Relay terminal identification for multi-hop relay communication links

Abstract

A network node maintains an active Radio Resource Control (RRC) context with each terminal of a plurality of terminals that will facilitate a multi-hop relay communication link between a remote terminal and the network node. The network node receives a sidelink information message identifying a L2ID of a remote terminal that has sent an RRC Setup Request message requesting an RRC connection to the network node. In response to receiving the sidelink information message, the network node sends a plurality of RRC Reconfiguration messages to establish the multi-hop communication link. The plurality of RRC Reconfiguration messages comprising an RRC Reconfiguration message to each terminal of the plurality of terminals and a remote terminal RRC Reconfiguration message to the remote terminal.

Description

TUTL 00413 PC-1- RELAY TERMINAL IDENTIFICATION FOR MULTI-HOP RELAY COMMUNICATION LINKSCLAIM OF PRIORITY

[0001] The present application claims priority to Provisional Application No.63 / 754,794 entitled “Path Identification in Multihop Relay”, filed February 06, 2025, and assigned to the assignee hereof and hereby expressly incorporated by reference in its entirety.FIELD

[0002] This invention generally relates to wireless communications and more particularly to relay terminal identification for multi-hop relay communication links.BACKGROUND

[0003] Many wireless communication systems that employ several base stations (network nodes) that provide wireless service to terminals (user equipment (UE) devices) enable sidelink communication between two or more terminals where the terminals can communicate directly with other terminals. In addition, one or more terminal can be used as relay devices to form relay communication links between terminal and a cell of a base station or between a source UE device and a destination UE device. A relayed connection between a remote UE and the network through a relay device is often referred to as a UE-to-Network (U2N) link. The U2N link includes a PC5 link between the relay device and the remote UE and Uu link between the relay device and a cell of a base station in the network.

[0004] In some conventional systems, the U2N communication links use a Sidelink Relay Adaptation Protocol (SRAP) defined by one or more revisions of the 3rdGeneration Partnership Project (3GPP) standards to transmit control and data signals over the PC5 link and the Uu link. The SRAP is used to perform bearer mapping (signaling radio bearers (SRBs) and data radio bearers (DRBs)) between the two links.TUTL 00413 PC-2- For U2N relays, a local Remote UE ID is included in both the PC5 SRAP header and the Uu SRAP header. The Layer 2 (L2) U2N Relay UE is configured by the gNB (network node) with the local Remote UE ID to be used in SRAP headers. In some situations, the U2N communication link may include more than one relay terminal.SUMMARY

[0005] A network node maintains an active Radio Resource Control (RRC) context with each terminal of a plurality of terminals that will facilitate a multi-hop relay communication link between a remote terminal and the network node. The network node receives a sidelink information message identifying a L2ID of a remote terminal that has sent an RRC Setup Request message requesting an RRC connection to the network node. In response to receiving the sidelink information message, the network node sends a plurality of RRC Reconfiguration messages to establish the multi-hop communication link. The plurality of RRC Reconfiguration messages comprising an RRC Reconfiguration message to each terminal of the plurality of terminals and a remote terminal RRC Reconfiguration message to the remote terminal.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 A is a block diagram of an example of a communication system where a multi-hop relay terminal sends sidelink information including a L2ID of a remote terminal initiating an RRC connection through a multi-hop relay communication link between the remote terminal and a network node.

[0007] FIG. 1 B is a block diagram of an example of the communication system where a last relay terminal sends, to the network node, an enhanced sidelink information message including the L2ID of the remote terminal.

[0008] FIG. 1 C is a block diagram of an example of the communication system where a last relay terminal sends, to the network node, an enhanced sidelink information message including the L2ID of the remote terminal using the Local ID of the intermediate relay terminal.TUTL 00413 PC-3-

[0009] FIG. 1 D is a block diagram of an example of the communication system where a first relay terminal sends, to the network node, a sidelink information message including the L2ID of the remote terminal through the last relay terminal and the network node responds with sending a plurality of RRC Reconfiguration messages to the plurality of terminals to establish the multi-hop relay communication link.

[0010] FIG. 2 is a block diagram of an example of a base station suitable for use as the network node providing the serving cell and as the network node providing the target cell, as well as network nodes providing the candidate target cells.

[0011] FIG. 3 is a block diagram of an example of a UE device suitable for use as each of the terminals including remote terminal and relay terminals.

[0012] FIG. 4A is a message flow diagram for an example where a last relay terminal sends, to the network node, an enhanced sidelink information message including the L2ID of the remote terminal.

[0013] FIG. 4B is a message flow diagram for an example where the first relay terminal sends, to the network node, a sidelink information message including the L2ID of the remote terminal through the last relay terminal and the network node responds with sending a plurality of RRC Reconfiguration messages to the plurality of terminals to establish the multi-hop relay communication link.

[0014] FIG. 5 is a flow chart of an example of method of managing a multi-hop relay communication link where a multi-hop relay terminal sends sidelink information including a L2ID of a remote terminal to a network node.

[0015] FIG. 6 is a flow chart of an example of method of managing a multi-hop relay communication link where a last relay terminal sends an enhanced sidelink information message including am L2ID of the remote terminal to the network node.

[0016] FIG. 7 is a flow chart of an example of method of managing a multi-hop relay communication link where a first intermediate relay terminal sends a sidelink information message including an L2ID of the remote terminal to the network node over a relay link through the last relay terminal.TUTL 00413 PC-4-

[0017] FIG. 8 is a flow chart of an example of method of managing a multi-hop relay communication link where a multi-hop relay terminal sends sidelink information including a L2ID of a remote terminal to a network node.

[0018] FIG. 9 is a flow chart of an example of method of managing a multi-hop relay communication link where a last relay terminal sends sidelink information including an L2ID of a remote terminal to a network node.

[0019] FIG. 10 is a flow chart of an example of method of managing a multi-hop relay communication link where a first intermediate relay terminal sends sidelink information including an L2ID of a remote terminal to a network node.DETAILED DESCRIPTION

[0020] As discussed above, a relay communication link can be established between a serving cell and a remote terminal (remote user equipment (UE) device) through one or more relay terminals (relay UE devices). The relay communication link, often referred to as a UE-to-Network (U2N) communication link, includes PC5 links between the remote terminal and the relay terminal and between relay terminals when more than one relay terminal forms the U2N communication link. The remote terminal is connected through a first PC5 link to an intermediate relay terminal. The intermediate relay terminal is connected through a second PC5 link to another relay terminal that may be another intermediate terminal or a last relay terminal connected over a Uu link to the serving cell of a network node (e.g., gNB). The relay communication link may include any number of intermediate relay terminals where a PC5 ingress link of each relay terminal is a PC5 egress link of an adjacent relay terminal. Except for the last relay terminal, therefore, each relay terminal in the U2N link has a PC5 ingress link to a terminal and a PC5 egress link to another terminal. The last relay terminal has a Uu egress link to the network node. The link between the remote terminal and the network node is typically referred to as a multi-hop relay communication link since more than one relay terminal facilitates the relayed connection between the remote terminal and the network node.TUTL 00413 PC-5-

[0021] In some situations, a remote terminal initiates an RRC connection to the serving cell through a multi-hop relay communication link when the relay terminals of the multi-hop communication link are the RRC CONNECTED state. The serving cell of the network node, therefore, is maintaining an active RRC context for each of the relay terminals when the remote terminal sends an RRC Setup Request to an intermediate relay terminal connected to the remote terminal via a PC5 link. After PC5 connection establishment of the multi-hop relay communication link, the RRC Setup Request is propagated through the multi-hop relay communication link to the serving cell of the network node. The last relay terminal forwards to RRC Setup Request to the network node and the network node sends a RRC Setup to the remote terminal via the multi-hop relay communication link. Currently, the communication specifications, such as the 3GPP specification, do not provide a defined procedure for establishing the RRC connection through the multi-hop relay communication link when a new remote terminal sends an RRC Setup Request. In conventional systems, therefore, the connection procedure does not provide a mechanism for the network node to identify the relay terminals (other than the last relay terminal) forming the multi-hop relay communication link.

[0022] In one example, a first remote terminal is connected through a first multi-hop relay communication link to the network node where the first multi-hop relay communication link is facilitated by a first intermediate relay terminal, a second intermediate relay terminal, and a last relay terminal when a second remote terminal sends an RRC Setup Request to the first intermediate relay terminal. The RRC Setup Request is to the network node through the second intermediate relay terminal and the last relay terminal without providing path information regarding the first intermediate relay terminal and the second intermediate relay terminal. Although conventional techniques allow for the network node to receive RRC Setup Request message, it is not clear how the network node identifies the intermediate relay terminals facilitating the multi-hop relay communication link. Since the network node must configure each relay terminal to establish the multi-hop relay communication link, a mechanism for identifying the relay path at the cell is needed.TUTL 00413 PC-6-

[0023] For the examples discussed herein, a multi-hop relay terminal provides L2ID information to the network node that allows the network node to determine the relay path to the remote terminal and identify the relay terminals facilitating the multi-hop relay communication link to remote terminal. In some examples discussed herein, the multi-hop relay terminal is the first intermediate relay terminal connected directly to the remote terminal via a PC5 link. In other examples, the multi-hop relay terminal is the last relay terminal connected directly to the network node via a Uu link.

[0024] In examples where the multi-hop relay terminal is the first intermediate relay terminal, the first intermediate relay terminal sends a sidelink information message, such as a SidelinkllEInformation message, to the network node through the other relay terminals forming the multi-hop relay communication path where the sidelink information message includes the L2ID for the remote terminal. Since the local ID of the first intermediate relay terminal and the path to the first intermediate relay terminal is known to the network node, the network node can determine the path to the remote terminal and send an RRC Reconfiguration message to each relay terminal.

[0025] In examples where the multi-hop relay terminal is the last relay terminal, the last relay terminal sends an enhanced sidelink information message to the network node over the Uu link where the enhanced sidelink information message includes the L2ID for the remote terminal and the L2ID of each intermediate relay terminal facilitating the path to the remote terminal. In response to a PC5-S link modification procedure between the last relay terminal and the intermediate relay terminal that is the child terminal of the last relay terminal, the last relay terminal sends the enhanced sidelink information message. The child intermediate relay terminal initiates the PC5-S link modification procedure by sending a Link Modification Request message to the last relay terminal that includes the L2ID of the remote terminal and of each additional intermediate relay terminal between the child intermediate relay terminal and the remote terminal. Accordingly, the network node identifies the L2ID of each relay terminal in the multi-hop relay communication link and configures the relay terminals and the remote terminal to establish the multi-hop relay communication link. In another example, the enhanced sidelink information message includes the L2ID for the remote terminalTUTL 00413 PC-7-without including the L2IDs of other relay terminals. The enhanced sidelink information message, however, includes the Local ID of the intermediate relay terminal connected to the remote terminal via the PC5 link in this situation. The network node identifies the path to the intermediate relay terminal based on the Local ID and can then determine the L2ID of each relay terminal in the multi-hop relay communication link.

[0026] A network node is any apparatus, equipment, device, or combination of devices, on the network side of the communication system that is connected to the communication network or is part of communication network. Some examples of a network node include a base station, a node B, an E-UTRA Node B, Evolved Node B, eNodeB, eNB, a New Generation eNB (ng-eNB), a gNodeB (also known as a gNB) in new radio (NR) technology, a macro station, pico station, and a femto station. The network node may form, or be a part of, the radio access network (RAN) that provides a connection between the core network and terminal communication devices. A RAN may be organized into three functional blocks including a Radio Unit (RU), a Distributed Unit (DU) and a Centralized Unit (CU). The RU transmits, receives, amplifies, and digitizes radio frequency signals and typically located near, or integrated into, the antenna. The DU and CU perform computations and / or processing to send and receive digitalized radio signals to and from the core network. The DU is typically located at or near the RU and the CU may be closer to the core network. The infrastructure or connection between the RU and the DU is often referred to as fronthaul and the infrastructure or connection between the DU and the CU is often referred to as a midhaul. The communication node, therefore, may perform the functions of one or more of the RU, DU and / or CU depending on the particular implementation.

[0027] A terminal communication device (terminal), such as a remote terminal and a relay terminal, is a communication device on the terminal side of the communication system and is sometimes referred to as user equipment (UE), a UE device, a terminal device, wireless mobile device, wireless communication device and other terms. Some examples of a terminal communication device include a mobile phone, a smart phone, a personal digital assistant (PDA), tablet, and laptop computer. In some situations, the terminal communication device is a machine type communication (MTC) communicationTUTL 00413 PC-8-device or Internet-of-Things (IOT) device. In addition, the terminal communication device may be, or may be a part of, a wearable device or a vehicle where the vehicle may be terrestrial vehicle, watercraft, or aircraft (including unmanned aerial vehicles). The terminal communication device, therefore, is any fixed, mobile, or portable equipment that performs the functions of the terminal device described herein.

[0028] FIG. 1 A is a block diagram of an example of a communication system 100 where a multi-hop relay terminal 102 sends sidelink information 104 including a L2ID of a remote terminal 106 initiating an RRC connection through a multi-hop relay communication link 108 between the remote terminal 106 and a network node 110 and where the multi-hop relay communication link 108 will be facilitated by a plurality of relay terminals comprising the multi-hop relay terminal 102. The multi-hop relay communication link 108 is facilitated by at least two relay terminals. For the example of FIG. 1A, therefore, the multi-hop relay communication link 108 is facilitated by at least one additional relay terminal that is not shown in FIG. 1A. A multi-hop relay terminal 102 may be a first intermediate relay terminal connected directly to the remote terminal 106 via a PC5 link, may be a last relay terminal connected directly to the network node 110 via a Uu link, or may be an intermediate relay terminal connected to two other relay terminals via PC5 links. Accordingly, FIG. 1A shows each arrow representing a transmitted message having a dashed line portion to indicate that the message may not be directly transmitted to the receiving device and that another relay terminal may forward the message or retransmit information in another message, depending on the particular situation.

[0029] For the examples discussed herein, the plurality of relay terminals are in the RRC CONNECTED state with the network node 110 when the remote terminal sends an RRC Setup Request message 112 to the first intermediate relay terminal. The network node 110, therefore, is maintaining an active RRC context with each terminal of the plurality of terminals at the time the remote terminal 106 sends the RRC Setup Request message 112 to the network node 110 to initiate establishment of an RRC connection over the multi-hop relay communication link 108 between the remote terminal 106 and the network node 110. An active RRC context maintained (stored) at the network node 110 typically includes the current RRC configuration, the radioTUTL 00413 PC-9-security context, and the Cell Radio-Network Temporary Identifier (C-RNTI) of the terminal. The multi-hop relay terminal 102 determines the remote terminal 106 has transmitted the RRC Setup Request message 112 and in response, transmits a sidelink information message 104 identifying a Layer 2 identification (L2ID) of the remote terminal 106. In some situations, the multi-hop relay terminal 102 determines the remote terminal 106 has transmitted the RRC Setup Request message 112 based on the receipt of the RRC Setup Request message 112 from the remote terminal 106 over the direct PC5 link (i.e. , over the SL-RLC0). An example of such situations is discussed below with reference to FIG. 1C. In other situations, the multi-hop relay terminal 102 determines the remote terminal 106 has transmitted the RRC Setup Request message 112 based on the initiation of a PC5 link modification procedure by a child relay terminal of the multi-hop relay terminal 102. An example of such situations is discussed below with reference to FIG. 1B.

[0030] The network node 110 receives the sidelink information message 104 identifying the Layer 2 identification (L2ID) of the remote terminal 106 and determines the identity of each relay terminal of the plurality of relay terminals and, in response to receiving the sidelink information message, sends a plurality of RRC Reconfiguration messages 116 to enable the multi-hop communication link 108 between the remote terminal 106 and the network node 110. The plurality of RRC Reconfiguration messages 112 comprises an RRC Reconfiguration message to each relay terminal of the plurality of relay terminals and a remote terminal RRC Reconfiguration message to the remote terminal 106.

[0031] The multi-hop relay terminal 102 applies the RRC Reconfiguration assigned to the multi-hop relay terminal 102 and forwards, to the remote terminal 106, the RRC Reconfiguration information assigned to the remote terminal 106. Where the multi-hop relay terminal 102 is not the first intermediate relay terminal, the multi-hop relay terminal 102 forwards the RRC Reconfiguration information assigned to relay terminal(s) between the remote terminal 106 and the multi-hop relay terminal 102.

[0032] After all the relay terminals of the plurality are RRC reconfigured to facilitate the multi-hop relay communication link 108, the network node 110 sends an RRC Setup message 118 to the remote terminal 106. The remote terminal 106 sends an RRCTUTL 00413 PC-10- Setup Complete message 120 through the multi-hop relay communication link 108 to the network node 110 and the RRC connection to the remote terminal 110 is established.

[0033] FIG. 1 B is a block diagram of an example of the communication system 100 where a last relay terminal 130 sends, to the network node 110, an enhanced sidelink information message 132 including the L2ID of the remote terminal 106. Accordingly, the situation described with reference to FG. 1 B is an example of the techniques described above with reference to FIG. 1 A where the last relay terminal 130 is the multihop relay terminal 102 and the sidelink information 104 is transmitted in an enhanced sidelink information message 132. In addition to the L2ID of the remote terminal (RT L2ID), the enhanced sidelink information message 132 includes the L2ID of each intermediate relay terminal between the last relay terminal 130 and the remote terminal 106. For the example, the multi-hop relay communication link 108 is facilitated by the last relay terminal 130 and a first intermediate relay terminal 134. Accordingly, the enhanced sidelink information message 132 conveys the L2ID of the intermediate relay terminal 134 (IRT L2ID) and the RT L2ID.

[0034] The last relay terminal 130 is connected to the network directly through a Uu link 136, the intermediate relay terminal 134 is connected directly to the remote terminal 106 through a PC5 link 138, and the intermediate relay terminal 134 is connected to the last relay terminal 130 through a PC5 link 140. After the remote terminal 106 performs relay (re)selection and establishes the PC5 link 138, the remote terminal 106 sends the RRC Setup Request message 112 to the intermediate relay terminal 134. In response, the intermediate relay terminal 134 initiates a PC5-S link modification 142 with the last relay terminal 130 where the modification conveys the RT L2ID. For the example, the intermediate relay terminal 134 sends a Link Modification Request comprising the RT L2ID to initiate the PC5-S link modification 142.

[0035] After the PC5-S link modification is complete, the last relay terminal 130 generates the enhanced sidelink information message 132 that comprises the RT L2ID. For the example, the last relay terminal generates an enhanced SidelinkUEInformation (SUI) message that includes the RT L2ID. As compared to current 3GPP specification revisions, the enhanced SidelinkUEInformation (SUI) message includes the RT L2IDTUTL 00413 PC-11-and the IRT L2ID where conventional SidelinkUEInformation (SUI) messages can only convey a single L2ID, and only the L2ID of the relay terminal it is directly PC5 connected to.

[0036] In response to the enhanced sidelink information message 132, the network node generates and sends the plurality of RRC Reconfiguration messages to configure the last relay terminal 130, the intermediate relay terminal 134 and the remote terminal 106. Therefore, the last relay terminal (LRT) RRC Reconfiguration message is transmitted over the Uu link to the last relay terminal 110. The last relay terminal RRC Reconfiguration message comprises a mapping of ingress Sidelink Radio Link Control (SL-RLC) entities to egress Uu RLC entities for Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) traffic and a Local ID for inclusion in Sidelink Relay Adaptation Protocol (SRAP) headers. An intermediate relay terminal (IRT) RRC Reconfiguration message is sent through the last relay terminal 110 to the intermediate relay terminal 134. The IRT RRC Reconfiguration message comprises SL-RLC entities for ingress and egress for SRB and DRB traffic and the Local ID. The remote terminal (RT) RRC Reconfiguration message is sent through the last relay terminal and the intermediate relay terminal to the remote terminal. The RT RRC Reconfiguration message comprises SL-RLC entities for egress for SRB and DRB traffic and the Local ID. The Local ID for delivery of SRB and DRB intended for the remote terminal differs from the Local ID used to deliver SRB and DRB intended for the intermediate relay terminal.

[0037] After the terminals are configured, the network node sends the RRC Setup message to the remote terminal 106 through the multi-hop relay communication link 108 facilitated by the relay terminals 130, 134. The remote terminal 106 responds with the RRC Setup complete to establish the RRC connection with the network node 110.

[0038] FIG. 1 C is a block diagram of an example of the communication system 100 where a last relay terminal 130 sends, to the network node 110, an enhanced sidelink information message 152 including the L2ID of the remote terminal 106 and the Local ID of the intermediate relay terminal 134. Accordingly, the situation described with reference to FG. 1 C is an example of the techniques described above with reference to FIG. 1 A where the last relay terminal 130 is the multi-hop relay terminal 102 and the sidelink information 104 is transmitted in an enhanced sidelink information messageTUTL 00413 PC-12- 152. The example of FIG. 1 C is similar to the example of FIG. 1 B except that the enhanced sidelink information message 152 is transmitted by including the Local ID of the intermediate relay terminal 134 without the L2IDs of any other relay terminal (e.g., IRT L2ID). Instead, the enhanced sidelink information message includes the Local ID of the intermediate relay terminal. For the example, the multi-hop relay communication link 108 is facilitated by the last relay terminal 130 and a first intermediate relay terminal 134. Accordingly, the enhanced sidelink information message 152 conveys the Local ID of the intermediate relay terminal 134 and the RT L2ID which allows the network node to identify the relay terminals that will facilitate the multi-hop relay communication link.

[0039] FIG. 1 D is a block diagram of an example of the communication system 100 where a first relay terminal 134 sends, to the network node 110, a sidelink information message 132 including the L2ID of the remote terminal 106 through the last relay terminal 130 and the network node 110 responds with sending a plurality of RRC Reconfiguration messages to the plurality of terminals to establish the multi-hop relay communication link 108. Accordingly, the situation described with reference to FIG. 1D is an example of the techniques described above with reference to FIG. 1 A where the first intermediate relay terminal 134 is the multi-hop relay terminal 102 and the sidelink information 104 is transmitted in a sidelink information message 160.

[0040] For the example, the multi-hop relay communication link 108 is facilitated by the last relay terminal 130 and a first intermediate relay terminal 134. The last relay terminal 130 is connected to the network directly through the Uu link 136, the intermediate relay terminal 134 is connected directly to the remote terminal 106 through the PC5 link 138, and the intermediate relay terminal 134 is connected to the last relay terminal 130 through the PC5 link 140. After the remote terminal 106 performs relay (re)selection and establishes the PC5 link 138, the remote terminal 106 sends the RRC Setup Request message 112 to the intermediate relay terminal 134. In response, the intermediate relay terminal 134 generates and sends the sidelink information message 160. For the example, the intermediate relay terminal 134 generates a SidelinkUEInformation (SUI) message that includes the RT L2ID. The SidelinkUEInformation (SUI) message 160 is transmitted through the last relay terminal 130.TUTL 00413 PC-13-

[0041] In response to the sidelink information message 160, the network node generates and sends the plurality of RRC Reconfiguration messages to configure the last relay terminal 130, the intermediate relay terminal 134 and the remote terminal 106. After the terminals are configured, the network node sends the RRC Setup message to the remote terminal 106 through the multi-hop relay communication link 108 facilitated by the relay terminals 130, 134. The remote terminal 106 responds with the RRC Setup complete to establish the RRC connection with the network node 110.

[0042] For the example of FIG. 1 D, therefore, the network node 110 configures all of the relay terminals in response to receipt of a single Sill message 160, and the only relay terminal of the plurality of relay terminals facilitating the multi-hop relay communication link is the first intermediate relay terminal.

[0043] FIG. 2 is a block diagram of an example of a base station 200 suitable for use as the network node 110 providing the serving cell. The base station 200 includes a controller 204, transceiver 205 that includes a transmitter 206 and receiver 208, and an antenna 210, as well as other electronics, hardware, and code. The base station 200 is any fixed, mobile, or portable equipment that performs the functions described herein. The various functions and operations of the blocks described with reference to the network nodes providing cells and base station 200 may be implemented in any number of devices, circuits, or elements. Two or more of the functional blocks may be integrated in a single device, and the functions described as performed in any single device may be implemented over several devices. The base station 200 may be a fixed device or apparatus that is installed at a particular location at the time of system deployment. Examples of such equipment include fixed base stations or fixed transceiver stations. Although the base station 200 may be referred to by different terms, the base station 200 is typically referred to as a gNodeB or gNB when operating in accordance with one or more communication specifications of the 3GPP V2X operation. In some situations, the base station 200 may be mobile equipment that is temporarily installed at a particular location. Some examples of such equipment include mobile transceiver stations that may include power generating equipment such as electric generators, solar panels, and / or batteries. Larger and heavier versions of suchTUTL 00413 PC-14-equipment may be transported by trailer. In still other situations, the base station 200 may be a portable device that is not fixed to any particular location.

[0044] The controller 204 includes any combination of hardware, software, and / or firmware for executing the functions described herein as well as facilitating the overall functionality of the base station 200. An example of a suitable controller 204 includes code running on a microprocessor or processor arrangement connected to memory. The transmitter 206 includes electronics configured to transmit wireless signals. In some situations, the transmitter 206 may include multiple transmitters. The receiver 208 includes electronics configured to receive wireless signals. In some situations, the receiver 208 may include multiple receivers. The receiver 208 may receive signals through multiple antennas or through a selected antenna of a plurality of antennas of the antenna 210. The antenna 210 may include separate transmit and receive antennas or separate arrays in some situations.

[0045] The transmitter 206 and receiver 208 in the example of FIG. 2 perform radio frequency (RF) processing including modulation and demodulation. The receiver 208, therefore, may include components such as low noise amplifiers (LNAs) and filters. The transmitter 206 may include filters and amplifiers. Other components may include isolators, matching circuits, and other RF components. These components in combination or cooperation with other components perform the base station functions. The required components may depend on the particular functionality required by the base station.

[0046] The transmitter 206 includes a modulator (not shown), and the receiver 208 includes a demodulator (not shown). The modulator modulates the signals to be transmitted as part of the downlink signals and can apply any one of a plurality of modulation orders. The demodulator demodulates any uplink signals received at the base station 200 in accordance with one of a plurality of modulation orders.

[0047] The base station 200 includes a communication interface 212 for transmitting and receiving messages with other base stations and network nodes. The communication interface 212 may be connected to a backhaul or network enabling communication with other base stations. In some situations, the link between base stations may include at least some wireless portions. The communication interface 212,TUTL 00413 PC-15-therefore, may include wireless communication functionality and may utilize some of the components of the transmitter 206 and / or receiver 208.

[0048] FIG. 3 is a block diagram of an example of a user equipment (UE) device 300 suitable for use as each of the terminals including the remote terminal 106 and the relay terminals 102, 130, 134. In some examples, the UE device 300 is any wireless communication device such as a mobile phone, a transceiver modem, a personal digital assistant (PDA), a tablet, or a smartphone. In other examples, the UE device 300 is a machine type communication (MTC) communication device or Internet-of-Things (IOT) device. The UE device 300, therefore is any fixed, mobile, or portable equipment that performs the functions described herein. The various functions and operations of the blocks described with reference to UE device 300 may be implemented in any number of devices, circuits, or elements. Two or more of the functional blocks may be integrated in a single device, and the functions described as performed in any single device may be implemented over several devices.

[0049] The UE device 300 includes at least a controller 302, a transmitter 304 and a receiver 306. The controller 302 includes any combination of hardware, software, and / or firmware for executing the functions described herein as well as facilitating the overall functionality of a communication device. An example of a suitable controller 302 includes code running on a microprocessor or processor arrangement connected to memory 310. The transmitter 304 includes electronics configured to transmit wireless signals. In some situations, the transmitter 304 may include multiple transmitters. The receiver 306 includes electronics configured to receive wireless signals. In some situations, the receiver 306 may include multiple receivers. The receiver 306 and transmitter 304 receive and transmit signals, respectively, through the antenna 308. The antenna 308 may include separate transmit and receive antennas. In some circumstances, the antenna 308 may include multiple transmit and receive antennas.

[0050] The transmitter 304 and receiver 306 in the example of FIG. 3 perform radio frequency (RF) processing including modulation and demodulation. The receiver 306, therefore, may include components such as low noise amplifiers (LNAs) and filters. The transmitter 304 may include filters and amplifiers. Other components may includeTUTL 00413 PC-16-isolators, matching circuits, and other RF components. These components in combination or cooperation with other components perform the communication device functions. The required components may depend on the particular functionality required by the communication device.

[0051] The transmitter 304 includes a modulator (not shown), and the receiver 306 includes a demodulator (not shown). The modulator can apply any one of a plurality of modulation orders to modulate the signals to be transmitted as part of the uplink signals. The demodulator demodulates the downlink signals in accordance with one of a plurality of modulation orders.

[0052] The UE device 300 is capable of transmitting and receiving sidelink signals to and from other UE devices as well as communicating with a base station. The controller 302, in conjunction with the receiver 306, measures signals, such as discovery signals, transmitted by nearby UE devices to facilitate relay selection and relay reselection.Information related to sidelink and other communication, well as other information, may be stored in the memory 310. Some of the stored information may be transmitted to the base station 106 when the UE device 300 reports information.

[0053] FIG. 4A is a message flow diagram 400 for an example where a last relay terminal 130 sends, to the network node 110, an enhanced sidelink information message 132 including the L2ID of the remote terminal 106. Accordingly, the messaging example of FIG. 4A is an example of messaging in the example of FIG. 1 B.

[0054] At event 402, the remote terminal maintains a non-RRC_CONNECTED state. Accordingly, the remote terminal 106 is in RRC IDLE or RRC INACTIVE to begin the example.

[0055] At event 404, the last relay terminal 130 maintains an RRC CONNECTED state with the network node 110. The network node 110 maintains and active context for the last relay terminal 130 at event 406.

[0056] At event 408, the intermediate relay terminal 134 maintains an RRC CONNECTED state with the network node 110. The network node 110 maintains and active context for the intermediate relay terminal 134 at event 410.TUTL 00413 PC-17-

[0057] At event 412, the remote terminal 106 receives discovery signals form candidate relay terminals and performs relay reselection. The remote terminal 106 identifies a preferred relay path to the network node 110 that includes the intermediate relay terminal 134 and the last relay terminal 130.

[0058] At transmission 414, the remote terminal 106 sends a Direct Communication Request message, a PC5-S message to initiate the establishment of PC5 link between the intermediate relay terminal and the remote terminal 106. After the PC5 link is established, the remote terminal 106 sends an RRC Setup Request to the intermediate relay terminal 134 at transmission 416.

[0059] At event 418, a PC5-S link modification procedure is performed which includes identifying the remote terminal 106 to the last relay terminal 130. For the example, the PC5 link modification is initiated by a Link Modification Request comprising the remote terminal L2ID (RT L2ID).

[0060] In response to the PC5-S link modification, the last relay terminal 130 generates and transmits an enhanced SUI message including the RT L2ID and the L2ID of the intermediate relay terminal (IRT L2ID) at transmission 420. The enhanced SUI message is received at the network node 110. Based on the RT L2ID and the IRT L2ID, the network node identifies the plurality of terminals that will facilitate the multi-hop relay communication link 108. For the example therefore, the network node 110 determines that the intermediate relay terminal 134 and the last relay terminal 130 will facilitate the multi-hop relay communication link 108. In another example, as discussed with reference to FIG. 1 C, the enhanced SUI message may include the Local ID of the intermediate relay terminal and the L2ID of the intermediate relay terminal may be omitted.

[0061] In response to the enhanced SUI message, the network node 110 sends a plurality of RRC Reconfiguration messages. At transmission 422, the network node 110 sends a last relay terminal (LRT) RRC Reconfiguration message to the last relay terminal. After forwarding other RRC Reconfiguration information directed to the other terminals, the last relay terminal applies the RRC configuration provided the LRT RRC Reconfiguration message.TUTL 00413 PC-18-

[0062] At transmission 424, the network node 110 sends an intermediate relay terminal (IRT) RRC Reconfiguration message to the last relay terminal. At transmission 426, the network node 110 sends a remote terminal (RT) RRC Reconfiguration message to the last relay terminal.

[0063] At transmission 428, the last relay terminal 130 forwards the confirmation information for the remote terminal and the intermediate relay terminal to the intermediate relay terminal. IRT configuration information received in the IRT RRC Reconfiguration message and the RT configuration information received in the RT RRC Reconfiguration message are forwarded in the reconfiguration message to the intermediate relay terminal 134.

[0064] At transmission 430, the intermediate relay terminal 134 forwards the confirmation information for the remote terminal to the remote terminal 106. The RT configuration information received in transmission 428 is forwarded in the Reconfiguration message to the remote terminal 106 at transmission 430.

[0065] After forwarding other RRC Reconfiguration information directed to the other terminals, the relay terminals apply the RRC configuration provided by the network node in the RRC Reconfiguration messages to establish the multi-hop relay communication link 108.

[0066] At transmission 432, the intermediate relay terminal 134 forwards the RRC Setup Request to the network node. After applying the RRC Reconfiguration, the intermediate relay terminal 134 sends to the last relay terminal an encapsulated remote terminal RRC Setup Request message within the SRAP layer using the Local ID assigned to the remote terminal .The last relay terminal forwards the encapsulated remote terminal RRC Setup Request message within a SRAP Control PDU, along with the remote terminal’s Local ID in the SRAP layer and transmits the contents to the cell using the configured RLC on the Uu link at transmission 434..

[0067] At transmission 436, the network node 110 sends an RRC Setup message to the remote terminal 106 via the last relay terminal 130 and the intermediate relay terminal 134. The remote terminal 106 responds with an RRC Setup Complete message at transmission 438 to establish the RRC connection between the remoteTUTL 00413 PC-19-terminal 106 and the network node 110, thereby placing the remote terminal 106 in the RRC CONNECTED state.

[0068] FIG. 4B is a message flow diagram 450 for an example where the first relay terminal 134 sends, to the network node 110, a sidelink information message 132 including the L2ID of the remote terminal 106 through the last relay terminal 130 and the network node 110 responds with sending a plurality of RRC Reconfiguration messages to the plurality of terminals to establish the multi-hop relay communication link 108. Accordingly, the messaging example of FIG. 4B is an example of messaging in the example of FIG. 1D. The events and transmissions labeled with the same reference numbers as in FIG. 4B are performed in the same manner as described with reference to FIG. 4A. For the example of FIG. 4B, therefore, the remote terminal 106 is initially in a non-RRC CONNECTED state and event 402 and the intermediate relay terminal 134 and the last relay terminal 130 are in the RRC CONNECTED state at events 404, 406, 408, 410. The remote terminal performs discovery and relay selection at event 412 and established a PC5 link to the intermediate relay terminal 134 before sending the RRC Setup Request at transmission 416.

[0069] At transmission 452, the intermediate relay terminal 134 generates and sends the sidelink information message 160. For the example, the intermediate relay terminal 134 generates a SidelinkllEInformation (Sill) message that includes the RT L2ID. The SidelinkUEInformation (SUI) message is transmitted through the last relay terminal 130 and received at the network node 110.

[0070] Transmissions 422, 424, 426, 428, 430, 432, 434, 436 and 438 are performed as described above with reference to FIG. 4A. In response to the sidelink information message 160, therefore, the network node 110 generates and sends the plurality of RRC Reconfiguration messages to configure the last relay terminal 130, the intermediate relay terminal 134 and the remote terminal 106. After the terminals are configured, the network node 110 sends the RRC Setup message to the remote terminal 106 through the multi-hop relay communication link 108 facilitated by the relay terminals 132, 134. The remote terminal 106 responds with the RRC Setup complete to establish the RRC connection with the network node 110.TUTL 00413 PC-20-

[0071] For the example of FIG. 4B, therefore, the network node 110 configures all of the relay terminals in response to receipt of a single Sill message 160 and the only relay terminal of the plurality of relay terminals facilitating the multi-hop relay communication link is the first intermediate relay terminal 134.

[0072] FIG. 5 is a flow chart of an example of method of managing a multi-hop relay communication link where a multi-hop relay terminal 102 sends sidelink information 104 including an L2ID of a remote terminal 106 to a network node 110. The method may be performed in a system such as the system 100 discussed herein. For the example, the method is performed by a network node, such as the network node 110. The method may be performed using any of several techniques involving any combination of software, hardware, and firmware. For example, software code running on electronics including a processor, computer or other processor arrangement within the network node may facilitate the generation, formatting, reception and transmission of signals and messages. One or more of the steps may be omitted, combined, performed in parallel, or performed in a different order than that described herein or shown in FIG. 5. In still further examples, additional steps may be added that are not explicitly described in connection with the example discussed with reference to FIG. 5.

[0073] At step 502, an active RRC context is maintained for each terminal of a plurality of terminals that will facilitate the multi-hop relay communication link 108 between a remote terminal 106 and the network node 110. For the example, the network node 110 maintains an active RRC context for the last relay terminal 130 and each intermediate relay terminal 134 in accordance with known techniques.

[0074] At step 504, a sidelink information message is received from a multi-hop relay terminal of the plurality of relay terminals where the sidelink information message comprises the L2ID of the remote terminal (RT L2ID). In some situations, the multi-hop relay terminal is the first intermediate relay terminal and the sidelink information message is transmitted over the relay link through the last relay terminal. In another situations, the multi-hop relay terminal is the last relay terminal and the sidelink information message is an enhanced sidelink information message that comprises the RT L2ID and the L2ID(s) of the intermediate relay terminal(s) between the remoteTUTL 00413 PC-21-terminal and the network node. In still other situations, the enhanced sidelink information message includes the RT L2ID and the Local ID of the intermediate relay terminal (first intermediate relay terminal) directly connected to the remote terminal via a PC5 link.

[0075] At step 506, plurality of RRC Reconfiguration messages are transmitted in response to receipt of the sidelink information message. After receiving the sidelink information message including the L2ID of the remote terminal, the network node identifies the relay terminals that will facilitate the multi-hop relay communication link. In some situations, the sidelink information message directly identifies the relay terminals with their L2IDs. In other situations, the sidelink information message provides information to the network node that allows the network node to identify, with other information, the relay terminals. The plurality of RRC Reconfiguration messages include a RT RRC Reconfiguration message for configuring the remote terminal, an LRT RRC Reconfiguration message for configuring the last relay terminal and an IRT RRC reconfiguration message for each intermediate relay terminal. The RRC configurations of the plurality of RRC Reconfiguration messages enables the multi-hop relay communication link. The network node 110 transmits each RRC Reconfiguration message to the last relay terminal where the last relay terminal forwards the RRC configuration information directed to other terminals in another RRC Reconfiguration message transmitted to the child intermediate relay terminal.

[0076] At step 508, an RRC Setup message is sent to the remote terminal over the multi-hop relay communication link.

[0077] At step 510, an RRC Setup Complete message is received from the remote terminal over the multi-hop relay communication link.

[0078] FIG. 6 is a flow chart of an example of method of managing a multi-hop relay communication link where a last relay terminal 102 sends an enhanced sidelink information message including am L2ID of the remote terminal 106 to the network node 110. The method may be performed in a system such as the system 100 discussed herein. For the example, the method is performed by a network node, such as the network node 110. The method may be performed using any of several techniquesTUTL 00413 PC-22-involving any combination of software, hardware, and firmware. For example, software code running on electronics including a processor, computer or other processor arrangement within the terminal may facilitate the generation, formatting, reception and transmission of signals and messages. One or more of the steps may be omitted, combined, performed in parallel, or performed in a different order than that described herein or shown in FIG. 6. In still further examples, additional steps may be added that are not explicitly described in connection with the example discussed with reference to FIG. 6.

[0079] At step 602, an active RRC context is maintained for each terminal of a plurality of terminals that will facilitate the multi-hop relay communication link 108 between a remote terminal 106 and the network node 110. For the example, the network node 110 maintains an active RRC context for the last relay terminal 130 and each intermediate relay terminal 134 in accordance with known techniques.

[0080] At step 604, an enhanced sidelink information message is received where the enhanced sidelink information message identifies the L2ID of the remote terminal and each intermediate relay terminal of the plurality of terminals. For the example, network node 110 receives, from the last relay terminal, an enhanced SidelinkUEInformation message comprising the L2ID of the remote terminal and the L2ID of each intermediate relay terminal that will facilitate the multi-hop relay communication link 108. In some situations, the Local ID of the first intermediate relay terminal is included in the enhanced sidelink information message instead of the L2IDs.

[0081] At step 606, plurality of RRC Reconfiguration messages are transmitted in response to receipt of the sidelink information message. The plurality of RRC Reconfiguration messages include a RT RRC Reconfiguration message for configuring the remote terminal, an LRT RRC Reconfiguration message for configuring the last relay terminal and an IRT RRC reconfiguration message for each intermediate relay terminal. The RRC configurations of the plurality of RRC Reconfiguration messages enables the multi-hop relay communication link. The network node 110 transmits each RRC Reconfiguration message to the last relay terminal where the last relay terminalTUTL 00413 PC-23-forwards the RRC configuration information directed to other terminals in another RRC Reconfiguration message transmitted to the child intermediate relay terminal.

[0082] At step 608, an RRC Setup message is sent to the remote terminal over the multi-hop relay communication link.

[0083] At step 610, an RRC Setup Complete message is received from the remote terminal over the multi-hop relay communication link.

[0084] FIG. 7 is a flow chart of an example of method of managing a multi-hop relay communication link where a first intermediate relay terminal 102 sends a sidelink information message including an L2ID of the remote terminal 106 to the network node 110 over a relay link through the last relay terminal. The method may be performed in a system such as the system 100 discussed herein. For the example, the method is performed by a network node, such as the network node 110. The method may be performed using any of several techniques involving any combination of software, hardware, and firmware. For example, software code running on electronics including a processor, computer or other processor arrangement within the terminal may facilitate the generation, formatting, reception and transmission of signals and messages. One or more of the steps may be omitted, combined, performed in parallel, or performed in a different order than that described herein or shown in FIG. 7. In still further examples, additional steps may be added that are not explicitly described in connection with the example discussed with reference to FIG. 7.

[0085] At step 702, an active RRC context is maintained for each terminal of a plurality of terminals that will facilitate the multi-hop relay communication link 108 between a remote terminal 106 and the network node 110. For the example, the network node 110 maintains an active RRC context for the last relay terminal 130 and each intermediate relay terminal 134 in accordance with known techniques.

[0086] At step 704, a sidelink information message is received from the first intermediate relay terminal where the sidelink information message identifies the L2ID of the remote terminal. For the example, network node 110 receives, from the first intermediate relay terminal over the relay link through the last relay terminal, a SidelinkllEInformation message comprising the L2ID of the remote terminal.TUTL 00413 PC-24-

[0087] At step 705, the network node 110 identifies each relay terminal of the plurality of terminals that will facilitate the multi-hop relay communication link. The network node is able to identify the terminals since the network node is aware the identity of the first intermediate relay terminal and aware of the identity of each relay terminal facilitating the relay path from the network node to the first intermediate relay terminal.

[0088] At step 706, plurality of RRC Reconfiguration messages are transmitted in response to receipt of the sidelink information message. The plurality of RRC Reconfiguration messages include a RT RRC Reconfiguration message for configuring the remote terminal, an LRT RRC Reconfiguration message for configuring the last relay terminal and an IRT RRC reconfiguration message for each intermediate relay terminal. The RRC configurations of the plurality of RRC Reconfiguration messages enables the multi-hop relay communication link. The network node 110 transmits each RRC Reconfiguration message to the last relay terminal where the last relay terminal forwards the RRC configuration information directed to other terminals in another RRC Reconfiguration message transmitted to the child intermediate relay terminal.

[0089] At step 708, an RRC Setup message is sent to the remote terminal over the multi-hop relay communication link.

[0090] At step 710, an RRC Setup Complete message is received from the remote terminal over the multi-hop relay communication link.

[0091] FIG. 8 is a flow chart of an example of method of managing a multi-hop relay communication link where a multi-hop relay terminal 102 sends sidelink information 104 including a L2ID of a remote terminal 106 to a network node 110. The method may be performed in a system such as the system 100 discussed herein. For the example, the method is performed by a multi-hop relay terminal, such as the multi-hop relay terminal 102. The method may be performed using any of several techniques involving any combination of software, hardware, and firmware. For example, software code running on electronics including a processor, computer or other processor arrangement within the multi-hop relay terminal may facilitate the generation, formatting, reception and transmission of signals and messages. One or more of the steps may be omitted,TUTL 00413 PC-25-combined, performed in parallel, or performed in a different order than that described herein or shown in FIG. 8. In still further examples, additional steps may be added that are not explicitly described in connection with the example discussed with reference to FIG. 8.

[0092] At step 802, an active RRC CONNECTED state is maintained at the multi-hop relay terminal 102 with the network node 110. For the example, all the relay terminals that will facilitate the multi-hop relay communication link are in the RRC CONNECTED state with the network node 110.

[0093] At step 804, the multi-hop relay terminal 102 determines that the remote terminal has transmitted an RRC Setup Request to request an RRC connection to the network node 110. The remote terminal transmits the RRC Setup Request to initiate establishment of the RRC connection over the multi-hop relay communication link between the remote terminal and the network node. In some situations, the multi-hop relay terminal is the first intermediate relay terminal that determines the RRC Setup Request was transmitted by receiving the RRC Setup Request from the remote terminal. In another situations, the multi-hop relay terminal is the last relay terminal that determines the RRC Setup Request was transmitted based on a PC5-S link modification procedure initiated by transmission of a Link Modification Request from the child relay terminal of the last relay terminal.

[0094] At step 806, sidelink information is transmitted to the network node in response to the determination that the RRC Setup Request was transmitted by the remote terminal. The sidelink information identifies the L2ID of the remote terminal. Where the multi-hop relay terminal is the last relay terminal, the sidelink information is transmitted in an enhanced sidelink information message that comprises the RT L2ID and the L2ID(s) of the intermediate relay terminal(s) between the remote terminal and the network node. Where the multi-hop relay terminal is the first intermediate relay terminal, the sidelink information is transmitted in a sidelink information message comprising the L2ID of the remote terminal (RT L2ID).

[0095] At step 808, an RT RRC Reconfiguration message for configuring the remote terminal is received. Where the multi-hop relay terminal is the last relay terminal, the RTTUTL 00413 PC-26- RRC Reconfiguration message is received from the network node over the Uu link. Where the multi-hop relay terminal is the first intermediate relay terminal, the RRC Reconfiguration message is received from a parent relay terminal over a PC5 link.

[0096] At step 810, an RRC Reconfiguration message is generated and transmitted to the child terminal of the multi-hop relay terminal where the RRC Reconfiguration message includes the RRC configuration information for the remote terminal. Where the multi-hop relay terminal is the last relay terminal, the child terminal is an intermediate relay terminal and the RRC Reconfiguration message also includes the RRC configuration information for the intermediate relay terminal(s). Where the multi-hop relay terminal is the first intermediate relay terminal, the child terminal is a remote terminal and the RRC Reconfiguration message is transmitted to the remote terminal over the PC5 link.

[0097] FIG. 9 is a flow chart of an example of method of managing a multi-hop relay communication link where a last relay terminal 130 sends sidelink information including an L2ID of a remote terminal 106 to a network node 110. The method may be performed in a system such as the system 100 discussed herein. For the example, the method is performed by a relay terminal, such as the last relay terminal 130. The method may be performed using any of several techniques involving any combination of software, hardware, and firmware. For example, software code running on electronics including a processor, computer or other processor arrangement within the last relay terminal may facilitate the generation, formatting, reception and transmission of signals and messages. One or more of the steps may be omitted, combined, performed in parallel, or performed in a different order than that described herein or shown in FIG. 9. In still further examples, additional steps may be added that are not explicitly described in connection with the example discussed with reference to FIG. 9.

[0098] At step 902, an active RRC CONNECTED state is maintained at the last relay terminal 130 with the network node 110. For the example, all the relay terminals that will facilitate the multi-hop relay communication link are in the RRC CONNECTED state with the network node 110.TUTL 00413 PC-27-

[0099] At step 904, the last relay terminal 130 receives a Link Modification Request message from its child intermediate relay terminal. The Link Modification Request message identifies the L2ID of the remote terminal.

[0100] At step 906, an enhanced sidelink information message is transmitted to the network node in response to receipt of the Link Modification Request message. The enhanced sidelink information message identifies the L2ID of the remote and the L2ID(s) of the intermediate relay terminal(s) between the remote terminal and the network node. Accordingly, the enhanced sidelink information message identifies the L2ID of the first intermediate relay terminal as well as the RT L2ID. In some situations, the Local ID of the first intermediate relay terminal is included in the enhanced sidelink information message instead of the L2ID.

[0101] At step 908, an LRT RRC Reconfiguration message for configuring the last relay terminal is received. The LRT RRC Reconfiguration message is received from the network node over the Uu link.

[0102] At step 910, an RT RRC Reconfiguration message for configuring the remote terminal is received. The RT RRC Reconfiguration message is received from the network node over the Uu link.

[0103] At step 912, an IRT RRC Reconfiguration message for configuring the intermediate relay terminal is received. The IRT RRC Reconfiguration message is received from the network node over the Uu link. Where more than one intermediate relay terminal facilitates the multi-hop relay communication link, an IRT RRC Reconfiguration message is received or each intermediate relay terminal.

[0104] At step 914, another RRC Reconfiguration message is generated and transmitted to the child intermediate relay terminal where the RRC Reconfiguration message includes the RRC configuration information for the remote terminal and the intermediate relay terminal(s).

[0105] At step 916, last relay terminal applies the LRT RRC configuration for the multi-hop relay communication link.TUTL 00413 PC-28-

[0106] FIG. 10 is a flow chart of an example of method of managing a multi-hop relay communication link where a first intermediate relay terminal 134 sends sidelink information including an L2ID of a remote terminal 106 to a network node 110. The method may be performed in a system such as the system 100 discussed herein. For the example, the method is performed by a relay terminal, such as the first relay terminal 134. The method may be performed using any of several techniques involving any combination of software, hardware, and firmware. For example, software code running on electronics including a processor, computer or other processor arrangement within the intermediate relay terminal may facilitate the generation, formatting, reception and transmission of signals and messages. One or more of the steps may be omitted, combined, performed in parallel, or performed in a different order than that described herein or shown in FIG. 10. In still further examples, additional steps may be added that are not explicitly described in connection with the example discussed with reference to FIG. 10.

[0107] At step 1002, an active RRC CONNECTED state is maintained at the intermediate relay terminal 134 with the network node 110. For the example, all the relay terminals that will facilitate the multi-hop relay communication link are in the RRC CONNECTED state with the network node 110.

[0108] At step 1004, the last relay terminal 130 receives an RRC Setup Request message from the remote terminal 106. After a PC5 link is established between the remote terminal and the first intermediate relay terminal, the remote terminal sends the RRC Setup Request over the PC5 link to the remote terminal.

[0109] At step 1006, a sidelink information message is transmitted to the network node in response to receipt of the RRC Setup Request message. The sidelink information message identifies the L2ID of the remote and is transmitted over a relay path through the last relay terminal.

[0110] At step 1008, an RRC Reconfiguration message is received from the parent relay terminal which is the last relay terminal where the plurality of terminals includes two relay terminals. The RRC Reconfiguration message is generated by the parent relay terminal and includes RT RRC configuration information assigned to the remoteTUTL 00413 PC-29-terminal by the network and IRT RRC configuration information assigned to the first intermediate relay terminal by the network. The RT RRC Reconfiguration message is received from the parent relay terminal over the PC5 link.

[0111] At step 1010, another RRC Reconfiguration message is generated and transmitted to the remote terminal where the RRC Reconfiguration message includes the RRC configuration information for the remote terminal.

[0112] At step 1012, the first intermediate relay terminal applies the IRT RRC configuration for the multi-hop relay communication link.

[0113] To clearly illustrate this interchangeability of hardware, firmware 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, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. The described functionality may be implemented in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure. In accordance with various embodiments, a processor, device, component, circuit, structure, machine, module, etc. can be configured to perform one or more of the functions described herein. The term "configured to" or "configured for" as used herein with respect to a specified operation or function refers to processors, devices, components, circuits, electronics, and equipment that are physically constructed, programmed, instructed and / or arranged to perform the specified operation or function. Furthermore, the various illustrative logical blocks, modules, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), other electronics or combinations thereof. (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, electronics, and circuits can further include antennas and / or transceivers to communicate with various components within the network or within the device. A general-purpose processor can be a microprocessor, but in the alternative, theTUTL 00413 PC-30-processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.

[0114] When implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0115] Therefore, the methods and apparatus of this invention may take the form, at least partially, of program logic or program code (i.e., instructions) embodied in tangible media, such as a machine-readable storage medium. When the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. The methods and apparatus of the present invention may also be embodied in the form of program code that is transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via any other form of transmission. When the program code is received and loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code combines with the processor to provide a unique apparatus that operates analogously to specific logic circuits.

[0116] Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present disclosure. It will be appreciated that, for clarity purposes, the above description has describedTUTL 00413 PC-31-embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present disclosure. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Therefore, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0117] Clearly, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. The above description is illustrative and not restrictive. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.

Claims

TUTL 00413 PC-32- CLAIMS1. A method comprising:maintaining, by a network node, an active Radio Resource Control (RRC) context with each terminal of a plurality of terminals;receiving a sidelink information message identifying a Layer 2 identification (L2ID) of a remote terminal that has sent an RRC Setup Request message requesting an RRC connection to the network node;in response to receiving the sidelink information message at the network node, sending a plurality of RRC Reconfiguration messages to establish a multi-hop communication link between the remote terminal and the network node, the plurality of terminals facilitating the multi-hop relay communication link, the plurality of RRC Reconfiguration messages comprising an RRC Reconfiguration message to each terminal of the plurality of terminals and a remote terminal RRC Reconfiguration message to the remote terminal.

2. The method of claim 1 , wherein the plurality of terminals comprises a last relay terminal and an intermediate relay terminal, the last relay terminal connected to the network node through a Uu link, the intermediate relay terminal connected to the remote terminal through a PC5 link.

3. The method of claim 2, wherein sending the plurality of RRC Reconfiguration messages comprises:sending a last relay terminal RRC Reconfiguration message over the Uu link to the last relay terminal, the last relay terminal RRC Reconfiguration message comprising a mapping of ingress Sidelink Radio Link Control (SL-RLC) entities to egress Uu RLC entities for Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) traffic and a Local ID for inclusion in Sidelink Relay Adaptation Protocol (SRAP) headers;sending an intermediate relay terminal RRC Reconfiguration message through the last relay terminal to the intermediate relay terminal, the intermediate relay terminal RRC Reconfiguration message comprising SL-RLC entities for ingress and egress for SRB and DRB traffic and the Local ID; andTUTL 00413 PC-33- sending a remote terminal RRC Reconfiguration message through the last relay terminal and the intermediate relay terminal to the remote terminal, the remote terminal RRC Reconfiguration message comprising SL-RLC entities for egress for SRB and DRB traffic and the Local ID.

4. The method of claim 3, wherein the sidelink information message is a SidelinkUEInformation (SUI) message generated by the intermediate relay terminal in response to receiving the RRC Setup Request message, the SUI message received through the multi-hop relay communication link at the network node.

5. The method of claim 3, wherein the sidelink information message is a SidelinkUEInformation (SUI) message generated by the last relay terminal and comprises the L2ID of the remote terminal and an intermediate relay terminal L2ID of the intermediate relay terminal.

6. The method of claim 5, wherein the SUI message is generated in response to a PC5-S link modification procedure identifying the remote terminal L2ID to the last relay terminal.

7. A method comprising:maintaining, by a relay terminal, an active Radio Resource Control (RRC) CONNECTED state with a network node;determining a remote terminal has transmitted an RRC Setup Request to the network node to initiate establishment of an RRC connection over a multi-hop relay communication link between the remote terminal and the network node;in response to determining the remote terminal has transmitted the RRC Setup Request, transmitting a sidelink information message identifying a Layer 2 identification (L2ID) of the remote terminal;receiving, from the network node, a remote terminal RRC Reconfiguration message comprising RRC Reconfiguration information; andTUTL 00413 PC-34- forwarding the RRC Reconfiguration information in a child RRC Reconfiguration message to a child terminal.

8. The method of claim 7, wherein:the relay terminal is an intermediate relay terminal;the remote terminal is the child terminal; anda plurality of terminals facilitates the multi-hop relay communication link, the plurality of terminals comprising a last relay terminal and an intermediate relay terminal, the last relay terminal connected to the network node through a Uu link, the intermediate relay terminal connected to the remote terminal through a PC5 link.

9. The method of claim 8, wherein the determining the remote terminal has transmitted the RRC Setup Request comprises receiving the RRC Setup Request from the remote terminal and wherein transmitting the Sill message comprises transmitting the SUI message through the last relay terminal to the network node.

10. The method of claim 9, wherein the RRC Reconfiguration message is a remote terminal RRC Reconfiguration message received from the last relay terminal, the remote terminal RRC Reconfiguration message comprising SL-RLC entities for egress for Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) traffic for the remote terminal, the child terminal RRC Reconfiguration message comprising the SL-RLC entities for egress for SRB and DRB traffic for the remote terminal.

11. The method of claim 7, wherein:the relay terminal is a last relay terminal;the child terminal is an intermediate relay terminal; anda plurality of terminals facilitates the multi-hop relay communication link, the plurality of terminals comprising the last relay terminal and the intermediate relay terminal, the last relay terminal connected to the network node through a Uu link, the intermediate relay terminal connected to the remote terminal through a PC5 link.TUTL 00413 PC-35- 12. The method of claim 11 , wherein the determining the remote terminal has transmitted the RRC Setup Request comprises receiving a Link Modification Request comprising the remote L2ID and wherein transmitting the Sill message comprises transmitting, to the network node, an enhanced Sill message comprising the remote terminal L2ID and an intermediate relay terminal L2ID of the intermediate relay terminal.

13. The method of claim 12, wherein the RRC Reconfiguration message is an intermediate relay terminal RRC Reconfiguration message received from the gNB and comprises SL-RLC entities for ingress and egress for Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) traffic for the intermediate relay terminal and Local ID of the remote terminal.

14. A relay terminal comprising:a controller configured to determine, while the relay terminal is in an active Radio Resource Control (RRC) CONNECTED state with a network node, a remote terminal has transmitted an RRC Setup Request to the network node to initiate establishment of an RRC connection over a multi-hop relay communication link between the remote terminal and the network node;a transmitter configured to transmit, in response to determining the remote terminal has transmitted the RRC Setup Request, a sidelink information message identifying a Layer 2 identification (L2ID) of the remote terminal;a receiver configured to receive, from the network node, a remote terminal RRC Reconfiguration message comprising RRC Reconfiguration information,the transmitter configured to transmit the RRC Reconfiguration information in a child RRC Reconfiguration message to a child terminal.

15. The relay terminal of claim 14, wherein:the relay terminal is an intermediate relay terminal;the remote terminal is the child terminal; anda plurality of terminals facilitates the multi-hop relay communication link, the plurality of terminals comprising the last relay terminal and an intermediate relayTUTL 00413 PC-36-terminal, the last relay terminal connected to the network node through a Uu link, the intermediate relay terminal connected to the remote terminal through a PC5 link.

16. The relay terminal of claim 15, wherein:the receiver is configured to receive the RRC Setup Request from the remote terminal;the controller is configured to determine the remote terminal has transmitted the RRC Setup Request, at least partially, in response to receiving the RRC Setup Request from the remote terminal; andthe transmitted is configured to transmit the Sill message by transmitting the Sill message through the last relay terminal to the network node.

17. The relay terminal of claim 16, wherein:the RRC Reconfiguration message is a remote terminal RRC Reconfiguration message received from the last relay terminal:the remote terminal RRC Reconfiguration message comprises SL-RLC entities for egress for Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) traffic for the remote terminal; andthe child terminal RRC Reconfiguration message comprises the SL-RLC entities for egress for SRB and DRB traffic for the remote terminal.

18. The method of claim 14, wherein:the relay terminal is a last relay terminal;the child terminal is an intermediate relay terminal; anda plurality of terminals facilitates the multi-hop relay communication link, the plurality of terminals comprising the last relay terminal and the intermediate relay terminal, the last relay terminal connected to the network node through a Uu link, the intermediate relay terminal connected to the remote terminal through a PC5 link.

19. The relay terminal of claim 18, wherein:TUTL 00413 PC-37- the receiver is configured to receive a Link Modification Request Comprising the remote L2ID from the intermediate relay terminal,the controller is configured to determine the remote terminal has transmitted the RRC Setup Request, at least partially, based on receiving the Link Modification Request Comprising the remote L2ID; andthe transmitted is configured to transmit, to the network node, an enhanced SUI message comprising the remote terminal L2ID and an intermediate relay terminal L2ID of the intermediate relay terminal.

20. The relay terminal of claim 19, wherein the RRC Reconfiguration message is an intermediate relay terminal RRC Reconfiguration message received from the gNB and comprises SL-RLC entities for ingress and egress for Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) traffic for the intermediate relay terminal and Local ID of the remote terminal.

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