Method and apparatus for radio resources management in multi-radio access technology wireless systems

0001The present invention relates to wireless communication technology.

0002<u style="single">Cross-reference of related applications</u> This application claims the benefit of US Provisional Application No. 61 / 513,180, filed July 29, 2011, the contents of which are incorporated herein by reference.

0003The demand for improved network coverage, improved capacity, and increased bandwidth for voice and data services in wireless systems has led to the constant development of a number of wireless access technologies (RATs). Examples of such RATs are, for example, Global Systems for Mobile Communications (GSM), Broadband Channel Split Multiple Access (WCDMA®), High Speed Packet Access (High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packets). Access (HSUPA) and its respective multi-carrier versions can be included), 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (LTE Release 10 and later can include carrier aggregation support) ), IEEE802.11b / a / g / n, IEEE802.16a / e, IEEE802.20, Code Division Multiple Access 2000 1x (CDMA2000 1x), and cdma2000 Evolution Data Optimized for 3rd Generation Partnership Project 2 (3GPP2) Includes (cdma200 EV-DO).

0004Methods and devices for performing wireless communication in a wireless transmit / receive unit (WTRU) configured for multi-RAT operation are disclosed. The method comprises the step of the WTRU transmitting information wirelessly on the first operating frequency according to the first RAT and the step of transmitting information wirelessly on the second operating frequency according to the second RAT.

0005A more detailed understanding can be obtained from the following description given by way of example in conjunction with the accompanying drawings.<figref num="1A">FIG. 5 is a system diagram of an exemplary communication system capable of implementing one or more disclosed embodiments.</figref><figref num="1B">FIG. 5 is a system diagram of an exemplary wireless transceiver unit (WTRU) that can be used within the communication system shown in Figure 1A.</figref><figref num="1C">FIG. 5 is a system diagram of an exemplary radio access network and an exemplary core network that can be used within the communication system shown in FIG. 1A.</figref><figref num="2">It is a block diagram of an exemplary system for multi-RAT communication.</figref><figref num="3">It is a block diagram of an exemplary control plane for multi-RAT operation using one RRC instance and one RRC connection per WTRU.</figref><figref num="4">FIG. 5 is a flow diagram of an exemplary method of performing wireless communication in a WTRU configured for multi-RAT operation corresponding to the embodiment shown in FIG.</figref><figref num="5">FIG. 6 is a block diagram of an exemplary control plane for multi-RAT operation using an RRC instance for each configured RAT and one RRC connection per WTRU.</figref><figref num="6">FIG. 5 is a flow diagram of an exemplary method of performing wireless communication in a WTRU configured for multi-RAT operation corresponding to the embodiment shown in FIG.</figref><figref num="7">FIG. 6 is a block diagram of an exemplary control plane for multi-RAT operation using RRC instances and RRC connections for each configured RAT.</figref><figref num="8">FIG. 5 is a flow diagram of an exemplary method of performing wireless communication in a WTRU configured for multi-RAT operation corresponding to the embodiment shown in FIG.</figref><figref num="9">It is a block diagram which shows the E-UTRA RRC state and the mobility support between E-UTRAN, UTRAN, and GERAN.</figref>

0006FIG. 1A is a diagram of an exemplary communication system 100 capable of implementing one or more disclosed embodiments. The communication system 100 can be a multiple access system that provides content such as voice, data, video, messaging, and broadcasting to a plurality of wireless users. Communication system 100 can allow multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, Communication System 100 includes one code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), and single carrier FDMA (SC-FDMA). Alternatively, multiple channel access methods can be used.

0007As shown in FIG. 1A, the communication system 100 includes wireless transmit / receive units (WTRU) 102a, 102b, 102c, 102d, wireless access network (RAN) 104, core network 106, public switched telephone network (PSTN) 108, and Internet 110. , And other networks 112 can be included, but it will be appreciated that the disclosed embodiments are intended for any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRU102a, 102b, 102c, 102d can be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRU102a, 102b, 102c, 102d can be configured to transmit and / or receive wireless signals, such as user equipment (UE), mobile stations, fixed or mobile subscriber units, pages, and cellular. It can include telephones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, home appliances and more.

0008Communication system 100 can also include base station 114a and base station 114b. Each of the base stations 114a, 114b is at least one of WTRU102a, 102b, 102c, 102d to facilitate access to one or more communication networks such as core network 106, internet 110, and / or network 112. It can be any type of device that is configured to interface wirelessly. For example, base stations 114a and 114b are base transceiver stations (BTS), node B, e-node B, home node B, home e-node B, site controller, access point (AP), wireless router, etc. Can be done. Although base stations 114a and 114b are shown as single elements, respectively, it will be appreciated that base stations 114a and 114b can include any number of interconnected base stations and / or network elements. ..

0009Base station 114a can be part of RAN104, where RAN104 is another base station and / or network elements such as base station controller (BSC), wireless network controller (RNC), relay node (not shown). Can also be included. Base station 114a and / or base station 114b can be configured to transmit and / or receive wireless signals within a particular geographic area, sometimes referred to as a cell (not shown). The cell can be further divided into cell sectors. For example, the cell associated with base station 114a can be divided into three sectors. Thus, in one embodiment, base station 114a can include three transceivers, one for each sector of the cell. In another embodiment, base station 114a can utilize multi-input multi-output (MIMO) technology and thus can utilize multiple transceivers per sector of the cell.

0010Base stations 114a, 114b can communicate with one or more of WTRU102a, 102b, 102c, 102d via air interface 116, which air interface 116 can communicate with any suitable wireless communication link (eg, radio frequency). (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 can be established using any suitable radio access technology (RAT).

0011More specifically, as mentioned above, Communication System 100 can be a multiple access system, with one or more channel access methods such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA. It can be used. For example, base stations 114a in RAN104 and WTRU102a, 102b, 102c can establish air interface 116 using wideband CDMA (WCDMA), such as Universal Mobile Communication System (UMTS) Terrestrial Radio Access (UTRA). The technology can be implemented. WCDMA is fast packet access may include communication protocols such as scan (HSPA) and / or Evolved HSPA (HSPA +). HSPA can include High Speed Downlink Packet Access (HSDPA) and / or High Speed Uplink Packet Access (HSUPA).

0012In another embodiment, base stations 114a, and WTRU102a, 102b, 102c can establish an air interface 116 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A), an advanced UMTS terrestrial radio. Wireless technologies such as access (E-UTRA) can be implemented.

0013In other embodiments, the base stations 114a, and WTRU102a, 102b, 102c are IEEE802.16 (ie, Global Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, interim standard. 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM®), High Speed Data Rate for GSM Evolution (EDGE), Wireless technologies such as GSM EDGE (GERAN) can be implemented.

0014Base station 114b in Figure 1A can be, for example, a wireless router, home node B, home e-node B, or access point, facilitating wireless connectivity in local areas such as work, home, vehicles, and campus. Any suitable RAT can be utilized to do this. In one embodiment, base stations 114b and WTRU102c, 102d can implement wireless technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, base stations 114b and WTRU102c, 102d can implement wireless technologies such as IEEE802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base stations 114b and WTRU102c, 102d utilize cellular-based RATs (eg, WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish picocells or femtocells. Can be done. As shown in FIG. 1A, base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not need to access the Internet 110 via the core network 106.

0015The RAN104 can communicate with the core network 106, which provides voice, data, applications, and / or voice over Internet Protocol (VoIP) services to one or more of the WTRU102a, 102b, 102c, 102d. It can be any type of network configured to do so. For example, core network 106 can provide call control, billing services, mobile location-based services, prepaid calls, internet connectivity, video delivery, and / or perform high-level security features such as user authentication. can do. Although not shown in Figure 1A, it will be appreciated that the RAN 104 and / or the core network 106 can communicate directly or indirectly with other RANs that utilize the same or different RATs as the RAN 104. For example, in addition to connecting to a RAN 104 that can utilize E-UTRA radio technology, the core network 106 can also communicate with another RAN (not shown) that utilizes GSM radio technology.

0016Core network 106 can also serve as a gateway for WTRU102a, 102b, 102c, 102d to access PSTN108, Internet 110, and / or other networks 112. PSTN108 can include a circuit-switched telephone network that provides basic telephone services (POTS). Internet 110 is an interconnected computer network that uses common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Protocol (IP) within the TCP / IP Internet Protocol Suite. It can include a global system consisting of devices. The network 112 may include a wired or wireless communication network owned and / or operated by another service provider. For example, network 112 can include another core network connected to one or more RANs that have the same or different RATs as RAN104.

0017Some or all of the WTRU102a, 102b, 102c, 102d within the communication system 100 can include multimode functionality, i.e., the WTRU102a, 102b, 102c, 102d communicate with different wireless networks over different wireless links. Can include multiple transceivers for. For example, the WTRU102c shown in FIG. 1A can be configured to communicate with base station 114a, which can utilize cellular-based radio technology, and to communicate with base station 114b, which can utilize IEEE802 radio technology.

0018FIG. 1B is an exemplary WTRU102 system diagram. As shown in FIG. 1B, the WTRU102 includes a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, and a non-detachable memory 130. It can include a removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and other peripherals 138. The WTRU102 can include any subcombination of the above elements while maintaining consistency with one embodiment.

0019Processor 118 is a general purpose processor, dedicated processor, conventional processor, digital signal processor (DSP), multiple microprocessors, one or more microprocessors that work with DSP cores, controllers, microcontrollers, and application-specific integrated circuits. It can be an ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, and so on. Processor 118 can perform signal coding, data processing, power control, input / output processing, and / or any other function that allows the WTRU102 to operate in a wireless environment. Processor 118 can be coupled to transceiver 120, which can be coupled to transmit / receive element 122. Although Figure 1B shows processor 118 and transceiver 120 as separate components, it will be appreciated that processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

0020The transmit / receive element 122 can be configured to transmit or receive a signal from a base station (eg, base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In another embodiment, the transmit / receive element 122 can be, for example, a radiator / detector configured to transmit and / or receive an IR, UV, or visible light signal. In yet another embodiment, the transmit / receive element 122 can be configured to transmit and receive both RF and optical signals. It will be appreciated that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.

0021In addition, although the transmit / receive element 122 is shown as a single element in FIG. 1B, the WTRU102 can include any number of transmit / receive elements 122. More specifically, the WTRU102 can utilize MIMO technology. Thus, in one embodiment, the WTRU102 may include two or more transmit / receive elements 122 (eg, a plurality of antennas) for transmitting and receiving wireless signals via the air interface 116.

0022The transceiver 120 can be configured to modulate the signal transmitted by the transmit / receive element 122 and demodulate the signal received by the transmit / receive element 122. As mentioned above, the WTRU102 can have multimode capabilities. Thus, the transceiver 120 can include a plurality of transceivers to allow the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11.

0023Processor 118 of the WTRU102 can be coupled to a speaker / microphone 124, keypad 126, and / or display / touchpad 128 (eg, a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). User input data can be received from them. Processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. In addition, processor 118 can obtain information from any type of suitable memory, such as non-detachable memory 130 and / or removable memory 132, and can store data in them. The non-detachable memory 130 can include random access memory (RAM), read-only memory (ROM), hard disk, or any other type of memory storage device. The removable memory 132 can include a subscriber identification module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, processor 118 can obtain information from memory located on a server or home computer (not shown), etc., rather than memory physically located on the WTRU102. Data can be stored in them.

0024Processor 118 can be configured to receive power from power supply 134 and to distribute and / or control power to other components within WTRU102. The power supply 134 can be any suitable device for powering the WTRU102. For example, the power supply 134 may be one or more batteries (eg, nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc. And so on.

0025The processor 118 can also be coupled to the GPS chipset 136, which can be configured to provide location information (eg, longitude and latitude) about the current position of the WTRU102. In addition to, or instead of, the information from the GPS chipset 136, the WTRU102 can receive location information from a base station (eg, base stations 114a, 114b) via air interface 116 and / or more than one. It can determine its position based on the timing of the signal received from a base station near. It will be appreciated that WTRU102 can acquire position information using any suitable position-fixing method while maintaining consistency with one embodiment.

0026Processor 118 can be further coupled to other peripherals 138, which are one or more software modules that provide additional features, functionality, and / or wired or wireless connectivity. And / or can include hardware modules. For example, peripherals 138 include accelerometers, e-compasses, satellite transceivers, digital cameras (for photos or videos), universal serial bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth®. It can include modules, frequency modulation (FM) radio units, digital music players, media players, video game player modules, internet browsers, and more.

0027FIG. 1C is a system diagram of the RAN 104 and the core network 106 according to one embodiment. As mentioned above, the RAN104 can utilize E-UTRA radio technology to communicate with the WTRU102a, 102b, 102c via the air interface 116. The RAN104 can also communicate with the core network 106.

0028Although RAN104 can include e-nodes B140a, 140b, 140c, it will be appreciated that RAN104 can include any number of e-nodes B while maintaining consistency with one embodiment. The e-nodes B140a, 140b, 140c can each include one or more transceivers for communicating with the WTRU102a, 102b, 102c via the air interface 116. In one embodiment, the e-nodes B140a, 140b, 140c can implement MIMO technology. Therefore, the e-node B140a can transmit a wireless signal to the WTRU102a and receive a wireless signal from the WTRU102a using, for example, a plurality of antennas.

0029Each of the e-nodes B140a, 140b, 140c can be associated with a particular cell (not shown) to handle radio resource management decisions, handover decisions, user scheduling on the uplink and / or downlink, etc. Can be configured. As shown in Figure 1C, the e-nodes B140a, 140b, 140c can communicate with each other via the X2 interface.

0030The core network 106 shown in Figure 1C can include a mobility management gateway (MME) 142, a serving gateway 144, and a packet data network (PDN) gateway 146. Although each of the above elements is shown as part of the core network 106, it will be appreciated that any one of these elements can be owned and / or operated by a different entity than the core network operator.

0031The MME142 can be connected to each of the e-nodes B142a, 142b, and 142c in the RAN 104 via the S1 interface, and can serve as a control node. For example, the MME142 can be responsible for authenticating users of the WTRU102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during the initial connection of the WTRU102a, 102b, 102c, and so on. The MME142 can also provide control plane functionality for exchange between the RAN 104 and other RANs (not shown) that utilize other radio technologies such as GSM or WCDMA.

0032The serving gateway 144 can be connected to each of the e-nodes B140a, 140b, 140c in the RAN 104 via the S1 interface. The serving gateway 144 can generally route and forward user data packets to / from WTRU102a, 102b, 102c. The serving gateway 144 provides anchoring of the user plane during e-node B-to-handover, triggering a mass call when downlink data is available for WTRU102a, 102b, 102c, in the context of WTRU102a, 102b, 102c. Other functions such as management and memory can also be performed.

0033The serving gateway 144 can also connect to the PDN gateway 146, which provides access to packet-switched networks such as the Internet 110 to the WTRU102a, 102b, 102c and IP-enabled devices with the WTRU102a, 102b, 102c. Communication with and can be facilitated.

0034The core network 106 can facilitate communication with other networks. For example, core network 106 can provide access to circuit-switched networks such as PSTN108 to WTRU102a, 102b, 102c to facilitate communication between WTRU102a, 102b, 102c and traditional land-based communication devices. it can. For example, the core network 106 can include an IP gateway (eg, an IP Multimedia Subsystem (IMS) server) that acts as an interface between the core network 106 and the PSTN108, or can communicate with the IP gateway. it can. In addition, core network 106 can provide access to network 112 to WTRU102a, 102b, 102c, which includes other wired or wireless networks owned and / or operated by other service providers. be able to.

0035When RATs such as WCDMA and LTE were developed, they were created to allow the use of two or more component carriers (CCs) for transmission and reception between WTRUs and base stations. .. CC can be, for example, the frequency on which the WTRU operates. For example, a WTRU can receive transmissions over a downlink (DL) CC, and a DL CC can include multiple DL physical channels. As another example, a WTRU can perform transmissions over an uplink (UL) CC, which can contain multiple UL physical channels.

0036The cell contains at least a DL CC that can be associated with a UL CC based on the SI received by the WTRU, using a dedicated configuration broadcast on the DL CC or transmitted from the network. For example, if SI is broadcast over DL CC, the WTRU (for example, if it is in RRC_IDLE for LTE, or idle / CELL_FACH for WCDMA (ie, the WTRU still has an RRC connection to the network). If not)) The UL frequency and bandwidth of the associated UL CC can be received as part of SI IE.

0037More specifically, 3GPP WCDMA Release 8 provides support for simultaneous use of two HSDPA component carriers (2C-HSDPA), and Release 9 provides support for MIMO in multi-carrier DL WCDMA, as well as two. It also introduced support for HSUPA UL CC, and Release 10 introduced support for up to four DL CCs (4C-HSDPA). For Release 11, the number of DL CCs can be increased to 8 (8C-HSDPA). 3GPP LTE Release 10 introduced support for simultaneous transmission and / or reception using multiple CC radio resources between base and mobile stations within the same transmission interval. The transmit time interval (TTI) for HSPA is a 2ms subframe and the TTI for 3GPP LTE releases 8, 9, and 10 is a 1ms subframe (each radio frame (10ms) is a 1ms). Contains 10 subframes of equal size).

0038Network architectures for different RATs can support different functionality in different entities within the architecture. In some RATs, similar functions (eg MAC functions) can be performed by different entities within the same architecture, and architectures for different RATs can include different entities. For example, for UTRAN, Radio Resource Control (RRC), Packet Data Control Protocol (PDCP), Radio Link Control (RLC), Medium Access Control Individual (MAC-d), and MAC-is sublayers are Radio Network Controllers (RNCs). ), While medium access control high speed (MAC-hs), MAC-i, and layer 1 (L1) are located in node B. In addition, for Universal Terrestrial Radio Access Networks (UTRAN), security for MAC (eg encryption), segmentation, and reassembly services, as well as ordered delivery services for PDCP, are provided by RLC, while MAC provides. Guarantee order between hybrid automatic repeat request (HARQ) processes for the RLC layer. As another example, in the case of evolved UTRAN (eUTRAN), there is no RNC and the RRC, PDCP, RLC, and MAC layers are all located within e-node B (eNB). Security (eg, encryption, integrity, and authentication) and ordered delivery services (eg, at the time of handover) are provided by PDCP, while RLC brings segmentation, re-segmentation, and reassembly services to the MAC. Provided against.

0039One of the design objectives of LTE Release 8 is to enable operators to deploy LTE using the same site for legacy WCDMA deployments to reduce deployment and radio planning costs. Met. Therefore, network operators can deploy both WCDMA / HSPA and LTE within the same coverage area, and LTE deployments can have the same coverage as existing WCDMA / HSPA deployments, WCDMA / HSPA. Multimode WTRUs that support both access and LTE access can be widely deployed.

0040However, the spectrum is a costly resource and not all frequency bands may be available to all carriers. Therefore, while carriers are expected to be able to provide support for both HSPA and LTE services, carrier aggregation scenarios are for a given carrier to have at most 2-3 component carriers per RAT. May be limited to. In addition, while LTE is being deployed, legacy deployments may be maintained in the near future, which is a period of underutilization of radio resources / spectrum and capacity on one side of the RAT. Can bring about the situation that is experienced.

0041HSPA Release 10 with MIMO provides a downlink peak data rate of 42 Mbps, and Release 10 Multicarrier HSPA can further increase the peak rate by introducing support for up to four DL CCs. LTE Releases 8 and 9 offer up to 100 Mbps in a single CC DL, and LTE Release 10 with intra-RAT carrier aggregation further increases peak rates by combining transmit resources of up to 5 CCs. Can be done. Some motivations for taking advantage of the combined data rates / capacities of multi-RAT deployments are, for example, reducing the cost of providing higher data rates (data enhancement scenarios), limiting the spectrum available from WCDMA / HSPA. Migrating to LTE (migration scenario), maximizing the use of deployed RAT (eg through load balancing), and maximizing the use of radio components in WTRU (eg dual band receiver) ) Can be included.

0042In addition to taking advantage of the increased peak rates, carriers may want to reserve frequency bandwidth for other reasons (eg, for home eNB deployments). In addition, combining HSPA resources with LTE resources provides a means to ensure service continuity (eg, for circuit-switched (CS) voice and / or for services that require LTE data rates). Further can be provided. Therefore, it may be desirable to have a method that allows the WTRU to operate on multiple frequencies simultaneously and that the WTRU operates on at least one of the frequencies according to different RATs.

0043The embodiments described herein can relate to a multimode WTRU that supports simultaneous (or quasi-simultaneous) operation of multiple different RATs on CC. The embodiments described herein can also relate to how the multimode WTRU can perform radio resource management and related RRC procedures when using different RATs. In one embodiment, the WTRU can use different RATs on different frequencies to perform radio resource management and related RRC procedures.

0044Some embodiments described herein are described with respect to a first RAT that is LTE and a second RAT that is WCDMA, HSUPA, and / or HSDPA, and vice versa. However, the embodiments described herein can be made applicable to any wireless technology. Further, although not explicitly described herein, embodiments described herein make transmissions using different RATs on different frequencies only at different time intervals (ie, some TTI based). The form of time division operation) and / or such transmissions can be made applicable to WTRUs performed within the same frequency band.

0045FIG. 2 is a block diagram of an exemplary system 200 for multi-RAT communication. The system 200 shown includes a WTRU204 and two base stations (eg, eNBs) 202, and 206. In FIG. 2, one WTRU204 uses channels 208, 210, 212, and 214 to communicate with two base stations 202, and 206. Channels 208, 210, 212, and 214 can be any combination of UL and DL channels of any number of different RATs.

0046Multi-RAT operation includes at least one CC in the first RAT (eg DL CC, UL CC, or one or more serving cells) and at least one CC in the second RAT (eg DL CC, UL CC). , Or any multimode WTRU that is configured simultaneously for operation with one or more serving cells). Operations on different CCs can occur simultaneously or quasi-simultaneously in time. For example, operations according to different RATs can be used sequentially on the same CC. Multimode WTRU can be any of GSM, WCDMA, HSPA, HSDPA, HSUPA, LTE, IEEE802.11b / a / g / n, IEEE802.16a / e, IEEE802.20, cdma2000 1x, and cdma2000 EV-DO, for example. It can include any mobile device that supports multiple RATs, such as combinations.

0047The serving cell can include, for example, a primary cell (PCell) or a secondary cell (SCell). More specifically, in the case of a WTRU that is not configured to use any SCell or does not support operation on multiple CCs (carrier aggregation), there may be only one serving cell (PCell). For WTRUs configured to use at least one SCell, the serving cell can include a set of one or more cells, including all configured PCells and all configured SCells.

0048In one embodiment, the WTRU204 can transmit information wirelessly on the first operating frequency according to the first RAT and wirelessly transmit information on the second operating frequency according to the second RAT. it can. Communication on the first and second operating frequencies can be done via any combination of channels 208, 210, 212, and 214. For example, the WTRU204 can wirelessly transmit information on the first operating frequency according to the first RAT (eg LTE) on DL channel 208 (eg LTE DL) and DL channel 212 (eg WCDMA). On HSDPA), information can be transmitted wirelessly on the second operating frequency according to the second RAT (eg WCDMA). As another example, the WTRU204 can wirelessly transmit information over the first operating frequency according to the first RAT (eg WCDMA) on UL channel 212 (eg WCDMA HSDPA) and UL channel 214 (eg WCDMA HSDPA). For example, LTE On UL), information can be transmitted wirelessly on the second operating frequency according to the second RAT (eg LTE).

0049WTRUs, such as the WTRU204 shown in Figure 2, can be configured for multi-RAT operation. A WTRU that supports access to multiple RATs is one of a number of different control plane configurations, and one of a number of different methods, for example, the control planes and methods illustrated and described with reference to FIGS. 3-8. You can use one to access those resources.

0050Figure 3 shows an exemplary control plane 300 for multi-RAT operation using one RRC instance 302, one state machine 304, one RRC connection 306 per WTRU, and one or more SRB308s. It is a block diagram of. The term RRC instance, when referred to hereafter, is a single state machine that operates using multiple RRC states (eg, CONNECTED or IDLE for the LTE RRC protocol) with corresponding state transitions, and RRC. RRC procedures including control and measurement procedures (including associated timers), RRC PDUs and information elements (IE), RRC configurations (including parameters for RRC, PDCP, RLC, MAC configurations), and physical ( The use of the RRC protocol, which can include a PHY) layer, can be conceptually expressed without limiting to a subset of possible additional aspects or aspects below. In the example shown in Figure 3, one RRC instance 302 can handle the management of radio resources for all configured RATs.

0051For HSPA, there are at least four RRC states: CELL_DCH, CELL_FACH, CELL_PCH / URA_PCH, and UTRA_IDLE. For LTE, there are two RRC states, RRC_CONNECTED and RRC_IDLE. If the RRC connection is established, the WTRU is in RRC_CONNECTED. Otherwise, the WTRU is in RRC_IDLE.

0052In the RRC_IDLE state, the WTRU detects incoming calls, changes in SI, and, in one embodiment, early terrestrial warning system (ETWS) / commercial mobile alert system (CMAS) notifications. To perform at least a mass call channel, perform neighbor cell measurement, cell selection, cell reselection, and SI acquisition. In the RRC_CONNECTED state, the WTRU sends / receives on the unicast channel and at least the call channel and / or SI block to detect incoming calls, SI changes, and, in one embodiment, ETWS / CMAS notifications. Type 1 can be monitored. The WTRU can also be configured to use one or more secondary cells in addition to the primary cell.

0053For each of the RRC protocols described in the paragraph above, a set of states, transitions, messages (eg, protocol data units (PDUs)), and procedures are defined. FIG. 9 shows, for example, CELL_DCH state 902, CELL_FACH state 904, CELL_PCH and URA_PCH state 906, UTRA_IDLE state 908, E-UTRA RRC CONNECTED state 910, E-UTRA RRC IDLE state 912, GSM_Connected state 914, GPRS packet transfer mode 916, FIG. 900 is a block diagram showing an E-UTRA (eg LTE) RRC state, including the GSM Idle / GPRS Packet Idle state 918. Figure 9 also shows mobility support between E-UTRAN, UTRAN, and GERAN.

0054In one embodiment, a single RRC instance 302 can manage a single RRC connection 306, which is used to handle radio resource management for all configured serving cells of any RAT. be able to. According to this embodiment, there can be at most one RRC instance and one RRC connection per WTRU at any given time.

0055FIG. 4 is a flow diagram 400 of an exemplary method of performing wireless communication in a WTRU configured for multi-RAT operation, corresponding to the embodiment shown in FIG. In the example shown in Figure 4, the WTRU can first access the network and use RRC instance 302 to establish an RRC connection 306 on the first RAT (eg, the primary RAT (PRAT)). (402). The WTRU can then receive a configuration on the RRC connection 306 that adds at least one serving cell for the second RAT (eg, the secondary RAT (SRAT)) (404). The WTRU can then use a single RRC instance 302 to configure the radio resource (406).

0056The primary cell (PCell) can include, for example, cell operation on the primary frequency where the WTRU performs the initial access to the system (eg, the cell where the WTRU performs the initial connection establishment procedure, the WTRU reconnects). The cell that initiates the establishment procedure, or the cell that is designated as the primary cell in the handover procedure). PCell can also support the frequencies shown as part of the RRC configuration procedure. Some features can only be supported on PCell. For example, PCell's UL CC supports CC, where the physical UL control channel resource is configured to carry all HARQ acknowledgment (ACK / NACK) feedback for a given WTRU. can do. For example, in LTE, WTRU can use PCell to derive parameters for security features and for higher layer SI such as non-access layer (NAS) mobility information. PCell Other features that can only be supported on the DL can include SI acquisition and change monitoring procedures on the broadcast channel (BCCH), as well as broadcast calls. For example, WCDMA PCell can be similar to LTE PCell. A secondary cell (SCell) can include, for example, a cell operating on a secondary frequency that can be configured after an RRC connection has been established and can be used to provide additional radio resources. The SI associated with the operation in the associated SCell can be provided using dedicated signaling when the SCell is added to the WTRU configuration. The parameters may have different values than those broadcast on the DL of the associated SCell using SI signaling, but this information is not the method used by WTRU to obtain this information. Regardless, it is sometimes referred to as the SI of the associated SCell.

0057The primary RAT (PRAT) (or anchor RAT) can include radio access network technology. At least one serving cell can be configured as a PCell for PRAT. PCell establishes a first RRC connection, derives security parameters (eg when a single security context is used), UCI is transmitted only on the serving cell of the first RAT. If) use the UL resource to send UL control information (UCI) and / or at least one serving cell with the UL resource (for example, if the UL resource is configured only in the first RAT). Can support at least one of the configurations. As a result, in some embodiments, the PRAT or anchor RAT may be referred to as the first RAT. A secondary RAT (SRAT) (or non-anchor RAT) can include a RAT in which none of the serving cells configured for it is for a PRAT in a WTRU configuration.

0058In one embodiment, the WTRU can access the LTE cell and use the corresponding RRC connection establishment procedure to establish an RRC connection 306 using LTE as the PRAT. The WTRU can be configured to use an additional serving cell, which can include one or more HSPA serving cells as the SRAT, using PRAT's RRC connection reconfiguration procedure. In one embodiment, the RRC connection reconfiguration procedure can only be performed after security has been activated in PRAT. Further, in one embodiment, the WTRU includes one or more IEs for HSPA configuration (eg, SI configuration IE, radio bearer IE, transport channel IE, and physical channel IE) during the RRC reconfiguration procedure. You can receive messages.

0059In another embodiment, the WTRU can access the HSPA cell and use the corresponding RRC connection establishment procedure to establish an RRC connection 306 with HSPA as the PRAT. The WTRU can be configured to use an additional serving cell (eg, one or more LTE serving cells) as the SRAT using PRAT's RRC connection reconfiguration procedure. In one embodiment, the WTRU can be configured to use PRAT's RRC radio bearer setup procedure to configure PRAT-specific information, while at the same time configuring the WTRU to use SRAT serving cells. Alternatively, the WTRU can be configured to use SRAT in the RRC connection setup using PRAT's Signaling Radio Bearer (SRB). In one embodiment, the RRC connection reconfiguration procedure can only be performed after security has been activated in PRAT. Further, in one embodiment, the WTRU will perform MAC-MainConfig for one or more IEs (eg, DL configuration of serving cells) for LTE configuration during the RRC reconfiguration procedure. PUSCH-Config IE, and / or Sounding RS for at least one of IE, CQI-ReportConfig IE, PDSCH-Config IE, PhysicalConfigDedicated IE, RadioResourceConfigDedicated IE, and / or RadioConfigCommon IE, and / or UL configuration of serving cells. -UL-Config Can receive RRC messages containing SI configuration IE and / or RRC IE), which can contain at least one of IE.

0060SRB is a wireless bearer used only for sending RRC and NAS messages. SRB0 is used for RRC messages that use a common control channel (CCH) logical channel. SRB1 is for RRC messages (eg, with NAS messages being piggybacked) and for NAS messages prior to the establishment of SRB2 using individual control channel (DCCH) logical channels. SRB2 is for NAS messages and is always configured after security activation. After security is activated, all RRC messages on SRB1 and SRB2 can be integrity protected and encrypted.

0061If CCs (or serving cells) of different RATs are aggregated and configured for a given WTRU, it may be necessary to have a way to handle the management of radio resource connections. In particular, for multi-RAT access, if multiple RRC connections and / or state machines (SM) can be used (eg, one per RAT on which the WTRU operates), each RRC connection and possible dialogue between them. It may be desirable to define a method that allows for proper handling. Alternatively, if only a single RRC connection and / or state machine is available for multi-RAT access, it may be desirable to define how a single RRC state machine can thereby control multiple radio resources. ..

0062Figure 5 shows an exemplary control plane 500 for multi-RAT operation using an RRC instance for each configured RAT, a state machine for each RRC instance, and one RRC connection per WTRU. It is a block diagram. More specifically, the examples shown are a single RRC instance 502 for PRAT, a state machine 504 for PRAT, an RRC instance 508 for SRAT, and a state machine 506 for SRAT. RRC connection 510 and one or more SRB 512s. In the example shown in Figure 5, radio resources for multiple RATs (eg PRAT and SRAT) are managed using multiple RRC instances (eg, one control plane instance per configured RAT). be able to.

0063In one embodiment, the RRC instance 508 for SRAT comprises a subset of the RRC protocol for the associated RAT. For example, the RRC instance 508 for SRAT has at least some radio resource management capabilities for the corresponding RAT (eg, intra-frequency and inter-frequency measurement configuration and reporting, radio link monitoring (RLM), SI). Can handle maintenance and error handling). In one embodiment, the RRC instance 508 for each SRAT can interact with the RRC instance 502 for PRAT. In the embodiments shown, RRC instance 502 manages a single RRC connection 510, which can be used to handle radio resource management for at least one RAT. There are also additional RRC instances for each additional configured RAT (eg, RRC instance 508 for SRAT), which can include a subset of the RRC protocol for the associated RAT (SRAT).

0064For LTE serving cells, if the WTRU performs RLM and reaches the maximum number of preamble transmissions for a random access procedure and / or the maximum number of repeatable failures when performing a random access procedure on an associated serving cell. It can be determined as UL radio link failure (RLF). In addition, for LTE serving cells, the WTRU receives an RRC instance from the physical (PHY) layer for a number of consecutive out-of-sync indications, after which the timer T310 starts the timer from the error state of the WTRU. If it expires before it recovers, it can be determined as DL RLF.

0065FIG. 6 is a flow diagram 600 of an exemplary method of performing wireless communication in a WTRU configured for multi-RAT operation corresponding to the embodiment shown in FIG. In the example shown in Figure 6, the WTRU first accesses the network and uses the first RRC instance (RRC instance 502 for PRAT) to make an RRC connection in the first RAT (eg PRAT). 510 can be established (602). The WTRU can then receive a configuration on the RRC connection 510 that adds at least one serving cell for the second RAT (eg SRAT) (604). The WTRU can then use the RRC PDU (for example, received on a different SRB) and / or the configuration information received on the RRC connection 510 to configure the radio resources for the SRAT, a second RRC instance (SRAT). You can use the RRC instance 508) for (606). In one embodiment, the second RRC instance 508 is initially in RRC connection mode (eg LTE CONNECTED or HSPA). It can operate according to CELL_DCH). The state of the RRC instance for SRAT may not be active, or RRC connection mode can be initiated by PRAT.

0066For example, the WTRU can access the LTE cell and use the corresponding RRC connection establishment procedure to establish an RRC connection using LTE as the PRAT. The WTRU can be configured to use additional serving cells as the SRAT, including, for example, one or more HSPA serving cells. In one embodiment, the configuration procedure can only be performed after security has been activated in PRAT.

0067In one embodiment, the configuration can be received via PRAT's RRC connection reconfiguration procedure. In one embodiment, the WTRU includes, for example, SI configuration IE, wireless bearer IE, transport channel IE, physical channel IE, and at least one of the secondary serving HS-DSCH IE during the RRC reconfiguration procedure. Can receive RRC messages containing one or more IEs about HSPA configuration. In one embodiment, the PRAT RRC instance can transfer the received SRAT configuration information to a corresponding SRAT RRC instance that can configure the SRAT's corresponding radio resources.

0068In another embodiment, the configuration can be received on an SRB configured to be associated with an RRC instance 508 of SRAT. In one embodiment, the WTRU can receive RRC PDUs of SRAT's RRC protocol on the SRB. In one embodiment, the RRC message may include one or more IEs for HSPA configurations, which may include, for example, at least one of SI configuration IE, radio bearer IE, transport channel IE, and physical channel IE. Can include. In one embodiment, the SRAT RRC instance is capable of performing corresponding configuration procedures, such as radio bearer control procedures and physical channel configuration procedures.

0069For example, the WTRU can access the HSPA cell and use the corresponding RRC connection establishment procedure to establish an RRC connection 306 with HSPA as the PRAT. The WTRU can be configured to use an additional serving cell as the SRAT, which may include, for example, one or more LTE serving cells. In one embodiment, this configuration procedure can only be performed after security has been activated in PRAT.

0070In one embodiment, the configuration can be received via PRAT's RRC connection reconfiguration procedure. In one embodiment, the WTRU is, for example, of SI Configuration IE, (MAC-MainConfig IE, CQI-ReportConfig IE, PDSCH-Config IE, PhysicalConfigDedicated IE, RadioResourceConfigDedicated IE, and RadioConfigCommon IE for DL configuration of serving cells. Can contain at least one and can also contain at least one of PUSCH-Config IE and SoundingRS-UL-Config IE for UL configuration of serving cells) RRC You can receive RRC messages that include one or more IEs about LTE configurations that can contain at least one of the IEs. In one embodiment, the PRAT RRC instance 502 can transfer the configuration information received by the SRAT to the corresponding SRAT RRC instance that can configure the SRAT's corresponding radio resources.

0071In another embodiment, the configuration can be received on an SRB configured to be associated with an RRC instance 508 of SRAT. In one embodiment, the WTRU can receive RRC PDUs of SRAT's RRC protocol on the SRB. In one embodiment, the RRC message is, for example, of SI Configuration IE, (MAC-MainConfig IE, CQI-ReportConfig IE, PDSCH-Config IE, PhysicalConfigDedicated IE, RadioResourceConfigDedicated IE, and RadioConfigCommon IE for DL configuration of serving cells. PUSCH-Config IE, and SoundingRS-UL-Config for UL configuration of at least one of, and serving cells Can include one or more IEs for LTE configurations, which can include at least one of the radio resource control IEs (including at least one of the IEs). In one embodiment, the SRAT RRC instance can perform the corresponding RRC reconfiguration procedure, such as the radio resource configuration procedure.

0072Figure 7 is an illustration for multi-RAT operation using an RRC instance for each configured RAT, a state machine for each RRC instance, and an RRC connection for each configured RAT. It is a block diagram of the control plane 700. More specifically, the examples shown are RRC instance 702 for PRAT, state machine 704 for PRAT, RRC instance 708 for SRAT, state machine 706 for SRAT, and PRAT. Includes RRC connection 710 for, RRC connection 712 for SRAT, and one or more SRB 714. In the example shown in Figure 7, radio resources for multiple RATs (eg PRAT and SRAT) are managed using multiple RRC instances (eg, one control plane instance per configured RAT). be able to.

0073FIG. 8 is a flow diagram 800 of an exemplary method of performing wireless communication in a WTRU configured for multi-RAT operation corresponding to the embodiment shown in FIG. In the example shown in FIG. 8, the WTRU can use the first RRC instance 702 to establish a first RRC connection 710 in a first RAT (eg PRAT) (802). The WTRU can also use the second RRC instance 708 to establish a second RRC connection 712 in the second RAT (eg SRAT) (804).

0074In the embodiment shown in FIG. 7, each RRC instance 702, 708 manages one RRC connection 710, 712 for each configured serving cell of the associated RAT.

0075In one embodiment, RRC connections 710, 712 can be established according to any number of different methods. In one embodiment, the WTRU can receive RRC signaling from the network over an existing RRC connection. RRC signaling, for example, requests to establish an additional RRC connection to SRAT, parameters for uniquely identifying the associated cell (eg, frequency (DL and UL), cell identification information, and SI). Can include. In another embodiment, the WTRU can receive an RRC reconfiguration message from the network over an existing RRC connection to add at least one serving cell for SRAT. The RRC reconfiguration message can include, for example, parameters for uniquely identifying the associated cell (eg, frequency (DL and UL), cell identification information, and SI). In another embodiment, when a packet data protocol (PDP) context is established for a new application, the WTRU can receive a request to establish an additional RRC connection to the SRAT. In another embodiment, the WTRU can autonomously initiate access to the cell of the second RAT when it is already connected to the first RAT. This embodiment can be used, for example, when the WTRU uses two independent RRC instances to support multi-RAT access.

0076The WTRU accesses the cell of the second RAT when the WTRU is camping on the cell with an RRC instance in idle mode, for example, in response to receiving a mass call message on the RAT. Can be started autonomously. Alternatively, the WTRU can autonomously initiate access to the secondary RAT's cells if it determines that the application is requesting service. For example, if the WTRU wants to initiate a CS call, and if it determines that it is a multi-RAT capable WTRU, it can initiate access to the cell in the secondary RAT. In the embodiment, the reason can be shown in establishing the RRC connection. In another embodiment, the WTRU can send a request over the PRAT to inform it that it can start the SRAT setup (eg, following a WTRU-specific trigger). The WTRU can, for example, send a request to the network in response to receiving a service request, and in one embodiment can indicate the reason in an RRC message sent over PRAT. In this embodiment, the WTRU can wait for an explicit setup message from the network to instantiate the SRAT RRC connection.

0077In one embodiment, there may be no dialogue between RRC instance 702 and RRC instance 708. For example, this is when the multimode WTRU operates as a multihomed IP device that can be configured using NAS procedures (eg, from the perspective of network connectivity, when each RAT can accommodate different IP interfaces. ) Can be true. More specifically, the WTRU appears to the network as a single device that implements two different IP network interfaces, and in one embodiment, each has its own PDP context (ie IP address), control / user. It has a data path and a security context. RRM, mobility management, scheduling, and admission control for each RRC connection can be independent of each other.

0078In another embodiment, there may be additional dialogue between RRC instance 702 and RRC instance 708. For example, an RRC message on the first RRC connection (eg 710) goes into idle mode, camps on (or, as an alternative, camps on the cell at the frequency indicated in the RRC message) and gains SI. WTRU can initiate a procedure in which WTRU can perform at least one of the cell selection steps to monitor the mass call channel and determine the appropriate cell to perform access to SRAT. .. Alternatively, it can immediately perform initial access to the cell selected by the WTRU using the cell selection procedure, or, as an alternative, to the cell at the frequency indicated in the RRC message.

0079In one embodiment, the parameters can be exchanged or shared by multiple RRC instances, using security parameters, NAS configuration (including PDP context), and (single data path). Includes at least one of the user plane parameters (if any). For example, from a network connectivity perspective, WTRU still uses a single PDP context (ie, IP address), a single data path, and a single security context to provide a single IP network interface. Looks like a single device to implement. The required parameters can be common to all RRC instances and can be obtained from, for example, PRAT connections and / or initial NAS configurations. In one embodiment, the RRM and mobility management for each RRC connection can be configured independently of each other. Alternatively, mobility can be based on a PRAT connection (eg, 710).

0080In one embodiment, the WTRU can be configured to use zero or more SCells for PRAT.

0081For the embodiments described with respect to FIGS. 5-8, where the control plane contains separate RRC instances for each configured RAT for radio resource management, the different RRC instances may be, for example, security configuration, security active. One of a number of different methods for transformation, security failure, failure handling, RRC connection reconfiguration, RLM, error recovery, state transitions, transaction return to idle mode, and action on PUCCH / SRS release requests. You can use one to interact with each other.

0082Regarding security configuration, activation, and failure, WTRU can use a second RRC instance if it adds a first serving cell for SRAT. In one embodiment, if security is activated for another RRC instance, WTRU considers security already activated for a second RRC instance and, where applicable, if applicable. The same configuration can be applied for integrity protection and encryption for the access layer.

0083For fault handling, the WTRU can receive control plane information (eg, RRC PDU or IE) about the RRC instance of SRAT that it may have failed to handle. If the WTRU receives control plane information about the failed SRAT RRC instance, it informs the network that the configuration has failed and suspends any ongoing transmissions on the associated SRAT serving cell. , Disable the configuration for all SRAT serving cells, remove the configuration for all SRAT serving cells, notify the network that the configuration has failed, and / or the secondary RAT RRC instance or secondary RAT. The RRC connection can be terminated. If the WTRU receives a configuration message to add, change, or remove at least part of the configuration for at least one serving cell of SRAT, the WTRU may not succeed in applying the relevant configuration. In this case, WTRU invalidates the configuration of the associated serving cell, deletes the configuration of the associated serving cell, invalidates the configuration for all SRAT serving cells, deletes the configuration for all SRAT serving cells, You can notify the network that the configuration has failed and / or terminate the SRAT RRC instance or secondary RAT connection. None of these failures can affect the behavior and / or configuration of the RRC connection for PRAT.

0084Regarding the reconfiguration of the RRC connection, the WTRU can receive a radio resource reconfiguration message to add a configuration for the first LTE serving cell that uses the configured UL resource. The WTRU can then initiate a procedure for acquiring UL timing synchronization (eg, a random access procedure on the cell's UL PRACH resource). In one embodiment, the WTRU can receive a handover command, which can include a configuration with at least one LTE serving cell with configured UL resources. In this embodiment, in addition to initiating access to the HSPA target cell, the WTRU also initiates a procedure for acquiring UL timing synchronization (eg, a random access procedure on the UL PRACH resource of the LTE target cell). can do.

0085With respect to RLM, WTRU can perform RLM for SRAT configured serving cells. In one embodiment, the WTRU can determine that it is covered by RLF, for example, according to the criteria for RLF of the corresponding RAT serving cell. If the WTRU determines that the serving cell of the first RAT is RLF (DL or UL), it removes the configuration for all serving cells of the first RAT and replaces the wireless front end for the first RAT. It can be turned off and / or inform the network of the RLF status of the associated serving cell. In one embodiment, the RRC instance of the first RAT can inform the RRC instance of the second RAT of the UL RLF state.

0086For state transitions and related procedures, changes in RRC state in the first RRC instance can trigger state changes and / or procedures in the second RRC instance. For example, a state transition in the first RRC instance can trigger a state transition in the second RRC instance, release of the RRC connection in the second RRC instance, and / or WTRU to the second RRC instance. The wireless front end for the corresponding second RAT can be turned off. In one embodiment, an RRC state transition from CELL_DCH to any other state for an HSPA RRC instance performs a state transition to RRC_IDLE, frees RRC LTE connections, and / or turns off the LTE front end. You can trigger an LTE RRC instance to do this. For example, if HSPA is PRAT, LTE can be SRAT, LTE UL resources may not be configured due to RAT. In another embodiment, the RRC state transition to idle mode in the first RAT can trigger a state transition to idle mode for each RRC instance of each configured SRAT, or, as an alternative, eg, RRC. It can be triggered to release the connection and / or turn off the front end of each configured SRAT. If HSPA is PRAT, LTE can be SRAT and only HSPA RRC instances can perform the cell reselection procedure.

0087As another example, state transitions in the second RRC instance may not be allowed, depending on the state of the first RRC instance. In one embodiment, an RRC instance for SRAT may not allow an RRC state based on the current state of another RRC instance. In particular, if the LTE RRC instance is in the RRC_CONNECTED state, the WTRU cannot transition to the CELL-FACH or CELL_PCH state for the HSPA RRC instance.

0088As another example, the operational state of the second RRC instance may follow the state of the first RRC instance. In one embodiment, if the state of the RRC instance of LTE PRAT is RRC_CONNECTED, the initial state of the RRC instance of HSPA SRAT can be CELL_DCH.

0089For a transition back to idle mode, a transition to RRC idle for an RRC connection that is a PRAT for WTRU can trigger the release of other RRC connections and / or the transition to RRC IDLE for another RRC instance. Yes (for example, all RATs, or only RATs where the WTRU should be in IDLE mode when not connected to the network). An RRC instance of PRAT can notify another RRC instance for SRAT of the state change to IDLE. The RRC instance for SRAT then goes into IDLE mode, removes the dedicated configuration for SRAT, reverts to the default configuration, and / or activates the SRAT transceiver module and / or some function and / or You can take steps to turn it off.

0090Regarding the action when the PUCCH / SRS release request is made, the PRAT LTE RRC instance can receive the display for releasing the PUCCH / SRS dedicated resource from the lower layer (for example, LTE MAC). This can happen, for example, when the maximum number of SR transmissions on a configured PUCCH resource for a scheduling request (SR) is reached, or when the timing alignment timer (TAT) expires. When the TAT expires, the WTRU no longer has a valid timing advance and is no longer in sync for UL transmissions. In this case, the RRC instance of PRAT can notify the RRC instance of SRAT of the loss of UL synchronization in PRAT.

0091For embodiments that use a single RRC connection for all configured RATs (eg, the embodiments described above with respect to FIGS. 3, 4, 5, and 6), the WTRU is, for example, RRC messages and configuration parameters for SRAT can be received via SRAT IE piggybacked into the PRAT's RRC PDU. In this embodiment, the WTRU multiplexes and / or demultiplexes the RAT-specific IE within the RRC PDU for a single RRC connection and identifies the explicit identifier within the RRC PDU (eg, the RRC state machine or SRAT). Information) can be used to identify IE.

0092In one embodiment, the PRAT RRC message can include an SRAT container IE. The SRAT container IE can contain information about SRAT that can be processed according to SRAT's RRC. For example, if PRAT is LTE, HSPA SRAT can be established by including utra-Secondarycell-Container IE. In one embodiment, the presence of this IE can trigger the start of a secondary RAT.

0093SRAT type IE and SRAT message container IE can be used if more than one SRAT can be established. The SRAT message container IE can carry messages specified by another standard indicated by SRAT type IE. This container can carry the information and radio parameters needed for the configured SRAT.

0094For example, a WTRU can be configured such that each group of cells configured for a given RAT is associated with the identification information for that RAT. When the WTRU receives an RRC PDU, it can determine which RAT the IE is associated with and, for example, process the RRC PDU according to the applicable RAT. Similarly, the WTRU can send an RRC PDU that contains one or more information elements within an RRC PDU. If at most two RATs are supported, this can be implicitly determined by the presence of IE itself in the PDU.

0095For embodiments that use a separate RRC instance for each configured RAT (eg, the embodiments described above with respect to FIGS. 5, 6, 7, and 8), the WTRUs are, for example, different SRBs. The identifier (SRB_ID) can be used to multiplex the RRC PDUs for PRAT and SRAT to receive configuration parameters for SRAT. In one embodiment, the WTRU multiplexes and / or demultiplexes RRC PDUs on the data path and RRC connections to which RRC messages are applicable based on the radio bearer identity used to transmit the RRC PDUs. And / or state machines can be identified.

0096For example, a WTRU can be configured such that one or more SRBs are associated with control signaling for a particular RAT, eg, based on SRB_ID. When the WTRU receives an RRC PDU, it determines which radio bearer the PDU is associated with, for example, authentication (if necessary) and encryption if the WTRU is configured to use a RAT-specific security context. RRC PDUs can be processed using an RRC state machine that applies the appropriate security context for deactivation and / or is applicable to the associated RAT. Similarly, the WTRU can send RRC PDUs using an association with an applicable RRC state machine.

0097In one embodiment, after security activation and association with a given priority, an SRB applicable to SRAT can be configured. For example, the WTRU ensures that the SRB applicable to a subset or type of HSPA RRC PDU, for example, has the same (or lower alternative) priority as SRB1 for transporting HSPA RRC PDUs over LTE MAC. , Can be configured. For example, the WTRU can be configured such that logical channels applicable, for example to a subset or type of LTE RRC PDU, are mapped to specific priorities in the MAC-ehs multiplexing feature.

0098For embodiments that use a single RRC instance for all configured RATs (eg, the embodiments described above with respect to FIGS. 3 and 4), the WTRU provides at least one serving cell for the SRAT. If you receive the configuration you want to add, you can use one or more of the examples described below to perform radio resource management. In such an embodiment, the WTRU can have an established RRC connection using PRAT (eg, 306 in FIG. 3).

0099In one embodiment, if security is activated (eg, for PRAT), the WTRU may add a serving cell for SRAT, in which case it is applicable (eg, multiple data). The same configuration can be applied to integrity protection and encryption for the access layer (if routes are used).

0100In one embodiment, the WTRU may receive an RRC message to add, modify, or remove at least part of the configuration for at least one serving cell of SRAT. The WTRU may not succeed in applying the associated configuration, in which case it invalidates the associated serving cell configuration, removes the associated serving cell configuration, and invalidates the configuration for all SRAT serving cells. , Remove the configuration for all serving cells of SRAT, turn off the wireless front end for SRAT, notify the network that the configuration has failed, and / or terminate the SRAT RRC instance of the SRAT RRC connection. it can. In particular, the failure to apply the configuration to SRAT cannot affect the behavior and / or configuration of the RRC connection for PRAT. If the successful completion of the RRC procedure applicable to the SRAT fails, the WTRU may abort the procedure and return the procedure for the associated SRAT to the state it was in before the WTRU started.

0101If LTE is PRAT, the RRC instance can perform radio resource management for SRAT according to any of the following embodiments: In one embodiment, the WTRU operation for PRAT can follow the typical procedure for the associated RAT. In one embodiment, the WTRU can perform an RLM for an LTE PRAT configured serving cell, eg, for a PCell. The WTRU can determine that it is suffering from UL RLF on the LTE PRAT PCell according to the criteria for RLF of the corresponding RAT serving cell. If the WTRU determines that it is RLF (DL or UL) for the LTE PRAT PCell, it can perform an RRC state transition from RRC_CONNECTED to RRC_IDLE, in which case it will be on all serving cells of HSPA SRAT. You can remove the configuration for and / or turn off the wireless front end for HSPA SRAT.

0102WTRU can also perform RLM for a configured serving cell of HSPA SRAT. The WTRU can determine that it is suffering from UL RLF on the primary serving cell according to the criteria for RLF of the corresponding RAT serving cell. If the WTRU determines that the serving cell of HSPA SRAT is UL RLF, the WTRU invalidates the configuration of the associated serving cell, deletes the configuration of the associated serving cell, invalidates the random access configuration of the associated serving cell, and associates it. Remove the random access configuration for serving cells, disable the configuration for all serving cells in HSPA SRAT, remove the configuration for all serving cells in HSPA SRAT, turn off the wireless front end for HSPA SRAT, It can inform the network of the UL RLF status for the associated serving cell, consider the secondary RAT serving cell as deactivated, and / or terminate the SRAT RRC instance of the SRAT RRC connection.

0103In one embodiment, the WTRU can determine that it suffers from DL RLF according to the criteria for RLF in the serving cell of the corresponding RAT. If WTRU determines that the serving cell of HSPA SRAT is DL RLF, WTRU invalidates the configuration of the associated serving cell, deletes the configuration of the associated serving cell, and invalidates the configuration for all serving cells of HSPA SRAT. You can remove the configuration for all serving cells in HSPA SRAT, turn off the wireless front end for HSPA SRAT, and / or inform the network of the DL RLF status for the associated serving cell.

0104The WTRU can perform an RRC state transition from LTE RRC_CONNECTED to LTE RRC_IDLE, in which case the WTRU will invalidate the configuration for all SRAT serving cells and remove the configuration for all SRAT serving cells. You can then turn off the wireless front end for SRAT and / or terminate the secondary RAT RRC instance or SRAT RRC connection.

0105PRAT LTE RRC instances can receive indications from lower layers (eg LTE MAC) to release PUCCH / SRS dedicated resources. This can happen, for example, when the maximum number of SR transmissions on the configured PUCCH resource for SR is reached, or when the TAT expires. When the TAT expires, the WTRU no longer has a valid timing advance and is no longer in sync for UL transmissions. In this case, the WTRU disables the configuration for all SRAT serving cells, removes the configuration for all SRAT serving cells, turns off the radio front end for SRAT, and / or the SRAT RRC instance or SRAT RRC connection can be terminated.

0106If the HSPA is PRAT, the RRC instance can perform radio resource management for SRAT according to any of the following embodiments: In addition, the WTRU operation for PRAT can follow the typical procedure for the associated RAT.

0107In one embodiment, the WTRU receives a radio resource reconfiguration message to add a configuration for a first LTE serving cell that uses the configured UL resource, and then a procedure for obtaining UL timing synchronization (eg, for example). , Random access procedure on the cell's UL PRACH resource) can be started. In one embodiment, the WTRU can receive a handover command that can include a configuration for at least one LTE serving cell that uses the configured UL resource. In addition to the initial access to the HSPA target cell, the WTRU can also initiate a procedure to obtain UL timing synchronization (eg, a random access procedure on the UL PRACH resource of the LTE target cell).

0108In one embodiment, the WTRU can perform RLM for one or more of the PRAT's configured serving cells, especially for the HSPA PRAT's primary serving cell. The WTRU can determine that it is covered with RLF on the primary serving cell, for example, according to the criteria for RLF of the corresponding RAT serving cell. If it determines that it is UL RLF for the HSPA PRAT primary serving cell, the RRC instance for HSPA PRAT can receive the first out-of-sync indication from the physical layer and refrain from performing UL transmissions. Can be done. If at least one serving cell of LTE SRAT is configured to use UL resources and UL feedback information can be transmitted on the serving cell, the WTRU may continue any transmission on LTE SRAT.

0109If the WTRU determines that it is LTE (DL and / or UL) for the HSPA PRAT primary serving cell, it can perform an RRC state transition from CELL_DCH (and / or to CELL_FACH), in which case. It can remove the configuration for all serving cells of LTE SRAT, turn off the radio front end for LTE SRAT, and / or consider LTE SRAT deactivated by order.

0110In one embodiment, the WTRU can perform RLM for an LTE SRAT configured serving cell. The WTRU can determine that it is suffering from UL RLF on the LTE SRAT serving cell, especially on the PCell, according to the criteria for the RLF of the corresponding RAT serving cell. If it determines that the LTE SRAT serving cell is UL RLF, the WTRU invalidates the associated serving cell configuration, deletes the associated serving cell configuration, disables the associated serving cell random access configuration, and associates it. Remove the random access configuration for serving cells, disable the configuration for all LTE SRAT serving cells, remove the configuration for all LTE SRAT serving cells, turn off the wireless front end for LTE SRAT, It can inform the network of the UL RLF status for the associated serving cell and / or terminate the SRAT RRC instance or SRAT RRC connection.

0111In one embodiment, the WTRU can determine that it suffers from DL RLF according to the criteria for RLF in the serving cell of the corresponding RAT. If it determines that it is a DL RLF for an LTE SRAT serving cell, WTRU invalidates the associated serving cell configuration, removes the associated serving cell configuration, and invalidates the configuration for all LTE SRAT serving cells. And remove the configuration for all LTE SRAT serving cells, turn off the wireless front end for LTE SRAT, notify the network of DL RLF status for the associated serving cell, and / or SRAT RRC instance or SRAT RRC You can terminate the connection.

0112In one embodiment, the WTRU can perform an RRC state transition from the connected state (eg, CELL_DCH, CELL_PCH, or URA_PCH) to idle mode, in which case the WTRU is for all LTE SRAT serving cells. You can disable the configuration, remove the configuration for all LTE SRAT serving cells, and / or turn off the wireless front end for LTE SRAT.

0113Embodiment

01141. A method of performing wireless communication in a wireless transmit / receive unit (WTRU) configured for multi-radio access technology (RAT) operation, in which the WTRU provides information on the first operating frequency according to the first RAT. A method that includes steps to communicate wirelessly.

01152. The method of embodiment 1, wherein the WTRU further comprises the step of transmitting information wirelessly over the second operating frequency according to the second RAT.

01163. The first RAT is one of Long Term Evolution (LTE) and High Speed Packet Access (HSPA), and the second RAT is one of HSPA, LTE, and WiFi, Embodiment 1 or The method described in 2.

01174. The method of any one of embodiments 1-3, wherein the WTRU further comprises the step of establishing a radio resource control (RRC) connection in the first RAT using the RRC instance.

01185. The method of embodiment 4, further comprising a step in which the WTRU receives a configuration for at least one serving cell of the second RAT over the RRC connection.

01196. The method of embodiment 5, wherein the WTRU further comprises the step of configuring a radio resource for a second RAT using an RRC instance.

01207. If the WTRU performs an RRC state transition from LTE RRC_CONNECTED to LTE RRC_IDLE on the first RAT, it will invalidate the configuration for all serving cells of the second RAT, of the second RAT. Described in any one of embodiments 1-6, performing at least one of removing the configuration for all serving cells and turning off the radio front end for the second RAT. the method of.

01218. The WTRU is the step of sending and receiving the RRC protocol data unit (PDU) of the type corresponding to the first RAT, and the type of RRC PDU corresponding to the first RAT corresponds to the second RAT. The method according to any one of embodiments 1-7, further comprising steps, comprising at least one information element (IE).

01229. The method according to any one of embodiments 1-8, wherein the WTRU further comprises the step of establishing a radio resource control (RRC) connection in the first RAT using the first RRC instance.

012310. The method of embodiment 9, wherein the WTRU further comprises receiving a configuration for at least one serving cell of the second RAT over the RRC connection.

012411. The method of embodiment 9 or 10, wherein the WTRU further comprises the step of configuring a radio resource for a second RAT using a second RRC instance.

012512. The WTRU is the step of sending and receiving PDUs over an RRC connection, where each PDU has a signaling radio bearer identifier (SRB_ID) that corresponds to one of the first RRC instance and the second RRC instance. , The method according to any one of embodiments 9-11, further comprising a step.

012613. If the WTRU performs an RRC state transition from LTE RRC_CONNECTED to LTE RRC_IDLE on the first RAT, it will invalidate the configuration for all serving cells of the second RAT, of the second RAT. Embodiments that perform at least one of removing the configuration for all serving cells, turning off the radio front end for the second RAT, and terminating the second RRC instance. The method described in any one of 9 to 12.

012714. One of embodiments 1-13, wherein the WTRU further comprises the step of establishing a first radio resource control (RRC) connection in the first RAT using the first RRC instance. Method.

012815. The method of embodiment 14, wherein the WTRU further comprises the step of establishing a second RRC connection in the second RAT using the second RRC instance.

012916. Embodiment 14 or 15 further comprising the step of adding a serving cell for the second RRC connection in the second RAT in response to the security activated for the first RAT by the WTRU. The method described in.

013017. The step in which the WTRU performs wireless link monitoring (RLM) on the configured serving cell of the first RAT, where the first RAT is LTE, further comprising a step, embodiment 14 or The method described in 15.

013118. The method of embodiment 17, wherein the WTRU further comprises the step of determining whether the configured serving cell of the first RAT suffers from a radio link failure (RLF).

013219. If WTRU determines that the configured serving cell of the first RAT is covered by RLF, remove the configuration for all serving cells of the second RAT, and for the second RAT. The method of embodiment 17 or 18, wherein the second RAT is HSPA, further comprising a step of performing at least one of turning off the radio front end of the device.

013320. The method of embodiment 14 or 15, wherein the WTRU further comprises configuring mobility management for a second RRC connection based on the first RRC connection.

013421. A transceiver configured for multi-radio access technology (RAT) operation that transmits information wirelessly over the first operating frequency according to the first RAT. With, WTRU.

013522. WTRU according to embodiment 21, wherein the transceiver is further configured to wirelessly transmit information over a second operating frequency according to a second RAT.

013623. The first RAT is one of Long Term Evolution (LTE) and High Speed Packet Access (HSPA), and the second RAT is one of HSPA, LTE, and WiFi, embodiment 21 or WTRU described in 22.

013724. The WTRU of embodiment 21 or 22, further comprising a processor configured to establish a radio resource control (RRC) connection in the first RAT using an RRC instance.

013825. The WTRU according to embodiment 24, wherein the transceiver is further configured to receive a configuration for at least one serving cell of the second RAT over the RRC connection.

013926. WTRU according to embodiment 24 or 25, wherein the processor is further configured to use an RRC instance to configure a radio resource for a second RAT.

014027. The transceiver is further configured to send and receive RRC protocol data units (PDUs) of the type corresponding to the first RAT, and RRC PDUs of the type corresponding to the first RAT correspond to the second RAT. WTRU according to any one of embodiments 24-26, comprising at least one information element (IE).

014128. The WTRU according to any one of embodiments 21-27, further comprising a processor configured to establish a radio resource control (RRC) connection in the first RAT using the first RRC instance. ..

014229. WTRU according to embodiment 28, wherein the transceiver is further configured to receive a configuration for at least one serving cell of the second RAT over the RRC connection.

014330. WTRU according to embodiment 28 or 29, wherein the processor is further configured to use a second RRC instance to configure radio resources for a second RAT.

014431. The transceiver is further configured to send and receive PDUs over the RRC connection, where each PDU has a signaling radio bearer identifier (SRB_ID) that corresponds to one of the first RRC instance and the second RRC instance. WTRU according to any one of embodiments 28-30.

014532. If the processor performs an RRC state transition from LTE RRC_CONNECTED to LTE RRC_IDLE on the first RAT, disable the configuration for all serving cells in the second RAT, the second RAT. Further to perform at least one of removing the configuration for all serving cells, turning off the radio front end for the second RAT, and terminating the second RRC instance. WTRU according to any one of embodiments 28-30, which comprises.

014633. In any one of embodiments 21-32, further comprising a processor configured to establish a first radio resource control (RRC) connection in the first RAT using the first RRC instance. The listed WTRU.

014734. WTRU according to embodiment 33, wherein the processor is further configured to use a second RRC instance to establish a second RRC connection in the second RAT.

014835. The processor is further configured to add a serving cell for the second RRC connection in the second RAT in response to the security activated for the first RAT, embodiment 33. Or the WTRU described in 34.

014936. WTRU according to any one of embodiments 33-35, wherein the processor is further configured to perform wireless link monitoring (RLM) on the serving cell configured for the first RAT.

015037. The first RAT is LTE, the WTRU according to embodiment 36.

015138. The processor is further configured to determine if the configured serving cell of the first RAT suffers from an uplink (UL) radiolink failure (RLF), any one of embodiments 33-37. WTRU described in one.

015239. If the processor determines that the configured serving cell of the first RAT is covered by UL RLF, it removes the configuration for all serving cells of the second RAT, and of the second RAT. The WTRU according to any one of embodiments 33-37, further configured to perform at least one of turning off the radio front end for, the second RAT is HSPA.

015340. WTRU according to any one of embodiments 33-39, wherein the processor is further configured to configure mobility management for a second RRC connection based on the first RRC connection.

0154Although features and elements have been described above in specific combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. In addition, the methods described herein can be performed with computer programs, software, or firmware contained within a computer-readable medium, performed by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, optomagnetic media, and CD-ROMs. Includes, but is not limited to, optical media such as discs and digital multipurpose discs (DVDs). The processor that works with the software can be used to implement a WTRU, UE, terminal, base station, RNC, or radio frequency transceiver for use with any host computer.