresponding to the selection of the broadcast service part in the wireless communication system.

[0012] FIG. 4 is a message flow flowchart of a broadcast service in a wireless communication system topology.

[0013] FIG. 5 is a functional diagram of a wireless communication system supporting broadcast transmission, which is a multicast Internet protocol transmission of broadcast content.

[0014] FIG. 6 is a structural diagram of a multicast tree structure applied to a communication system.

[0015] FIG. 7 is a flowchart of broadcast processing in a wireless communication system, which includes multicast Internet protocol transmission.

[0016] FIG. 8 is a flowchart of a process for establishing a multicast tree in a wireless communication system.

[0017] FIG. 9A is a flowchart of multicast processing in a wireless communication system.

[0018] FIG. 9B is a signal flow diagram for establishing a data path in a wireless communication system using a multicast Internet protocol.

[0019] FIG. 10 is a flowchart of multicast processing of a broadcast message in a wireless communication system.

[0020] FIG. 11A is a flowchart of multicast processing of a broadcast message in a wireless communication system.

[0021] FIG. 11B is a signal flow diagram of broadcast processing in a wireless communication system using a multicast Internet protocol.

[0022] FIG. 12 is a flowchart of a message flow of a group call service in a wireless communication system layout.

Specific implementation plan

[0023] The phrase "exemplary" is used herein to refer exclusively to "serving as an example, instance, or example." Any embodiment described herein as "exemplary" need not be construed as preferred or superior to other embodiments.

[0024] The effective use of available bandwidth affects the performance and breadth of the system. For this goal, various technologies have been applied to reduce the size of additional overhead information sent with data or content information. For example, in data transmission, data is sent in units of frames. A frame of information usually includes header information, data payload information, and tail. These frames may be part of a data packet, part of a data message, or continuous frames in the form of an information stream, such as an audio and/or video stream. Attached to each frame of data (and each packet or message) is a header containing processing information, which enables the receiver to understand the information contained in the frame. This header information is considered as additional overhead, that is, processing information that is sent along with the information content. The content of the information is called the payload.

[0025] Data frames are sent through the communication system through a variety of infrastructure elements. In conventional systems, the transmission of information to multiple users requires copying information at a central packet control point, such as a packet data service node (PDSN). This duplication increases the processing needs of the PDSN and wastes effective bandwidth. For example, the expansion of a given system requires a router, and the trunk connecting the PDSN must be of sufficient size to handle the duplicated traffic. The PDSN sends multiple copies to the base station, and the base station forwards the information to each user. Conventional methods are particularly disadvantageous in unidirectional broadcast services, where many users receive broadcast transmissions. In this way, the PDSN must make a large number of copies, use specific addresses for each copy and send these copies separately.

[0026] PDSN is usually required to provide additional header information to identify each target recipient. For broadcast services, the number of target receivers can be very large, which causes resource allocation and loss of available bandwidth.

[0027] Example embodiments of a wireless communication system use a data transfer method that reduces the bandwidth used by infrastructure elements while meeting the accuracy and transmission requirements of the system. In an exemplary embodiment, the replication is performed at the BS or the packet control function (PCF) node, releasing the PDSN or the central packet data router to transfer the message with the multicast header

CN 101005457 Β

The information is sent to each BS or PCF participating in this broadcast. For example, the message can be processed to the PCF through the MC tree, where the PCF copies the message for each BSC, and then sends each message through a different unicast connection, that is, a connection or a secure channel established between the PCF and a specific BSC. It is worth noting that the UC connection can be considered as a point-to-point connection. The exemplary embodiment supports one-way broadcast services. This broadcast service provides video and/or audio for six to multiple users. Subscribers of the broadcast service "tune" to a designated channel to access the broadcast transmission. The bandwidth requirement for high-speed transmission of video broadcasting is large, and it is hoped to reduce the amount of replication and transmission of replicated packets on the relay segment in the network.

[0028] The following discussion further illustrates exemplary embodiments, first giving a general spread spectrum wireless communication system. Next, a broadcast service is introduced; where this service is called a high-speed broadcast service (HSBS), and this discussion includes the channel allocation of an exemplary embodiment. Then give the reservation model, including the choice of paid reservations, free reservations, and mixed reservation plans, similar to those currently used in television broadcasting. Next, the details of accessing this broadcast service are explained in detail, and the use of service options is given to define the details of a given transmission. For the topology of the system, that is, the infrastructure elements discuss the message flow in the broadcast system. Finally, the header compression used in the exemplary embodiment is discussed.

[0029] It is worth noting that this exemplary embodiment is provided as an example throughout the discussion; however, other embodiments may include various aspects and do not depart from the scope of the present invention. The present invention is particularly suitable for data processing systems, wireless communication systems, one-way broadcast systems, and any other systems where effective information transmission is desired.

[0030] Wireless communication system

[0031] The exemplary embodiment uses a spread spectrum wireless communication system that supports broadcast services. Wireless communication systems are widely used to provide various types of communication, such as voice, data, and so on. These systems are based on code division multiple access (CDMA), time division multiple access (TDMA), or some other modulation technique. CDMA systems offer certain advantages over other types of systems, including increased system capacity.

[0032] The system may be designed to support one or more standards, such as the "ΊΊΑ/EIA/IS-95-B Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System, referred to herein as the IS-95 standard, The standards referred to here as 3GPP provided by the association named 3W GenerationPartnership Project and included in a group including file numbers 3G TS25. 211.3G TS25. 212, 3G TS25. 213 and 3G TS25. 214, 3G TS25. 215 In the document and here referred to as the W-CDMA standard, the standard here referred to as 3GPP2 provided by the association named 3" Generation Partnership Project 2, and here referred to as the cdma2000 standard TR-45.5, before TR-45.5 Called IS-2000MC. The standards cited above are hereby expressly incorporated by reference.

[0033] Each standard specifically defines the processing of transmitting data from the base station to the mobile station and from the mobile station to the base station. As an exemplary embodiment, the following discussion considers that the spread spectrum communication system is consistent with the cdma200 standard. Other embodiments may incorporate another standard. Other embodiments can apply the compression method disclosed herein to other types of data processing systems.

[0034] FIG. 1 is an example of a communication system 100, which supports several users and can implement at least some aspects and embodiments of the present invention. Any of a variety of algorithms and methods can be used to determine the transmission time in the system 100. The system 100 provides communications for several cells from 102A to 102G, and each cell is served by a base station 104A to 104G, respectively. In this exemplary embodiment, some of the base stations 104 have multiple receiving antennas, while others have only one receiving antenna. Likewise, some of the base stations 104 have multiple transmit antennas, while others have only a single transmit antenna. There is no restriction on the combination of the transmitting antenna and the receiving antenna. Therefore, the base station 104 may have multiple transmitting antennas and a single receiving antenna, or multiple receiving antennas and a single transmitting antenna, or having the same single or multiple transmitting antennas and receiving antennas.

[0035] The terminal 106 in the coverage area may be fixed (ie, stationary) or mobile. As shown in Figure 1, a variety of

CN 101005457 Β

The terminals 106 can be dispersed throughout the system. At a given time, each terminal 106 communicates with at least one and possibly more base stations 104 on the downlink and uplink. For example, the given time may depend on whether soft handover is used or whether the terminal is designed and operated to Receive multiple transmissions from multiple base stations (parallel or serial). The soft handoff in the CDMA communication system is well known in the art. It is described in detail in the patent entitled Method and system for providing a Soft Handoff in a CDMA Cellular Telephone System, US Patent No. 510150L, which is assigned to the present invention. authorizer.

[0036] The downlink refers to the transmission from the base station to the terminal, and the uplink refers to the transmission from the terminal to the base station. In this exemplary embodiment, some terminals 106 have multiple receiving antennas, while others have only one receiving antenna. In FIG. 1, base station 104A sends data to terminals 106A and 106J on the downlink, base station 104B sends data to terminals 106B and 106J, base station 104C sends data to terminal 106C, and so on.

[0037] The increasing requirements for service expansion available through wireless data transmission and wireless communication technologies have promoted the development of specific data services. One such service is called High Data Rate (HDR). Exemplary HDR services are proposed in "EIΑ/TIA-IS856 cdma2000 High Rate Packet Data Air Interface specification" and are called "HDR specifications." HDR services generally cover voice communication systems This system provides an effective way to send data packets in a wireless communication system. When the amount of data sent and the number of transmissions increase, the limited bandwidth available for radio transmission becomes a very important resource. Therefore, the optimal use of effective bandwidth requires a communication system. An effective and fair method for determining the transmission time. In this embodiment, the system 100 shown in FIG. 1 is consistent with a CDMA type system with HDR service.

[0038] High Speed Broadcasting System (HSBS)

[0039] A wireless communication system 200 is shown in FIG. 2 in which video and audio information is provided to a packet data service node (PDSN) 202. Video and audio information come from programs transmitted by television or radio transmission. PDSN202 handles IP packets distributed within the access network (AN). As shown, AN is defined as a part of a system that includes a BS204 that communicates with multiple MSs 206. PDSN 202 is coupled to BS 204. For HSBS service, BS 204 receives an information stream from PDSN 202 and provides information to subscribers in system 200 on a designated channel.

[0040] In a given cell, there are several ways to use the HSBST broadcast service. Factors involved in designing the system include but are not limited to the number of HSBS sessions supported, the number of frequency allocations, and the number of broadcast physical channels supported.

[0041] HSBS is an information flow provided through an air interface in a wireless communication system. "HSBS channel" refers to a single logical HSBS broadcast session, which is defined by the broadcast content. It is worth noting that the content of a given HSBS channel can change over time, such as 7am news, 8am weather, 9am movies, and so on. Time-based timing is similar to a single TV channel. "Broadcast channel" refers to a single forward link physical channel, that is, a given Walsh code, which transmits broadcast traffic. The broadcast channel BCH corresponds to a single code division multiplexing (CDM) channel.

[0042] A single broadcast channel can transmit one or more HSBS channels; in this way, the HSBS channels will be multiplexed in a single broadcast channel in a time division multiplexing (TDM) manner. In an embodiment, a single HSBS channel is provided on more than one broadcast channel in a cell. In another embodiment, a single HSBS channel is provided on different frequencies to serve subscribers within those frequencies.

[0043] According to the present exemplary embodiment, the system 100 shown in FIG. 1 supports a high-speed multimedia broadcasting service called a high-speed broadcasting service (HSBS). The broadcast capacity of this service needs to provide programs with sufficient data rates to support video and audio communications. As an example, the application HSBS includes video streams of movies, sports, and so on. The HSBS service is a packet data service based on the Internet Protocol (IP).

[0044] According to this exemplary embodiment, the content server (CS) notifies system users of the availability of these high-speed broadcast services.

Sex. Any user who wants to receive HSBS services can subscribe to CS. Then, the subscriber scans the broadcast service timing in a variety of methods provided by CS. For example, the broadcast timing can be communicated through advertisements, short management system (SMS) messages, wireless application protocol (WAP), and/or other methods generally compatible with and convenient for mobile wireless communication. Mobile users are called mobile stations (MSs). Base stations (BSs) send HSBS-related parameters in additional overhead messages, such as those that are sent on the channel and/or frequencies designated for control and information, that is, non-payload messages. The payload refers to the transmitted information content, where the payload for the broadcast session is the broadcast content, that is, the video program, and so on. When a broadcast service subscriber expects to receive a broadcast session, that is, a certain broadcast timing program, the MS reads the overhead message and learns the appropriate configuration. Then, the MS tunes to the frequency containing the HSBS channel and receives the broadcast service content.

[0045] The channel structure of the exemplary embodiment is consistent with the cdma2000 standard, where the forward auxiliary channel (F-SCH) supports data transmission. One embodiment bundles a large number of forward fundamental channels (F-FCH) or forward dedicated control channels (F-DCCH) to obtain higher data rate requirements for data services. The exemplary embodiment uses F-SCH as the basis of F-BSCH supporting a payload of 64 kbps (except for RTP overhead). The F-BSCH can also be modified to support other payload rates, for example by dividing the 64kbps payload rate into lower rate substreams.

[0046] An embodiment also supports group calls in a number of different ways. For example, by using existing unicast channels, that is, one forward link channel for each MS, F-FCH (or F-DCCH) is not shared on the forward and reverse links. In another example, F-SCH (shared by group members in the same cell) and F-DCCH (most of the time there is no frame except for the forward power control sub-signal) is applied on the forward link. Apply R-DCCH to the link. In another embodiment, the high-rate F-BSCH on the forward link and the access channel on the reverse link (or enhanced access channel/reverse common control channel combination) used.

[0047] The forward broadcast auxiliary channel (F-BSCH) of this exemplary embodiment has a high data rate and can use a large part of the forward link power of the base station to provide sufficient coverage. Therefore, the physical layer design of HSBC focuses on improving efficiency in the broadcast environment.

[0048] In order to provide sufficient support for video services, the system design considers the base station power required by various methods to transmit the channel and the corresponding video quality. On the one hand, this design is to obtain a subjective compromise between the perceived video quality at the boundary of the coverage area and the perceived video quality close to the cell address. When the effective load rate is reduced, the effective error correction code rate is increased, and a given level of base station transmit power will provide better coverage at the cell boundary. For mobile stations located close to the base station, the channel reception remains zero error and the video quality is reduced due to the reduced source rate. The same compromise also applies to other non-video applications supported by F-BSCH. Reducing the effective load rate supported by the channel increases the coverage at the expense of reducing the download speed of these applications. The balance between video quality and the relative importance of data throughput and coverage area is objective. The selected configuration seeks to optimize the configuration for the specific application and a good compromise between all possibilities. [0049] The load rate of the F-BSCH is an important design parameter. According to the embodiment, the following assumptions can be used in designing a system that supports broadcast transmission: (1) The target payload rate is 64kbps, providing acceptable video quality; (2) For streaming video services, the payload rate is assumed to be each The packet overhead of RTP packet includes 12 8-bit words Section; (3) The average additional overhead of all layers between the RTP and the physical layer is about 64 8-bit bytes per packet, and the F-SCH frame used by each MUXPDU header is 8 bits.

[0050] In an exemplary embodiment, for non-video broadcast services, the maximum rate supported is 64 kbps. However, many other possible payload rates below 64 kbps are also available.

[0051] Subscriber Model

[0052] For HSBS services, there are concentrated possible subscription/revenue models, including free access, controlled access, and part

CN 101005457 Β

Sub-control access. For free access, no subscription is required to receive the service. BS broadcasts this content without encryption, and interested mobile terminals can receive this content. The service provider's revenue can be generated through advertisements, which are also sent in the broadcast channel. For example, a movie clip that is about to take place can be sent, for which the studio will pay the service provider.

[0053] For controlled access, MS users subscribe to this service and pay corresponding fees to receive broadcast services. Users without subscriptions cannot receive HSBS services. Controlled reception can be obtained by encrypting HSBS transmission/content, so that only subscribed users can decrypt the content. This can use an over-the-air encryption key exchange process. This mechanism provides strong security and prevents theft of services.

[0054] The hybrid access mechanism, called partially controlled access, provides HSBS service as a subscription-based service, which is encrypted using intermittent non-encrypted advertisement transmission. These advertisements can be used to encourage subscriptions for encrypted HSBS services. MS knows the mechanism of these unencrypted segments through external methods. HSBS service selection

[0055] HSBS service selection is defined by (1) the protocol stack; (2) the selection in the protocol stack; and (3) the process of establishing and synchronizing services. The protocol stack according to this exemplary embodiment is shown in FIGS. 3 and 4, that is, the MS, BS, PDSN, and CSo in this exemplary embodiment

[0056] Continuing with FIG. 3, for the application layer of the MS, the protocol specifies the audio codec, video codec, and any video characteristics. Moreover, the protocol specifies the wireless transmission protocol (RTP) load class when RTP is used. For the MS transport layer, this protocol specifies the User Datagram Protocol (UDP) port. The security layer of the MS is specified by this protocol, where the security parameters are provided through the out-of-band channel when security starts to be related to the CS. The network layer specifies the IP header compression parameters. According to one embodiment, data packets are compressed at the link layer, and then the appropriate framing protocol is applied to the compressed data.

[0057] Message Flow

[0058] FIG. 4 illustrates a call flow for a given system layout of an embodiment. This system includes MS, BS, PDSN and CS, as listed on the horizontal axis. The vertical axis represents time. The user or MS is a subscriber to the HSBS service. At time tl, the MS and CS negotiate the subscriber security of the broadcast service. The negotiation includes exchanging and maintaining encryption keys, etc., which are used to receive the broadcast content on the broadcast channel. This user establishes the security associated with the CS receiving the encrypted information. This encrypted information can include broadcast access keys (BAK) or key combinations, etc., all from the CSo. According to an embodiment, during the packet data session, CS provides encrypted information on a dedicated channel, such as through PPP, WAP, or other out-of-band method.

[0059] At time t2, the MS tunes to the broadcast channel and starts to receive packets. At this point in time, the MS cannot process the received packet because the IP/ESP header is compressed by ROHC and the MS's decompressor has not been initialized. At time t3, PDSN provides header compression information (described in detail below). From the ROHC packet header, the MS detects and obtains the ROHC initialization and update (IR) packet, which is periodically sent from the PDSN to the broadcast channel. The ROHC IR packet is used to initialize the state of the decompressor in the MS, allowing it to decompress the IP/ESP header of the received packet. Then, the MS can process the IP/ESP header of the received packet. However, the MS also requires information to process the ESP payload, because the payload is encrypted with a short-term key (SK) in the CS. SK and BAK work together, where SK is encrypted using BAK at the receiving end. The CS also provides encrypted information, such as updated key information or the current SK at time t4. It is worth noting that the CS periodically provides information to the MS to ensure the current broadcast security. At time t5, the MS receives broadcast content from the CS. It is worth noting that alternative embodiments can be combined with alternative compression and decompression methods, which provide effective transmission of header information. Moreover, alternative embodiments can implement multiple security mechanisms to protect broadcast content. There are alternative embodiments that can provide non-secure broadcast services. MS uses encrypted information, such as SK, to encrypt and display broadcast content.

[0060] access network

[0061] The general access network layout of the system 300 is illustrated in FIG. 5, with one CS326 and two PDSN320,

CN 101005457 Β

322, -One PCF310, one coexisting PCF and BSC312, and three BSC302, 304, 306. Through the way of IP cloud 324, CS326 is coupled to PDSN320 and 322. The IP cloud 324 and the IP clouds 314 and 308 are basically a configuration of interconnected routers, which form an IP path from the CS to multiple recipients of data from the CS. In this IP cloud 308, the actual channel, called A8 channel, is formed to send information from PCF 310 to BSC302 and BSC304. This channel can be a GRE channel. A protocol called A9 is used to establish the A8 channel. IP cloud 308 can be labeled as A8/A9 cloud. In IP cloud 314, the actual channel, called A10 channel, is formed to send information from PDSN320 to each PCF310 and PCF/BSC312. It is worth noting that the AIO channel is formed from PDSN320 to PCF310, and the second A10 channel From PDSN320 to PCF/BSC 312 is formed. This channel can be a GRE channel. The protocol called All is used to establish the A10 channel. The IP cloud 314 may be labeled A10/A11 cloud. An embodiment is described in detail in the cdma2000 and HDR standards Consistent, as described above. Access network (AN) is defined as the elements and connections from PDSN to end users such as MS. [0062] According to an embodiment, the broadcast CS326 sends IP packets containing encrypted broadcast content to multiple multicast groups identified by class D multicast IP addresses. This address is used in the destination address field of the IP packet. A given PDSN320 participates in the multicast routing of these packets. After compression, PDSN320 places each packet in the transmitted HDLC frame. HDLC frames are encapsulated by general routing encapsulation (GRE) packets. It is worth noting that GRE encapsulation forms the A10 channel described above. The key field of the GRE packet header uses a special value to indicate the broadcast carrier connection. The GRE packet is appended with a 20-byte IP packet header, which has a source address field that identifies the IP address of the PDSN320, and the destination address field uses a class D multicast IP address. The multicast IP address is the same as that used for the initial IP packet from CS326. The packets provided in the broadcast connection are provided in sequence; in one embodiment, the GRE ordering feature is activated. Complete the replication of IP multicast packets in the multicast router. It is worth noting that, according to an optional embodiment, the IP cloud 314 implements a point-to-point, or unicast channel to the recipient's PCF. For us, the multicast link or unicast link of this connection point is decided at a higher layer, where the UC channel provides increased security, and the MC tree provides effectiveness.

[0063] According to an exemplary embodiment, CS326 sends data to PDSN320 through a multicast IP address, and PDSN320 also sends data to PCFA310 and PCF/BSC312 through a multicast IP address. For example, PCF 310 then determines the number of individual users in the active set, which is in the target subscriber group, and copies the frames received from CS326 for each user. PDSN PCF310 determines the BSC, which corresponds to each user in the subscriber group.

[0064] In an embodiment, the BSC304 is used to send to the nearest BSC, where the BSC304 can copy the received packets and send them to one or more neighboring BSCs. The BSC link has produced better soft handover performance. The "anchor" BSC method produces better soft handoff performance. The anchored BSC304 replicates the transmission frame and sends it to its neighboring BSC with the same time stamp. When the mobile station receives transmission frames from different BSCs, the time stamp information is very critical for soft handover operations.

[0065] Multicast Service

[0066] One type of broadcast service is called a multicast (MC) service or "group call (GC)", where the "GC group" includes other users participating in the GC, and a group of users in the GC is identified for a given MC content. This group of users can be called the MC group. MC content is only used for MC group members. Each active user in the MC group registers with AN. Then, AN tracks the location of each registered user and targets the transmission of MC messages at these locations. In particular, the AN determines a cell, sector, and/or geographic area, where each user of each MC group is located, and then sends a message to the PCFo associated with those cells, sectors, and/or geographic areas

[0067] In some other types of broadcast services, BC messages do not require the location and activity information of the receiver or subscriber to be sent. In contrast to them, the MC service uses the information of active users to operate, especially the location of each active user. and,

CN 101005457 Β

The user provides location information to the AN. In an embodiment, the active users in the MC group register with the AN through IP communication, especially through the use of Internet Group Management Protocol (IGMP) messages. The MC service can identify the location of each user, as well as the target transmission of MC to those locations. The MC service uses the router between the PCF and the PDSN. The MC service establishes a connection tree, which provides a path from the CS to each PCF that is communicating with the active users in the MC group. This tree is called the MC tree; an example of the MC tree is shown in Figure 6 and will be discussed below.

[0068] In a general IP network or system, such as a computer network coupled to the Internet, if a user wishes to receive MC type information (called MC content), the user uses the Internet Packet Management Protocol (IGMP) to register with the nearest router. Then, this router starts the process of establishing the MC tree by registering with the next neighboring router. Next, the CS sends the MC content in the form of MC IP packets. Subsequently, the MC IP packet is routed to the initial router through the MC tree. This router replicates data for every user who expects MC content. The public broadcast medium in computer networks is an Ethernet hub that connects multiple users to the same information stream.

[0069] The combination of the Internet and IP networks with wireless communication systems introduces several obvious problems. One problem is routing information from the IP network through the wireless network. Several interconnections are predefined in the wireless system. For example, as discussed above, the interface between BSC and PCF is defined by the A8/A9 connection. Similarly, the PCF connected to the PDSN is defined by the A10/A11 connection. In one embodiment, an internal MC tree is formed between PDSN and PCF, and an external MC tree is formed between PDSN and CS. Then, the PCF forms a specific channel to multiple BSCs that require MC content. This embodiment provides operational efficiency, which will be discussed below. Another embodiment forms an external MC tree between the PDSN and the CS, and at the same time establishes a channel from the PDSN to each independent PCF that receives MC content. This embodiment provides secure communication.

[0070] Generally, the MC path is considered end-to-end, where MC content starts from one source and is sent to the end user. This end user can be an MS. Alternatively, the MS may be a mobile router that routes MC content to a network. End users do not forward MC content. It is worth noting that the MC path can include many different types of interconnections. For example, one embodiment includes the internal MC tree discussed above with terminal points at the PCF, and the external MC tree with terminal points at the PDSN. Similarly, the MC path may include point-to-point channels, where each channel is formed between a node and a unique independent node.

[0071] According to the exemplary embodiment shown in FIG. 5, the communication system 300 includes a CS326 that communicates with the PDSNs 320 and 322 via the IP cloud 324. It is worth noting that the CS326 also communicates with other PDSNs not shown. The IP cloud 324 includes routing configurations such as multicast routers (as described above) and other routers for transferring data through the cloud 324. The transmission through the IP cloud 324 is IP communication. The routers in the IP cloud 324 access communications, such as BC messages and MC messages, to target recipients conforming to the Internet Engineering Task Force (IETF) protocol.

[0072] Continuing with FIG. 5, PDSN 320 and 322 communicate with PCF 310 and 312 through another IP cloud 314, and also communicate with other PCFs not shown. The IP cloud 314 includes the configuration of routers, such as multicast routers and other routers for transmitting data transmission through the cloud 314. The transmission through the IP cloud 314 is IP communication. The routers in the IP cloud 314 access communications, such as BC messages and MC messages, to target recipients conforming to the Internet Engineering Task Force (IETF) protocol. Moreover, the PCF 310 communicates with the BSC 304 through another IP cloud 308. The IP cloud 314 includes the configuration of routers, such as multicast routers and other routers for transmitting data transmission through the cloud 314. The transmission through the IP cloud 314 is IP communication. The PCF 312 also operates as a BSC and communicates with any user in the system 300 (not shown). It is worth noting that, for the sake of clarity, three BSCs are described, specifically BSC302.304 and 306. The system 300 may include any number of additional BSCs (not shown). It is worth noting that optional embodiments may include optional configurations, in which any or connection represented by multiple IP clouds such as IP cloud 308.314.324 may be replaced by a point-to-point connection. The point-to-point connection can be at one point

A secure connection established between a device such as PCF± and another point such as BSC. The point-to-point connection can be obtained on an IP cloud, such as IP cloud 308, through a method called channel establishment. The basic idea of establishing a channel is to take an IP packet, encapsulate the packet with GRE/IP, and send the obtained packet to the destination. If the destination address of the external IP header is a unicast IP address, this process obtains a point-to-point channel. If the target address is a multicast IP address, this process obtains a point-to-multicast channel. It is worth noting that all of these are in the same IP cloud. For example, in IP cloud 314, there are several different applicable methods. One method forms a point-to-point channel, and the second method forms a point-to-multicast channel. This is in contrast to the connection method used in cloud 324, where GRE is not used to establish a channel and the initial multicast IP packet is sent. [0073] In an exemplary embodiment, the CS326 uses the information of the multicast IP address to configure the HSBS channel, and the multicast IP address is used in the IP cloud 324. The CS uses the MC IP address to send HSBS content information, and this information becomes the payload. It is worth noting that the configuration of Figure 8 can be used to broadcast a variety of BS services.

[0074] In order to form a channel, this message can be encapsulated in an external IP packet. When the encapsulated message is sent through the channel, the internal IP address, that is, the IP address of the initial IP packet, is ignored. Encapsulation changes the Internet routing of the original IP packet. In this exemplary embodiment, MC routes BC or MC messages between PDSN and PCF through the MC tree.

[0075] In this exemplary embodiment, PDSN320 and PCF310.312 are related to the MC group. In other words, MC group members are determined to be in the cell, sector, and/or geographic area served by PCF 310 and 312. The system 300 builds an external MC tree from CS 326 to PDSN 320, and builds an internal tree from PDSN 320 to PCF 310 and 312. The PDSN 320 establishes an external MC tree by successively registering with neighboring multicast routers in the IP cloud 324. This external MC tree is established through the IP network from PDSN320 to CS326. PDSN320 receives MC messages from MC group members through the external MC tree. In other words, MC messages can be sent through the external MC channel constructed by the external MC tree. Each PCF 310 and 312 establishes an internal MC tree to the PDSN 320 through the IP cloud 314. The MC message from PDSN320 is sent through the internal MC tree in the GRE/IP channel. [0076] FIG. 6 is an MC tree with one source 402 and multiple routers 404 to 450. The source 402 is the basis of the MC tree 400. The end users 412, 414, 420, 422, 424, 434, and 450 are considered as leaves of the MC tree 400. Two main branches are formed by routers 404 and 406. On the first main branch is another branch that passes through the router 410. in On the second main branch are two subsequent branches: one through 430 and the other through 432.

[0077] In an embodiment, the tree 400 has CS as a source. For broadcast services, where the broadcast message starts at the CS, the source 402 is the CS. In an alternative embodiment, the source may be another device in the network. For example, for a group call service, the message content can start from another user, where the user-related BSC is the source of the MC tree. Moreover, there is a group call management function in the network. The network receives a message from a member, and then forwards the message to the group call member through the MC tree. In these cases, the tree provides a path for providing the same information content to multiple users, while saving bandwidth and avoiding redundant duplication and information processing.

[0078] FIG. 7 illustrates a method 500 for processing BC messages according to an embodiment. The process 500 establishes an MC tree between at least one BSC and one PCF. This tree can include multiple BSCs. Likewise, additional trees are built for additional PCF. The MC tree establishes a path for sending BC messages to multiple receivers without establishing a point-to-point connection. The process 500 also establishes an MC tree between at least one PCF and one PDSN. This tree includes multiple PCFs and one PDSN. According to an embodiment, an internal multicast tree may only flow through one PDSN, that is, each tree has only one root. Moreover, the process 500 establishes another MC tree between at least one PDSN and one CS. This tree can include multiple PDSNo

[0079] The broadcast service of the embodiment illustrated in FIG. 7 is the broadcast of the BC message to the transmission range. In the first step 502, the process 500 determines the transmission range of the cell, sector, and/or geographic area for BC message transmission. This transmission range information can be used to build the MC tree. In particular, the identification transmission range identifies the leaves of the MC tree. MC tree is changed from leaf to root

set up. In step 504, the BSC sends a broadcast indicator to the PCF. The broadcast indicator is used to remind the BSC that the PCF wants this PCF to receive broadcast signaling messages. Next, in step 505, this process establishes the first connection between the BSC in the transmission range and the relevant PCF. This connection is a GRE secure channel between each BSC and PCF pair. Next, in step 506, this process establishes an MC tree between the PDSN and the PCF. This transmission range is the BC transmission identification PCF. Each PCF within the transmission range initializes the MC tree by registering with neighboring multicast routers. According to this exemplary embodiment, in step 508, this process establishes another MC tree from the PDSN to the CS. In step 510, the CS sends a BC message to the PDSN, where the BC message is encapsulated in an MC IP packet. The MC IP packet is addressed to the MC IP address and the CS is identified as the source of the packet. The MC IP packet address represents any PDSNo transmitted to the MC tree between the PDSN and CS. In step 512, the BC message flows through the MC tree. Then, in step 513, the BC message is sent to the BSC through the secure channel or UC connection. In step 514, the BSC sends a BC message to users in each coverage area.

[0080] It is worth noting that at this point, in order to adapt to soft handover, the receiving BSC can be used to fix the BSC to time-identify the BC message, and then forward it to the neighboring BSCo. In this way, the BC message is sent from multiple BSCs To a given user, enabling the user to switch to a better connection without losing transmission. Moreover, when the PCF only sends the BC message to one BSC, the anchor point BSC is used to provide efficiency, but this message can be provided to multiple other BSCos

[0081] FIG. 8 illustrates a process 550 of establishing an MC tree from PCF to PDSN. Register with the multicast router to initialize the registration chain, where each member of the chain registers to the next successive router. Registering with the multicast router also includes identifying the registered PCF as a member of a given MC group and the target of any IP packet addressed to the MC IP address of the MC group. It is worth noting that for BC messages, this MC group can be considered as the target range. In decision diamond 554, if the multicast router is registered, the process ends when the MC tree is completed. If the multicast router is not registered, that is, it is not yet part of the MC tree, then in step 556 the multicast router is registered to the next successive neighboring multicast router.

[0082] FIG. 9A illustrates the BC message flow through multiple MC trees, as described in the process 500 of FIGS. 7 and 8. Figure 9B illustrates the corresponding information signal flow, that is, broadcast message processing. As illustrated in Figure 9A, the BC message starts at CS326. This initial message is considered the payload. CS326 encapsulates the payload by applying MC IP to generate MC IP packets. The MC IP packet indicates that CS is the source of this packet and the secondary destination is given as the MC IP address. The MC IP packet is sent to the next touch point on the tree. In other words, MC IP packets traverse the tree from the source or root of the tree outward toward the leaves. For clarity, a separate PDSN is described, especially PDSN320. However, the MC tree can include any number of PDSNs, and each PDSN is identified by the MC IP address. PDSN320 and any other PDSN in the MC tree, compress MC IP packets, And apply a framing protocol, such as HDLC, to form a compressed framing packet (CFP). Then, this CFP is encapsulated by the GRE protocol to form a GRE packet. The generated GRE packet is also encapsulated according to MC IP to generate MC CFP, that is, multicast is compressed into frame packets. MC CFP identifies PDSN320 as the source and MC IP address as the destination. In the example illustrated in Figure 9A, PDSN320 transmits MC CFP to PCF 310 and 312, Every part of the MC tree. Each PCF 310 and 312 processes the received MC to form a secure channel to the BSC, such as to BSC 304, where the generated packets are UC BSC packets, each PCF is identified as the source, and the BSC IP address is identified as the destination. It is worth noting that each PCF can form multiple channels to the respective BSC. As explained, MCIP addressing is used until the message reaches the PCF. From the PCF to the end user, the embodiment uses a secure channel or UC connection.

[0083] FIG. 9 illustrates the corresponding signal flow, where the CS starts to establish the HSBS channel. At time t1, a GRE channel is established between the BSC and the PCF. At time t2, PCF uses IGMP to register with neighboring multicast routers. At time t3, the PCF confirms the GRE channel established with the BSC. At time t4, MC Routing Protocol (MRP) is used to register the multicast router between PCF and PDSN. At time t5, the PDSN registers with the neighboring multicast router. This process forms the exterior of the MC tree. Every of the MC tree

Π/14 page level, CS to PDSN, and PDSN to PCF, can be considered as an independent MC tree or the entire structure from CS to PCF can be considered as a tree. At this point, the BSC is established from the BC CS for a given HSBS channel through the MC IP to receive the BC message.

[0084] FIG. 10 illustrates an alternative embodiment of a process 700 for sending a BC message. This process starts by determining the transmission range of the broadcast in step 702. In step 704, the UC connection is established between the BSC and the PCF. UC connection can be A8/A9IP connection. Likewise, in step 706, a UC connection can be established between the PCF and the PDSN. Unlike the process 500 of FIG. 8, no MC tree is established between the PDSN and the PCF. Moreover, a point-to-point GRE channel is formed between each PDSN and PCF pair. The UC connection from PDSN to PCF can be A10/A11IP connection. In step 708, an MC tree is established between the CS and the PDSN.

[0085] Then, in step 709, the MC sends data to the PDSN, which is a part of the MC tree. In step 710, the data reaches the PDSNo through the MC tree. Next, in step 712, the PDSN processes the received data or BC message, and forwards the BC message to the PCF. It is worth noting that when multiple PCFs are used, the PDSN creates multiple copies of data for transmission to multiple PCFs. In step 714, the PCF sends data to the BSC through the UC connection. Next, in step 716, the data or BC message is sent from the BSC related to the MC group to the group members.

[0086] FIG. 11A illustrates the BC message flow through multiple MC trees, as described in the process 700 of FIG. 10. FIG. 11B illustrates the corresponding information signal flow, that is, broadcast message processing. Different from the process 500 in FIG. 7, the process 700 establishes the MC tree between the CS and the PDSN, but includes the point-to-point secure channel between the PDSN and the PCF, and also includes the secure channel between the PCF and the independent BSC. Users of point-to-point connections provide additional security at the expense of processing and bandwidth considerations.

[0087] As illustrated in FIG. 11A, the BC message starts with CS326. The initial message is considered as the payload. CS326 encapsulates this payload by applying MC IP to generate MC IP packets. The MC IP packet indicates that CS is the source of the packet, and the destination is given as the MC IP address. The MC IP packet is sent to the next node on the tree. In other words, MC IP packets traverse the tree from the source or root of the tree outward toward the leaves. For clarity of illustration, a single PDSN is described, specifically PDSN320, however, the MC tree can include any number of PDSNs, and each PDSN is identified by an MC IP address. PDSN320 and any other PDSNs in the MC tree compress MC IP packets and apply a framing protocol, such as HDLC, to form compressed framing packets (CFP). Then, this CFP is encapsulated by the GRE protocol to form a GRE packet. The generated GRE packet is also encapsulated in accordance with unicast (UC) IP to generate UC CFP, that is, a unicast compressed framed packet. UC CFP identifies PDSN320 as the source and the specific PCF address as the destination. In the example illustrated in FIG. 11A, the PDSN 320 transmits the UC CFP to the PCF 310 and 312. Each PCF 310 and 312 processes the received UC CFP in the same way as the PDSN320, and the resulting packet is the UC BSC component. Group, identify each PCF as the source and BSC as the destination.

[0088] FIG. 11B illustrates the corresponding signal flow, where the CS starts to establish the HSBS channel. At time t1, the BSC establishes a GRE channel between the BSC and the PCF. At time t2, PCF establishes a GRE channel between PCF and PDSN. At time t3, the PDSN confirms the GRE channel established with the PCF. At time t4, the PCF confirms the GRE channel established with the BSC. At time t5, the PDSN uses IGMP or MRP to join the multicast group. It is worth noting that this process forms an MC tree between CS and PDSN. At this point, the BSC has been established to receive the BC message from the BC CS for a given HSBS channel through the MC IP.

[0089] According to an embodiment, for BC service processing, the CS uses a local mechanism to configure the HSBS channel. This CS uses the MC IP address to send HSBS content. HSBS configuration generates CS and sends HSBS content to the corresponding MC group. This content is sent in the format of IP packets, the source is the IP address, and the destination IP address is the MC IP address.

[0090] Then, the BSC decides to join the HSBS channel on a given broadcast channel. The broadcast channel is transmitted through a group of cells/sectors. The mechanism in the BSC to add the HSBS channel to the broadcast channel depends on the specific implementation. This mechanism

An example is an interface for starting HSBS channel configuration on the BSC, such as an operation management and operation (OA&M) interface. The BSC uses a local mechanism to establish the HSBS channel, using information such as the HSBS_ID of the HSBS channel and the MC IP address corresponding to the HSBS content.

[0091] The BSC sends an A9-Setup-A8 message to the PCF. In the A9-Setup-A8 message, the BSC sends the A8_Traffic_ID parameter, the GRE key, and the IP address of the BSC entity included in the others, and the BSC entity terminates the A-8 connection for the HSBS channel. The additional domain IP_MulticastAddress is added to the A8_Traffic_ID parameter. The additional domain identifies the IP multicast address used by the CS to send HSBS content. A new service option for HSBS service is used in the A9-Setup-A8 message.

[0092] Once the A9-Setup-A8 message is received from the BSC, the PCF is alerted that the BSC wishes to join the IP multicast group. If the PCF is already a member of the desired multicast group, there is no need to join the multicast group. Otherwise, the PCF sends an IGMP request to its multicast router to join the multicast group. Once the IGMP is successfully established, the PCF sends the A9-Connect-A8 message back to the BSC. The multicast routing information is propagated all the way from the multicast router using the multicast routing protocol to the upstream router, and all the way to the CS through the PDSN. This establishes a multicast path or tree from CS to PCF. The PCF obtains the binding of the GRE A8-Key, the BSC IP address and the IP multicast address to correctly establish the IP multicast packet channel to the BSC.

[0093] In the IP environment, there are several multicast routing protocols used for multicast routing. The distance vector multicast routing protocol (DVMRP) is described in detail in RFC 1075 written by D. Waitzman, C. Partridge, and SE Deering and published on November 1, 1988. Protocol independent multicast-sparse mode (PIM-SM) is available in D. Estrin, D. Farinacci, A. Helmy, D. Thaler, S. Deering, M. Handley> V. Jacobson, C. Liu, P. Sharma> L It is described in detail in RFC2362 written by Wei and published in June 1998. There is also Multicast Open Shortest Path First (MOSPF), which is described in detail in RFC 1584 by J. Moy, published in March 1994, titled "Multicast Extensions to OSPF".

[0094] Continuing with FIG. 11B, a GRE connection is established from the BSC to the PCF, where a GRE channel establishment message is sent, such as illustrated at time t1 in FIG. 11B. In the GRE establishment message, the BSC sends the Traffic_ID parameter, including the GRE key and the IP address of the BSC entity, and the BSC entity terminates the connection for the HSBS channel. IP_MulticastAddress is added to the Traffic_ID parameter. The Traffic_ID parameter can include multiple other information. IP_MulticastAddress identifies the IP MC address used by CS to send HSBS content.

[0095] In operation, the CS sends HSBS content, for example, a BS message, to the MC IP address. The MC IP address is used in the destination address field of the IP packet. This multicast router routes the packet to the member PDSN_OIt is worth noting that this multicast group membership was established earlier using IGMP and MC routing protocols. After header compression (if it is implemented), the PDSN places each packet in an HDLC frame. HDLC frames are encapsulated in GRE/IP packets. The PDSN sets the key field of the GRE packet to the destination MC IP address of the encapsulated IP packet. The GRE packet is attached with a 20-byte IP packet header as the encapsulated packet, the PDSNIP address is the source address field, and the same MC IP address is used as the destination address field. The PDSN sends the encapsulated HDLC frame to the member multicast router. All the multicast member PCFs receive MC packets. Due to the compression of the header in the PDSN, it is necessary to sort. GRE includes a sequence number that identifies the packet. The GRE sequence number ensures the order delivery of packets.

[0096] Multiple BSCs can be used to broadcast the same HSBS channel to cover a certain geographic area. In this way, the HSBS channel is related to a certain frequency. In order to facilitate automatic soft handover, the transmission of the basic broadcast service channel or F-BSCH is synchronized within a geographic area. This allows broadcast packets to be combined at the mobile station. According to an embodiment, the MC tree includes a leaf that becomes the "anchor point BSC", and this leaf replicates the broadcast content to the level BSC. The anchor point BSC will replicate and send HDLC frames to any secondary BSC through an interface, where the transmission to the secondary BSC has a limited delay.

[0097] FIG. 12 illustrates the processing method for MC messages to be sent to the MC group. This process is used for group call services, where

The broadcasted message can start from a user in the system. This group call allows users to provide point-to-multicast transmission. A user in this group sends a message to multiple recipients. The process 600 starts at step 602, where the CS determines a start time for the MC message. In step 604, the MC group subscriber registers with the BSC. In step 605, the BSC sends a setup message to the PCF. The setup message starts the GRE channel between the BSC and the PCF, and also warns the PCF that the BSC is part of the group call. In step 606, this process establishes an MC tree between PDSN and PCF. Then in step 608, this process establishes an internal MC tree from PDSN to CS. In step 610, once the MC tree is established, the source sends an MC message addressed to the MC IP address. In step 612, the message traverses the tree. In step 614, the PCF sends an MC message to the BSC through the UC connection. Then in step 616, the BSC forwards the MC message to the group members in the corresponding geographic area.

[0098] It is worth noting that for MC messages sent to the MC group, group members move within the communication system. When a group member moves to a non-registered place in the MC tree or a non-MC message transmission part, the group member registers with the BSC of the new address. During a group call, group members will monitor the frequency assigned to the BC channel used for the group call. By registering with the new BSC, the group members provide the BC frequency to the system. Then, the system can page the group members of incoming calls. Once the group members register with the new BSC, the system creates an MC tree that includes the new BSC.

[0099] An alternative embodiment may apply the method discussed above to an optional BC service, in which point-to-multicast transmission is used. Using an MC tree formed by leaves or terminal points registered with successive routers provides a convenient and dynamic method to avoid redundancy in the communication system. Moreover, the use of the MC tree increases the scalability while reducing the amount of infrastructure required to expand the network.

[0100] Those skilled in the art understand that information and signals can be represented by various processes and technologies. For example, the data, instructions, commands, information, signals, bits, symbols, and slices referred to in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0101] Those skilled in the art can also understand that the various illustrative logical blocks, modules, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of both. In order to clearly illustrate the interactivity of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described according to their functionality. Whether these functionalities are implemented as hardware or software depends on the specific application and design constraints adopted by the entire system. Technicians can implement the described functions for specific applications in different ways, but these implementation decisions should not be considered as departing from the scope of the present invention.

[0102] The various illustrative logical blocks, modules, and circuits described in conjunction with the embodiments disclosed herein can be implemented or executed by: general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), A field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of devices designed to perform the functions described herein. The general purpose processor is preferably a microprocessor, however, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented by a combination of computer devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or other such configurations.

[0103] The implementation or execution of the method or algorithm steps described in conjunction with the embodiments disclosed herein may be directly included in hardware, a software module executed by a processor, or a combination of the two. The software module can reside in RAM memory, flash memory, ROM memory>EPROM memory, EEPROM memory, register, hard disk, removable disk>CD-ROM, or other storage media in any form known in the art. The exemplary storage medium is coupled to a processor that can read information from the storage medium and write information to it. Or, the storage medium is incorporated into the processor. The processor and storage medium can reside in the ASIC. The ASIC can reside in the user terminal. Alternatively, the processor and storage medium can reside on the user terminal

As an independent component.

[0104] The above description of the preferred embodiment enables those skilled in the art to make or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined here can be applied to other embodiments without using creative ability. Therefore, the present invention is not limited to the embodiments shown here, but should conform to the broadest scope consistent with the principles and novel features disclosed herein.