Method and apparatus for supporting remote user equipment to communicate with a network via a relay user equipment

Abstract

The present invention discloses a method and device for supporting remote user equipment to communicate with a network via a relay user equipment. In one embodiment, the relay user equipment establishes a PC5 radio resource control connection with the remote user equipment. The relay user equipment also transmits a radio resource control message to a network node to request a radio bearer configuration to support user equipment to network relay. In addition, the relay user equipment receives a radio resource control reconfiguration message from the network node, wherein the radio resource control reconfiguration message includes a Uu configuration for a Uu radio link control bearer associated with a signaling radio bearer. In addition, the relay user equipment receives a radio resource control reconfiguration completion message from the remote user equipment. The relay user equipment also transmits a radio resource control reconfiguration completion message to the network node on the Uu radio link control bearer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 220,329, filed on July 9, 2021, the entire disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to wireless communication networks, and more particularly, to a method and apparatus for radio bearer configuration for supporting UE-to-network relay in a wireless communication system. Background Art

[0004] As the demand for communicating large amounts of data to and from mobile communication devices grows rapidly, traditional mobile voice communication networks have evolved into networks that communicate with Internet Protocol (IP) data packets, which can provide IP-based voice, multimedia, multicast, and on-demand communication services to users of mobile communication devices.

[0005] An exemplary network structure is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The E-UTRAN system can provide high data throughput to enable the above-mentioned IP-borne voice and multimedia services. Currently, the 3GPP standards organization is discussing the next generation (e.g., 5G) new radio technology. Therefore, changes to the current body of 3GPP standards are currently being submitted and considered to evolve and complete the 3GPP standards. Summary of the invention

[0006] The present invention discloses a method and user equipment for supporting radio bearer configuration of user equipment to network relay (UE-to-Network relaying) from the perspective of a relay UE. In one embodiment, the relay UE establishes a PC5 radio resource control (PC5-Radio Resource Control, PC5-RRC) connection with a remote UE. The relay UE also transmits an RRC message to a network node to request that the radio bearer configuration support UE to network relay. In addition, the relay UE receives an RRC reconfiguration message from the network node, wherein the RRC reconfiguration message includes a Uu configuration for a Uu radio link control (Radio Link Control, RLC) bearer associated with a signaling radio bearer (signallingradio bearer, SRB). In addition, the relay UE receives an RRC reconfiguration completion message from the remote UE. The relay UE also transmits the RRC reconfiguration completion message to the network node on the Uu RLC bearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A diagram showing a wireless communication system according to an exemplary embodiment;

[0008] Figure 2 is a block diagram of a transmitter system (also referred to as an access network) and a receiver system (also referred to as a user equipment or UE) according to an exemplary embodiment;

[0009] Figure 3 is a functional block diagram of a communication system according to an exemplary embodiment;

[0010] Figure 4 According to an exemplary embodiment Figure 3 Functional block diagram of the program code;

[0011] Figure 5 It is 3GPP TS23.287V16.2.0 Figure 6 .3.3.1-1 reappearance;

[0012] Figure 6 It is 3GPP TR 23.752V17.0.0 Figure 5 .3.1-1 reappearance;

[0013] Figure 7 It is 3GPP TR 23.752V17.0.0 Figure 5 .3.1-2 reappearance;

[0014] Figure 8 It is 3GPP TR 23.752V17.0.0 Figure 5.3.1-3 reappearance;

[0015] Fig. 9 It is 3GPP TS23.304V1.0.0 Figure 6 .3.2.3.2-1 reappearance;

[0016] Fig.10 It is 3GPP TS23.304V1.0.0 Figure 6 .3.2.3.3-1 reappearance;

[0017] Fig.11 It is 3GPP TR 38.836V17.0.0 Figure 4 .1-1 reappearance;

[0018] Fig.12 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.1.1-1 reappearance;

[0019] Fig.13 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.1.1-2 reappearance;

[0020] Fig.14 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.1.1-3 reappearance;

[0021] Fig.15 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.1.1-4 reappearance;

[0022] Fig.16 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.4.1-1 reappearance;

[0023] Fig.17 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.4.2-1 reappearance;

[0024] Fig.18 It is 3GPP TR 38.836V17.0.0 Figure 4 .5.5.1-1 reappearance;

[0025] Fig.19 It is 3GPP TR 38.836V1.0.0 Figure 5 .5.1-2 reappearance;

[0026] Fig. 20It is 3GPP TS 38.331V16.3.1 Figure 5 .3.3.1-1 reappearance;

[0027] Fig.21 It is 3GPP TS 38.331V16.3.1 Figure 5 .3.3.1-2 reappearance;

[0028] Fig. 22 It is 3GPP TS 38.331V16.3.1 Figure 5 .3.5.1-1 reappearance;

[0029] Fig.23 is a table according to an exemplary embodiment;

[0030] Fig.24 is a message diagram according to an exemplary embodiment;

[0031] Fig.25 is a flow chart according to an exemplary embodiment;

[0032] Fig.26 is a flow chart according to an exemplary embodiment. DETAILED DESCRIPTION

[0033] The exemplary wireless communication systems and devices described below employ wireless communication systems that support broadcast services. Wireless communication systems are widely deployed to provide various types of communications, such as voice, data, etc. These systems may be based on code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), 3GPP Long Term Evolution (LTE) radio access, 3GPP Long Term Evolution Advanced (LTE-A), 3GPP2 Ultra Mobile Broadband (UMB), WiMax, 3GPP New Radio (NR), or some other modulation techniques.

[0034] Specifically, the exemplary wireless communication systems and devices described below may be designed to support one or more standards, such as those provided by a consortium named "3rd Generation Partnership Project" referred to herein as 3GPP, including: TS 23.287 V16.2.0, "Architecture Enhancements for 5G System (5G System, 5GS) to Support Vehicle-to-Everything (V2X) Services (Release 16)"; TR 23.752 V1.0.0, "Study of System Enhancements for Proximity-based Services (ProSe) in 5G System (5G System, 5GS) (Release 17)"; TS 23.304 V1.0.0, "Proximity-based Services (ProSe) in 5G System (5G System, 5GS) (Release 17)"; TR 38.836 V16.3.1, "Study of NR Sidelink Relay (Release 17)"; and TS 38.331 V14.0.0, "NR; Radio Resource Control (RRC) Protocol Specification (Release 17)". The standards and documents listed above are hereby expressly incorporated herein by reference in their entirety.

[0035] Figure 1 A multiple access wireless communication system according to an embodiment of the present invention is shown. An access network 100 (AN) includes multiple antenna groups, one antenna group includes antennas 104 and 106, another antenna group includes antennas 108 and 110, and another antenna group includes antennas 112 and 114. Figure 1 , only two antennas are shown for each antenna group, but each antenna group may utilize more or fewer antennas. Access terminal (AT) 116 communicates with antennas 112 and 114, where antennas 112 and 114 transmit information to access terminal 116 via forward link 120 and receive information from access terminal 116 via reverse link 118. Access terminal (AT) 122 communicates with antennas 106 and 108, where antennas 106 and 108 transmit information to access terminal (AT) 122 on forward link 126 and receive information from access terminal (AT) 122 on reverse link 124. In an FDD system, communication links 118, 120, 124, and 126 may use different frequencies for communication. For example, forward link 120 may use a different frequency than reverse link 118.

[0036] Each antenna group and / or the area in which the antenna group is designed to communicate is often referred to as a sector of the access network. In an embodiment, the antenna groups are each designed to communicate with access terminals in a sector of the area covered by the access network 100.

[0037] In communicating via forward links 120 and 126, the transmit antennas of access network 100 may utilize beamforming in order to improve the signal-to-noise ratio of the forward links for the different access terminals 116 and 122. Additionally, an access network that transmits to access terminals randomly dispersed throughout its coverage area using beamforming may cause less interference to access terminals in neighboring cells than an access network that transmits to all of its access terminals via a single antenna.

[0038] An access network (AN) may be a fixed station or base station for communicating with a terminal, and may also be referred to as an access point, Node B, base station, enhanced base station, evolved Node B (eNB), network node, network, or some other term. An access terminal (AT) may also be referred to as user equipment (UE), a wireless communication device, a terminal, an access terminal, or some other term.

[0039] Figure 2 2 is a simplified block diagram of an embodiment of a transmitter system 210 (also referred to as an access network) and a receiver system 250 (also referred to as an access terminal (AT) or user equipment (UE)) in a MIMO system 200. At the transmitter system 210, traffic data for a number of data streams is provided from a data source 212 to a transmit (TX) data processor 214.

[0040] In one embodiment, each data stream is transmitted via a respective transmit antenna.TX data processor 214 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

[0041] The decoded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and decoded data for each data stream is then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by execution of instructions in memory 232 by processor 230.

[0042] The modulation symbols for all data streams are then provided to a TX MIMO processor 220, which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 220 then provides NT modulation symbol streams to NT transmitters (TMTR) 222a through 222t. In certain embodiments, TX MIMO processor 220 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

[0043] Each transmitter 222 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. NT modulated signals from transmitters 222a through 222t are then transmitted from NT antennas 224a through 224t, respectively.

[0044] At receiver system 250, the transmitted modulated signals are received by NR antennas 252a through 252r and the received signal from each antenna 252 is provided to a respective receiver (RCVR) 254a through 254r. Each receiver 254 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding “received” symbol stream.

[0045] The RX data processor 260 then receives and processes the NR received symbol streams from the NR receivers 254 based on a particular receiver processing technique to provide NT "detected" symbol streams. The RX data processor 260 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by the RX data processor 260 is complementary to the processing performed by the TX MIMO processor 220 and the TX data processor 214 at the transmitter system 210.

[0046] Processor 270 executes instructions in memory 272 to periodically determine which precoding matrix to use (discussed below). Processor 270 formulates a reverse link message comprising a matrix index portion and a rank value portion.

[0047] The reverse link message may include various types of information related to the communication link and / or the received data stream. The reverse link message is then processed by the TX data processor 238, which also receives traffic data for a number of data streams from the data source 236, modulated by the modulator 280, conditioned by the transmitters 254a to 254r, and transmitted back to the transmitter system 210.

[0048] At the transmitter system 210, the modulated signal from the receiver system 250 is received by the antenna 224, conditioned by the receiver 222, demodulated by the demodulator 240, and processed by the RX data processor 242 to extract the reverse link message transmitted by the receiver system 250. The processor 230 then determines which precoding matrix to use to determine the beamforming weights and then processes the extracted message.

[0049] Steering Figure 3 , this figure shows an alternative simplified functional block diagram of a communication device according to one embodiment of the present invention. Figure 3 As shown in FIG. , the communication device 300 in the wireless communication system can be used to implement Figure 1 UE (or AT) 116 and 122 in or Figure 1 The base station (or AN) 100 in the wireless communication system is preferably an NR system. The communication device 300 may include an input device 302, an output device 304, a control circuit 306, a central processing unit (CPU) 308, a memory 310, a program code 312, and a transceiver 314. The control circuit 306 executes the program code 312 in the memory 310 through the CPU 308, thereby controlling the operation of the communication device 300. The communication device 300 can receive signals input by the user through the input device 302 (for example, a keyboard or a keypad), and can output images and sounds through the output device 304 (for example, a monitor or a speaker). The transceiver 314 is used to receive and transmit wireless signals, pass the received signals to the control circuit 306, and wirelessly output the signals generated by the control circuit 306. The communication device 300 in the wireless communication system can also be used to implement Figure 1 AN100 in.

[0050] Figure 4 According to an embodiment of the present invention Figure 34. In this embodiment, program code 312 includes application layer 400, layer 3 portion 402, and layer 2 portion 404, and is coupled to layer 1 portion 406. Layer 3 portion 402 generally performs radio resource control. Layer 2 portion 404 generally performs link control. Layer 1 portion 406 generally performs physical connectivity.

[0051] 3GPP TS23.287 specifies the identifiers for unicast mode Vehicle-to-Everything (V2X) communications and Layer 2 link establishment over the PC5 reference point as follows:

[0052] 5.6.1.4 Identifiers for unicast mode V2X communications over the PC5 reference point

[0053] For unicast mode V2X communications over the PC5 reference point, the destination Layer 2 ID used depends on the communicating peer. The Layer 2 ID of the communicating peer, identified by the application layer ID, may be discovered during establishment of the PC5 unicast link, or known to the UE via previous V2X communications (e.g. an existing or previous unicast link to the same application layer ID), or obtained from an application layer service announcement. The initial signaling for establishing the PC5 unicast link may use the known Layer 2 ID of the communicating peer, or a preset destination Layer 2 ID associated with the V2X service type (e.g. PSID / ITS-AID) configured for PC5 unicast link establishment, as specified in Section 5.1.2.1. During the PC5 unicast link establishment procedure, the Layer 2 IDs are exchanged and shall be used for future communications between the two UEs, as specified in Section 6.3.3.1.

[0054] The application layer ID is associated with one or more V2X applications within the UE. If a UE has more than one application layer ID, then from the perspective of a peer UE, each application layer ID of the same UE may be considered as an application layer ID of a different UE.

[0055] The UE maintains the mapping between the application layer ID and the source layer 2 ID for the PC5 unicast link, since the V2X application layer does not use the layer 2 ID. This allows the source layer 2 ID to be changed without interrupting the V2X application.

[0056] When the application layer ID changes, the source layer 2 ID of the PC5 unicast link should change if the link is used for V2X communication with the changed application layer ID.

[0057] Based on the privacy configuration as specified in section 5.1.2.1, updating the new identifier of the source UE to the peer UE for the established unicast link may result in the peer UE changing its Layer 2 ID and optionally IP address / prefix (if IP communication is used as defined in section 6.3.3.2).

[0058] A UE may establish multiple PC5 unicast links with a peer UE and use the same or different source layer 2 IDs for these PC5 unicast links.

[0059] […]

[0060] 6.3.3.1 Layer 2 link establishment over PC5 reference point

[0061] In order to perform V2X communication in unicast mode over the PC5 reference point, the UE is configured with relevant information as described in Section 5.1.2.1.

[0062] Figure 6 .3.3.1-1 shows the Layer 2 link establishment procedure for unicast mode V2X communication over the PC5 reference point.

[0063] [3GPP TS 23.287 V16.2.0 entitled "Layer-2 link establishment procedure" Figure 6 .3.3.1-1 Reproduced as Figure 5 ]

[0064] 1. The UE determines the destination layer 2 ID for signaling reception for PC5 unicast link establishment as specified in section 5.6.1.4. The UE is configured with the destination layer 2 ID as specified in section 5.1.2.1.

[0065] 2. The V2X application layer in UE-1 provides application information for PC5 unicast communication. The application information includes the V2X service type (e.g., PSID or ITS-AID) of the V2X application and the application layer ID of the initiating UE. The application information may include the application layer ID of the target UE.

[0066] The V2X application layer in UE-1 may provide the V2X application requirements for this unicast communication. UE-1 determines the PC5 QoS parameters and PFI as specified in Section 5.4.1.4.

[0067] If UE-1 decides to reuse the existing PC5 unicast link as specified in section 5.2.1.4, the UE triggers the Layer 2 Link Modification procedure as specified in section 6.3.3.4.

[0068] 3. UE-1 sends a direct communication request message to initiate the unicast layer 2 link establishment procedure. The direct communication request message contains:

[0069] - Source user information: the application layer ID of the originating UE (ie, the application layer ID of UE-1).

[0070] - If the V2X application layer provides the target UE's application layer ID in step 2, the following information is included:

[0071] - Target user information: Application layer ID of the target UE (ie, the application layer ID of UE-2).

[0072] - V2X service information: Information about one or more V2X services (e.g., one or more PSIDs or one or more ITS-AIDs) requesting Layer 2 link establishment.

[0073] -Security information: information used to establish security.

[0074] NOTE 1 Security information and the necessary protection of source user information and destination user information are defined by SA WG3.

[0075] As specified in Sections 5.6.1.1 and 5.6.1.4, the source layer 2ID and destination layer 2ID used to send the direct communication request message are determined. The destination layer 2ID can be a broadcast or unicast layer 2ID. When a unicast layer 2ID is used, the target user information should be included in the direct communication request message.

[0076] UE-1 sends a direct communication request message via PC5 by broadcast or unicast using the source layer 2ID and the destination layer 2ID.

[0077] 4. Establish security for UE-1 as follows:

[0078] 4a. If the target user information is included in the direct communication request message, the target UE (ie, UE-2) responds by establishing security with UE-1.

[0079] 4b. If the target user information is not included in the direct communication request message, the UE interested in using the notified V2X service over the PC5 unicast link with UE-1 responds by establishing security with UE-1.

[0080] NOTE 2 Signalling used for safety procedures is defined by SA WG3.

[0081] When security protection is enabled, UE-1 sends the following information to the target UE:

[0082] - If using IP communication:

[0083] -IP Address Configuration: For IP communication, this link requires IP address configuration, and it indicates one of the following values:

[0084] - "IPv6 Router" if the IPv6 address allocation mechanism is supported by the originating UE, i.e. acting as an IPv6 router; or

[0085] - If the initiating UE does not support the IPv6 address allocation mechanism, then "does not support IPv6 address allocation".

[0086] - Link-local IPv6 address: If UE-1 does not support the IPv6 IP address allocation mechanism, i.e., the IP address configuration indicates "IPv6 address allocation is not supported", then a link-local IPv6 address is formed locally based on RFC 4862

[21] .

[0087] -QoS Information: Information about PC5 QoS flows. For each PC5 QoS flow, PFI and corresponding PC5 QoS parameters (ie, PQI and conditionally other parameters, such as MFBR / GFBR, etc.).

[0088] As specified in sections 5.6.1.1 and 5.6.1.4, the source layer 2 ID for the security establishment procedure is determined. The destination layer 2 ID is set to the source layer 2 ID of the received direct communication request message.

[0089] Upon receiving the Security Establishment Procedure message, UE-1 obtains the Layer 2 ID of the peer UE for future communications for signaling and data traffic for this unicast link.

[0090] 5. The target UE, which has successfully established security with UE-1, sends a direct communication acceptance message to UE-1:

[0091] 5a. (Layer 2 Link Establishment Towards UE) If the target user information is included in the Direct Communication Request message, then if the application layer ID for UE-2 matches, the target UE (ie, UE-2) responds with a Direct Communication Accept message.

[0092] 5b. (Layer 2 Link Establishment for V2X Services) If the direct communication request message does not contain target user information, the UE interested in using the notified V2X service (in Figure 6 .UE-2 and UE-4 in 3.3.1-1) respond to the request by sending a direct communication accept message.

[0093] The direct communication acceptance message contains:

[0094] -Source user information: the application layer ID of the UE that sends the direct communication acceptance message.

[0095] -QoS information: Information about PC5 QoS flows. For each PC5 QoS flow, the PFI requested by UE-1 and the corresponding PC5 QoS parameters (ie, PQI and conditionally other parameters, such as MFBR / GFBR, etc.).

[0096] - If using IP communication:

[0097] -IP Address Configuration: For IP communication, this link requires IP address configuration, and it indicates one of the following values:

[0098] - "IPv6 Router" if the IPv6 address allocation mechanism is supported by the target UE, i.e. acting as an IPv6 router; or

[0099] - If the target UE does not support the IPv6 address allocation mechanism, then "does not support IPv6 address allocation".

[0100] - Link-local IPv6 address: If the target UE does not support the IPv6 IP address allocation mechanism, i.e. the IP address configuration indicates "IPv6 address allocation is not supported", and UE-1 includes a link-local IPv6 address in the Direct Communication Request message, then a link-local IPv6 address is formed locally based on RFC 4862

[21] . The target UE shall include a non-conflicting link-local IPv6 address.

[0101] If both UEs (ie, the initiating UE and the target UE) are selected to use link-local IPv6 addresses, they shall disable dual address detection as defined in RFC 4862

[21] .

[0102] NOTE 3: When the initiating UE or the target UE indicates support for IPv6 routers, the corresponding address configuration procedure shall be performed after the layer 2 link is established and the link-local IPv6 address shall be ignored.

[0103] The V2X layer of the UE that establishes the PC5 unicast link passes the PC5 link identifier assigned to the unicast link and information related to the PC5 unicast link down to the AS layer. The information related to the PC5 unicast link includes layer 2ID information (i.e., source layer 2ID and destination layer 2ID). This enables the AS layer to maintain the PC5 link identifier and PC5 unicast link related information.

[0104] 6. The V2X service data is transmitted via the established unicast link as follows:

[0105] The PC5 link identifier and PF are provided to the AS layer together with the V2X service data.

[0106] Additionally, layer 2 ID information (ie, source layer 2 ID and destination layer 2 ID) is optionally provided to the AS layer.

[0107] NOTE 4: It is up to the UE implementation to provide the Layer 2 ID information to the AS layer.

[0108] UE-1 sends V2X service data using a source Layer 2 ID (i.e., the Layer 2 ID of UE-1 for this unicast link) and a destination Layer 2 ID (i.e., the Layer 2 ID of the peer UE for this unicast link).

[0109] NOTE 5: The PC5 unicast link is bidirectional, so UE-1’s peer UE can send V2X service data to UE-1 via the unicast link with UE-1.

[0110] 3GPP TR 23.752 proposes to support UE-to-network relay for a later release (ie, Release 17), as described below. A UE-to-network relay solution based on layer 2 and layer 3 is described in 3GPP TR 23.752.

[0111] 5.3 Key Issue #3: Support for UE-to-Network Relay

[0112] 5.3.1 General description

[0113] According to TS22.261[3] and TS22.278[2], support for UE-to-network relay needs to be studied. In addition, Rel-16 5G architecture design (e.g., flow-based QoS communication over PC5 / Uu interface) should also be considered.

[0114] Need to consider Figure 5 .3.1-1 shows a situation in which the UE may be able to access the network via direct network communication or indirect network communication, where path #1 is a direct network communication path that may not exist, and path #2 and path #3 are indirect network communication paths via different UE-to-network relays.

[0115] [3GPP TR 23.752 V17.0.0 entitled "Example scenario of direct or indirect network communication path between UE and Network" Figure 5 .3.1-1 reproduced as Figure 6 ]

[0116] Therefore, 5G ProSe needs to support UE-to-network relay. Specifically, the following aspects need to be studied:

[0117] -How to authorize UE to be a 5G UE to network relay and how to authorize UE to access 5GC via 5G UE to network relay.

[0118] - How to establish a connection between a remote UE and a UE-to-network relay to support connectivity to the network for the remote UE.

[0119] - How to support end-to-end requirements between the remote UE and the network via the UE-to-network relay, including handling of QoS (e.g. data rate, reliability, latency) and PDU session related attributes (e.g. S-NSSAI, DNN, PDU session type and SSC mode).

[0120] -How the network allows and controls QoS requirements for 5G ProSe UE to NW relay.

[0121] - How to transfer data between a remote UE and the network via the UE-to-network relay.

[0122] NOTE 1: Security and privacy aspects will be handled by SA WG3.

[0123] - How to (re)select UE to network relay for two indirect network communication paths (i.e. Figure 5 .3.1-1) between path #2 and path #3).

[0124] - How to implement a direct network communication path (i.e. Figure 5 .3.1-1) and the indirect network communication path (i.e., Figure 5 .3.1-1) between path #2 or path #3).

[0125] - How to ensure service continuity during these communication path switching procedures for switching between a direct network communication path and an indirect communication path and for switching between two indirect network communication paths.

[0126] NOTE 2: Support for non-unicast mode communications (i.e., one-to-many communications / broadcast or multicast) between the network and UE to network relay UE and between UE to network relay and remote UE depends on the results of FS_5MBS operation.

[0127] Regarding the UE to network relay, Figure 5 .3.1-2 shows the UE served by the gNB to the network relay and Figure 5 Two cases can be considered for the support of UE to network relay served by ng-eNB as shown in .3.1-3.

[0128] [3GPP TR 23.752 V17.0.0 titled "UE-to-Network Relay served by gNB" Figure 5 .3.1-2 reproduced as Figure 7 ]

[0129] [3GPP TR 23.752 V17.0.0 entitled "UE-to-Network Relay served by ng-eNB" Figure 5 .3.1-3 reproduced as Figure 8 ]

[0130] NOTE 3: Whether support for the case where UE to network relay is served by ng-eNB depends on the solution that will be identified in this study and RAN decision.

[0131] NOTE 4: When UE-to-network relay moves to E-UTRAN, ProSe UE-to-network relay based on LTE PC5 may be supported as defined in TS 23.303 [9] for public safety.

[0132] […]

[0133] 3GPP TS23.304 specifies the strategies / parameters for 5G ProSe UE to network relay and UE to network relay discovery as follows:

[0134] Number of offers:

[0135] 3 Definitions of terms, symbols and abbreviations

[0136] 3.1 Terminology

[0137] […]

[0138] User Information ID: User Information ID is configured for Model A or Model B direct discovery for public safety or commercial applications based on the HPLMN's policy or via the ProSe application server that assigns it. The User Information ID is sent by notification to the UE over the air or by the discoverer or discoveree. The definition of the value of the User Information ID is outside the scope of this specification.

[0139] […]

[0140] 5.1.4.1 Policy / Parameter Provisioning for 5G ProSe UE to Network Relay

[0141] The following information is provided in the UE to support the UE acting as a ProSe UE to network relay:

[0142] 1) Authorization policy for acting as a 5G ProSe Layer 3 and / or Layer 2 UE to Network Relay when “served by NG-RAN”:

[0143] -PLMN where the UE is authorized to relay traffic for 5G ProSe Layer 3 and / or Layer 2 remote UEs.

[0144] 2) ProSe relay discovery strategy / parameters for 5G ProSe UE to network relay:

[0145] - Contains parameters that enable the UE to perform 5G ProSe Relay Discovery when provisioned from the PCF in the ME or configured in the UICC:

[0146] -5G ProSe UE to network relay discovery parameters (user information ID, relay service code);

[0147] - a preset destination layer 2 ID for initial signaling for sending and receiving discovery messages;

[0148] - For Layer 3 ProSe UE to Network Relay, the PDU session parameters (PDU session type, DNN, SSC mode, S-NSSAI, access type preference) to be used for the relay service for each ProSe relay service code;

[0149] - Contains security related content for 5G ProSe relay discovery for each ProSe relay service code.

[0150] Editor's Note: Whether the PCF can provide security parameters and the details of the security parameters will be determined by the SA3 WG.

[0151] NOTE 1: 5G ProSe relay discovery strategy / parameters may be provided from the ProSe application server to the 5G ProSe UE to the network relay.

[0152] 3) For layer 3 ProSe UE to network relay, QoS mapping:

[0153] - Each QoS map entry contains:

[0154] -Mapping between 5QI value and PQI value;

[0155] -PQIPDB adjustment factor for PC5 communications for UE to network relay operation;

[0156] - An optional relay service code is associated with the QoS map entry.

[0157] 4) For 5G ProSe layer 3 UE to network relays relaying Ethernet or unstructured traffic from a remote UE using IP type PDU sessions,

[0158] -Map the ProSe service to the ProSe application server address information (consisting of IP address / FQDN and transport layer port number).

[0159] The following information is provided in the UE to support the UE assuming the role of remote UE and thereby enable the use of ProSe UE to network relay:

[0160] 1) Authorization policy for UE-to-network relay using 5G ProSe Layer 3 and / or Layer 2:

[0161] -Indicates whether the UE is authorized to use 5G ProSe Layer 3 and / or Layer 2 UE-to-Network Relay.

[0162] 2) 5G ProSe relay discovery strategy / parameters:

[0163] - Contains parameters for 5G ProSe Relay discovery and is used to enable the UE to connect to the 5G ProSe UE to Network Relay after discovery when provisioned from the PCF in the ME or configured in the UICC:

[0164] -ProSe UE to network relay discovery parameters (user information ID, relay service code);

[0165] - a preset destination layer 2 ID for initial signaling for sending and receiving discovery messages;

[0166] - For 5G ProSe layer 3 UE to network relay, the PDU session parameters (PDU session type, DNN, SSC mode, S-NSSAI, access type preference) to be used for relay services per ProSe relay service code;

[0167] - Contains security related content of ProSe relay discovery for each ProSe relay service code.

[0168] Editor's Note: Whether the PCF can provide security parameters and the details of the security parameters will be determined by the SA3 WG.

[0169] NOTE 2: The ProSe relay discovery policy / parameters may be provided from the ProSe application server to the remote UE.

[0170] The following information is provided in the UE to support the UE in the role of 5G ProSe UE to Network Relay, and the following information is provided in the UE to support the UE in the role of 5G ProSe Remote UE, thereby enabling the use of 5G ProSe UE to Network Relay:

[0171] 1) Radio parameters discovered by 5G ProSe relay when UE is not “served by NG-RAN”:

[0172] -Contains radio parameters for NR PC5 with a geographical area, and an indication of whether the radio parameters are "operator managed" or "non-operator managed". The UE uses the radio parameters to perform 5G ProSe direct discovery over the PC5 reference point when "not served by NG-RAN" only if the UE can reliably locate itself in the corresponding geographical area. Otherwise, the UE is not authorized to transmit.

[0173] 2) Radio parameters for 5G ProSe relay communications when the UE is not “served by NG-RAN”:

[0174] -Contains radio parameters for NR PC5 with a geographical area, and an indication of whether the radio parameters are "operator managed" or "non-operator managed". The UE uses the radio parameters to perform 5G ProSe direct communication over the PC5 reference point when "not served by NG-RAN" only if the UE can reliably locate itself in the corresponding geographical area. Otherwise, the UE is not authorized to transmit.

[0175] […]

[0176] 5.8.1.8 User Information ID

[0177] The user information ID (including notifier information, discoverer information, target information, and discoverer information) is defined in Section 3.1.

[0178] […]

[0179] 6.3.2.3UE to Network Relay Discovery

[0180] 6.3.2.3.1 Overview

[0181] UE-to-network relay discovery is applicable to both layer 3 and layer 2 UE-to-network relay discovery for public safety usage and commercial services.To perform UE-to-network relay discovery, the remote UE and UE-to-network relay are pre-configured or provided with relevant information as described in Section 5.1.

[0182] In UE-to-network relay discovery, the UE uses pre-configured or provided information for the relay discovery procedure as defined in section 5.1.4.1.

[0183] Relay Service Code (RSC) is used in UE-to-network relay discovery to indicate that the UE-to-network relay provides connectivity services to the remote UE. The PSC is configured on the UE-to-network relay and the remote UE as defined in Section 5.1.4. The RSC may also indicate whether the UE-to-network relay is a layer 3 UE-to-network relay or a layer 2 UE-to-network relay. A UE-to-network relay that supports multiple RSCs may use multiple discovery messages to broadcast the RSCs with one RSC per discovery message.

[0184] A separate discovery message of type "Relay Discovery Additional Information" may be used to broadcast additional information for UE to network relay (re)selection and connection maintenance. This may include, for example, relevant system information of the serving cell of the UE to the network relay, as defined in TS 38.300

[12] .

[0185] Supports both Model A and Model B discovery:

[0186] - Model A uses a single discovery protocol message (Notify).

[0187] - Model B uses two discovery protocol messages (solicit and response).

[0188] For relay discovery of additional information, only Model A discovery is used.

[0189] 6.3.2.3.2 Procedure for UE to Network Relay Discovery using Model A

[0190] Figure 6 .3.2.3.2-1 describes the procedure for UE to network discovery using Model A.

[0191] [3GPP TS 23.304 V1.0.0 entitled "UE-to-Network Relay Discovery with Model A" Figure 6 .3.2.3.2-1 Reproduced as Fig. 9 ]

[0192] 1. UE to Network Relay sends a UE to Network Relay Discovery Notification message. The UE to Network Relay Discovery Notification message contains the notifier information and the RSC and is sent using the source layer 2 ID and the destination layer 2 ID as described in section 5.8.3.

[0193] For Layer 3 UE-to-Network Relay, the UE-to-Network Relay shall only include an RSC in the UE-to-Network Relay Discovery Notification when the S-NSSAI associated with the RSC belongs to the allowed NSSAIs for the UE-to-Network Relay.

[0194] The remote UE (1 to 3) determines the destination Layer 2 ID for signaling reception. The UE is configured with the destination Layer 2 ID as specified in Section 5.1.4.1.

[0195] The remote UEs (1 to 3) listen to the notification message with the UE-to-network RSC corresponding to the desired service.

[0196] Optionally, the ProSe UE-to-Network Relay may also send a UE-to-Network Relay Discovery Additional Information message. The parameters contained in this message are described in Section 5.8.3.

[0197] 6.3.2.3.3 Procedure for UE to Network Relay Discovery using Model B

[0198] Figure 6 .3.2.3.3-1 describes the procedure for UE to network relay discovery using Model B.

[0199] [3GPP TS 23.304 V1.0.0 entitled "UE-to-Network Relay Discovery with Model B" Figure 6 .3.2.3.3-1 Reproduced as Fig.10 ]

[0200] 1.5G ProSe Remote UE sends a 5G ProSe UE to Network Relay Discovery Solicitation message. The 5G ProSe UE to Network Discovery Solicitation message contains the discoverer information and RSC, and is sent using the source layer 2 ID and the destination layer 2 ID as described in Section 5.8.3. The 5G ProSe Remote UE discovering the 5G ProSe UE to Network Relay sends the solicitation message with the RSC associated with the desired connectivity service.

[0201] The manner in which the 5G ProSe UE to Network Relays (1 to 3) determine the destination Layer 2 ID for signaling reception is specified in Section 5.8.3. The destination Layer 2 ID is configured for the UE as specified in Section 5.1.4.1.

[0202] 2. The 5G ProSe UE to Network Relay (1 and 2) that matches the value of the RSC contained in the Solicitation message responds to the remote UE using a UE to Network Relay Discovery Response message. The 5G ProSe UE to Network Relay Discovery Response message contains the discoverer information and the RSC and is sent using the source layer 2 ID and the destination layer 2 ID as described in Section 5.8.3.

[0203] For the 5G ProSe Layer 3 UE-to-network Relay, the 5G ProSe UE-to-network Relay shall only respond to a matching RSC in the UE-to-network Relay Discovery Solicitation message when the S-NSSAI associated with the RSC belongs to the allowed NSSAIs of the 5G ProSe UE-to-network Relay.

[0204] The 5G ProSe remote UE selects a 5G ProSe UE to network relay based on the information received in step 2.

[0205] […]

[0206] 3GPP TR 38.836 documents the current protocol regarding UE to network relay as follows:

[0207] 4 UE-to-network relay based on sidelink

[0208] 4.1 Scenario, Assumptions and Requirements

[0209] UE-to-network relaying enables coverage extension and power saving for remote UEs. The coverage scenarios considered in this study are as follows:

[0210] -UE to network relay UE is in coverage and remote UE is out of coverage

[0211] -UE to network relay UE and remote UE are both within coverage

[0212] - For L3 UE to network relay, after the remote UE establishes a connection via the relay UE, the relay UE and the remote UE can be in the same cell or in different cells.

[0213] - For L2 UE to network relay, as a baseline support, after the remote UE is connected via the relay UE, the relay UE and the remote UE are controlled by the serving cell of the relay UE

[0214] For L2 UE to network relay, the following two cases are supported, namely:

[0215] - Before making a remote connection via the relay UE, the relay UE and the remote UE are in the same cell;

[0216] - Before making a remote connection via the relay UE, the relay UE and the remote UE are in different cells;

[0217] The situation considered is Figure 4 .Reflected in 1-1.

[0218] [3GPP TR 38.836 V17.0.0, entitled "Scenarios for UE-to-Network Relay" Figure 4 .1-1 reproduced as Fig.11 ]

[0219] Assume that NR Uu is on the Uu link from UE to network relay UE. Assume that NR side link is on PC5 between remote UE and UE to network relay UE.

[0220] Cross-RAT configuration / control of UE (remote UE or UE to network relay UE) is not considered, that is, eNB / ng-eNB does not control / configure NR remote UE and UE to network relay UE. For UE to network relay, this study focuses on unicast data services between remote UE and the network.

[0221] The UE (remote UE or UE-to-network relay UE) is configured / scheduled by the SN to perform NR sidelink communications which are outside the scope of this study.

[0222] For UE-to-network relay, relaying of unicast data between the remote UE and the network may occur after a PC5-RRC connection is established between the relay UE and the remote UE.

[0223] The Uu RRC states of the relay UE and the remote UE may change when connected via PC5. Both the relay UE and the remote UE may perform relay discovery in any RRC state. The remote UE may perform relay discovery when out of Uu coverage.

[0224] The relay UE must be in the RRC_CONNECTED state to perform relay of unicast data.

[0225] For L2 UE to network relay:

[0226] - The remote UE must perform transmission / reception of relay unicast data in the RRC CONNECTED state.

[0227] -As long as all PC5 connected remote UEs are in RRC_IDLE state, the relay UE can be in RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state.

[0228] - The relay UE can be in RRC_INACTIVE or RRC_CONNECTED as long as all PC5 connected remote UEs are in RRC_INACTIVE.

[0229] For L3 UE to network relay, both the relay UE and the remote UE may be in RRC_INACTIVE state.

[0230] In this release, the requirement for service continuity is only for UE-to-network relaying, not for inter-UE relaying.

[0231] RAN2 has studied the mobility scenarios of "between direct (Uu) path and indirect (via relay) path" for UE to network relay. RAN2 focuses on the mobility scenarios of the intra-gNB case in the study phase, and assumes that the inter-gNB case will also be supported. For the inter-gNB case, the potential different parts on the Uu interface can be discussed in detail in the WI phase compared to the intra-gNB case. RAN2 deprioritizes the work specific to the mobility scenarios of "between indirect (via first relay UE) and indirect (via second relay UE)" for path switching in the SI phase, which can be studied in the WI phase if needed.

[0232] RAN2 de-prioritizes group mobility scenarios in the SI phase, which may be addressed in the WI phase if needed.

[0233] […]

[0234] 4.3 Relay (re)selection criteria and procedures

[0235] The baseline solution for relay (re)selection is as follows:

[0236] Radio measurements at the PC5 interface are considered as part of the relay (re)selection criteria.

[0237] - The remote UE uses at least the radio signal strength measurements of the sidelink discovery messages to assess whether the PC5 link quality of the relay UE meets the relay selection and reselection criteria.

[0238] - When a remote UE is connected to a relay UE, it may use SL-RSRP measurements on the sidelink unicast link to assess whether the PC5 link quality of the relay UE meets the relay reselection criteria.

[0239] Additional details about PC5 radio measurement criteria, for example in the case of no transmission on the sidelink unicast link, may be discussed in the WI phase. If the remote UE has a PC5-RRC connection with the relay UE, how to perform RSRP measurements based on RSRP of discovery messages and / or SL-RSRP may be decided in the WI phase.

[0240] For relay selection, as in LTE, if the remote UE's direct Uu link quality is below a configured threshold, the remote UE within coverage searches for candidate relay UEs.

[0241] For relay (re)selection, the remote UE compares the relay UE's PC5 radio measurements with thresholds configured or pre-configured by the gNB. The remote UE also needs to consider higher layer criteria for relay (re)selection, but the details can be left to SA2. Relay (re)selection can be triggered by upper layers of the remote UE.

[0242] If the NR sidelink signal strength of the current sidelink relay is below a (pre)configured threshold, then relay reselection should be triggered. And, if the remote UE detects RLF of the PC5 link with the current relay UE, then relay reselection may be triggered.

[0243] The above baseline for relay (re)selection is applicable to both L2 and L3 solutions. However, for RRC_CONNECTED remote UE in L2 UE to network relay scenario, gNB decision on relay selection / reselection is considered in WI phase under the above baseline. Relay solutions for L2 and L3 UE to network may consider additional AS layer criteria in WI phase.

[0244] For relay (re)selection, when the remote UE has multiple suitable relay UE candidates that meet all AS layer and higher layer criteria and the remote UE needs to select a relay UE by itself, it is up to the UE implementation to decide which relay UE to select. This does not exclude the involvement of the gNB in ​​service continuity for UE to network relay scenarios.

[0245] […]

[0246] 4.5 Layer 2 Relay

[0247] 4.5.1 Architecture and Protocol Stack

[0248] 4.5.1.1 Protocol Stack

[0249] For the case where the PC5 interface does not support the adaptation layer Figure 4 .5.1.1-1 and Figure 4 .5.1.1-2 and for the case where the PC5 interface supports the adaptation layer Figure 4 .5.1.1-3 and Figure 4 .5.1.1-4 describes the protocol stack for the user plane and control plane of the L2 UE to network relay architecture.

[0250] For L2 UE-to-network relay, an adaptation layer is placed above the RLC sublayer for CP and UP at the Uu interface between the relay UE and the gNB. The Uu SDAP / PDCP and RRC are terminated between the remote UE and the gNB, while the RLC, MAC and PHY are terminated in each link (i.e., the link between the remote UE and the relay UE for UE-to-network and the link between the relay UE and the gNB for UE-to-network). Whether the adaptation layer is also supported at the PC5 interface between the remote UE and the relay UE depends on the WI stage (assuming that the down selection is done first before studying the detailed PC5 adaptation layer functionality too much).

[0251] [3GPP TR 38.836 V17.0.0 entitled "User plane protocol stack for L2 UE-to-Network Relay (adaptation layer is supported at the PC5 interface)" Figure 4 .5.1.1-1 Reproduced as Fig.12 ]

[0252] [3GPP TR 38.836 V17.0.0 entitled "Control plane protocol stack for L2 UE-to-Network Relay (adaptation layer is not supported at the PC5 interface)" Figure 4 .5.1.1-2 Reproduced as Fig.13 ]

[0253] [3GPP TR 38.836 V17.0.0 entitled "User plane protocol stack for L2 UE-to-Network Relay (adaptation layer is supported at the PC5 interface)" Figure 4 .5.1.1-3 reproduced as Fig.14 ]

[0254] [3GPP TR 38.836 V17.0.0 entitled "Control plane protocol stack for L2 UE-to-Network Relay (adaptation layer is supported at the PC5 interface)" Figure 4 .5.1.1-4 reproduced as Fig.15 ]

[0255] 4.5.1.2 Adaptation layer functionality

[0256] For L2 UE to network relay, for uplink:

[0257] - The Uu Adaptation Layer at the relay UE supports UL bearer mapping between the ingress PC5 RLC channel for relay and the egress Uu RLC channel on the relay UE Uu path. For uplink relay services, different end-to-end RBs (SRBs, DRBs) of the same remote UE and / or different remote UEs can be subjected to N:1 mapping and data multiplexing on one Uu RLC channel.

[0258] -Use of Uu Adaptation Layer to support Remote UE Identity for UL traffic (multiplexing data from multiple remote UEs). Remote UE Uu radio bearer and remote UE identity information is included in the Uu Adaptation Layer at UL so that the gNB correlates received data packets for a specific PDCP entity associated with the correct remote UE Uu radio bearer for the remote UE.

[0259] For L2 UE to network relay, for downlink:

[0260] - The Uu Adaptation Layer may be used to support DL bearer mapping at the gNB to map the end-to-end radio bearers (SRBs, DRBs) of the remote UE into the Uu RLC channels on the relay UE Uu path. The Uu Adaptation Layer may be used to support DL N:1 bearer mapping and data multiplexing between multiple end-to-end radio bearers (SRBs, DRBs) of the remote UE and / or different remote UEs and one Uu RLC channel on the relay UE Uu path.

[0261] - The Uu Adaptation Layer needs to support Remote UE Identity for downlink traffic. The identification information of the Remote UE Uu Radio Bearer and the identification information of the Remote UE needs to be placed in the Uu Adaptation Layer by the gNB at DL so that the relay UE maps the data packets received from the Remote UE Uu Radio Bearer to its associated PC5 RLC channel.

[0262] 4.5.2QoS

[0263] In case of L2 UE to network relay, gNB implementation may handle QoS decomposition on Uu and PC5 for end-to-end QoS enforcement for a specific session established between remote UE and network. The handling details in case of PC5 RLC channels with different end-to-end QoS mapped to the same Uu RLC channel may be discussed in the WI phase.

[0264] […]

[0265] 4.5.4 Service Continuity

[0266] 4.5.4.0 Overview

[0267] L2 UE to Network Relay uses the RAN2 principles of Rel-15 NR handover procedures as a baseline AS layer solution to ensure service continuity, i.e. the gNB hands over the remote UE to the target cell or target relay UE, including:

[0268] 1) Handover preparation type procedures between gNB and relay UE (if required);

[0269] 2) RRCReconfiguration to the remote UE, handover to the target remote UE, and;

[0270] 3) A handover completion message similar to that of conventional procedures.

[0271] The exact content of the message (eg, handover command) can be discussed in the WI phase. This does not imply that we will send inter-node messages via Uu.

[0272] In the following, the common parts of the intra-gNB case and the inter-gNB case are captured. For the inter-gNB case, the potential different parts on the RAN2 Uu interface can be discussed in detail in the WI phase compared to the intra-gNB case.

[0273] 4.5.4.1 Switching from indirect to direct path

[0274] For service continuity of L2 UE to network relay, in case of remote UE handover to the bootstrap Uu cell, the following baseline procedure is used.

[0275] [3GPP TR 38.836 V17.0.0 entitled "Procedure for Remote UE switching to direct Uu cell" Figure 4 .5.4.1-1 Reproduced as Fig.16 ]

[0276] Step 1: Measurement Configuration and Reporting

[0277] Step 2: Decision to switch to direct cell via gNB

[0278] Step 3: RRC reconfiguration message to remote UE

[0279] Step 4: Remote UE performs random access to gNB

[0280] Step 5: Using the target configuration provided in the RRC Reconfiguration message, the remote UE feeds back RRCReconfigurationComplete to the gNB via the target path.

[0281] Step 6: RRC reconfiguration to relay UE

[0282] Step 7: If necessary, release the PC5 link between the remote UE and the relay UE.

[0283] Step 8: Data path switching.

[0284] Note: The order of steps 6 / 7 / 8 is not limited. Further discussion below in the WI phase includes:

[0285] - whether the remote UE suspends data transmission via the relay link after step 3;

[0286] - whether step 6 can be before or after step 3 and its necessity;

[0287] - Step 7 can be after step 3 or step 5 and its necessity / replaced by PC5 reconfiguration;

[0288] - Whether step 8 can be after step 5.

[0289] 4.5.4.2 Switching from direct to indirect path

[0290] For service continuity of L2 UE to network relay, in case of handover of remote UE to indirect relay UE, the following baseline procedure is used:

[0291] [3GPP TR 38.836 V17.0.0 entitled "Procedure for Remote UE switching to indirect Relay UE" Figure 4 .5.4.2-1 Reproduced as Fig.17 ]

[0292] Step 1: The remote UE reports one or more candidate relay UEs after the remote UE measures / discovers the candidate relay UEs.

[0293] - In step 1, the remote UE may filter appropriate relay UEs that meet higher layer criteria when reporting.

[0294] - In step 1, the report may contain the relay UE's ID and SL RSRP information, where the measurement on PC5 details may be left to the WI phase.

[0295] Step 2: Decision to switch to target relay UE by gNB and target (re)configuration is optionally sent to the relay UE (similar to preparation).

[0296] Step 3: RRC reconfiguration message to remote UE. It may contain the following information: 1) identity of target relay UE; 2) target Uu and PC5 configuration.

[0297] Step 4: The remote UE establishes a PC5 connection with the target relay UE if the connection has not been set up yet.

[0298] Step 5: Using the target configuration provided in RRCReconfiguration, the remote UE feeds back RRCReconfigurationComplete to the gNB via the target path.

[0299] Step 6: Data path switching.

[0300] Note: This is further discussed below in the WI phase, including:

[0301] - Whether step 2 should be done after the relay UE is connected to the gNB (e.g. after step 4), if it has not been connected to the gNB before;

[0302] - Whether step 4 can precede steps 2 / 3.

[0303] 4.5.5 Control Plane Programs

[0304] 4.5.5.1 Connection Management

[0305] The remote UE needs to establish its own PDU session / DRB with the network before user plane data transfer.

[0306] Before the remote UE establishes a Uu RRC connection with the network via the relay UE, the PC5-RRC aspects of the Rel-16 NR V2X PC5 unicast link establishment procedure may be reused to set up a secure unicast link between the remote UE and the relay UE for L2UE to network relay.

[0307] For both in-coverage and out-of-coverage cases, when the remote UE initiates the first RRC message for its connection establishment with the gNB, the PC5 L2 configuration for transmission between the remote UE and the UE to the network relay UE may be based on the RLC / MAC configuration defined in the specification.

[0308] The establishment of Uu SRB1 / SRB2 and DRBs for the remote UE is subject to conventional Uu configuration procedures for L2 UE to network relay.

[0309] The following high-level connection establishment procedure applies to L2 UE to network relay:

[0310] [3GPP TR 38.836 V17.0.0 entitled "Procedure for Remote UE connection establishment" Figure 4 .5.5.1-1 Reproduced as Fig.18 ]

[0311] Step 1. The remote and relay UEs perform a discovery procedure and establish a PC5-RRC connection using the legacy Rel-16 procedure as a baseline.

[0312] Step 2. The remote UE sends a first RRC message (i.e., RRCSetupRequest) via the relay UE for its connection establishment with the gNB using the preset L2 configuration on PC5. The gNB responds to the remote UE with an RRCSetup message. The RRCSetup delivered to the remote UE uses the preset configuration on PC5. If the relay UE did not start in RRC_CONNECTED, then upon receiving the message on the preset L2 configuration on PC5, it needs to establish the connection itself. The details of the relay UE forwarding the RRCSetupRequest / RRCSetup message for the remote UE at this step can be discussed in the WI phase.

[0313] Step 3. gNB and relay UE perform relay channel setup procedure over Uu. Based on the configuration from gNB, relay / remote UE establishes RLC channel for relay of SRB1 towards remote UE through PC5. This step prepares relay channel for SRB1.

[0314] Step 4. The remote UE SRB1 message (e.g., RRCSetupComplete message) is sent to the gNB via the relay UE using the SRB1 relay channel via PC5. The remote UE then establishes an RRC connection over Uu.

[0315] Step 5. The remote UE and gNB establish security following conventional procedures and the security message is forwarded by the relay UE.

[0316] Step 6. The gNB sets up an additional RLC channel between the gNB and the relay UE for service relay. Based on the configuration from the gNB, the relay / remote UE sets up an additional RLC channel between the remote UE and the relay UE for service relay. The gNB sends RRCReconfiguration to the remote UE via the relay UE to set up relay SRB2 / DRB. The remote UE sends RRCReconfigurationComplete to the gNB via the relay UE as a response.

[0317] In addition to the connection establishment procedure, for L2 UE to network relay:

[0318] -RRC reconfiguration and RRC connection release procedures can reuse the traditional RRC procedures, where the message content / configuration design is left to the WI phase.

[0319] -RRC connection re-establishment and RRC connection recovery procedures may reuse the conventional RRC procedures as a baseline by handling the relay specific parts through the above connection establishment procedures considering the relay of L2 UE to network, where the message content / configuration design is left to the WI phase.

[0320] […]

[0321] 3GPP TS 38.331 specifies signaling radio bearers, paging, Radio Resource Control (RRC) connection establishment and RRC reconfiguration as follows:

[0322] 4.2.2 Signalling Radio Bearer

[0323] "Signalling Radio Bearer" (SRB) is defined as a Radio Bearer (RB) used only for transmitting RRC and NAS messages. More precisely, the following SRBs are defined:

[0324] -SRB0 is used for RRC messages using CCCH logical channel;

[0325] -SRB1 is used for RRC messages (which may include piggybacked NAS messages) and NAS messages before establishing SRB2, all of which use the DCCH logical channel;

[0326] -SRB2 is used for NAS messages and for RRC messages containing logged measurement information, all of which use the DCCH logical channel. SRB2 has a lower priority than SRB1 and can be configured by the network after AS security activation;

[0327] -SRB3 is used for specific RRC messages when the UE is in (NG)EN-DC or NR-DC, all of which use the DCCH logical channel.

[0328] In the downlink, piggybacking of NAS messages is used only for one related (ie, with joint success / failure) procedure: bearer establishment / modification / release. In the uplink, piggybacking of NAS messages is used only for the transfer of initial NAS messages during connection setup and connection recovery.

[0329] Note 1: The NAS message delivered via SRB2 is also included in the RRC message, however, the RRC message does not contain any RRC protocol control information.

[0330] Once AS security is activated, all RRC messages on SRB1, SRB2 and SRB3, including those containing NAS messages, are integrity protected and ciphered by PDCP. NAS independently applies integrity protection and ciphering to NAS messages, see TS 24.501

[23] .

[0331] Split SRB is supported for all MR-DC options for SRB1 and SRB2 (split SRB is not supported for SRB0 and SRB3).

[0332] For operation with shared spectrum channel access, SRB0, SRB1, and SRB3 are assigned the highest priority Channel Access Priority Class (CAPC), (ie, CAPC=1), while the CAPC for SRB2 is configurable.

[0333] […]

[0334] 5.3.2 Paging

[0335] 5.3.2.1 Overview

[0336] [3GPP TS 38.331 V16.3.1 entitled "Paging" Figure 5 .3.2.1-1 Reproduced as Fig.19 ]

[0337] The purpose of this program is to:

[0338] - Deliver paging information to the UE in RRC_IDLE or RRC_INACTIVE.

[0339] 5.3.2.2 Initiation

[0340] The network initiates the paging procedure by sending a Paging Message at the UE's paging occasion as specified in TS 38.304

[20] . The network can handle multiple UEs in a Paging Message by including one PagingRecord for each UE.

[0341] 5.3.2.3 UE Reception of Paging Message

[0342] After receiving the paging message, the UE shall:

[0343] 1> If in RRC_IDLE, then for each PagingRecord contained in the Paging Message (if any):

[0344] 2> If the ue-Identity contained in the PagingRecord matches the UE identity assigned by the upper layer:

[0345] 3> Forward ue-Identity and accessType (if present) to the upper layer;

[0346] 1> If in RRC_INACTIVE, then for each PagingRecord contained in the Paging Message (if any):

[0347] 2> If the ue-Identity contained in the PagingRecord matches the stored fullI-RNTI of the UE:

[0348] 3> If the UE is configured by upper layers with access identity 1:

[0349] 4> Initiate the RRC connection recovery procedure according to 5.3.13, where resumeCause is set to mps-PriorityAccess;

[0350] 3> Otherwise if the UE is configured by upper layers with access identity 2:

[0351] 4> Initiate the RRC connection recovery procedure according to 5.3.13, where resumeCause is set to mcs-PriorityAccess;

[0352] 3> Otherwise if the UE is configured by upper layers with one or more access identifiers equal to 11 to 15:

[0353] 4> Initiate the RRC connection recovery procedure according to 5.3.13, where resumeCause is set to highPriorityAccess;

[0354] 3> Otherwise:

[0355] 4> Initiate the RRC connection recovery procedure according to 5.3.13, where resumeCause is set to mt-Access;

[0356] 2> Otherwise if the ue-Identity contained in the PagingRecord matches the UE identity assigned by the upper layer:

[0357] 3> Forward ue-Identity to the upper layer and accessType (if any) to the upper layer;

[0358] 3> Perform actions after transitioning to RRC_IDLE as specified in 5.3.11 due to release reason 'other'.

[0359] […]

[0360] 5.3.3RRC Connection Establishment

[0361] 5.3.3.1 Overview

[0362] [3GPP TS 38.331 V16.3.1 entitled "RRC connection establishment, successful" Figure 5 .3.3.1-1 Reproduced as Fig. 20 ]

[0363] [3GPP TS 38.331 V16.3.1 entitled "RRC connection establishment, network reject" Figure 5 .3.3.1-2Copy as Fig.21 ]

[0364] The purpose of this procedure is to establish an RRC connection. The RRC connection establishment involves SRB1 establishment. The procedure is also used to transfer initial NAS dedicated information / messages from the UE to the network.

[0365] For example, the following network applications:

[0366] -When an RRC connection is established;

[0367] - When the UE is resuming or re-establishing an RRC connection and the network is unable to retrieve or verify the UE context. In this case, the UE receives RRCSetup and responds with RRCSetupComplete.

[0368] […]

[0369] 5.3.5RRC Reconfiguration

[0370] 5.3.5.1 Overview

[0371] [3GPP TS 38.331 V16.3.1 entitled "RRC reconfiguration, successful" Figure 5 .3.5.1-1 Reproduced as Fig. 22 ]

[0372] […]

[0373] The purpose of this procedure is to modify the RRC connection, such as establish / modify / release RB, perform reconfiguration with synchronization, set up / modify / release measurements, add / modify / release SCells and cell groups, add / modify / release conditional handover configuration, add / modify / release conditional PSCell change configuration. As part of the procedure, NAS specific information may be passed from the network to the UE.

[0374] […]

[0375] 5.3.5.2 Initiation

[0376] The network may initiate an RRC connection reconfiguration procedure to the UE in RRC_CONNECTED. The network applies the following procedure:

[0377] - Establishment of RBs is performed only when AS security has been activated (not SRB1, which is established during RRC connection establishment);

[0378] - Addition of secondary cell groups and SCells is performed only when AS security has been activated;

[0379] - reconfigurationWithSync is included in secondaryCellGroup only if at least one RLC bearer is set up in the SCG;

[0380] - reconfigurationWithSync is included in the masterCellGroup only if AS security has been activated, and SRB2 with at least one DRB or SRB2 for IAB is set and not suspended;

[0381] -ConditionalReconfiguration for CPC is included only if at least one RLC bearer is set up in the SCG;

[0382] -Contains conditionalReconfiguration for CHO only if AS security is activated, and SRB2 with at least one DRB or SRB2 for IAB is set up and not suspended.

[0383] […]

[0384] 6.2.2 Message Definition

[0385] […]

[0386] -Paging

[0387] The paging message is used to notify one or more UEs.

[0388] Paging message

[0389]

[0390]

[0391] IE NG-5G-S-TMSI contains the 5G S-Temporary Mobile Subscription Identifier (5G-S-TMSI), a temporary UE identity provided by the 5GC that uniquely identifies the UE within the tracking area, see TS 23.003

[21] .

[0392] NG-5G-TMSI information element

[0393]

[0394] 9 Specific and preset radio configurations

[0395] Specific and preset configurations are configurations where the details are specified in the standard. Specific configurations are fixed, whereas preset configurations can be modified using dedicated signaling. Unless explicitly stated otherwise, the preset values ​​of parameters not listed in the following subsections shall be set to the corresponding feature, e.g., not configured, i.e., release or error.

[0396] NOTE: The UE applies the preset values ​​specified in the field description of the ASN.1 parameter only if the parent IE is present. Therefore, when the UE applies the "Preset Radio Configuration" according to this section, the UE does not apply all the preset values ​​in the field description.

[0397] […]

[0398] 9.2.1 Preset SRB Configuration

[0399] parameter

[0400]

[0401] Key issue #4 in 3GPP TR 23.752 describes support for UE-to-network relay in the following release (i.e., Release 17), which generally means that a relay UE will be used to support communications between a remote UE and the network in the event that the remote UE cannot directly access the network. Two different types of solutions for UE-to-network relay proposed in 3GPP TR 23.752 include layer 2-based UE-to-network relay and layer 3-based UE-to-network relay.

[0402] As discussed in 3GPP TS23.304, both Model A discovery and Model B discovery are supported for remote UEs to discover UE-to-network relays. Model A uses a single discovery protocol message (i.e., discovery notification), and Model B uses two discovery protocol messages (i.e., discovery request and discovery response). In the case where there are multiple relay UEs near the remote UE, one of the relay UEs will be selected. After selecting the appropriate relay UE, the remote UE will then establish a PC5 RRC connection or PC5 unicast link with the relay UE to support UE-to-network relay operations. The UE-to-network relay discovery notification message and discovery response message transmitted by the relay UE may include the user information ID of the relay UE and the relay service code (RSC) associated with the connectivity service provided by the UE-to-network relay to the remote UE. The user information ID and RSC may be provided by a proximity-based services (ProSe) application server.

[0403] In order to access the service of interest from a data network (DN), a Protocol Data Unit (PDU) session should be established using the DN, and the PDU session establishment request message contains Single Network Slice Selection Assistance Information (S-NSSAI) and the Data Network Name (DNN) associated with the PDU session. In a layer 2 UE to network relay solution, the remote UE establishes a PDU session with the network via the relay UE, while the relay UE establishes a PDU session with the remote UE's network in a layer 3 UE to network relay solution.

[0404] Section 4.5.4.2 of 3GPP TR 38.836 specifies the procedure for handover of a remote UE from a direct communication path to an indirect communication path in the case of a Layer 2 based UE to network relay. Figure 4 .5.4.2-1 step 1, the diagram is reproduced as Fig.17 , the gNB may provide the measurement configuration to the remote UE, and the remote UE may then transmit a measurement report to the gNB. The measurement report may include measurement results of multiple relay UEs. Each measurement result of the relay UE may include at least one U2N relay UE ID, a serving cell ID of the U2N relay UE, and RSRP information measured via the sidelink. Figure 4 .5.4.2-1 step 2, the diagram is reproduced as Fig.17, the gNB transmits an RRC reconfiguration message to the relay UE to indicate the Uu and / or PC5 (or SL) configuration to be applied by the relay UE for supporting UE-to-network relay operation after path switch. In the case where the relay UE is not in RRC CONNECTED mode / state, the gNB needs to page the relay UE so that the relay UE can connect with the gNB to receive the RRC reconfiguration message from the gNB.

[0405] According to 3GPP TS 38.331, the gNB shall page the relay UE with the UE identity of the relay UE. The UE identity can be the NG-5G-S-TMSI (48 bits) or the full I-RNTI (40 bits), which is not equal to the user information ID of the relay UE included in the UE-to-network relay discovery notification message or the discovery response message, and is provided by the ProSe application server. One way to make the gNB page the relay UE is to also include the NG-5G-S-TMSI or full I-RNTI of the relay UE in the UE-to-network relay discovery message sent by the relay UE, so that the remote UE can include the NG-5G-S-TMSI or full I-RNTI of the relay UE in the measurement report after receiving the UE-to-network relay discovery notification message or the discovery response message from the relay UE. In other words, the U2N relay UE ID in the measurement report is set to the NG-5G-S-TMSI or full I-RNTI of the relay UE. Another way is that the core network can maintain a mapping between the user information ID of the relay UE and the NG-5G-S-TMSI / full I-RNTI, thereby allowing the gNB to query the NG-5G-S-TMSI / full I-RNTI of the relay UE based on the user information ID of the relay UE. In this case, the U2N relay UE ID included in the measurement report is set to the user information ID.

[0406] Another potential direction is to avoid the need for gNB paging and reduce the associated complexity. For example, after a PC5 RRC connection with a remote UE has been established, the relay UE may autonomously connect to the gNB. After establishing an RRC connection with the gNB, the relay UE may then transmit an RRC message (e.g., SidelinkUEInformation) to request that a radio bearer configuration support UE-to-network relay, and the gNB may transmit an RRC reconfiguration message to the relay UE to provide at least one Uu configuration for forwarding an RRC message (e.g., RRC reconfiguration complete) received from the remote UE to the gNB. The Uu configuration (e.g., RRC reconfiguration complete) for forwarding the RRC message may be associated with an SRB (e.g., SRB1). The RRC reconfiguration message may also include a PC5 (or SL) configuration for receiving an RRC message (e.g., RRC reconfiguration complete) from the remote UE. In one embodiment, the Uu configuration may include a Uu Radio Link Control (RLC) bearer configuration. The PC5 (or SL) configuration may include a PC5 (or SL) RLC bearer configuration. In the case where the relay UE is already connected to the gNB (i.e., in RRC CONNECTED), the relay does not need to establish an RRC connection with the gNB again. The relay UE can directly transmit an RRC message (e.g., SidelinkUEInformation) to request radio bearer configuration to support UE-to-network relay.

[0407] A prerequisite for the above solution is that there should be a way for the gNB to indicate which relay UE to select for path switching after receiving a measurement report from a remote UE. In one embodiment, the remote UE may report a list of measurement results of multiple relay UEs. Each measurement result in the list belongs to a relay UE. The items of the measurement results in the list may be indexed in sequential order. Each index corresponds to a relay UE associated with a measurement result in the list. Therefore, the index can be used to indicate the relay UE associated with the measurement result in the list. The index may start from 0 or 1.

[0408] Fig.23 The table in (titled "Table of a list of measurement results") describes an example where the index starts at 1. In one embodiment, the index is not included in the list. In other words, each measurement result is implicitly associated with an index. It is also possible to explicitly include the index in the list.

[0409] Thus, after receiving the measurement report from the remote UE, the gNB may indicate the relay UE with an index for path switching in an RRC reconfiguration message sent to the remote UE. The RRC reconfiguration message may indicate the Uu and / or PC5 (or SL) configuration to be used to reply the RRC reconfiguration complete message to the gNB via the relay UE, and / or the Uu and / or PC5 (or SL) configuration to be applied by the remote UE for data packet transmission via the relay UE after the path switch. The remote UE may then establish a PC5 RRC connection (or PC5 unicast link) with the relay UE indicated by the gNB. After establishing the PC5 RRC connection (or PC5 unicast link), if an RRC connection has not yet been established, the relay UE may then establish an RRC connection with the gNB. The relay UE may then transmit an RRC message (e.g., SidelinkUEInformation) to request radio bearer configuration support UE-to-network relay from the gNB, as described above.

[0410] Presumably, the RRC reconfiguration complete message sent by the remote UE will be forwarded (or relayed) to the gNB via the relay UE, and the relay UE will include information (e.g., the local UE ID of the remote UE) in the adaptation layer header to identify the remote UE. In one embodiment, the local UE ID may be assigned by the relay UE or the gNB and may be unique to the scope of relay UEs. After receiving the RRC reconfiguration complete message from the remote UE, the gNB may then transmit an RRC reconfiguration message to the relay UE to further provide Uu and / or PC5 configuration associated with the DRB for packet data transmission.

[0411] Taking into account that there may be multiple remote UEs connected to the relay UE for UE-to-network relay, the RRC reconfiguration message may include information (e.g., the local UE ID of the remote UE) to identify which remote UE is associated with the Uu and / or PC5 configuration. In addition, the gNB is required to associate the local UE ID with certain identities of the remote UE currently maintained in the gNB. To achieve this purpose, the remote UE may also need to include information in the RRC reconfiguration complete message to indicate the remote UE to the gNB. For example, the information used to identify (or indicate) the remote UE may be a cell-radio network temporary identifier (Cell-Radio Network Temporary Identifier, C-RNTI) or the initial UE identity of the remote UE. The C-RNTI may be provided to the remote UE by the network node (e.g., in a previous RRC reconfiguration message) for identifying the remote UE within the network node, and the initial UE identity of the remote UE should have been transmitted by the remote UE to the network node in the RRC setup request message when the RRC connection with the gNB was established. The initial UE identity of the remote UE may be ng-5G-S-TMSI-Part1 or a random value defined in the RRC specification (as discussed in 3GPP TS 38.331). Fig.24 An example of a procedure for direct to indirect communication path switching is presented.

[0412] It should be noted that the RRC Reconfiguration message is used by the gNB to provide the radio bearer configuration to the remote UE or relay UE, and the remote UE or relay UE may then reply with an RRC Reconfiguration Complete message. Another terminology may be used to replace these two RRC messages for the same purpose. Furthermore, it is possible that the gNB that transmits the RRC Reconfiguration message to the remote UE and the gNB that receives the RRC Reconfiguration Complete message from the remote UE may be different, i.e., the communication path is switched between two different gNBs.

[0413] Fig.25Flowchart 2500 is provided to illustrate a method for supporting radio bearer configuration of a UE to a network relay from the perspective of a relay UE. In step 2505, the relay UE establishes a PC5-Radio Resource Control (PC5-RRC) connection with a remote UE. In step 2510, the relay UE transmits an RRC message to a network node to request radio bearer configuration support for UE to network relay. In step 2515, the relay UE receives an RRC reconfiguration message from the network node, wherein the RRC reconfiguration message includes a Uu configuration for a Uu radio link control (Radio Link Control, RLC) bearer associated with a signaling radio bearer (signalling radio bearer, SRB). In step 2520, the relay UE receives an RRC reconfiguration complete message from the remote UE. In step 2525, the relay UE transmits the RRC reconfiguration complete message to the network node on the Uu RLC bearer.

[0414] Return to reference Figure 3 and Figure 4 In an exemplary embodiment of a method for a relay UE, the relay UE 300 includes a program code 312 stored in a memory 310. The CPU 308 can execute the program code 312 to enable the relay UE to (i) establish a PC5-Radio Resource Control (PC5-RRC) connection with a remote UE, (ii) transmit an RRC message to a network node to request a radio bearer configuration to support UE-to-network relay, (iii) receive an RRC reconfiguration message from the network node, wherein the RRC reconfiguration message includes a Uu configuration for a Uu RLC bearer associated with an SRB, (iv) receive an RRC reconfiguration complete message from the remote UE, and (v) transmit the RRC reconfiguration complete message to the network node on the Uu RLC bearer. In addition, the CPU 308 can execute the program code 312 to perform all of the above actions and steps or other actions and steps described herein.

[0415] Fig.26A flow chart 2600 is provided to illustrate a method for supporting radio bearer configuration of a UE to a network relay from the perspective of a network node. In step 2605, the network node receives an RRC message from a relay UE to request radio bearer configuration to support UE to network relay. In step 2610, the network node transmits an RRC reconfiguration message to the relay UE, wherein the RRC reconfiguration message includes a Uu configuration for a Uu RLC bearer associated with an SRB. In step 2615, the network node receives an RRC reconfiguration complete message from the relay UE on the Uu RLC bearer, wherein the RRC reconfiguration complete message is received by the relay UE from the remote UE.

[0416] Return to reference Figure 3 and Figure 4 In one exemplary embodiment of a method for a network node, the network node 300 includes program code 312 stored in a memory 310. The CPU 308 can execute the program code 312 to enable the network node to (i) receive an RRC message from a relay UE to request a radio bearer configuration to support UE to network relay, (ii) transmit an RRC reconfiguration message to the relay UE, wherein the RRC reconfiguration message includes a Uu configuration for a Uu RLC bearer associated with an SRB, and (iii) receive an RRC reconfiguration complete message from the relay UE on the Uu RLC bearer, wherein the RRC reconfiguration complete message is received by the relay UE from the remote UE. In addition, the CPU 308 can execute the program code 312 to perform all of the above actions and steps or other actions and steps described herein.

[0417] exist Fig.25 and Fig.26 In the context of the embodiments illustrated in and as discussed above, in one embodiment, the RRC reconfiguration message may include a sidelink (SL) configuration for a SL RLC bearer associated with the SRB. The relay UE may receive an RRC reconfiguration complete message from the remote UE on the SL RLC bearer. The RRC reconfiguration message may include a local UE identity (ID) of the remote UE.

[0418] In one embodiment, after establishing an RRC connection between the relay UE and the network node, the RRC message may be transmitted by the relay UE. The SRB may be SRB1.

[0419] In one embodiment, the RRC reconfiguration complete message may be included by the relay UE in an adaptation layer PDU, and the header of the adaptation layer PDU may include the local UE ID of the remote UE.

[0420] Various aspects of the present disclosure have been described above. It should be understood that the teachings herein can be implemented in a wide variety of forms, and any specific structure, function, or both disclosed herein are only representative. Based on the teachings herein, it should be understood by those skilled in the art that the aspects disclosed herein can be implemented independently of any other aspects, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement a device or practice method. In addition, other structures, functions, or structures and functions other than one or more of the aspects described herein or different from one or more of the aspects described herein can be used to implement this device or practice this method. As an example of some of the above concepts, in some aspects, parallel channels can be established based on pulse repetition frequency. In some aspects, parallel channels can be established based on pulse position or offset. In some aspects, parallel channels can be established based on time hopping sequences. In some aspects, parallel channels can be established based on pulse repetition frequency, pulse position or offset, and time hopping sequences.

[0421] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0422] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, processors, components, circuits, and algorithm steps described in conjunction with the aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of both, which may be designed using source decoding or some other technique), various forms of program or design code incorporating instructions (which may be referred to herein for convenience as "software" or "software modules"), or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0423] In addition, the various illustrative logical blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented within or performed by an integrated circuit ("IC"), an access terminal, or an access point. An IC may include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute code or instructions residing within the IC, outside the IC, or both. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a combination of multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0424] It should be understood that any specific order or hierarchy of steps in any disclosed process is an example of an exemplary method. It should be understood that based on design preferences, the specific order or hierarchy of steps in a process can be rearranged while remaining within the scope of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy presented.

[0425] The steps of the method or algorithm described in conjunction with the various aspects disclosed herein can be implemented directly with hardware, with a software module executed by a processor, or with a combination of the two. Software modules (e.g., including executable instructions and related data) and other data may reside in a data memory, such as a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of computer-readable storage medium known in the art. An example storage medium may be coupled to a machine such as a computer / processor (for convenience, the machine may be referred to as a "processor" in this article) so that the processor can read information (e.g., code) from the storage medium and write information to the storage medium. An example storage medium may be integrated with a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user device. In an alternative, the processor and the storage medium may reside in a user device as discrete components. In addition, in some aspects, any suitable computer program product may include a computer-readable medium, which includes a code related to one or more aspects of the present disclosure. In some aspects, a computer program product may include packaging materials.

[0426] Although the present invention has been described in conjunction with various aspects, it will be appreciated that the present invention is capable of further modification. This application is intended to cover any changes, uses or adaptations of the present invention that generally follow the principles of the present invention and include such deviations from the present disclosure that are within the scope of known and customary practice in the technical field to which the present invention belongs.

Claims

1. A method for supporting remote user equipment to communicate with a network via a relay user equipment, characterized in that: include: The network node receives a measurement report from a remote user equipment, wherein the measurement report includes measurement results of a plurality of relay user equipments; The network node transmits a first radio resource control reconfiguration message to the remote user equipment to instruct the relay user equipment to perform a switch from the direct communication path to the indirect communication path; The network node establishes a radio resource control connection with the relay user equipment; The network node receives sidelink UE information from the relay user equipment to request a radio bearer configuration to support the remote user equipment to communicate with the network via the relay user equipment; the network node transmitting a second radio resource control reconfiguration message to the relay user equipment, wherein the second radio resource control reconfiguration message comprises a Uu configuration for a Uu radio link control bearer associated with a signalling radio bearer; as well as The network node receives a radio resource control reconfiguration complete message from the relay user equipment over the Uu radio link control bearer, wherein the radio resource control reconfiguration complete message is received by the relay user equipment from a remote user equipment.

2. The method according to claim 1, characterized in that The second radio resource control reconfiguration message includes a sidelink configuration for a sidelink radio link control bearer associated with the signaling radio bearer.

3. The method according to claim 2, characterized in that The radio resource control reconfiguration complete message is received by the relay user equipment from the remote user equipment on the sidelink radio link control bearer.

4. The method according to claim 1, characterized in that The second radio resource control reconfiguration message includes a local user equipment identity of the remote user equipment.

5. The method according to claim 1, characterized in that The sidelink UE information message is received from the relay user equipment after a radio resource control connection is established between the relay user equipment and the network node.

6. The method according to claim 1, characterized in that The signaling radio bearer is signaling radio bearer 1.

7. The method according to claim 1, characterized in that The radio resource control reconfiguration complete message is included by the relay user equipment in an adaptation layer protocol data unit, and wherein a header of the adaptation layer protocol data unit includes a local user equipment identity of the remote user equipment.

8. A network node, characterized in that: include: Control circuit; a processor installed in the control circuit; as well as a memory installed in the control circuit and operatively coupled to the processor; wherein the processor is configured to execute program code stored in the memory to: receiving a measurement report from a remote user equipment, wherein the measurement report includes measurement results of a plurality of relay user equipments; transmitting a first radio resource control reconfiguration message to the remote user equipment to instruct the relay user equipment to switch from the direct communication path to the indirect communication path; Establishing a radio resource control connection with the relay user equipment; receiving a sidelink UE information message from the relay user equipment to request a radio bearer configuration to support communication of the remote user equipment with a network via the relay user equipment; transmitting a second radio resource control reconfiguration message to the relay user equipment, wherein the second radio resource control reconfiguration message comprises a Uu configuration for a Uu radio link control bearer associated with a signalling radio bearer; as well as A radio resource control reconfiguration complete message is received from the relay user equipment over the Uu radio link control bearer, wherein the radio resource control reconfiguration complete message is received by the relay user equipment from a remote user equipment.

9. The network node according to claim 8, characterized in that: The second radio resource control reconfiguration message includes a sidelink configuration for a sidelink radio link control bearer associated with the signaling radio bearer.

10. The network node according to claim 9, characterized in that: The radio resource control reconfiguration complete message is received by the relay user equipment from the remote user equipment on the sidelink radio link control bearer.

11. The network node according to claim 8, characterized in that: The second radio resource control reconfiguration message includes a local user equipment identity of the remote user equipment.

12. The network node according to claim 8, characterized in that: The sidelink UE information message is received from the relay user equipment after a radio resource control connection is established between the relay user equipment and the network node.

13. The network node according to claim 8, characterized in that: The radio resource control reconfiguration complete message is included by the relay user equipment in an adaptation layer protocol data unit, and wherein a header of the adaptation layer protocol data unit includes a local user equipment identity of the remote user equipment.

14. The network node according to claim 8, characterized in that The signaling radio bearer is signaling radio bearer 1.

Images