Method and apparatus for managing multi-path communication in multi-path relay

Abstract

A method and apparatus for managing multipath communications in a wireless communication system that supports relaying between a user equipment (UE) and a network including a first base station are disclosed. A method performed at a first base station, where a first communication path has been established between a UE and the first base station, the method comprising: transmitting a configuration message to the UE, the configuration message comprising configuration information for configuring the UE to communicate with a network, the configuration message also includes multipath information for indicating that the configuration information is associated with at least one other communication path to be configured between the UE and the network to provide multiple paths between the UE and the network, or information for indicating that multiple paths are to be configured.

Description

TECHNICAL FIELD

[0001] The present invention generally relates to managing multi-path communication in a wireless communication system supporting relaying, e.g. multi-path or multiple path relaying, between a user equipment, UE, and a base station. For example, the present invention relates to multi-path sidelink relaying in a communication system supporting sidelink (SL) relaying, e.g. multi-path relayed transmission. In particular, the present invention relates to a method for managing path addition to enable a user equipment, UE, and a base station of a multi-path supported communication system using sidelink relaying to communicate with each other over several paths. BACKGROUND

[0002] The third generation partnership project (3GPP) has initiated the development of a new radio access technology, referred to as fifth generation new radio (5G NR), to respond to requirements related to very high reliability and very low latency. 5G NR involves not only enhancements to the radio access technology, but also the handling of a wide range of new services to be implemented by future mobile communications. Three different categories of use cases are defined in NR from enhanced mobile broadband (eMBB), massive machine type communication (mMTC) to ultra-reliable low latency communication (URLLC).

[0003] The first release of 5G sidelink or new radio (NR) sidelink has been developed in 3GPP Release 16 as part of the 5G V2X work item to support advanced vehicle-to-anything (V2X) scenarios in addition to complementing the previous basic safety services, as well as commercial applications and services. NR V2X addresses advanced driving use cases in which vehicles are exchanging large amounts of data while complying with low latency requirements. NR sidelink is designed to provide three basic transmission scenarios: broadcast, groupcast and unicast communication, while taking into account both out-of-coverage deployment scenarios and in-network coverage deployment scenarios.

[0004] Based on NR sidelink technology, 3GPP introduced sidelink based relaying functionality as part of the 3GPP Release 17 framework, in which a relay UE can provide user plane (UP) and control plane (CP) data relay between a set of served remote UEs and the network (UE-to-network relaying or U2N relaying) or between a source remote UE or source UE and a target remote UE or target UE (UE-to-UE relaying or U2U relaying).

[0005] The objective of the sidelink relay functionality in Release 17 is to extend the sidelink / network coverage and improve the power efficiency, while considering a wide range of applications and services, including V2X, public safety, and commercial applications and services. Some of these new V2X scenarios require Ultra-Reliable Low-Latency (URLLC) performance to meet high-speed and high-density constraints, while requiring some network coverage extension, which can be achieved through sidelink relaying.

[0006] This first version of the sidelink relay functionality as defined in Release 17 specification is mainly intended to support UE-to-Network (U2N) relaying with basic functionality and limited features. To better support the use cases that require sidelink relaying, further enhancements are needed to introduce potential solutions identified during the Rel-17 study item. The subsequent 3GPP Release 18 work item “NR Sidelink Relay (SLR) Enhancements” has addressed several solutions that are considered as areas of needed enhancements for NR sidelink relay systems for V2X, public safety, and commercial use cases.

[0007] Multi-path relaying has been identified as a solution to be specified in the Release 18 NR SLR enhancements WI, where a remote UE is connected to the network via a direct path (e.g., the path is a link between the UE and a base station of the network, also referred to as gNB, which is referred to as Uu link) and an indirect path (e.g., a path between the remote UE and a base station of the network, also referred to as gNB, including the relay UE, where the link between the remote UE and the relay UE is referred to as PC5 link, and thus the path includes a PC5 link and a Uu link), and potentially improve reliability, robustness, and throughput.

[0008] This multi-path relaying solution aims to provide applications on 5G terminals that require high uplink data rates to achieve the required UL data rates, especially at the edge of the cell. In addition, if one of the paths is suffering from deteriorated channel conditions, the multi-path relaying can improve the reliability and stability of the provided service while reducing the latency.

[0009] A remote UE configured for multi-path relaying can transmit data via multiple paths. The transmitted data is associated with a radio bearer configured by the network. To improve reliability and / or throughput, data can be transmitted via multiple paths, and thus, one radio bearer can be mapped to multiple configured paths. This radio bearer has been considered in the RAN2 meeting for the Release 18 multi-path relaying scenario and has been named “MP split bearer” or “MP bearer”. The MP bearer can be a signaling radio bearer (SRB) for control data or a data radio bearer (DRB) for user data.

[0010] As data can be transmitted via multiple paths with MP bearers, it is possible to balance the amount of data transmitted over multiple paths to achieve higher reliability and / or throughput depending on the channel occupancy or radio conditions over different paths. To this end, data splitting can be used and data packets can be delivered over either direct or indirect paths or both of a multi-path relay system.

[0011] However, in order to improve data communication as described above using such a multi-path system, new procedures need to be defined to add a second path to an ongoing single-path configuration, thus enabling multi-path communication. Such path addition can also be seen as a multi-path setup procedure. Furthermore, when a multi-path has been established and depending on environmental changes, e.g. due to mobility of the involved user equipment (remote and / or relay UE) or due to load of the current serving node (cell, base station or relay) or due to occurrence of interference affecting the serving node, it can be desirable for the remote UE to adapt its configuration to maintain or improve high quality of service. Moreover, it is also an objective to define the behavior of the system when it fails to add a new path or to modify an existing path.

[0012] Therefore, there is a need for some new mechanisms taking into account the above considerations to define a multi-path setup or modification procedure in a communication system supporting sidelink relaying and / or multi-path relaying. SUMMARY

[0013] According to a first aspect of the present application, there is provided a method for managing multi-path communication in a wireless communication system supporting relaying between a user equipment (UE) and a network comprising at least a first base station, performed at a first base station as defined in claim 1 of the appended claims.

[0014] According to a second aspect of the present application, there is provided a method for managing multi-path communication in a wireless communication system supporting relaying between a user equipment (UE) and a network comprising at least a first base station, performed at a user equipment (UE) as defined in claim 23 of the appended claims.

[0015] According to a third aspect of the present application, there is provided a method for managing multi-path communication in a wireless communication system supporting relaying between a user equipment (UE) and a network comprising at least a first base station, performed at a relay node as defined in claim 70 of the appended claims.

[0016] According to a fourth aspect, a method is provided for managing multipath communication in a wireless communication system at a user equipment (UE), the wireless communication system supporting relay between the UE and a network including a first base station, wherein a first communication path has been established between the UE and the first base station, and wherein a second UE (e.g., near the UE) is capable of establishing a non-3GPP connection with the UE and supporting relay between the UE and the network. The method includes sending a measurement report message to the first base station, the measurement report message indicating that a non-3GPP connection can be established between the UE and the second UE. By sending a measurement report message (which may also include information about one or more other UEs near the UE, which may be one or more candidate relay nodes (e.g., 3GPP relay candidates) using 3GPP connections) indicating that a non-3GPP connection can be established between the UE and a second UE (e.g., a non-3GPP candidate), the base station receives information about all potential relay candidates (non-3GPP relay candidates and 3GPP relay candidates, if available) in one message and does not need to wait for additional messages to indicate the UE's candidate relay.

[0017] According to a fifth aspect of the invention, there is provided an apparatus for a base station of a wireless communication system supporting relay, as described in claim 88 of the appended claims.

[0018] According to a sixth aspect of the invention, an apparatus for a UE of a wireless communication system supporting relay is provided as described in claim 89 of the appended claims.

[0019] According to another aspect, a method is provided at a user equipment (UE) operating in a wireless communication system capable of supporting relaying between a UE and a network including a base station. The method includes receiving information (e.g., capability information) from at least one other UE. For each of the at least one other UE, the capability information indicates at least one of the following: the other UE is capable of operating as a relay node for providing an indirect communication path between the UE and the network; the other UE supports PC5 triggering, which allows the relay node to enter an RRC CONNECTED (RRC connected) state using a PC5 message. The capability information can be received from one or more neighboring UEs in a discovery message (e.g., as part of a discovery process) and before the UE is configured by the network (e.g., before the UE is configured to set up multiple communication paths). As discussed below, the capability information can be an indication that the UE has version 18 capabilities.

[0020] The method can further include transmitting capability information to the base station. For example, the capability information can be transmitted in a measurement report and / or in a SidelinkUEInformationNR message. The capability information can be used by the base station to configure the UE. For example, if the relay UE does not support PC5 triggering, the base station can use the information about the PC5 triggering support for the at least one candidate relay UE to configure SRB1 over the indirect path.

[0021] Further example features of the application are described in the other independent and dependent claims.

[0022] Any feature in one aspect of the application can be applied to other aspects of the application, in any appropriate combination. In particular, method aspects can be applied to apparatus / device / unit aspects, and vice versa.

[0023] Furthermore, features implemented in hardware can also be implemented in software, or vice versa. Any reference to software and hardware features herein should be construed accordingly. For example, in accordance with other aspects of the application, there is provided a computer program including instructions which, when executed by one or more processing units, cause the one or more processing units to carry out the method of any of the above-described aspects or examples, and a computer-readable storage medium carrying the computer program. BRIEF DESCRIPTION OF DRAWINGS

[0024] The different aspects of the application will now be described, by way of example only, and with reference to the following drawings in which:

[0025] Figure 1 a is a schematic diagram illustrating an example wireless communication system in which the application can be implemented according to one or more embodiments;

[0026] Figure 1 b is a schematic diagram illustrating a typical 5G Proximity-based Service (ProSe) Relay reference architecture;

[0027] Figure 2 is a schematic diagram illustrating a user plane stack involving some protocol layers in sidelink relay operation for UE-to-Network (U2N) based relaying;

[0028] Figures 3 to 8 is a schematic simplified diagram illustrating an example of a message flow for managing multi-path communication in a wireless communication system according to one or more embodiments of the application;

[0029] Figures 9 to 11is a simplified schematic diagram illustrating an example of a message flow for managing multi-path communication in a wireless communication system in case of multi-path adaptation failure according to one or more embodiments of the present application;

[0030] Figure 12 is a simplified schematic diagram illustrating an example of a message flow for managing multi-path communication in a wireless communication system according to one or more embodiments of the present application;

[0031] Figure 13 is a simplified schematic diagram illustrating an example of a message flow for managing multi-path communication in a wireless communication system in case of multi-path adaptation failure according to one or more embodiments of the present application;

[0032] Figure 14 is a simplified flowchart of a method performed at a base station according to one or more embodiments of the present application;

[0033] Figure 15 is a simplified flowchart of a method performed at a UE according to one or more embodiments of the present application;

[0034] Figure 16 is a simplified flowchart of a method performed at a relay node according to one or more embodiments of the present application;

[0035] Figure 17 is a schematic block diagram of an example wireless communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] Figure 1 a represents an example of a wireless communication system 100 capable of supporting relaying between a user equipment (UE) and a base station, and illustrates a relay arrangement or system (or network) comprising a plurality of nodes including one or more relay nodes (e.g., relay user equipment (UE)) serving one or more remote user equipment (UEs).

[0037] In the following description, reference is made to a wireless communication system 100 capable of supporting sidelink relaying, in which a path between a remote UE and a base station comprises a sidelink connection (also referred to as a PC5 link) between the remote UE and a relay UE and a network connection (also referred to as a Uu link) between the relay UE and the base station. However, the present application is not intended to be limited to a PC5 link between a remote UE and a relay UE, and can be applied to a relay configuration in which a link between a remote UE and a relay UE is via another type of connection (e.g., a non-3GPP connection) such as WiFi or Bluetooth.

[0038] Reference is made to Figure 1 aThe UE nodes 110 are served by the network node 101 and can operate as relay UE nodes relaying data between one of the UE nodes 111, 112, referred to as remote UE nodes, and the network node 101, thus acting as UE-to-Network (U2N) relays. In turn, the UE 111 can operate as a relay UE node relaying between the UE node 113 and the network node 101 through another relay node 110. In Figure 1 a the example, the UE 112 can act as both a remote UE and a relay UE. In examples where the network node 101 is part of a cellular network, the relay UE 110 is served by a cell controlled by the network node 101.

[0039] The UE node 120 is also served by the network node 101 and can have some relay capabilities, i.e., the UE node 120 can act as a UE-to-Network (U2N) relay UE (e.g., for the UE node 112 via link 112c) at some time, even though it does not serve any remote UEs at Figure 1 a the time indicated in.

[0040] The UE node 130 is served by the network node 102 and can also operate as a UE-to-Network (U2N) relay UE node (e.g., relaying data between a remote UE 131 and the network node 102).

[0041] The network nodes 101 and 102 can be base stations of a wireless network or network, such as a Fifth Generation (5G) New Radio (NR) network or a Long Term Evolution (LTE) network. For the sake of clarity, Figure 1 a only base stations of a wireless network are shown. Although Figure 1 a not shown in, the base stations are connected to a core network. For a 5G NR network, the network nodes 101 or 102 are referred to as gNBs and are part of the NG-RAN.

[0042] Even though sidelink relaying is most likely to be considered in the context of V2X networks, the present application is not intended to be limited to UE nodes in or as part of a vehicle. Each of the UE nodes (relay or remote) can be a wireless communication device located in or as part of a vehicle or a road side unit (RSU), or a wireless communication device of a vulnerable road user (VRU) (e.g., a mobile or portable communication device of a pedestrian or a cyclist, such as a smartphone, PDA, laptop, or similar device). In the following, the relay UE nodes will also be referred to as relay UEs, the remote UE nodes will also be referred to as remote UEs, and the network nodes will be referred to as base stations or gNBs. However, it should be understood that the terms first UE and second UE can be used instead of remote UE and relay UE. Although embodiments and examples of embodiments of the present application will be described in the following description with respect to a 5G NR network, it will be appreciated that the present application is not intended to be limited to 5G NR systems and can be used in any wireless communication system supporting sidelink (or peer-to-peer) relaying communications.

[0043] In Figure 1 aIn the example shown, in a UE-to-network (or U2N) scenario where the UE 110 (or UE 130) operates as a UE-to-network relay UE, the UE-to-network relay UE 110 (or relay UE 130) connects the UEs 111 and 112 (or UE 131) operating as remote UEs to the gNB 101 (or gNB 102). The remote UE 111 is connected to the relay UE 110 via or through a sidelink 111a, which can be referred to as a PC5 hop or link or connection or interface 111a. Similarly, the remote UEs 112, 113 and 131 have PC5 hops or links or connections or interfaces 112a, 113a and 131a with the relay UEs 110, 111 and 130, respectively. A Uu hop or link or connection or interface 110a connects the relay UE 110 to the gNB 101, while Uu hops or links or connections or interfaces 120a and 130a connect the relay UE 120 to the gNB 101 and the UE 130 to the gNB 102, respectively. The PC5 connections are used for relay traffic for the remote UEs (111, 112, 113 and 131) and non-relay traffic specific to the relay UEs 110, 111, 130, i.e. for direct communication between the relay UEs 110, 111, 130 and the other remote UEs (111, 112, 113 and 131). Thus, the remote UE 111 is connected to the gNB 101 through the relay UE 110 with the PC5 hop 111a and the Uu hop 110a. For uplink communication, the remote UE 111 is the source node (or transmitter node for transmitting data) and the gNB 101 is the destination or target node (or receiver node for receiving data) for a sidelink relay connection established between the remote UE 111 and the gNB 101 with the PC5 hop 111a and the second Uu hop 110a, and for downlink communication, the remote UE 111 is the destination or target node (or receiver node) and the gNB 101 is the source node (or transmitter node). Similarly, the remote UE 131 is connected to the gNB 102 through the relay UE 130 with the PC5 hop 131a and the Uu hop 130a. The remote UE 113 is connected to the gNB 101 by itself through the relay UE 111 with a first PC5 hop 113a and then through the relay UE 110 with a second PC5 hop 111a and the Uu hop 110a. It will be appreciated that the terms first and second can be used instead of source and target.

[0044] At some point, gNB 101 can decide to set up multipathing to remote UE 112. For example, to maintain QoS, even as application services are transmitted to / received from remote UE 112. Then, based on information such as measurement information received from different UEs (relay, remote) in measurement reports and / or measurements performed by, for example, gNB 101 itself, the source gNB 101 can decide to add additional paths (a direct path (link 112b) or a new indirect path via relay UE 120 (links 112c and 120a)) to set up multipathing between remote UE 112 and the network.

[0045] At some other point, gNB 101, acting as the source gNB, can decide to hand over relay UE 110 to gNB 102, which will then act as the target gNB. For example, in a serving cell controlled by source gNB 101 ( Figure 1 a The radio condition degradation in the target cell (not shown) controlled by target gNB 102 (not shown) makes the target cell (not shown) degrade. Figure 1 a If the radio conditions in the target gNB 102 (not shown) are better than those in the serving cell, the source gNB 101 may decide to hand over relay UE 110 to the target gNB 102. In this case, relay UE 110 will detach from the source gNB 101, thereby releasing Uu link 110a to be used via Uu link 110b (established as part of the reconstruction process). Figure 1 a (Shown in dashed lines) further connects to the target gNB 102. In addition to the handover of relay UE 110, gNB 101 can also decide to modify the multipath configuration of remote UE 112 to keep all paths within the same serving cell (i.e., gNB 101) by replacing the indirect path via relay UE 110 with a new path attached to gNB 101 (e.g., a direct path (link 112b) or a new indirect path via relay UE 120 (links 112c and 120a)), or to move remote UE 112 to gNB 102. The multipath used to connect remote UE 112 can be re-established to gNB 102. In another variation, remote UE 112 can maintain its multipath attached to two different gNBs (101 and 102).

[0046] At some other point, in the case where the remote UE 112 and the gNB 101 have established a multi-path with a direct path (link 112b) and an indirect path (links 112a and 110a) via the relay UE1 110, the gNB 101 can decide to modify one of the paths of the multi-path. For example, in the case where the radio conditions in the serving cell by the gNB 101 deteriorate, i.e. if the link quality or signal strength of the direct path (link 112b) to the gNB 101 becomes lower than a threshold and at the same time the relay UE 120 looks like a good candidate, i.e. if the link quality or signal strength of the candidate relay UE 120 served by the gNB 101 is greater than a threshold, the gNB 101 can decide to replace the direct path (link 112b) with the indirect path (links 112c and 120a) via the relay UE 120. In other words, the remote UE 112 will become out of coverage (no more direct link connection available, no matter the gNB) and the gNB 101 decides to modify the multi-path from one direct path and one indirect path to two indirect paths. In this case, the remote UE 112 can maintain multi-path enabled even in the case of out of coverage.

[0047] The remote UE and the relay UE are attached to the core network through their serving gNB. Figure 1 b represents a typical 5G Proximity Service (ProSe) relay reference architecture and shows the different connections between the core network entities of the 5G Core (5GC) such as the Access and Mobility Management Function (AMF) entity, the Session Management Function (SMF) entity and the User Plane Function (UPF) entity, the UEs (5G ProSe Remote and 5G ProSe Relay) and the NG-RAN (i.e. the base station or gNB). The 5G ProSe Remote UE and the 5G ProSe Relay can be served by the same or different PLMN (Public Land Mobile Network). If the serving PLMN of the 5G Remote UE and the 5G ProSe Relay are different, the NG-RAN is shared by the serving PLMNs.

[0048] In order to setup a relay service between a first node (remote UE) and a second node (gNB or remote UE), the sidelink relay architecture can be used according to 3GPP TR 38.836. The user plane architecture or protocol stack is shown in Figure 2 and represents the sidelink relay adaptation layer, called SRAP, which is introduced between the PDCP layer and the RLC layer at the end nodes and on top of the RLC layer in the relay UE. This architecture was first documented in TR 38.836 and finally refined in 3GPP TS 38.300, while the SRAP layer is defined in 3GPP TS 38.351.

[0049] Figure 2 The architecture shown illustrates a side-link trunk architecture 200 for a UE-to-network trunking scenario. As illustrated in the UE-to-network trunking scenario... Figure 2 As shown, a remote UE (such as remote UE 112) has a PC5 SRAP layer or entity 201 between its Uu PDCP layer 211 and its PC5 RLC layer 221. Similarly, a gNB (such as gNB 101) has a Uu SRAP layer or entity 204 between its Uu PDCP layer 212 and its Uu RLC layer 224.

[0050] Such as scenarios related to UE to network relay. Figure 2 As shown, at the relay UE (such as relay UE 110), there are two SRAP layers to engage with PC5 hop 112a and Uu hop 110a: the PC5 SRAP layer or entity 202 is connected to the PC5 SRAP 201 of the remote UE 112 via PC5 hop 112a; and the Uu SRAP layer or entity 203 is connected to the Uu SRAP layer 204 at the gNB side 101 via Uu link 110a. The remote UE 112 establishes an end-to-end radio bearer 205 with the gNB 101. These radio bearers can be signaling radio bearers (SRBs) or data radio bearers (DRBs). Figure 2 An example is shown of the E2E Uu DRB / SRB 205 between remote UE 112 and gNB 101.

[0051] The PC5 SRAP layer 202 of the network relay UE 110 receives data or packets (service data or signaling) from the remote UE 112 (at PC5 hop 112a) via the PC5-RLC layer in the uplink direction through the ingress PC5 relay RLC channel 206 or via the ingress PC5 relay RLC channel 206, and transmits the packets to the Uu SRAP entity 203 of the same relay UE 110.

[0052] The Uu SRAP 203 entity maps the corresponding ingress PC5 relay RLC channel 206 to the egress Uu relay RLC channels 207a and / or 207b at the Uu link 110a. Therefore, the uplink requires a mapping table, which is configured by gNB 101 at the Uu SRAP entity 203 of the relay UE 110.

[0053] The mapping table takes as its input the identifier of the remote UE 112 (e.g., L2-ID), the identifier of the E2E radio bearer 205 (e.g., E2E Uu DRB ID), and the identifier of the ingress PC5 relay RLC channel (or bearer) 206, and identifies the egress Uu relay RLC bearer ID that maps the E2E radio bearer. For example, the UE E2E bearer ID and the remote UE ID can be obtained from the header of the data packet received at the Uu SRAP entity 203 via the PC5-SRAP entity 202. An example of an entry of the uplink mapping table configured at the Uu SRAP entity 203 with one entry is shown in Table 1 below. It should be understood that the mapping table will be configured such that it has an entry for each remote UE connected to the relay UE.

[0054] Table 1

[0055] At the Uu side or link 110a, different radio bearers of the same remote UE or different remote UEs can be subject to N: 1 mapping and data multiplexing on the Uu RLC channels 207a and 207b.

[0056] In the downlink direction, data or packets transmitted from the gNB 101 reach the relay UE 110 over the Uu link 110a. The Uu SRAP layer 203 of the UE-to-network relay UE 110 receives data or packets (traffic data or signaling) from the gNB 101 over the Uu-RLC layer on or via the ingress Uu relay RLC channels 207a and 207b and transmits the packets to the PC5 SRAP entity 202 of the same relay UE 110. These ingress Uu relay RLC channels 207a and 207b are mapped at the PC5 SRAP entity 202 of the relay UE 110 to the egress PC5 relay RLC channels 206 at the PC5 hop 112a. Thus, a mapping table is needed for the downlink and this mapping table is configured by the gNB 101 at the PC5 SRAP entity 202 of the relay UE 110. The mapping table needs at its input the remote UE 112 L2-ID, the end-to-end radio bearer 205 ID, and the ingress Uu relay RLC channel (or bearer) 207a and 207b ID and identifies the egress PC5 relay RLC channel (or bearer) 206 ID of the PC5 hop 112a. The end-to-end radio bearer 205 is then mapped at the PC5 hop 112a to the egress PC5 relay RLC channel 206. The UE E2E bearer ID and the remote UE ID can be obtained, for example, from the header of the packets received at the PC5 SRAP entity 202 via the Uu SRAP entity 203. An example of a downlink mapping table configured at the PC5 SRAP entity 202 with one entry is shown in Table 2 below. It should be understood that the mapping table will be configured such that it has an entry for each remote UE connected to the relay UE.

[0057] Table 2

[0058] As mentioned in 3GPP TS 38.351, each SRAP entity has a transmit portion and a receive portion. Across PC5 interface 112a, the transmit portion of PC5 SRAP entity 201 at remote UE 112 has a corresponding receive portion at PC5 SRAP entity 202 at network relay UE 110, and vice versa. Across Uu interface 110a, the transmit portion of Uu SRAP entity 203 at network relay UE 110 has a corresponding receive portion at Uu SRAP entity 204 at gNB 101, and vice versa. In summary, the transmit portion of each SRAP entity at network relay UE 110 receives data packets with their SRAP headers from its corresponding receive portion (the receive portion of SRAP entity 202 forwards data to the transmit portion of SRAP entity 203, and vice versa). Each SRAP entity's transport portion has a mapping table configured by gNB 101, which allows identification of the egress RLC channel (at the Uu or PC5 link) based on the ingress RLC channel of the received data packet, the UE, and the bearer ID carried in the SRAP header. Specific mapping rules can be applied to SRB0 and SRB1 as specified in TS38.351 and TS38.331.

[0059] In a multipath scenario with one indirect path and one direct path, remote UE 112 and gNB 101 can communicate with each other via two paths. Therefore, each node has two protocol stacks: one for the indirect path, as described above, and one for the direct path. Separation between the direct and / or indirect paths is performed at the PDCP layer of each node. For the direct path, in the downlink direction, data or packets transmitted from gNB 101 via the direct path reach remote UE 112 via the ingress Uu direct path RLC channel 208 of Uu link 112b. On the other hand, in the uplink direction, data or packets transmitted from remote UE 112 via the direct path reach gNB 101 via the ingress Uu direct path RLC channel 208 of Uu link 112b.

[0060] Now for reference Figure 3 , Figure 3 This illustrates one or more embodiments of the invention for managing, such as Figure 1 a The diagram shows a simplified illustration of an example of multi-path communication (e.g., communication via multiple paths) in a relay-supported wireless communication system, particularly for managing the path addition process to enable or establish a multi-path (MP) message flow that includes a direct path and an indirect path.

[0061] In one example, a remote UE (such as remote UE 112) connects to a base station, such as base station 101 (also referred to as gNB 101), etc. Remote UE 112 and base station 101 (also referred to as first base station 101) communicate with each other, in other words, remote UE 112 transmits some uplink data or UL user data 310 to first base station 101 and / or first base station 101 transmits some downlink data or DL user data 310 to remote UE 112. As shown in Figure 3 The communication path between base station 101 and remote UE 112 can be direct (e.g., there is a direct connection between base station 101 and UE 112) for UL / DL user data 310 or indirect (e.g., there is an indirect connection between base station 101 and UE 112 via a relay node, such as a relay UE, etc.).

[0062] Remote UE 112 can also send some measurement reports to the first base station via measurement report message 311 defined in 3GPP TS 38.331, respectively. The report includes at least relay UE ID, serving cell ID of the relay UE and sidelink measurement quantity information. The sidelink measurement quantity information is further described below. Base station 101 can alternatively or additionally receive measurement report information from cells and / or UEs (possible candidate relay nodes) that are proximate to or around remote UE 112.

[0063] In a particular case where a relay UE and a remote UE can connect through non-3GPP connectivity (e.g., Bluetooth, wifi or other peer-to-peer technology, etc.), the remote UE can also indicate in the measurement report that a non-3GPP connection can be established between the remote UE and another UE that can support relaying for the remote UE. In this case, the information carried by the measurement report related to the relay UE(s) that can establish a non-3GPP connection can be all or part of the following: relay UE ID, serving cell ID of the relay UE, sidelink measurement quantity information, and information that the connectivity between the relay UE and the remote UE is a non-3GPP link or connection (e.g., an N3C_Relay flag or bit set to true or 1 or conditionally present). In this case, the relay UE ID can be one of the RNTIs of the relay UE (e.g., C-RNTI or I-RNTI). In addition, the sidelink measurement quantity information can carry measurement information related to the non-3GPP technology and an indication of the technology kind (e.g., wlan measurement or Bluetooth measurement). The measurement report can also include PLMN information of the relay that can be received through the non-3GPP link or connection. In a particular example, the PLMN information is carried in a 3GPP cellular network ANQP element (as specified in TS 24.302) received from a WLAN station.

[0064] Thus, in cases where another UE (or more than one UE) (or another node) in the vicinity or proximity of or adjacent to the remote UE 112 is capable of establishing a non-3GPP connection or link with the remote UE 112 and is capable of supporting relaying between the remote UE and the base station 101 (i.e., such other UE(s) are potential candidates to operate as a non-3GPP relay node for the remote UE 112), the remote UE 112 can transmit a measurement report message to the base station 101 indicating that a non-3GPP connection (e.g., Bluetooth, wifi, or other peer-to-peer technology, etc.) can be established between the remote UE 112 and the other UE. As discussed above, the measurement report message can include an information element indicating that a non-3GPP connection can be established between the remote UE 112 and another UE, such as the N3C_Relay flag or bit set to true or 1, etc. In another example, the measurement report message can include only an information element indicating that a non-3GPP connection can be established when a non-3GPP connection can be established (i.e., no IE is included in the measurement report message if a non-3GPP connection cannot be established). The measurement report message can include at least one of: identification information identifying the other UE(s) (e.g., I-RNTI or I-RNTI); serving cell identification information identifying a cell serving the other UE(s); link measurement quantity information associated with the non-3GPP connection. The link measurement quantity information can include information related to QoS, latency, link quality, signal strength of the non-3GPP connection. In addition to the non-3GPP connection measurement report information, the measurement report message can also include measurement report information for one or more 3GPP connections that can be established for relaying between the other UE and the remote UE 112. Such measurement report information is discussed in more detail below, but can include at least one of: identification information identifying the other UE(s) capable of supporting relaying using a 3GPP connection (e.g., I-RNTI or I-RNTI); serving cell identification information identifying a cell serving the other UE(s) capable of supporting relaying using a 3GPP connection; link measurement quantity information associated with the 3GPP connection that can be established.

[0065] In variations, for non-3GPP links, the remote UE can use a specific value in the sidelink measurement quantity information to indicate that the link is a non-3GPP link (e.g., the measurement quantity information value can be set to “0” or its maximum value).

[0066] On one hand, when the link quality of a non-3GPP connectivity meets a specific requirement (e.g., the link can be used to relay data), a remote UE can autonomously report information related to or associated with non-3GPP relay (e.g., non-3GPP relay ID) to the base station. For example, after a remote UE determines that a non-3GPP connection that can be established between another UE and the remote UE meets certain requirements, the remote UE sends a measurement report message indicating that a non-3GPP connection (e.g., Bluetooth, Wi-Fi, or other peer-to-peer technologies) can be established between the remote UE and the other UE. These requirements may involve one or more of QoS, latency, link quality, signal strength (and thresholds associated with such parameters). For example, when the measured latency of a non-3GPP connection is equal to or less than a certain threshold (which can be configured by the network as discussed below), the remote UE 112 can determine that it should report a non-3GPP connection to the base station 101. As another example, when the measured link quality of a non-3GPP connection is equal to or greater than a certain threshold (which can be configured by the network), a remote UE can determine that it should report a non-3GPP connection to the gNB. Similar thresholds exist for QoS and signal strength. These thresholds can be configured by the network as described above, or determined by the UE to meet the requirements of its application. The application layer can then provide these thresholds, or the UE can derive the thresholds from application requirements. Thresholds can also be based on QoS parameters such as 5QI (the 5G QoS index specified in TS23.501) provided to the network by the UE during PDU session establishment, or DSCP (Differential Service Code Points), or UP (User Priority), etc.

[0067] On the other hand, a remote UE can report the potential relevance of a non-3GPP link for further data relay based on some measurement reporting configuration provided by the network (gNB). In an example, such measurement reporting configuration may indicate whether the remote UE is authorized to report some information (e.g., non-3GPP relay UE ID) related to (one or more) non-3GPP relay UEs, and may also include one or more quality thresholds (related to certain or specific requirements to be met as described above) to determine whether to report some information related to (one or more) non-3GPP links to the network. In a variant, the gNB may also not authorize the remote UE to use non-3GPP relays to avoid interference (in which case, for example, the gNB may indicate to the remote UE that it is not authorized to use non-3GPP connections during RRC connection or PDU establishment), so non-3GPP link information is not included in the measurement report. In another variant, the remote UE may only report non-3GPP relays when no other relays are available.

[0068] Based on the information carried by the received measurement report message, the first base station 101 can decide to adapt the connection or connectivity of the remote UE 112 to the network (step 320). In reference to Figure 4 In another variant of the illustration, the step 320 can be triggered when a QoS failure (latency, reliability) is detected or a request from the core network (see below in reference to Figure 4 More details are described) or when the resources allocated to the remote UE 112 are not sufficient to meet the bandwidth requirements (a continuously reported BSR indicates an increase in the size of the buffer at the remote UE 112) or when the remote UE 112 requests. Then, in this case, the base station 101 requests the remote UE 112 to provide a measurement report so that the base station 101 can obtain information on the environment of the remote UE 112, in particular information related to surrounding cells and relays.

[0069] According to an aspect, the first base station can decide to set a multi-path by adding a second path (which can be direct or indirect) that will also connect the remote UE 112 to the first base station 101 to the existing path that connects the remote UE 112 to the first base station 101 (e.g. a communication path established between the base station 101 and the remote UE 112, such as a direct path as Figure 3 illustrated, etc.). In the example of Figure 3 the second path is an indirect path. The second path can alternatively be a direct path. The base station 101 can decide to add more than one communication path to the existing or already established communication path. The first base station 101 can decide to add a second path to meet the requirements of the remote UE 112, i.e. to increase the available bandwidth (UL or DL or both) for this particular remote UE or to improve the reliability by combining the two paths to obtain spatial diversity or to meet some other QoS parameters such as latency, etc.

[0070] According to another aspect, in the case where a multi-path has already been set (i.e. at least two communication paths or connections have already been established between the base station 101 and the remote UE 112), the first base station 101 can decide to modify the existing multi-path to adapt the connection or connectivity of the remote UE 112 to the network. The modification can involve modifying one or more than one of the existing at least two communication paths.

[0071] More specifically, in one aspect, the first base station 101 can decide to add a new direct path towards the remote UE 112 if the link quality level or signal strength of the cell served by the base station (101 or 102) is greater than or equal to a certain predefined threshold, or if the link quality level or signal strength of the serving relay UE 110 is lower than a second predefined offset threshold, and if the link quality level or signal strength of the cell served by the base station (101 or 102) is greater than or equal to a third predefined threshold. It should be appreciated that the new direct path can be added to an existing path, which can be an indirect path or a direct path.

[0072] In another aspect, the first base station 101 can decide to modify or change the direct path towards the remote UE 112 if the link quality level or signal strength of the cell served by the second base station 102 reported in the received MEASUREMENT REPORT message 311 is greater than the link quality level or signal strength of the cell served by the first base station 101 to which the remote UE 112 is currently connected by a predefined offset threshold. Thus, in this case, the change is from a direct path to a different direct path. Alternatively, the change can be from a direct path to an indirect path.

[0073] In another aspect, the first base station 101 can decide to add a new indirect path towards the remote UE 112 if the link quality level or signal strength of a candidate relay UE 110 or 120 served by the base station 101 or 102 reported in the received MEASUREMENT REPORT message 311 is greater than a predefined offset threshold, or if the link quality level or signal strength of a candidate relay UE 110 or 120 served by the base station 101 or 102 reported in the received MEASUREMENT REPORT message 311 is greater than a second predefined offset threshold, and if the link quality level or signal strength of the cell to which the remote UE 112 is connected or the serving relay UE 110 to which the remote UE 112 is connected becomes worse than a third threshold. It should be appreciated that the new indirect path can be added to an existing path, which can be an indirect path or a direct path.

[0074] In another aspect, the first base station 101 can decide to modify or change the indirect path towards the remote UE 112 if the link quality level or signal strength of the serving relay UE 110 reported in the received MEASUREMENT REPORT message 311 is below a predefined offset threshold, or if the link quality or signal strength of the candidate relay UE 120 reported in the received MEASUREMENT REPORT message 311 is greater than a predefined offset threshold. The candidate relay UE 120 can be served by the same base station 101 or by another base station, e.g. base station 102. Thus, in this case the change is from an indirect path to a different indirect path. Or, the change can be from an indirect path to a direct path.

[0075] The base station can also decide to make a remote UE connection adaptation based on any combination of the above listed events. Thus, the base station can also decide to modify or change an indirect path to a direct path, or vice versa, or to add a second direct path when a first direct path has been established, or to add a second indirect path when a first indirect path has been established. The different paths can be served by the same or different base stations.

[0076] The above link qualities can be reported in the received MEASUREMENT REPORT message 311.

[0077] According to one example, the link quality level or signal strength measurements considered by the first base station 101 (e.g. at step 320) for the connection adaptation decision include all or parts of the following metrics: Reference Signal Received Power (RSRP), which provides a measure of the received power of the strongest reference signal from the considered cell; Reference Signal Received Quality (RSRQ), which provides a measure of the quality of the received reference signal from the considered cell relative to the interference level in the cell; Signal to Noise Ratio (SNR), which provides a measure of the quality of the signal relative to the noise level in the cell and can be used to determine the strength of the signal from the considered cell; Channel Quality Indicator (CQI), which provides a measure of the quality of the received signal; Sidelink Reference Signal Received Power (SL-RSRP) or Sidelink Discovery Reference Signal Received Power (SD-RSRP), which provide a measure of the received power of the strongest reference signal from a relay UE based on data or discovery messages, respectively. In addition to the above metrics, for the link quality level or signal strength measurements, other measurements such as cell identification, beamforming quality and channel state information (e.g. sidelink channel busy ratio or interference) can also be considered.

[0078] The first base station 101 can inform the remote UE 112 to perform a connection adaptation, i.e. to set up one or more additional paths or to modify an existing path by sending a configuration message, such as an RRC reconfiguration message 321 as defined in 3GPP TS 38.331.

[0079] In an aspect, the configuration message (e.g. the RRC reconfiguration message 321) comprises all or part of the following information elements or information:

[0080] - a multi-path information indicating that the RRC reconfiguration is intended to set up a multi-path by adding a new path to an existing path. In a variant, the multi-path information indicates that the RRC reconfiguration is intended to modify a multi-path configuration by updating or changing at least one of the existing indirect or direct paths. For example, the multi-path information included in the configuration message indicates that the configuration information included in the configuration message is associated with at least one other communication path to be configured between the remote UE 112 and the network to provide a multi-path between the remote UE 112 and the network, the multi-path comprising a first communication path already established between the remote UE 112 and the first base station 101. In an example, the configuration message comprises information (or multi-path information) for indicating that at least one other communication path is to be configured between the UE and the network in addition to the first communication path already established between the remote UE 112 and the first base station to provide a plurality of paths (e.g. communication paths) between the UE and the network. In other words, the configuration message comprises information (or multi-path information) for indicating that a plurality of paths is to be configured.

[0081] - a relay list: this list contains at least one relay identified by its ID. This list indicates to the remote UE 112 which relay UE (e.g. relay node) the remote UE should connect to. If the RRC reconfiguration is intended to establish several indirect paths, this list can carry several relay UEs. For example, the relay list provides relay identification information for identifying at least one relay node to which a connection is to be established with the remote UE 112 for a respective at least one communication path of the multi-path. This relay list is associated with the primary relay UE(s) or main relay UE and is also referred to as target relay UE(s).

[0082] - a backup relay list: this list includes at least one backup relay identified by its ID. This list indicates to the remote UE 112 which relay UE the remote UE should connect to in case the primary or main relay UE is not available. If the list includes several relays, priority information can also be provided to indicate a priority order of the relays so that the remote UE can try to connect to the relays in the order indicated by the priority information. If no priority information is provided, the remote UE can try to connect sequentially.

[0083] - a primary cell for indicating a primary cell to connect to. This cell is identified by a cell ID (e.g., physCellld). For example, the configuration message can include primary cell information or main cell information for identifying a primary cell or a main cell to establish a connection (e.g., for a direct path between the UE and the network) with the UE to provide a multi-path, and the primary cell information can include a cell ID.

[0084] - a secondary cell list: this list includes at least one cell identified by its cell ID (e.g., sCellld). This list can be used as a backup list if the connection to the primary cell fails, or can be used to connect a second direct path. For example, the configuration message can include backup cell information (e.g., a secondary cell list), and the backup cell information can include a cell ID of each of the at least one secondary cell, where the backup cell information (e.g., the secondary cell list) is used to identify at least one secondary cell to establish a connection (e.g., for a direct path between the UE and the network) with the UE to provide a multi-path in case of a failure of establishing a connection with the primary cell identified by the primary cell information.

[0085] - a path ID for identifying each connection / path. If the RRCReconfiguration has included an identifier as part of the configuration of the UE, the UE considers the procedure as a path modification, otherwise the UE considers the procedure as a path addition.

[0086] The above two lists can be concatenated into a single list, and an additional element can indicate the number of indirect paths to be established.

[0087] Further, the RRCReconfiguration message includes configuration information for one or more additional paths and / or for the communication path to be updated / changed / modified. The configuration information for an indirect path can include a PC5 relay RLC channel configuration for relay traffic and associated end-to-end radio bearer(s). The configuration information for an indirect path (e.g., an information element for configuration of an indirect path) can also include information for indicating to the remote UE that the remote UE is to trigger the relay node to enter an RRC-CONNECTED state by using a PC5 message (as further discussed in Figure 8 ). This information can be a bit or a field or a flag in the configuration message.

[0088] In an aspect, the RRCReconfiguration message 321 includes only the configuration related to the new path or the path to be modified (and the multipath information or information indicating that multiple paths are to be configured). The remote UE 112 infers based on the multipath information that this configuration is for a multipath setup. This multipath information or information indicating that multiple paths are to be configured can be a bit or field set to 1 or enabled or true (e.g., a multipath bit or field), or an information element including all information related to the multipath configuration, or the presence of SCell configuration or SpCell configuration in the CellGroupConfig information element carried in the RRCReconfiguration message (in addition to the relay UE identity(s) for the new or modified indirect path). In another aspect, the RRCReconfiguration message can include the configuration of all paths, existing path(s) and new (or to be modified) path(s). The full configuration can be included if a fullconfig flag carried in the RRCReconfiguration message is set to true.

[0089] By providing the multipath information in the configuration message sent to the remote UE, the remote UE 112 is informed that a multipath is to be setup or the existing multipath configuration is to be changed / modified. This also means that only the configuration information of the new path or the path to be modified needs to be sent to the remote UE.

[0090] In another aspect, if the new path to be setup involves another or second base station (such as base station 102), the mrdc-SecondaryCellGroup information element can also be included in the configuration message 321. This element included in the configuration message 321 includes an RRCReconfiguration message as generated by the second base station and thus includes configuration information for configuring at least one communication path between the UE and the second base station. This second RRCReconfiguration can also include the configuration for the direct path or indirect path or both as described above. For example, the remote UE 112 will be connected to the base station 101 through the relay UE 110 and directly to the second base station 102.

[0091] Base station 101 selects a relay UE to add an indirect path based on information included in measurement reports received at base station 101 from different UEs (measurement report 311a from remote UE 112, measurement report 311b from relay UE 110, and measurement report 311c from relay UE 120). Base station 101 evaluates the different relays included in the measurement report of remote UE 112 by evaluating global connectivity (i.e., different hops in the paths of the various relay UEs). If the available relays reported by remote UE 112 suffer from unstable link quality and are therefore prone to connection failures, RRC reconfiguration may include a primary relay UE or a target relay UE (or, in the case of adding multiple indirect paths, multiple such relays) and one or more backup relays. In relay selection, when selecting one or more primary relay UEs, base station 101 may prioritize relay UEs already in the RRC_CONNECTED (RRC connected) state to reduce the latency of new path establishment. If one or more relay UEs reported by remote UE 112 are not in the RRC_CONNECTED state, base station 101 may also include backup relays in RRC_Reconfiguration if there are insufficient primary relay UEs selected. For example, if a primary relay UE in RRC_INACTIVE (RRC inactive) or RRC_IDLE (RRC idle) state has already performed or is in the process of cell reselection to another base station (e.g., base station 102), path establishment may fail when a remote UE attempts to connect to base station 101.

[0092] Upon receiving an RRC reconfiguration message 321 including multipath information from the first base station 101 as described above, the remote UE 112 starts a Path_Addition_Modification_failure timer in step 331 and attempts to establish (one or more) additional paths to set up multipathing or modify existing paths in the multipath between the remote UE 112 and the network. The Path_Addition_Modification_failure timer (not shown in the figure) can be implemented in hardware or software (e.g., through a module including a program containing instructions to be executed by one or more processing units, such as central processing unit 1711, etc.) and is configured to time a certain or predefined period of time from the timer's start (i.e., when the path failure timer reaches a certain or predefined value). Figure 3In the example of FIG. 3, the remote UE 112 is notified to add an indirect path through the relay UE 110 to set up a multi-path. Then, the remote UE 112 attempts to establish a PC5 connection with the relay UE 110 identified in the RRC reconfiguration. The establishment of the PC5 connection is exemplified by the message exchange 322. With reference to Figure 8 The PC5 connection establishment procedure 322 is further described. In the example of the present figure, the PC5 connection establishment between the remote UE 112 and the relay UE 110 is successfully completed. As a result, the remote UE 112 and the relay UE 110 are able to directly communicate with each other. At the same time, the base station 101 sends an RRC reconfiguration 341 to the primary relay UE 110, the RRC reconfiguration 341 including the remote UE identifier (local and L2 ID), the RLC layer configuration (Uu and PC5 RLC channel configuration for relaying) and the SRAP configuration (bearer mapping configuration as described above). The relay UE 110 configures its different layers as instructed by the RRC reconfiguration message 341 to enable its L2 relay functionality. Then, the relay UE 110 sends an RRC reconfiguration complete message 342 to the base station 101 in response. The reception of this RRC reconfiguration message 342 completes the relay UE configuration procedure. In the example of FIG. 3, the RRC reconfiguration 341 is sent by the base station 101 to the relay UE 110 after the establishment of the PC5 connection between the remote UE 112 and the relay UE 110. However, the RRC reconfiguration 341 can be sent by the base station 101 at any time between the step 320 and the message 323, as described in the example of FIG. 4. Figure 3 In the example of FIG. 3, the relay UE is already in RRC_CONNECTED state, so that the base station 101 can send the RRC reconfiguration message 341 at any time between the step 320 and the message 323. With reference to Figure 4 , Figure 5 , Figure 6 and Figure 7 The description of FIG. 2 and FIG. 3 describes some examples where the selected relay UE is in RRC_IDLE or RRC_INACTIVE state, i.e. not in RRC_CONNECTED state.

[0093] In a variant with several relays (backup relays and / or multiple indirect paths), the base station 101 can transmit a configuration to several relays (e.g. an RRC reconfiguration procedure 340 in addition to the RRC reconfiguration 341). Considering the uncertainty of the use of the configuration by the backup relays, the base station 101 can provide the configuration for the relays as a conditional configuration, i.e. the configuration for the relays should be applied if the remote UE establishes a PC5 connection with the backup relay. Moreover, the configuration can be cancelled after a predefined time period.

[0094] Returning to the remote UE 112, and after the PC5 connection is established, the remote UE 112 configures its different layers according to the configuration (e.g., configuration information) received from the base station 101 in the RRC reconfiguration message 321. At this time, for example, the remote UE 112 applies a signal radio bearer (control plane) configuration (if any) for the new indirect path. If SRB1 is configured for this new path, the remote UE 112 can send an RRC reconfiguration message 323 to the base station 101 via the relay UE 110 using this new path. On one hand, successful transmission of the RRC reconfiguration message 323 (e.g., the remote UE 112 can determine that the transmission of the RRC reconfiguration message 323 is successful when it receives an acknowledgment of the RRC reconfiguration message 323 from the base station 101 or from the relay 110) confirms the addition of the path and thus the multipath setup at the remote UE side 112, and then the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332 after the successful transmission of the RRC reconfiguration message 323. On the other hand, when the RRC reconfiguration message is received at base station 101, base station 101 completes the path addition process and multipath setup (step 350). As a result, base station 101 and remote UE 112 can communicate with each other via two paths of multipath (a direct path and an indirect path via relay UE 110). In other words, remote UE 112 transmits some uplink data or UL user data to first base station 101 directly via the direct path shown as UL / DL user data 360a, or via the indirect path shown as UL / DL user data 360b via relay UE, and / or first base station 101 transmits some downlink data or DL ​​user data to remote UE 112.

[0095] Now for reference Figure 4 , Figure 4 This illustrates one or more embodiments of the invention for managing, such as Figure 1 a The diagram illustrates a simplified example of multipath communication in a relay-supported wireless communication system, particularly for managing the path addition process to enable multipath message flows including a direct path and an indirect path. Figure 4In some embodiments, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC CONNECTED. This figure illustrates a way to move a relay UE from an RRC IDLE or RRC INACTIVE state to an RRC CONNECTED state according to one example. In the example of this figure, a trigger to move the relay UE from a non-connected RRC state (e.g., from RRC INACTIVE or RRC IDLE) to an RRC CONNECTED state is sent by the network. Figure 4 In some embodiments, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC CONNECTED. This figure illustrates a way to move a relay UE from an RRC IDLE or RRC INACTIVE state to an RRC CONNECTED state according to one example. In the example of this figure, a trigger to move the relay UE from a non-connected RRC state (e.g., from RRC INACTIVE or RRC IDLE) to an RRC CONNECTED state is sent by the network. Figure 3 In some embodiments, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC CONNECTED. This figure illustrates a way to move a relay UE from an RRC IDLE or RRC INACTIVE state to an RRC CONNECTED state according to one example. In the example of this figure, a trigger to move the relay UE from a non-connected RRC state (e.g., from RRC INACTIVE or RRC IDLE) to an RRC CONNECTED state is sent by the network. Figure 4 In some embodiments, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC CONNECTED. This figure illustrates a way to move a relay UE from an RRC IDLE or RRC INACTIVE state to an RRC CONNECTED state according to one example. In the example of this figure, a trigger to move the relay UE from a non-connected RRC state (e.g., from RRC INACTIVE or RRC IDLE) to an RRC CONNECTED state is sent by the network. Figure 3 In some embodiments, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC CONNECTED. This figure illustrates a way to move a relay UE from an RRC IDLE or RRC INACTIVE state to an RRC CONNECTED state according to one example. In the example of this figure, a trigger to move the relay UE from a non-connected RRC state (e.g., from RRC INACTIVE or RRC IDLE) to an RRC CONNECTED state is sent by the network. Figure 3 In some embodiments, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC CONNECTED. This figure illustrates a way to move a relay UE from an RRC IDLE or RRC INACTIVE state to an RRC CONNECTED state according to one example. In the example of this figure, a trigger to move the relay UE from a non-connected RRC state (e.g., from RRC INACTIVE or RRC IDLE) to an RRC CONNECTED state is sent by the network.

[0096] In one example, a remote UE, such as remote UE 112, is connected to a base station, such as base station 101 (also referred to as gNB 101), etc. Remote UE 112 and base station 101 (also referred to as first base station 101) communicate with each other, in other words, remote UE 112 transmits some uplink data or UL user data 310 to first base station 101 and / or first base station 101 transmits some downlink data or DL user data 310 to remote UE 112.

[0097] Remote UE 112 can also send some measurement reports to first base station 101 through measurement report messages 311 defined in 3GPP TS 38.331, respectively.

[0098] Based on the information carried by the received measurement report messages, first base station 101 can decide to adapt the connection or connectivity of remote UE 101 to the network (step 320). In another variant illustrated in this figure, step 320 can be triggered upon detection of a QoS failure (latency, reliability) or a request from the core network, or when the resources allocated to the remote UE are not sufficient to meet the bandwidth needs (continuous reporting of BSR with increased buffer size) or the remote UE requests. Then, in this case, base station 101 requests measurement reports to remote UE 112 to obtain information on its environment, especially surrounding cells and relays.

[0099] In one aspect, during PDU session (end-to-end user plane session) resource setup or PDU session resource modification, the core network (e.g., core network entity 140, such as an AMF, etc.) sends a message to the base station (e.g., base station 101, also referred to as gNB 101, etc.) to request a measurement report from the remote UE (e.g., remote UE 112). Figure 1 bThe AMF entity, SMF entity, UPF entity, etc. shown can request monitoring of QoS (QoS monitoring request field in QoS flow level QoS parameters subclause 9.3.1.12 in TS 38.413). During the monitoring, the base station 101 or gNB can detect that the QoS requirements are no longer fulfilled for some UEs and thus decides to set up multipath (step 320). In a variant, the gNB 101 can inform the core network of the QoS problem through some QoS monitoring report 315 (specified in TS 23.501). Based on this report, the core network can request (message 316) the base station 101 to set up multipath to, for example, maintain the specified QoS. This multipath setup can be requested by the core network during PDU session resource setup or PDU session resource modification. In this variant, the base station 101 can inform the core network that the multipath has been successfully set up (or modified) by sending message MP setup acknowledgement (MP modification acknowledgement) 351.

[0100] The first base station 101 can inform the remote UE 112 to perform connection adaptation, i.e. to set up one or more additional paths or modify existing paths by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331.

[0101] In an aspect, the RRC reconfiguration message 321 comprises all or part of the information elements or information described in the foregoing description. Figure 3

[0102] Upon reception of the RRC reconfiguration message 321 including multipath information from the first base station 101 as described above, the remote UE 112 proceeds to add a new indirect path according to the information elements carried in the RRC reconfiguration 321. The path addition process at the remote UE starts with the initiation of the Path_Addition_Modification_failure timer in step 331, then the remote UE attempts to establish a PC5 connection with the primary relay UE identified by the identifier carried in the RRC reconfiguration 321 (e.g. targetRelayUE-Identity as specified in TS 38.331).

[0103] The establishment of the PC5 connection is exemplified by message exchange 322. Reference is made to Figure 8 The PC5 connection establishment procedure 322 is further described. In the example of the present figure, the PC5 connection establishment between the remote UE 112 and the relay UE 110 is successfully completed. As a result, the remote UE 112 and the relay UE 110 are able to directly communicate with each other.

[0104] ​Back to the base station 101, in step 320, the base station 101 informs or determines that the selected relay UE (e.g., relay UE 110) included or to be included in the RRC reconfiguration message 321 is not in RRC CONNECTED state. Then, the base station 101 can decide to send a trigger message to the selected relay UE. This message 400 is intended to trigger the L2 U2N relay UE to enter the RRC CONNECTED state.

[0105] In an aspect, this trigger message 400 can be a paging message as defined in TS 38.331. This paging message can include the identity of the relay UE 110 and a paging cause indicating that the relay UE should start a connection procedure. In a variant, the paging message can include a paging record indicating that the base station 101 has some data / control to send to the relay UE 110 for the remote UE 112. Note that the paging message will typically have to be sent within a specific time period called the paging occasion, in which the UE (even in power saving) has to be woken up to monitor in case the network sends any paging to it.

[0106] In another aspect, the base station 101 can use a system information block including a list of UE(s) that need to enter RRC CONNECTED. In the case of sidelink relaying, this SIB can be SIB12.

[0107] In a variant, a new message can be used to trigger the relay UE 110 to enter RRC CONNECTED.

[0108] Then, upon or after receiving the network trigger relay message 400, the relay UE 110 attempts to establish an RRC connection with the base station 101. To do so, the relay UE 110 follows the RRC Resume or RRC Setup procedure as defined in TS 38.331 clause 5.3.13 and 5.3.3, respectively. The RRC Resume / Setup is exemplified by the message or frame exchange 410.

[0109] Then, the base station 101 sends an RRC reconfiguration 341 to the primary relay UE 110 that just entered the RRC CONNECTED state, including the remote UE identifiers (local and L2 ID) as described above, the RLC layer configuration (Uu and PC5 RLC channel configuration for relaying) and the SRAP configuration (bearer mapping configuration). The relay UE 110 configures its different layers according to the RRC reconfiguration message to enable its L2 relay functionality. Then, as a response to the base station 101, the relay UE 110 sends an RRC reconfiguration complete message 342. The reception of this RRC reconfiguration message 342 completes the relay UE configuration procedure.

[0110] Returning to the remote UE 112, and after the PC5 connection establishment procedure 322 is completed, the remote UE 112 configures its different layers according to the configuration received from the base station 101 in the RRC reconfiguration message 321. At this time, the remote UE applies (or has applied) the signal radio bearer (control plane) configuration (if any) for the new indirect path. If SRB1 is configured for the new path, the remote UE 112 can send the RRC reconfiguration message 323 to the base station 101 via the relay UE 110 using the new path. On one hand, the successful transmission of the RRC reconfiguration message 323 confirms the addition of the path and thus the multipath setting on the remote UE side, and then, as described above, the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332. On the other hand, when the RRC reconfiguration message 323 is received at the base station 101, the base station 101 completes the path addition procedure and the multipath setting (step 350). As a result, base station 101 and remote UE 112 can communicate with each other via two paths (a direct path and an indirect path via relay UE 110). In other words, remote UE 112 transmits some uplink data or UL user data to first base station 101, and / or first base station 101 transmits some downlink data or DL ​​user data to remote UE 112 directly 360a or via relay UE 360b.

[0111] Now for reference Figure 5 , Figure 5 This is an example used to manage things such as Figure 1 a The diagram illustrates a simplified example of multipath communication in a relay-supported wireless communication system, particularly for managing the path addition process to enable a multipath message flow including a direct path and an indirect path. In this diagram, when relay UE 110 is selected as the relay UE in the multipath configuration, relay UE 110 is not in RRC_CONNECTED. The diagram illustrates, according to an example, how relay UE 110 is moved from a non-connected RRC state (such as RRC_IDLE or RRC_INACTIVE) to the RRC_CONNECTED state. In the example in this diagram, the network triggers relay UE 110 to enter the RRC_CONNECTED state. When relay UE 110 has effectively entered RRC_CONNECTED and its relay configuration has been applied, relay UE 110 notifies remote UE 112. Figure 5 Zhongyu Figure 3 and Figure 4 The same elements (e.g., steps, messages, frames, entities, nodes, etc.) are represented by the same reference numerals. For simplicity, this will refer to... Figure 5 Omission and Figure 3and Figure 4 the same elements, but the details of these same elements can be found in the above Figure 3 and Figure 4 descriptions.

[0112] In one example, a remote UE, such as remote UE 112, connects to a base station, such as base station 101. The remote UE 112 and the base station 101 communicate with each other, in other words, the remote UE 112 transmits some uplink data or UL user data 310 to the first base station 101 and / or the first base station transmits some downlink data or DL user data 310 to the remote UE 112.

[0113] The remote UE 112 can also send some measurement reports to the first base station 101 through the measurement report message 311 defined in 3GPP TS 38.331, respectively.

[0114] Based on the information carried by the received measurement report message, the first base station 101 can decide to adapt the connection or connectivity of the remote UE 112 to the network (step 320).

[0115] The first base station 101 can inform the remote UE 112 to make the connection adaptation, i.e., to set up one or more additional paths or modify the existing path by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331.

[0116] In an aspect, the RRC reconfiguration message 321 includes all or part of the information elements or information described in the foregoing descriptions of Figure 3

[0117] Upon receiving the RRC reconfiguration message 321 including the multi-path information from the first base station 101 as described above, the remote UE 112 continues to add a new indirect path according to the information elements carried in the RRC reconfiguration 321. The path addition process at the remote UE 112 starts with the initiation of the Path_Addition_Modification_failure timer in step 331, then the remote UE 112 attempts to establish a PC5 connection with the primary relay UE identified by the identifier carried in the RRC reconfiguration 321, e.g., targetRelayUE-Identity as specified in TS 38.331.

[0118] The establishment of the PC5 connection is exemplified by message exchange 322. Reference is made to Figure 8 The PC5 connection establishment procedure 322 is further described. In the example of the present figure, the PC5 connection establishment between the remote UE 112 and the relay UE 110 is successfully completed. As a result, the remote UE 112 and the relay UE 110 are able to directly communicate with each other.​

[0119] Back to the base station 101, in step 320, the base station informs or determines that the selected relay UE (e.g., relay UE 110) included or to be included in the RRC reconfiguration message 321 is not in RRC CONNECTED state. Then, the base station 101 can decide to send a trigger message to the selected relay UE 110. This message 400 is intended to trigger the relay UE to enter RRC CONNECTED state.

[0120] Then, upon reception of the network trigger relay message 400, the relay UE 110 attempts to establish an RRC connection with the base station 101. To this end, the relay UE 110 follows the RRC resume or RRC setup procedure as defined in TS 38.331 clauses 5.3.13 and 5.3.3, respectively. The RRC resume / setup is exemplified by the frame or message exchange 410.

[0121] Then, the base station 101 sends to the primary relay UE 110, which just entered the RRC CONNECTED state, an RRC reconfiguration message 341 including the remote UE identifier (local and L2 ID), the RLC layer configuration (Uu and PC5 RLC channel configuration for relaying) and the SRAP configuration (bearer mapping configuration). The relay UE 110 configures its different layers according to the RRC reconfiguration message 341 to enable its L2 relay functionality. Then, as a response to the base station 101, the relay UE 110 sends an RRC reconfiguration complete message 342. The reception of this RRC reconfiguration message 342 completes the relay UE configuration procedure.

[0122] Once the relay UE 110 has sent the message 342, the relay UE 110 sends a notification (relay feedback 500) to the remote UE 112 to inform the latter that it (relay UE 110) has entered the RRC CONNECTED state and has applied the relay configuration and can thus be used as an active relay for the remote UE 112. The relay feedback message includes a feedback cause set to relayUE-RRC-CONNECTED.

[0123] In an aspect, this relay feedback message 500 can be a NotificationMessageSidelink message as defined in TS 38.331 clause 6.6.2 with a new input “relayUE-RRC-Connected” in indicationType.

[0124] In another variant, the relay feedback message 500 can be a RRCReconfigurationCompleteSidelink message as defined in TS 38.331. This message is as referenced in Figure 8 Further part of the PC5 connection establishment procedure or state 322 is described, and is transmitted in response to the RRCReconfigurationSidelink 811. In this variant, the relay UE 110 can delay the transmission of the RRCReconfigurationCompleteSidelink 812 to the remote UE 112 until it enters the RRC_CONNECTED state. By doing so, the reception of the RRCReconfigurationCompleteSidelink 812 (e.g. as relay feedback message 500) at the remote UE 112 indicates both that the sidelink configuration has been successfully and that the relay UE 110 is in the RRC_CONNECTED state.

[0125] Upon reception of the relay feedback message 500 indicating that the relay UE 110 is now RRC_CONNECTED, the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332. Indeed, the remote UE 112 considers the reception of the relay feedback message 500 as the completion of the addition of the new indirect path. The reception of the relay feedback message 500 is a stop condition of the Path_Addition_Modification_failure timer.

[0126] At this point, the remote UE 112 applies (or has already applied) the remote UE configuration included in the RRC reconfiguration message 321 for the new indirect path, i.e. the PC5 relay RLC channel configuration and the associated end-to-end radio bearer(s) for the relay traffic. Among the end-to-end radio bearer(s), the configuration of the signalling radio bearer (SRB dedicated to the control plane) can have an impact on the way the path addition or path modification procedure is completed. Indeed, if SRB1 is configured for this new path, the remote UE 112 can send an RRC reconfiguration message 323 (as shown in Figure 3 and Figure 4 ) to the base station via the relay UE 110 using this new path. Otherwise, the remote UE 112 sends the RRC reconfiguration complete message 501 through the previously existing path for which SRB1 or more generally the control plane is configured.

[0127] The reception of the RRC Reconfiguration message 501 at the base station 101 completes the procedure of path addition (modification) and the setup of the multiple paths (step 350). As a result, the base station 101 and the remote UE 112 can communicate with each other via two paths (the direct path and the indirect path through the relay). In other words, the remote UE 112 transmits some uplink data or UL user data to the first base station 101 and / or the first base station 101 transmits some downlink data or DL user data to the remote UE 112 either directly via the direct path as indicated by the UL / DL user data 360a or indirectly via the indirect path through the relay UE as indicated by the UL / DL user data 360b.

[0128] Reference will now be made to Figure 6 , Figure 6 is a simplified schematic diagram illustrating an example of a message flow for managing a multi-path communication in a relay supported wireless communication system such as the one shown in Figure 1 a Fig. 1 in accordance with one or more embodiments of the present application. In this diagram, when the relay UE 110 is selected to be used as a relay UE in a multi-path configuration, the relay UE 110 is not in RRC_CONNECTED. This diagram illustrates how the network triggers the relay UE to enter the RRC_CONNECTED state according to one example. However, in this diagram, the network triggers the relay UE once it has received the RRCReconfigurationComplete message from the remote UE over the direct path. Figure 6 The same elements (e.g., steps, messages, frames, entities, nodes, etc.) in Figure 3 , Figure 4 and Figure 5 are denoted by the same reference signs. For simplicity of the description, the description of the same elements will be omitted here for Figure 6 but the details of these same elements can be found in the description of Figure 3 , Figure 4 and Figure 5 above. Figure 3 , Figure 4 and Figure 5 .

[0129] This Figure 6The procedure in Figure 10 starts as the procedure of the previous figures. Remote UE 112 and base station 101 communicate with each other (e.g. UL / DL user data 310). When its environment modifies (e.g. link quality or signal strength with the candidate relay UE(s) improves or link quality or signal strength with its serving cell degrades, etc.), remote UE 112 sends a measurement report 311a to base station 101. The measurement report includes one or more candidate relay UE and Uu (surrounding cell) measurements. Each candidate relay UE is identified by its relay UE ID and its serving cell, and is accompanied with sidelink measurement quantity information, e.g. SL-RSRP or SD-RSRP as referred to in the previous figures. Base station 101 can also receive measurement report information (e.g. measurement report 311b) from UEs that can be candidates for relaying for remote UE 112. Figure 3

[0130] For example, based on the information carried by the received measurement report messages (311a, 311b), base station 101 can decide in step 320 to adapt the remote UE configuration to set up multiple paths in order to improve the connection (reliability, bandwidth,...) between remote UE 112 and the network. Then, first base station 101 informs remote UE 112 to perform connection adaptation, i.e. to set up one or more additional paths or modify existing paths, by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331. As mentioned above, this message 321 can also include multiple path information, relay list and backup relay list, primary cell, secondary cell list, path ID for each configured path (each element is optional and added by the base station on purpose).

[0131] Upon reception of the RRC reconfiguration message 321 including multiple path information from first base station 101 as described above, remote UE 112 proceeds to add a new indirect path according to the information elements carried in RRC reconfiguration 321. The path addition process at remote UE 112 starts with the initiation of a Path_Addition_Modification_failure timer in step 331, then remote UE 112 attempts to establish a PC5 connection with the primary relay UE identified by the identifier carried in RRC reconfiguration 321 (e.g. targetRelayUE-Identity as specified in TS 38.331). At the same time, remote UE 112 applies the remote UE configuration included in RRC reconfiguration message 321 for the new indirect path, i.e. the PC5 relay RLC channel configuration for relay traffic and the associated end-to-end radio bearer(s).

[0132] ​In an aspect, the remote UE 112 can send a UEAssistanceInformation message 610 to the base station 101 in response to the RRCReconfiguration 321 or at any other moment in time prior to receiving the RRCReconfiguration 321. This message can include all or part of the following information elements or information:

[0133] - the remote UE’s preference on the relay UE selection, i.e., whether the remote UE prefers a relay UE in RRC CONNECTED state (preferredRelayUE-RRC-State: connected, idle, inactive, no_preference) and whether the relay UE can belong to a different cell or gNB than the remote UE serving cell (preferredRelayUE-cell: intra-cell, inter-cell, inter-gNB). If this element is set to RRC CONNECTED for the relay UE preference state, the network can select a relay UE in RRC INACTIVE or RRC IDLE, but the network is responsible for triggering the selected relay UE to connect to the network and enter RRC CONNECTED state. This preference can also be referred to as relay state preference information.

[0134] - the remote UE’s preference on triggering the relay UE, i.e., whether the remote UE prefers to trigger the relay UE to enter RRC CONNECTED or whether the remote UE prefers the network to trigger the relay UE to enter RRC CONNECTED (preferredRelayUE-trigger: PC5, network). If the preference is set to network, it means that the network has to trigger the relay UE or configure SRB1 on the new path (via the relay UE) to allow the use of, e.g., RRCReconfigurationComplete message as a trigger for the relay UE on the new path. This preference can also be referred to as relay trigger preference information.

[0135] In the example of Figure 6 In this example, the remote UE 112 informs the base station 101 that the remote UE 112 prefers the network to trigger the relay UE 110.

[0136] For example, if the relay UE 110 does not support PC5_trigger to enter RRC CONNECTED and its current state is not RRC CONNECTED, the UEAssistanceInformation message 610 can also be sent after the PC5 setup to require the network to trigger the relay UE 110 to enter RRC CONNECTED. The capabilities of the remote UE 112 and the relay UE 110 can be provided through, e.g., the UEAssistanceInformation message 610 as referred to in Figure 8The described UECapabilitylnformationSidelink to share.

[0137] In another aspect, the remote UE and the relay UE can inform the base station 101 of their capability to support PC5_trigger (as transmitter or receiver). This information can be part of the UECapabilitylnformation message.

[0138] In another aspect, this information can be part of the SidelinkUEInformationNR.

[0139] If the capability to support PC5_trigger is received after sending the RRCReconfiguration 321 requiring the remote UE to adapt its connectivity, and this RRCReconfiguration is not suitable for the actual capability of the UE, the gNB can send a new RRCReconfiguration allowing the configuration with SRB1 on the indirect path or by requiring the remote UE to use the PC5_RRC trigger to trigger the relay.

[0140] When the establishment of the PC5 connection 322 is successfully completed, i.e. the remote UE 112 and the relay UE 110 can directly communicate with each other, the remote UE 112 sends an RRCReconfigurationComplete message 501 to the base station 101. The message 501 is sent on the direct path which can be indicated by the non-configuration of the control path on the new indirect path or can be decided for any other reason.

[0141] Upon reception of the RRCReconfigurationComplete message 501 and in order to complete the multi-path setup, the base station 101 checks in step 600 the actual status of the relay UE 110. If the latter is RRC_INACTIVE or RRC_IDLE, the base station 101 sends a message 400 (e.g. a paging or SIB12) to trigger the relay UE 110 to enter the RRC_CONNECTED state. Thus, the relay UE 110 attempts to setup an RRC connection with the base station 101 by the RRC resume or RRC setup procedure defined in TS 38.331 clauses 5.3.13 and 5.3.3 respectively. The RRC resume / setup is exemplified by the frame or message exchange 410.

[0142] Once in RRC CONNECTED state, the relay UE 110 receives an RRC reconfiguration message 341 including the remote UE identifier (local and L2 ID), RLC layer configuration (Uu and PC5 RLC channel configuration for relaying) and SRAP configuration (bearer mapping configuration). The relay UE 110 configures its different layers according to the RRC reconfiguration message 341 to enable its L2 relay functionality. Then, as a response to the base station 101, the relay UE 110 sends a relay feedback message 500 to the remote UE 112, such as an RRC reconfiguration complete message 342.

[0143] When receiving the RRC reconfiguration message 342, the base station 101 considers that the relay UE configuration procedure and the multipath setup have been completed (step 350).

[0144] Upon reception of the relay feedback message 500 indicating that the relay UE 110 is now in RRC CONNECTED, the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332. Indeed, the remote UE 112 considers that the reception of the relay feedback message completes the addition of the new indirect path. The reception of the relay feedback message 500 is a stop condition for the Path_Addition_Modification_failure timer.

[0145] As a result, the base station 101 and the remote UE 112 can communicate with each other via two paths (direct path and indirect path through the relay UE 110). In other words, the remote UE 112 transmits some uplink data or UL user data to the first base station 101 either directly via the direct path as illustrated by UL / DL user data 360a or indirectly via the relay UE as illustrated by UL / DL user data 360b, and / or the first base station 101 transmits some downlink data or DL user data to the remote UE either directly via the direct path as illustrated by UL / DL user data 360a or indirectly via the relay UE as illustrated by UL / DL user data 360b.

[0146] Reference is now made to Figure 7 , Figure 7 is a simplified schematic diagram illustrating an example of a message flow for managing a multipath communication in a relay supported wireless communication system such as the one illustrated in Figure 1 a the figure illustrates how, according to one example, the remote UE triggers the relay UE to enter the RRC CONNECTED state when the relay UE 110 is selected to be used as a relay UE in a multipath configuration. Figure 7 withFigures 3 to 6 Elements (e.g., steps, messages, frames, entities, nodes, etc.) common to the figures are denoted with the same reference label. For the sake of conciseness, the description herein will be made Figure 7 with reference to Figures 3 to 6 the same elements being omitted from the description of Figures 3 to 6 the figures.

[0147] The remote UE 112 and the base station 101 communicate with each other (e.g., UL / DL user data 310). Upon an environmental modification (e.g., an improvement of the link quality or signal strength with the candidate relay UE(s) or a decrease of the link quality or signal strength with its serving cell, etc.), the remote UE 112 sends a measurement report 311a to the base station 101. The measurement report includes one or more candidate relay UE and Uu (surrounding cell) measurements. Each candidate relay UE is identified by its relay UE ID and its serving cell, and is accompanied with sidelink measurement quantity information, e.g., SL-RSRP or SD-RSRP as described with reference to Figure 3 The base station 101 can also receive measurement report information (e.g., measurement report 311b) from UEs that can be candidates for relaying for the remote UE 112.

[0148] For example, based on the information carried by the received measurement report messages (311a, 311b), the base station 101 can decide in step 320 to adapt the remote UE configuration to set up multiple paths in order to improve the connection (reliability, bandwidth,...) between the remote UE and the network. Then, the first base station 101 informs the remote UE 112 to perform connection adaptation, i.e., to set up one or more additional paths or to modify an existing path, by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331. As mentioned above, this message 321 can also include multiple path information, a relay list, a backup relay list, a primary cell, a secondary cell list, and a path ID for each configured path (each element is optional and added by the base station on purpose).

[0149] Upon receiving the RRC Reconfiguration message 321 including the multipath information from the first base station as described above, the remote UE 112 continues to add the new indirect path according to the information elements carried in the RRC Reconfiguration 321. The path addition process at the remote UE 112 starts with the initiation of the Path_Addition_Modification_failure timer in step 331, then the remote UE 112 attempts to establish a PC5 connection with the primary relay UE identified by the identifier carried in the RRC Reconfiguration 321 (e.g., targetRelayUE-Identity as specified in TS 38.331). At the same time, the remote UE 112 applies the remote UE configuration included in the RRC Reconfiguration message 321, i.e., the PC5 relay RLC channel configuration and associated end-to-end radio bearer(s) for relay traffic, for the new indirect path.

[0150] Once the PC5 connection is established after the PC5 connection establishment 322, the remote UE 112 sends a message 700 to trigger the relay UE 110 to enter the RRC_CONNECTED state. This message can be sent regardless of the RRC state of the relay UE 110. In another variant, the relay UE 110 can inform the remote UE of its RRC state before the remote UE 112 sends the trigger message 700.

[0151] According to an aspect, this trigger message 700 can be a RemoteUEInformationSidelink as specified in TS 38.331. However, in this new use, the RemoteUEInformationSidelink message is sent when the remote UE 112 is in RRC_CONNECTED. In this case, the RemoteUEInformationSidelink message includes a new IE Sl_RelayUE_RRCConnected_Req that, if present, requests the relay UE 110 to enter the RRC_CONNECTED state.

[0152] Upon receiving the message 700, the relay UE 110 not in RRC_CONNECTED state starts the procedure to connect to the base station 101 through an RRC resume or RRC setup procedure as defined in TS 38.331. The RRC resume / setup is exemplified by the frame or message exchange 410.

[0153] Once in RRC_CONNECTED state, the relay UE 110 sends a relay feedback message 500 to the remote UE 112. When receiving the relay feedback message 500 indicating that the relay UE 110 is now in RRC_CONNECTED, the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332.

[0154] The relay UE 110 can receive an RRC reconfiguration message 341 including a remote UE identifier (local and L2 ID), an RLC layer configuration (Uu and PC5 RLC channel configuration for relaying) and an SRAP configuration (bearer mapping configuration). The relay UE 110 configures its different layers according to the RRC reconfiguration message 341 to enable its L2 relaying functionality. Then, as a response to the base station 101, the relay UE 110 sends an RRC reconfiguration complete message 342. When receiving the RRC reconfiguration message 342, the base station 101 considers that the relay UE configuration procedure and the multi-path setup have been completed (step 350).

[0155] As a result, the base station 101 and the remote UE 112 can communicate with each other via two paths (direct path and indirect path through the relay UE 110). In other words, the remote UE 112 transmits some uplink data or UL user data to the first base station 101 either directly via the direct path as illustrated by UL / DL user data 360a or indirectly via the relay UE as illustrated by UL / DL user data 360b and / or the first base station 101 transmits some downlink data or DL user data to the remote UE 112 either directly via the direct path as illustrated by UL / DL user data 360a or indirectly via the relay UE as illustrated by UL / DL user data 360b.

[0156] Reference is now made to Figure 8 , Figure 8 is a simplified schematic diagram illustrating an example of a message flow for managing a multi-path communication in a relay supported wireless communication system such as the one illustrated in Figure 1 a . In this diagram, the relay UE 110 is not in RRC_CONNECTED when it is selected to be used as a relay UE in a multi-path configuration. The diagram illustrates how the remote UE 112 triggers the relay UE 110 to enter the RRC_CONNECTED state according to one example. The diagram presents an alternative to the one illustrated in Figure 7 . Figure 8 In contrast to Figures 3 to 7Elements (e.g., steps, messages, frames, entities, nodes, etc.) that are the same as in the previous figures are denoted by the same reference signs. To simplify the description, reference will be made here to Figure 8 the description of the previous figures, but the details of these same elements can be found in the description of the previous figures. Figures 3 to 7 Figures 3 to 7 The description of the same elements is omitted here, but the details of these same elements can be found in the description of the previous figures.

[0157] The remote UE 112 and the base station 101 communicate with each other (e.g., UL / DL user data 310). Upon an environment modification (e.g., an improvement of the link quality or signal strength with the candidate relay UE(s) or a decrease of the link quality or signal strength with its serving cell, etc.), the remote UE 112 sends a measurement report 311a to the base station 101. The measurement report includes one or more candidate relay UEs and Uu (surrounding cell) measurements. Each candidate relay UE is identified by its relay UE ID and its serving cell, and is accompanied by sidelink measurement quantity information, e.g., SL-RSRP or SD-RSRP as described with reference to Figure 3 The base station 101 can also receive measurement report information (e.g., measurement report 311b) from UEs that can be candidates for relaying for the remote UE 112.

[0158] For example, based on the information carried by the received measurement report messages (311a, 311b), the base station 101 can decide in step 320 to adapt the remote UE configuration to set up multiple paths in order to improve the connection (reliability, bandwidth,...) between the remote UE and the network. Then, the first base station 101 informs the remote UE 112 to perform a connection adaptation, i.e., to set up one or more additional paths or to modify an existing path, by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331. As mentioned above, this message 321 can also include multiple path information, a relay list, a backup relay list, a primary cell, a secondary cell list, a path ID for each configured path (each element is optional and added by the base station on purpose).

[0159] ​Upon reception of the RRC Reconfiguration message 321 including the multipath information from the first base station 101 as described above, the remote UE 112 proceeds to add the new indirect path according to the information elements carried in the RRC Reconfiguration 321. If the path addition configuration does not include an SRB1 configuration, it means that the remote UE 112 will not be able to send an RRCReconfigurationComplete over the new indirect path, so it will not be able to trigger a relay UE not in RRC_CONNECTED state by sending an RRCReconfigurationComplete message. Therefore, in this example, the remote UE 112 has to trigger the relay UE 110 with a PC5_trigger as described below. However, even if SRB1 or more generally the control plane is configured on this new path, the remote UE 112 can decide to use this PC5_trigger.

[0160] The path addition handling at the remote UE 112 starts with the start of the Path_Addition_Modification_failure timer in step 331, then the remote UE 112 tries to establish a PC5 connection with the primary relay UE identified by the identifier carried in the RRC Reconfiguration 321 (e.g. targetRelayUE-Identity as specified in TS 38.331). At the same time, the remote UE 112 applies the remote UE configuration included in the RRC Reconfiguration message 321 for the new indirect path, i.e. the PC5 Relay RLC channel configuration and the associated end-to-end radio bearer(s) for relay traffic.

[0161] The PC5 connection establishment 322 starts with a PC5-S frame exchange. The remote UE 112 sends a Direct Communication Request 801 to the relay UE 110 to initiate the PC5 connection establishment. The Direct Communication Request message 801 includes at least one of the following:

[0162] - Source user information: application layer ID of the initiating UE (i.e. application layer ID of the remote UE);

[0163] - Target user information: application layer ID of the target UE (i.e. application layer ID of the relay UE). This information can be provided by an upper layer (e.g. ProSe application);

[0164] - ProSe service information: information related to the ProSe identifier(s) requesting the link establishment;

[0165] - Security information: information for establishing security.

[0166] Two types of link establishment (as specified in TS 23.287) can be used: UE-oriented link establishment based on target user information (if target user information is included in the direct communication request), or ProSe service-oriented link establishment (if target user information is not included in the direct communication request).

[0167] If the included target user information matches the application layer ID of the relay UE, or if the announced ProSe service is of interest to the relay UE, the relay UE 110 that has successfully established security with the remote UE 112 sends a direct communication accept message to the remote UE 112 (security establishment is not shown autonomously in the figure for clarity). The direct communication accept message includes at least one of the following:

[0168] - Source user information: application layer ID of the UE sending the direct communication accept message (i.e. the relay UE);

[0169] - QoS information: information related to the PC5 QoS flow(s). For each PC5 QoS flow, a PC5 QoS flow identifier (PFI) and corresponding PC5 QoS parameters requested by the remote UE (i.e. PC5 5G QoS identifier (PQI) and conditional other parameters such as maximum flow bit rate (MFBR) / guaranteed flow bit rate (GFBR)) and optionally associated ProSe identifier(s).

[0170] - Optional PC5 QoS rule(s).

[0171] At the end of this direct communication request / accept exchange, the remote UE 112 and the relay UE 110 can use the PC5 link to communicate with each other.

[0172] The remote UE 112 can then initiate an RRCReconfigurationSidelink procedure. The purpose of this procedure is to modify the PC5-RRC connection, e.g., to establish / modify / release sidelink DRBs or PC5 relay RLC channels, to (re)configure NR sidelink measurements and reporting, etc. The remote UE 112 sends an RRCReconfigurationSidelink message 811 to the relay UE, which includes parameters or configuration information to configure the relay UE 110. In an aspect, the RRCReconfigurationSidelink sent by the remote UE 112 can include a new IE Sl_RelayUE_RRCConnected_Req, which, if present, requests the relay UE 110 to enter the RRC CONNECTED state.

[0173] Upon receiving the RRCReconfigurationSidelink message 811, the relay UE 110 can apply the received configuration and, in response, sends an RRCReconfigurationCompleteSidelink 812 to the remote UE 112 to acknowledge the configuration procedure. In an aspect, the relay UE 110 can include its RRC state to inform the remote UE 112 whether the relay UE 110 is RRC CONNECTED or not. The remote UE 112 can use this information to know whether it has to trigger the relay UE 110 to enter the RRC CONNECTED state. If the relay UE 110 cannot support the configuration informed by the remote UE 112, the relay UE sends an RRCReconfigurationFailureSidelink (not shown in the figure).

[0174] In another aspect, the remote UE 112 can configure the sidelink measurement report such that when the relay UE 110 enters RRC CONNECTED, or more generally, if its RRC state changes, the relay UE 110 sends a MeasurementReportSidelink 831. In this variant, in addition to the existing events (link quality level or signal strength of the serving cell of the relay UE 110 being below a predefined low threshold or above a predefined high threshold), new event(s) based on the RRC state are defined. In other words, a new event is defined to trigger the sending of a sidelink measurement report including the relay UE RRC state, and thus informing the remote UE about the relay UE RRC state change. Furthermore, the MeasurementReportSidelink 831 includes the RRC state as a new information element. Thereby, when the measurement report sidelink is configured (after sending the RRCReconfigurationCompleteSidelink 812), the relay UE 110 can inform its current RRC state to the remote UE 112, e.g., through the MeasurementReportSidelink message 831.

[0175] In an aspect, the remote UE 112 can inquire the capabilities of the relay UE 110 by sending a UECapabilityEnquirySidelink message 821. This message can optionally include the capabilities of the remote UE 112 in a UECapabilityInformationSidelink information element. This capability can carry information to inform or inform the relay UE 110 that the remote UE 112 supports sending a message (e.g., message 700) to trigger the relay UE to enter RRC_CONNECTED or has the capability to send a message (e.g., message 700) to trigger the relay UE to enter RRC_CONNECTED. From the remote UE’s perspective, this means it is able to send this trigger message (e.g., message 700) to the relay UE 110. In response, the relay UE 110 sends a UECapabilityInformationSidelink message 822 including the capabilities of the relay UE 110 and more particularly, if the relay UE 110 supports being triggered by the remote UE 112 to enter RRC_CONNECTED, the relay UE 110 sends information to the remote UE 112 indicating that the relay UE supports PC5_trigger to enter RRC_CONNECTED, for example. In a variant, this feature can be mandatory for Release 18 sidelink relay UEs, so a relay UE or remote UE that sets the AccessStratumReleaseSidelink field to rel18 in the UECapabilityInformationSidelink shall support this functionality (i.e., PC5_trigger). This message 822 can also be sent by the relay UE 110 autonomously to inform the remote UE 112 of its capabilities. The UEs capabilities can also be exchanged prior to the RRCReconfigurationSidelink procedure (frame exchange 811 / 812) as long as the direct communication is established.

[0176] In a variant, the relay UE 110 can inform the remote UE 112 of its preference to be triggered over PC5_RRC or by receiving an RRC message (e.g., RRCReconfigurationComplete message) via SRB. In an example, the relay UE 110 can use the UECapabilityInformationSidelink message to carry this preference information. The remote UE 112 can use this information to build its own preference which is sent to the gNB, for example, with the UECapabilityInformation message 610. The remote UE 112 can also forward this information to the gNB 101.

[0177] In the following description, Release 18 capability can refer to or indicate a relay UE’s support of PC5 triggering into RRC CONNECTED state. For example, in a case where the feature of supporting PC5 triggering is mandatory for Release 18 UEs, when a UE indicates it has Release 18 capability, such capability can indicate that the UE supports PC5 triggering into RRC CONNECTED state, where in the case of a relay UE, the relay UE can be triggered into RRC CONNECTED using a PC5 message (e.g., using a PC5 connection or link).

[0178] In a variant, the Release 18 capability can be carried in a discovery message shared between the relay UE and the remote UE. For example, as part of the discovery procedure (solicitation and response frame exchange), the relay UE can send the capability information indicating whether the relay node supports PC5 triggering to the remote UE in a discovery announcement message or in response to a request from the remote UE.

[0179] In another variant, the relay UE can transmit its capability to support PC5 triggering to the gNB in response to SIB12 or autonomously, e.g., in a SidelinkUEInformationNR message.

[0180] The Rel-18 capability can also be forwarded by the remote UE to the gNB (e.g., part of SidelinkUEInformationNR message). When receiving this capability, and similarly to receiving the remote UE preference on triggering the relay UE to enter RRC_CONNECTED state (see previous description), the gNB can include in the RRCReconfiguration message (such as message 321 or the like) an indication for the remote UE to trigger the relay UE. This indication can be implicit (i.e., if the configuration in the RRCReconfiguration message does not include SRB1 configuration for the new indirect path, the remote UE has to trigger the relay UE with a PC5_RRC trigger) or explicit. In the explicit case, the configuration message sent by the gNB to the remote UE can include information to indicate to the remote UE that the remote UE is to trigger the relay node to enter RRC-CONNECTED state by using a PC5 message. This information can be a bit or a field or a flag in the configuration message (RRCReconfiguration message 321). More specifically, this information can be included in the indirect path configuration. On the other hand, if the network learns that the relay UE does not support PC5_RRC trigger (e.g., the network learns that the relay UE is not a Rel-18 relay UE that supports PC5_RRC trigger), the gNB can decide to configure SRB1 on the new path so that the remote UE can send an RRCReconfigurationComplete message on the new path to trigger the relay UE to enter RRC_CONNECTED state. The acquisition of the UE capability can be explicit, i.e., the network can receive information from the UE (relay or remote or both) indicating or stating that the relay UE does not support PC5_RRC trigger, or the acquisition of the UE capability is implicit, where the network can not receive information related to the PC5_RRC trigger capability and therefore infer that the relay UE does not support PC5_RRC trigger. In both cases of not supporting PC5 trigger, the network can decide to trigger the relay UE, e.g., by sending SRB1 configuration to the remote UE to allow the remote UE to trigger the relay UE to enter RRC_CONNECTED, or by directly triggering by sending a paging message to trigger the relay UE to enter RRC_CONNECTED.

[0181] Once the PC5 connection is established after PC5 connection establishment 322 is performed, the remote UE 112 sends a message 700 to trigger the relay UE 110 to enter RRC CONNECTED state. This message can be sent regardless of the RRC state of the relay UE 110. In another variant, the relay UE 110 can inform the remote UE 112 of its RRC state before the remote UE 112 sends the trigger message 700, e.g., through RRCReconfigurationCompleteSidelink 812 or through MeasurementReportSidelink 831 as described above. The trigger message 700 can be conditional on the remote UE and relay UE capabilities shared through messages 821 and 822, i.e., whether the relay UE supports PC5_trigger to enter RRC CONNECTED.

[0182] The trigger message 700 can be a new message RemoteUETriggerSidelink.

[0183] In a variant, this trigger message 700 can be RemoteUEInformationSidelink as specified in TS 38.331. However, in this new use, the RemoteUEInformationSidelink message will be sent when the remote UE 112 is in RRC CONNECTED. In this case, the RemoteUEInformationSidelink message includes a new IE Sl_RelayUE_RRCConnected_Req that, if present, requests the relay UE 110 to enter RRC CONNECTED state.

[0184] In another variant, the trigger message 700 can be RRCReconfigurationSidelink including a new IE Sl_RelayUE_RRCConnected_Req that, if present, requests the relay UE 110 to enter RRC CONNECTED state.

[0185] In another variant, the trigger message 700 can be a RRCReestablishmentRequest, which uses the default configuration for SL-RLC0 (as specified in TS 38.331 clause 9.1.1.4) and for SRB0 (as specified in TS 38.331 clause 9.1.1.2). Similarly, even if a dedicated configuration is received in the RRCReconfiguration message 321, other message(s) belonging to SRB0 or SRB1 can be used by using the default configuration, in order to prevent the use of SRB0 and / or SRB1 on the new path. The dedicated configuration should be applied after the relay UE 110 enters RRC_CONNECTED. In this variant, the relay UE 110 can be triggered by a SRB0 or SRB1 message from the remote UE 112, but these messages, which are normally forwarded to the base station 101, can be filtered by the relay UE 101, so that they are not sent to the base station 101, or the base station 101 can be configured to ignore these messages.

[0186] Upon reception of the message 700, the relay UE 110, which is not in RRC_CONNECTED state, starts the procedure to connect to the base station 101 by a RRC resume or RRC setup procedure as defined in TS 38.331. The RRC resume / setup is exemplified by the frame or message exchange 410.

[0187] And the relay UE 110 can receive from the base station 101 a RRC reconfiguration message including the remote UE identifier (local and L2 ID), the RLC layer configuration (Uu and PC5 RLC channel configuration for relaying) and the SRAP configuration (bearer mapping configuration). The relay UE 110 configures its different layers according to the RRC reconfiguration message to enable its L2 relaying functionality. Then, as a response to the base station 101, the relay UE 110 sends a RRC reconfiguration complete message. This procedure is exemplified by the frame exchange 340. This procedure can be performed at any time after the procedure 410 and independently of the sending of the relay feedback message 500: in other words, this RRC reconfiguration 340 can occur after the sending of the relay feedback message 500.

[0188] Once in RRC_CONNECTED state, the relay UE 110 sends to the remote UE 112 the relay feedback message 500. This message can be a MeasurementReportSidelink 831 including the RRC state set to connected or a NotificationMessageSidelink as described above.

[0189] When receiving the relay feedback message 500 indicating that the relay UE 110 is now RRC_CONNECTED, the remote UE sends an RRCReconfigurationComplete message 501 to the base station 101 over the direct path. The successful transmission of this RRCReconfigurationComplete message 501 confirms the addition of the path at the remote UE side and thus the setup of the multipath, then the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332.

[0190] In a variant, the relay feedback message 500 can be optional and the remote UE 112 can send the RRCReconfigurationComplete message 501 to the base station 101 after sending the PC5_trigger message 700.

[0191] When receiving the RRCReconfiguration message 501, the base station 101 considers that the multipath setup has been completed (step 350).

[0192] As a result, the base station 101 and the remote UE 112 can communicate with each other via two paths (the direct path and the indirect path through the relay UE 110). In other words, the remote UE transmits some uplink data or UL user data to the first base station either directly via the direct path as illustrated by UL / DL user data 360a or indirectly via the relay UE as illustrated by UL / DL user data 360b, and / or the first base station transmits some downlink data or DL user data to the remote UE.

[0193] Reference will now be made to Figure 9 , Figure 9 is a simplified schematic diagram illustrating an example of a message flow for managing a multipath communication in a relay-enabled wireless communication system such as the one illustrated in Figure 1 a . The diagram presents a multipath failure management case where the new path addition / modification fails and more particularly when the remote UE and the relay UE fail to establish together a PC5 connection. In the example of this diagram, the failure cancels the path addition or modification, i.e. the base station 101 and the remote UE 112 go back to the configuration before the reconfiguration request. Figure 9 The same elements (e.g. steps, messages, frames, entities, nodes, etc.) in Figures 3 to 8 are denoted by the same reference signs. For simplicity of the description, here we will refer to Figure 9 the example of the diagram of Figures 3 to 8The descriptions of the same elements are the same, but the details of these same elements can be found above. Figures 3 to 8 It was found in the description.

[0194] In one example, a remote UE (such as remote UE 112) is connected to a base station (such as base station 101). Remote UE 112 and base station 101 communicate with each other: in other words, remote UE 112 transmits some uplink data or UL user data 310 to the first base station 101, and / or the first base station 101 transmits some downlink data or DL ​​user data 310 to remote UE 112.

[0195] The remote UE 112 can also send some measurement report information to the first base station 101 through the measurement report message 311 defined in 3GPP TS 38.331.

[0196] Based on the information carried by the received measurement report message, the first base station 101 can determine whether to adapt the remote UE 112 to the network connection or connectivity (step 320). In another variation illustrated in the figure, step 320 can be performed after detecting a QoS failure (latency, reliability) or from entity 140 of the core network (e.g., such as...). Figure 1 b As shown, this is triggered when the remote UE 112 requests a measurement report (AMF entity; SMF entity; UPF entity), or when the resources allocated to the remote UE 112 are insufficient to meet bandwidth requirements (BSRs reported continuously as the buffer size increases), or when requested by the remote UE 112 (e.g., through the use of a dedicated MAC control element), or when requested by a second base station during mobility operations by including multipath information, for example, in a handover (handover request / request confirmation) or (as defined in TS38.423) inter-gNB path handover message. Then, in this case, base station 101 requests the measurement report to be sent by the remote UE 112 to obtain information about its environment, particularly surrounding cells and relays.

[0197] In an aspect of the application, during PDU session (end-to-end user plane session) resource setup or PDU session resource modification, the core network can request monitoring of QoS (QoS monitoring request field in QoS flow level QoS parameters subclause 9.3.1.12 in TS 38.413). During the monitoring, the base station or gNB 101 can detect that the QoS requirements are no longer fulfilled for some UEs and therefore decides to setup a multipath (step 320). In a variant, the gNB 101 can inform the core network of this QoS issue through some QoS monitoring report 315 (specified in TS 23.501). Based on this report, the core network can request (message 316) the base station 101 to setup a multipath to, for example, maintain the specified QoS. This multipath setup can be requested by the core network during PDU session resource setup or PDU session resource modification. When receiving the MP setup request message 316, the base station 101 can request measurement reports to be sent by its UEs (not shown in the figure) to get up-to-date information of its environment.

[0198] Then, based on step 320, the base station 101 can inform the remote UE 112 to perform a connection adaptation, i.e. to setup one or more additional paths or to modify the existing path, by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331.

[0199] In an aspect of the application, the RRC reconfiguration message 321 comprises all or part of the information elements or information described in the foregoing description. Figure 3

[0200] Upon receiving the RRC reconfiguration message 321 including the multipath information from the base station 101 as described above, the remote UE 112 proceeds to add a new indirect path according to the information elements carried in the RRC reconfiguration 321. The path addition process at the remote UE 112 starts with the Path_Addition_Modification_failure timer being started in step 331. Then, the remote UE 112 attempts to establish a PC5 connection with the primary relay UE identified by the identifier (e.g. targetRelayUE-Identity as specified in TS 38.331) carried in the RRC reconfiguration 321. The establishment of the PC5 connection is exemplified by the message exchange 322. Reference is made to Figure 8 ​The PC5 connection establishment procedure 322 is further described. In the example of this figure, the PC5 connection establishment between the remote UE 112 and the relay UE 110 fails: for example, the relay UE 110 can not positively respond to the direct communication request 801 (e.g., due to a security establishment failure, a mismatch with the target user information or ProSe service information carried in the direct communication request message), or the remote UE 112 receives a RRCReconfigurationFailureSidelink in response to the RRCReconfigurationSidelink indicating a failure of the PC5 RRC reconfiguration to the remote UE 112 811. As a result, the remote UE 112 and the relay UE 110 cannot communicate with each other or establish a configuration suitable for relaying.

[0201] When the remote UE 112 cannot establish a PC5 connection with the target relay UE 110 indicated in the RRCReconfiguration message 321 and the Path_Addition_Modification_failure timer expires (e.g., when a time period measured from the start of the timer expires) or reaches a predefined or certain value (step 333), the remote UE 112 enters a failure management procedure. In this procedure, the remote UE 112 can send a failure report message or failure message 900 to the base station 101. This failure message 900 can include all or part of the following information:

[0202] - a failure cause (or failure type) indicating a multi-path setup (or modification) failure or a path addition / modification failure or a path failure timer expiration;

[0203] - a RelayUE-identity indicating an identity of the relay UE with which the remote UE connected failed (if any);

[0204] - a Cell ID indicating an identity of the cell with which the remote UE connected failed (if any);

[0205] - a new candidate relay list including a list of potential relay UE(s) that can be used for further path addition based on measurements collected up to the moment the UE detected the failure. Each input of the new candidate relay list can include a signal quality (SD-RSRP or SL-RSRP) measured by the remote UE and an ID to identify the relay. For example, the failure message can include candidate relay information (e.g., a new candidate relay list) for one or more relay nodes that are or can be considered as candidates to provide one or more new communication paths (e.g., to provide multiple paths) to connect the UE to the network. The candidate relay nodes can be 3GPP nodes or non-3GPP relay nodes (e.g., WiFi nodes). The candidate relay information can include signal quality information for each candidate relay node and / or an identifier of each candidate relay node;

[0206] - a neighboring cell report including best measured cells ordered such that the best cell is listed first and based on measurements collected up to the moment the UE detected the failure. For example, the neighboring cell report can include neighboring cell information indicating one or more cells neighboring the remote UE that are or can be considered as candidates to provide one or more new direct paths (e.g., to provide multiple paths) to connect the UE to the network. For example, the candidate cells can include suitable cells (e.g., cells for which the signal quality measured up to the moment the UE detected the failure is above a threshold) to establish a new direct path. The neighboring cell report or the neighboring cell information can include an identifier(s) of the cell(s) or of each base station associated with the cell(s);

[0207] - a path ID to identify each failed connection / path.

[0208] In an aspect, the failure report message 900 can be a MCGFailurelnformation as specified in TS 38.331.

[0209] In another aspect, the failure report message 900 can be a RRCRestablishmentRequest as specified in TS 38.331 clause 5.3.7. This second option can be particularly useful if the control plane and more specifically SRB0 and SRB1 configurations are released from the existing path and moved to the new path through the RRCReconfiguration message 321. In this case, the RRCRestablishmentRequest will allow to re-establish the control plane based on the previous configuration (i.e., based on the existing path) and thus will enable the remote UE 112 to communicate again with the base station 101.

[0210] Simultaneously, remote UE 112 returns to the previous configuration illustrated in step 920 (before receiving RRCReconfiguration 321). From the perspective of the remote UE, this concludes the path addition / modification failure management.

[0211] When a failure report 900 is received, base station 101 also returns to the previous configuration by canceling the latest modification (step 910), and optionally may send an MP setting (or modification) failure message 352 to core network 140 in response to MP setting (or modification) request message 316.

[0212] As a result, base station 101 and remote UE 112 can communicate with each other via a previously existing path.

[0213] Now for reference Figure 10 , Figure 10 This is an example used to manage things such as Figure 1 a The diagram illustrates a simplified example of multipath communication in a relay-supported wireless communication system, particularly for managing the path addition process to enable a multipath message flow including a direct path and an indirect path. The diagram presents a multipath failure management scenario where new path addition / modification fails, and more specifically, when the remote UE and the relay UE fail to establish a PC5 connection together. In this diagram, based on the failure report, the base station provides the remote UE with a new configuration to establish a second or another path, or to modify the path requested by the base station. Figure 10 Zhongyu Figures 3 to 9 The same elements (e.g., steps, messages, frames, entities, nodes, etc.) are represented by the same reference numerals. For simplicity, this will refer to... Figure 10 Omission and Figures 3 to 9 The descriptions of the same elements are the same, but the details of these same elements can be found above. Figures 3 to 9 It was found in the description.

[0214] In one example, a remote UE (such as remote UE 112) is connected to a base station (such as base station 101). Remote UE 112 and base station 101 communicate with each other: in other words, remote UE 112 transmits some uplink data or UL user data 310 to the first base station 101, and / or the first base station 101 transmits some downlink data or DL ​​user data 310 to remote UE 112.

[0215] The remote UE 112 can also send some measurement report information to the first base station 101 through the measurement report message 311 defined in 3GPP TS 38.331.

[0216] Based on the information carried by the received measurement report message or other triggers as described in the previous figures, the first base station 101 can decide to adapt the remote UE to network connection or connectivity (step 320).

[0217] Then, based on step 320, the base station 101 can inform the remote UE 112 to perform connection adaptation, i.e. to setup one or more additional paths or to modify existing paths by sending an RRC reconfiguration message 321 as defined in 3GPP TS 38.331.

[0218] Upon reception of the RRC reconfiguration message 321 including the multi-path information from the base station 101 as described above, the remote UE 112 proceeds to add a new indirect path according to the information elements carried in the RRC reconfiguration 321. The path addition process at the remote UE 112 starts with the start of the Path_Addition_Modification_failure timer in step 331. Then, the remote UE 112 attempts to establish a PC5 connection with the primary relay UE identified by the identifier carried in the RRC reconfiguration 321, e.g. targetRelayUE-Identity as specified in TS 38.331. The establishment of the PC5 connection is exemplified by the message exchange 322. Reference is made to Figure 8 The PC5 connection establishment procedure 322 is further described. In the example of the present figure, the PC5 connection establishment between the remote UE 112 and the relay UE 110 fails: for example, the relay UE 110 can not positively respond to the direct communication request 801 (e.g. due to a failure of security establishment, mismatch with the target user information or Prose service information carried in the direct communication request message), or the remote UE 112 receives a RRCReconfigurationFailureSidelink in response to the RRCReconfigurationSidelink indicating a failure of the PC5 RRC reconfiguration to the remote UE 112. As a result, the remote UE 112 and the relay UE 110 cannot communicate with each other or establish a configuration suitable for relaying.

[0219] When the remote UE 112 cannot establish a PC5 connection with the target relay UE 110 indicated in the RRCReconfiguration message 321 and the Path_Addition_Modification_failure timer expires (e.g. upon expiration of a time period measured from the start of the timer) or reaches a predefined or certain value (step 333), the remote UE 112 enters a failure management procedure.

[0220] As shown in the previous diagram, remote UE 112 can send a failure report message 900 to base station 101. This failure message 900 may include all or part of the following information:

[0221] - The failure reason (or failure type) indicates that the multipath setting (or modification) failed, the path addition / modification failed, or the path failure timer expired;

[0222] -RelayUE-identity indicates the identifier (if any) of the relay UE from which the remote UE connection failed;

[0223] - The cell ID indicates the identifier of the cell from which the remote UE connection failed (if any);

[0224] - The new candidate relay list includes a list of (one or more) potential relay UEs, which can be used to add further paths based on measurements collected up to the time the UE detects a failure. Each input to the new candidate relay list may include signal quality (SD-RSRP or SL-RSRP) measured by the remote UE and an ID for identifying the relay. For example, a failure message may include candidate relay information (e.g., the new candidate relay list) for one or more relay nodes that are or can be considered as candidates for providing one or more new communication paths (e.g., providing multipathing) to connect the UE to the network. Candidate relay nodes may be 3GPP nodes or non-3GPP relay nodes (e.g., WiFi nodes). Candidate relay information may include signal quality information for each candidate relay node and / or an identifier for each candidate relay node;

[0225] The neighboring cell report includes the best-measured cells, ordered such that the best cells are listed first and based on measurements collected up to the time the UE detects the failure. For example, the neighboring cell report may include neighboring cell information indicating one or more cells adjacent to the remote UE, which are or can be considered candidates for providing one or more new direct paths (e.g., providing multipath) to connect the UE to the network. For example, candidate cells may include suitable cells for establishing new direct paths (e.g., cells whose signal quality is above a threshold measured up to the time the UE detects the failure). The neighboring cell report or neighboring cell information may include (one or more) cells or (one or more) identifiers of the base stations associated with those (one or more) cells;

[0226] - Path ID, used to identify each failed connection / path.

[0227] In one aspect, the failure report message 900 can be a MCGFailurelnformation as specified in TS 38.331.

[0228] In another aspect, the failure report message 900 can be a RRCRestablishmentRequest as specified in TS 38.331 clause 5.3.7. This second option can be particularly useful if the control plane and more specifically SRB0 and SRB1 configurations are released from the existing path and moved to the new path through the RRCReconfiguration message 321. In this case, the RRCRestablishmentRequest will allow to re-establish the control plane based on the previous configuration (i.e. based on the existing path) and thus will enable the remote UE 112 to communicate again with the base station 101.

[0229] When receiving the failure report 900, the base station 101 tries to setup or modify the multi-path by using a backup relay (new candidate relay) based on the measurements (neighboring cell report or / and candidate relay list) that can be included in the failure report. Then, in a processing or phase 1000, the base station 101 and the remote UE 112 try to setup or modify the multi-path with this new relay (or a new cell for another direct path). This phase 1000 is similar to any one of the phases or processes 390-890 (i.e. Figures 3 to 8 described in the phase x90 of the figure where x is replaced by the figure number).

[0230] At the end of this phase 1000, the remote UE 112 and the base station 101 successfully setup or modify the multi-path and thus they can communicate with each other via two paths (a direct path and an indirect path through a backup relay UE). In other words, the remote UE 112 transmits some uplink data or UL user data to the first base station 101 and / or the first base station 101 transmits some downlink data or DL user data to the remote UE 112 either directly via a direct path as illustrated by the UL / DL user data 360a or indirectly via a backup relay UE via an indirect path as illustrated by the UL / DL user data 360c.

[0231] Reference is now made to Figure 11 , Figure 11 is an example of a system for managing a multi-path communication between a remote UE and a base station, such as Figure 1 aA simplified diagram of an example of a multi-path communication in a wireless communication system supporting relaying, such as the one shown above, particularly for managing a path addition procedure to enable a message flow comprising one direct path and one indirect path. The diagram presents a multi-path failure management case where a new path addition / modification fails, and more particularly when the remote UE and the relay UE fail to establish a PC5 connection together. In this diagram, upon detecting the failure, the remote UE attempts another configuration to establish a second path or another path or to modify the path requested by the base station. Figure 10 The same elements (e.g., steps, messages, frames, entities, nodes, etc.) are denoted by the same reference numerals in the Figures 3 to 9 same elements (e.g., steps, messages, frames, entities, nodes, etc.) are denoted by the same reference numerals in the Figure 10 description will be made here for Figures 3 to 9 the same elements are omitted, but the details of these same elements can be found in the description above Figures 3 to 9 .

[0232] In one example, a remote UE, such as remote UE 112, is connected to a base station, such as base station 101. The remote UE 112 and the base station 101 communicate with each other: in other words, the remote UE 112 transmits some uplink data or UL user data 310 to the first base station 101, and / or the first base station 101 transmits some downlink data or DL user data 310 to the remote UE 112.

[0233] The remote UE 112 can also send some measurement report information to the first base station 101 through the measurement report message 311 defined in 3GPP TS 38.331, respectively.

[0234] Based on the information carried by the received measurement report messages (311a, 311b, 311c) or other triggers as described in the previous figures, the first base station 101 can decide to adapt the remote UE to network connection or connectivity (step 320).

[0235] Then, based on step 320, the base station 101 can inform the remote UE 112 to make a connection adaptation, i.e., to set up one or more additional paths or to modify an existing path, by sending a configuration message such as an RRC reconfiguration message 321 as defined in 3GPP TS 38.331.

[0236] In one aspect, the configuration message (e.g., RRC reconfiguration message 321) comprises all or part of the following information elements or information:

[0237] - Multi-path information indicating that the RRC reconfiguration intends to setup a multi-path by adding a new path to an existing path. In a variant, the multi-path information indicates that the RRC reconfiguration intends to modify a multi-path configuration by updating or changing at least one of the existing indirect or direct paths. For example, the multi-path information included in the configuration message indicates that the configuration information included in the configuration message is associated with at least one other communication path to be configured between the remote UE 112 and the network to provide a multi-path between the remote UE 112 and the network, the multi-path including a first communication path already established between the remote UE 112 and the first base station 101.

[0238] - Relay list: This list contains at least one relay identified by its ID. This list indicates to the remote UE 112 which relay UE (e.g., relay node) the remote UE should connect to. If the RRC reconfiguration intends to establish several indirect paths, this list can carry several relay UEs. For example, the relay list provides relay identification information for identifying at least one relay node with which the remote UE 112 is to establish a connection for a respective at least one communication path of the multi-path. This relay list is associated with the primary relay UE(s) or main relay UE and is also referred to as target relay UE(s).

[0239] - Backup relay list: This list includes at least one backup relay identified by its ID. This list indicates to the remote UE 112 which relay UE the remote UE should connect to in case the primary or main relay UE(s) is / are not available. If this list includes several relays, priority information can also be provided to indicate a priority order of the relays so that the remote UE can try to connect to the relays in the order indicated by the priority information. If no priority information is provided, the remote UE can try to connect sequentially.

[0240] - Primary cell for indicating the primary cell to be connected. This cell is identified by a cell ID (e.g., physCellId). For example, the configuration message can include primary cell information or main cell information for identifying a primary cell or main cell with which the UE is to establish a connection (e.g., for a direct path between the UE and the network) to provide a multi-path, and this primary cell information can include a cell ID.

[0241] - Secondary Cell List: This list includes at least one cell identified by its cell ID (e.g., sCellld). This list can be used as a backup list if the connection to the primary cell fails, or can be used to connect a second direct path. For example, the configuration message can include backup cell information (e.g., secondary cell list), and the backup cell information can include a cell ID for each of the at least one secondary cell, where the backup cell information (e.g., secondary cell list) is used to identify at least one secondary cell to establish a connection with the UE (e.g., for a direct path between the UE and the network) to provide a multi-path in the event that a connection to the primary cell identified by the primary cell information fails.

[0242] - Path ID, used to identify each connection / path. If the RRCReconfiguration has included an identifier as part of the configuration of the UE, the UE considers the procedure as a path modification, otherwise the UE considers the procedure as a path addition.

[0243] The above two lists can be concatenated into a single list, and an additional element can indicate the number of indirect paths to be established.

[0244] Further, the RRCReconfiguration message includes configuration information for one or more additional paths and / or for a communication path to be updated / changed / modified. The configuration information for an indirect path can include a PC5 Relay RLC channel configuration for the relay service and the associated end-to-end radio bearer(s). The configuration information for an indirect path (e.g., an information element for the configuration of an indirect path) can also include information to indicate to the remote UE that the remote UE is to trigger the relay node to enter the RRC-CONNECTED state by using a PC5 message (as discussed further in Figure 8 ). This information can be a bit or field or flag in the configuration message.

[0245] In an aspect, the RRCReconfiguration message 321 includes only the configuration related to the new path or the path to be modified (and the multipath information or information indicating that multiple paths are to be configured). The remote UE 112 infers based on the multipath information that this configuration is for a multipath setup. This multipath information or information indicating that multiple paths are to be configured can be a bit or field set to 1 or enabled or true (e.g., multipath bit or field), or an information element including all information related to multipath configuration, or the presence of SCell configuration or SpCell configuration in the CellGroupConfig information element carried in the RRCReconfiguration message (in addition to the relay UE identity(s) for the new or modified indirect path). In another aspect, the RRCReconfiguration message can include the configuration of all paths, existing path(s) and new (or to be modified) path(s). The full configuration can be included if the fullconfig flag carried in the RRCReconfiguration message is set to true.

[0246] In another aspect, the RRCReconfiguration can include a conditional configuration to be applied in case of failure. This conditional configuration can replace the backup relay list. This conditional configuration can include all the configuration needed to connect to the backup relay(s) in case of connection failure of the primary relay UE. The configuration can also include the condition or attempt condition to be satisfied in order to apply the configuration. In case the condition is based on path addition failure (e.g., establishing a PC5 connection with the remote UE after path addition failure), the conditional configuration can include a new cell (as in the case of conditional handover CHO) and a relay UE attached to this new cell. This reconfiguration can result in a multipath handover when applying such conditional configuration in case of path addition failure.

[0247] At the same time, the base station 101 can transmit configurations to several relay UEs (e.g., RRC reconfiguration procedure 1101 for relay UE1 110 and RRC reconfiguration procedure 1102 for relay UE2 120). For each relay UE, these configurations include remote UE identifiers (local and L2 ID), RLC layer configurations (Uu and PC5 RLC channel configurations for relaying), and SRAP configurations (bearer mapping configurations). In view of the uncertainty of the use of the configurations by the backup relay UE, the base station 101 can provide the configurations for relaying to the backup relay UE as conditional configurations: i.e., the configurations for relaying should only be applied in case the remote UE establishes a PC5 connection with the backup relay. Furthermore, in examples, the configurations can be cancelled after a predefined time period. The RRCReconfiguration of the relay UEs can happen at any time after they become RRC_CONNECTED. The above has been described with reference to Figures 3 to 8 Ways of triggering a relay UE in RRC_IDLE or RRC_INACTIVE state to enter RRC_CONNECTED state by the network or by a remote UE are described.

[0248] Upon receiving the RRCReconfiguration message 321 including multipath information from the base station 101 as described above, the remote UE 112 proceeds to add a new indirect path according to the information elements carried in the RRCReconfiguration 321. The path addition process at the remote UE 112 starts with the initiation of the Path_Addition_Modification_failure timer in step 331. Then, the remote UE 112 attempts to establish a PC5 connection with the primary relay UE 110 identified by the identifier (e.g., targetRelayUE-Identity as specified in TS 38.331) carried in the RRCReconfiguration 321. The establishment of the PC5 connection is exemplified by the message exchange 322. Reference is made to Figure 8 The PC5 connection establishment procedure 322 is further described. In the example of the present figure, the PC5 connection establishment between the remote UE 112 and the relay UE 110 fails: e.g., the relay UE 112 can not positively respond to the direct communication request 801 (e.g., due to a failure of security establishment, mismatch with the target user information or ProSe service information carried in the direct communication request message), or the remote UE 112 receives an RRCReconfigurationFailureSidelink in response to the RRCReconfigurationSidelink 811 indicating a failure of the PC5 RRC reconfiguration to the remote UE 112. As a result, the remote UE 112 and the relay UE 110 cannot communicate with each other or establish a configuration suitable for relaying.

[0249] When the remote UE cannot establish a PC5 connection with the target relay UE indicated in the RRCReconfiguration message 321 and the Path_Addition_Modification_failure timer expires (e.g., when a time period measured from the start of the timer expires) or reaches a predefined or certain value (step 333), the remote UE 112 enters a failure management procedure.

[0250] Upon detecting a path addition / modification failure, the remote UE 112 searches for a backup relay UE 120 to connect to, thereby replacing the relay UE (110) it could not connect to (step 1110). The remote UE can select a backup relay from the information provided in the RRCReconfiguration 321 (e.g., from a backup relay list).

[0251] In a variant where the RRCReconfiguration does not include a backup relay list, the remote UE 112 can autonomously select a new relay UE based on its own measurements, as it can do in a relay reselection procedure.

[0252] In case more than one additional path is to be established, the remote UE 112 can select more than one backup relay UE.

[0253] When the remote UE 112 finds a suitable backup relay UE (e.g., relay UE 120), it starts a Path_Addition_Modification_recovery timer in step 1131 and attempts to establish the additional path(s). The Path_Addition_Modification_recovery timer (not shown in the figure) can be implemented in hardware or software (e.g., by a module comprising a program of instructions for execution by one or more processing units, such as central processing unit 1711, etc.), and is configured to time a certain or predefined time period from the start of the timer (i.e., when the path recovery timer reaches a certain or predefined value). In a variant, the timer can be started upon sending the RRCReestablishment message 1112. The remote UE 112 then attempts to establish a PC5 connection with the backup relay UE(s) (120) identified in the RRCReconfiguration as backup relays or identified relying on a relay reselection procedure. The establishment of the PC5 connection with the backup relay UE 120 is exemplified by the message exchange 1111. The PC5 connection establishment procedure 1111 follows the reference Figure 8The process or stage 322 is described. Ultimately, the remote UE 112 successfully establishes a PC5 connection with the backup relay UE 120. As a result, the remote UE 112 and the backup relay UE 120 are able to communicate directly with each other.

[0254] Then, remote UE 112 initiates a rebuild procedure. The rebuild procedure is designed to continue the RRC connection even if a failure condition occurs (in this example, a path addition / modification failure). To this end, remote UE 112 first establishes an SRAP entity, and if necessary, applies the default configuration (such as SL-RLC0 as defined in TS38.331 Clause 9.1.1.4, SDAP and PDCP as defined in TS38.331 Clause 9.1.1.2) to SRB0. SRB0 is used to send an RRCReestablishmentRequest message. Then, remote UE 112 (e.g., via release and addition) establishes or modifies the connection. Figure 2 The PC5 RLC entity 221 (or SL RLC) in the system applies the default configuration (such as SL-RLC1 as defined in TS38.331 Clause 9.2.4, PDCP as defined in TS38.331 Clause 9.2.1, and SRAP as defined in TS38.331 Clause 9.2.5) to SRB1 (control plane) and restores SRB1. SRB1 is used to receive RRCReestablishment message 1113 from base station 101 and transmit RRCReestablishmentComplete message 1114 to base station 101. Then, remote UE 112 sends RRCReestablishmentRequest message 1112 to base station 101 through backup relay UE 120. This message 1112 provides UE identifier to gNB 101 (e.g., the PCI and C-RNTI of remote UE 112 can be included in message 1112). In addition, message 1112 may include all or part of the following information:

[0255] - The reason for failure (or the type of failure) indicates that the multipath setting (or modification) failed, the path addition / modification failed, or the timer expired;

[0256] -RelayUE-identity indicates the identifier (if any) of the relay UE from which the remote UE connection failed;

[0257] - The cell ID indicates the identifier of the cell from which the remote UE connection failed (if any);

[0258] - Path ID, used to identify each failed connection / path.

[0259] If the relay 120 is not RRC_CONNECTED, the reception of the RRCReestablishmentRequest message 1112 can trigger the relay UE 120 to enter the RRC_CONNECTED state. This has already been described above with reference to Figures 3 to 8 Other methods to trigger the relay UE are described.

[0260] In a variant, the RRCReestablishmentRequest can also be sent over the direct path if the previous configuration received in the message 321 does not include SRB0 and SRB1 for the new path.

[0261] When receiving the RRCReestablishmentRequest message 1112, the base station 101 infers that this message is related to the recovery of the addition / modification of the path based on the cause failure and / or the presence of the RelayUE-identity and / or the Path ID, then the base station 101 prepares and sends an RRCReestablishment message 1113. This message 1113 can include information associated with the RRC procedures for continuing the RRC connection of the UE, such as information for security and part of the remote UE configuration (SRAP configuration for SRB1 and local UE ID) and an RRC-TransactionIdentifier for identifying the RRC procedure. If the configuration has already been transmitted in the main RRCReconfiguration message 321, the part of the UE configuration can be ignored. Depending on the configuration wanted by the base station 101, this message 1113 can be sent to the remote UE 112 on the direct or indirect path.

[0262] Upon receiving this RRCReestablishment message 1113, the remote UE 112 applies the configuration included in this message if needed and sends in response an RRCReestablishmentComplete message 1114. This message 1114 can include all or at least some of the following information:

[0263] - an RRC-TransactionIdentifier for identifying the RRC procedure and set to the same value as the one received in the RRCReestablishment message 1113;

[0264] - the new candidate relay list includes a list of potential relay UE(s) that can be used for further path addition based on measurements collected until the moment the UE detected a failure. Each input of the new candidate relay list can include a signal quality (SD-RSRP or SL-RSRP) measured by the remote UE and an ID to identify the relay. For example, the message 1114 can include candidate relay information (e.g., a new candidate relay list) for one or more relay nodes that are or can be considered as candidates to provide one or more new communication paths (e.g., to provide multiple paths) to connect the UE to the network. The candidate relay nodes can be 3GPP nodes or non-3GPP relay nodes (e.g., WiFi nodes). The candidate relay information can include signal quality information for each candidate relay node and / or an identifier of each candidate relay node;

[0265] - the neighboring cell report includes the best measured cell ordered such that the best cell is listed first and based on measurements collected until the moment the UE detected a failure. For example, the neighboring cell report can include neighboring cell information indicating one or more cells neighboring the remote UE that are or can be considered as candidates to provide one or more new direct paths (e.g., to provide multiple paths) to connect the UE to the network. For example, the candidate cells can include suitable cells (e.g., cells for which the signal quality measured until the moment the UE detected a failure is above a threshold) to establish a new direct path. The neighboring cell report or the neighboring cell information can include an identifier(s) of the cell(s) or of each base station associated with the cell(s);

[0266] - information related or associated to the connection failure with the primary relay UE; for example, the information can include a RelayUE-identity information indicating the identity of the relay UE for which the remote UE connection failed (if any) and / or a path ID to identify the failed path.

[0267] Depending on the configuration provided by the base station 101 in the RRCReconfiguration message 321 or based on the partial configuration received in the RRCReestablishment message 1113 or based on a default configuration, the message 1114 can be sent on a direct or indirect path. This completes the path addition / modification recovery management from the remote UE’s perspective, so the remote UE 112 stops the Path_Addition_Modification_recovery timer in step 1132.

[0268] In another aspect, at the end of the recovery procedure, the remote UE 112 can apply the complete configuration received in the RRCReconfiguration 321 (or a new configuration subsequently received during the RRCReestablishment procedure) and send an RRCReconfigurationComplete 1115 as a response over the direct or indirect path depending on the configuration for the control plane and more particularly for SRB1.

[0269] When receiving the RRCReestablishmentComplete message 1114 and the optional RRC reconfiguration message 1115, the base station 101 considers that the multipath setup has been completed (step 350).

[0270] As a result, the base station 101 and the remote UE 112 can communicate with each other via two paths (the direct path and the indirect path through the backup relay UE 120). In other words, the remote UE 112 transmits some uplink data or UL user data to the first base station 101 and / or the first base station 101 transmits some downlink data or DL user data to the remote UE 112 either directly via the direct path as illustrated by UL / DL user data 360a or indirectly via the backup relay UE as illustrated by UL / DL user data 360c.

[0271] From the above description, the behavior of the Path_Addition_Modification_failure timer (also referred to as path failure timer) is summarized as follows:

[0272] - Start condition: the reception of a configuration message (such as the RRC reconfiguration message 321) including a multipath configuration to add or modify an indirect path triggers the remote UE to start the path failure timer.

[0273] - Stop condition: Successful transmission of the RRCReconfigurationComplete message by the remote UE to the base station through the relay UE in case the control plane is configured over this new path (e.g. signaling radio bearers such as SRB1 are configured over the new indirect path), or reception of a relay feedback message including an indication that the relay is configured or is RRC_CONNECTED, or successful transmission of the RRCReconfigurationComplete message by the remote UE to the base station through the direct path and information indicating that the remote UE is RRC_CONNECTED, which triggers the remote UE to stop the path failure timer. Different examples of messages that can trigger the remote UE to stop the path failure timer are described above. These include for example the feedback message 500, the PC5_RRCReconfigurationComplete message, the NotificationMessageSidelink message, the RRCReconfigurationCompleteSidelink 812, the MeasurementReportSidelink 831.

[0274] - Failure condition: At expiry, the remote UE 112 transmits a failure report and / or attempts an RRCRestablishment procedure through a backup relay UE. The backup relay UE is provided by the base station or autonomously selected by the remote UE (as in the relay reselection procedure). In other words, the path addition / modification failure can trigger the remote UE to perform a relay (re)selection.

[0275] With respect to receiving a configuration message including configuration information and multi-path information, the above description of the behavior of the Path_Addition_Modification_failure timer (also referred to as path failure timer) has been made. However, it should be understood that the behavior of the Path_Addition_Modification_failure timer (also referred to as path failure timer) as outlined above can also apply in case the configuration information does not include multi-path information and includes configuration information for configuring the UE (e.g. remote UE 112) to communicate with the network. In this case, the path failure timer is started by the remote UE 112 upon reception of the configuration information.

[0276] From the above description, the behavior of the Path_Addition_Modification_recovery timer (also referred to as path recovery timer) is summarized as follows:

[0277] - Start condition: Successful transmission of an RRCReestablishmentRequest message (such as message 1112) in response to the expiry of the path failure timer, which triggers the remote UE to start the path recovery timer.

[0278] - Stop condition: Successful transmission of the RRCReestablishmentComplete message to the base station by the relay UE over the control plane configured on this new path, or reception of a relay feedback message including an indication that the relay is RRC CONNECTED, or successful transmission of the RRCReestablishmentComplete message to the base station over the direct path and information indicating that the relay UE is RRC CONNECTED, which triggers the remote UE to stop the path recovery timer. Different examples of messages that can trigger the remote UE to stop the path recovery timer are described above. These include, for example, the feedback message 500, the PC5_RRCReconfigurationComplete message, the NotificationMessageSidelink message, the RRCReconfigurationCompleteSidelink 812, the MeasurementReportSidelink 831.

[0279] - Failure condition: At expiry, the remote UE keeps the previous configuration before receiving the RRCReconfiguration requesting a new configuration, and can send a failure report.

[0280] With respect to receiving a configuration message including configuration information and multipath information, the above description of the behavior of the Path_Addition_Modification_recovery timer (also referred to as the path recovery timer) has been made. However, it should be understood that the behavior of the Path_Addition_Modification_recovery timer (also referred to as the path recovery timer) as outlined above can also apply in the case where the configuration information does not include multipath information and includes configuration information for configuring the UE (e.g., remote UE 112) to communicate with the network.

[0281] The above description relating to the path addition to set up a multipath (refer to Figures 3-11) can also be used for path modification: i.e. modification of at least one path among multiple paths (multi-path setup) that have been setup and established between the remote UE and the network. In this case, the RRCReconfiguration message 321 from the base station 101 to the remote UE 112 includes configurations related to paths to be released and configurations related to paths to be added, for example in RadioBearerConfig (for PDCP) and CellGroupConfig (for MAC and RLC) information elements. Path modification can also require SRAP modification, especially in the mapping table associating bearers with PC5 RLC channels to be used. By this, the mapping table defines which bearer will go through Uu and which bearer will go through PC5 link. This release and add information is interpreted as path modification.

[0282] Similarly, the behavior for adding / modifying direct paths Figure 12 and Figure 13 can use the description of the above figures. But for the addition / modification of direct paths, the RRCReconfiguration can not include the list of relay UEs and the connection with the base station requires a RACH (Random Access Channel) procedure as specified in TS 38.300 clause 9.2.6 for its initial access.

[0283] Figure 12 and Figure 13 illustrate direct path addition / modification in normal and failure cases, respectively.

[0284] Reference is now made to Figure 12 , Figure 12 is a simplified schematic diagram illustrating an example of a message flow for managing multi-path communication in a relay supported wireless communication system, in particular for managing a path addition procedure to enable multi-path, such as the one shown in Figure 1 a . In this figure, the remote UE 112 and the base station are connected through the relay UE 110 and try to add a new direct or indirect path to setup a multi-path. Figure 12 The same elements (e.g. steps, messages, frames, entities, nodes, etc.) in Figures 3 to 11 are denoted by the same reference numerals. For simplicity of the description, the description of the same elements will be omitted here for Figure 12 , but the details of these same elements can be found in the description of Figures 3 to 11 above. Figures 3 to 11

[0285] ​In one example, the remote UE (such as remote UE 112) is connected to a base station (such as base station 101) through a relay UE 110. The remote UE 112 and the base station 101 communicate with each other through the relay UE 110, in other words, the remote UE 112 transmits some uplink data or UL user data 310 to the first base station 101 through the relay UE 110, and / or the first base station also transmits some downlink data or DL user data 310 to the remote UE 112 through the relay UE 110.

[0286] The remote UE 112 and the relay UE 110 can also send some measurement report information to the first base station through MEASUREMENT REPORT messages 311a and 311b, respectively. In the example of the present figure, message 311a is forwarded by the relay UE 110 (relay traffic or messages are indicated by the circles in the figure).

[0287] Based on the information carried by the received Measurement Report messages, the first base station 101 can decide to adapt the remote UE to network connection (step 320).

[0288] In other variants, step 320 can be triggered upon detection of a QoS failure (latency, reliability) or a request 316 from an entity 140 of the core network (for example, Figure 1 b The illustrated AMF entity, SMF entity, UPF entity). It can also be triggered when the resources allocated to the remote UE are insufficient to meet the bandwidth requirements (BSR reported continuously as the buffer size increases), or when requested by the remote UE (for example, by using a dedicated MAC control element), or when requested by the second base station in a mobility procedure by including multi-path information in the handover (handover request / request acknowledgement) or (as defined in TS 38.423) inter-gNB path switch messages. Then, in this case, the base station requests the remote UE 112 to send a measurement report to obtain information on its environment, in particular the surrounding cells and relays.

[0289] Then, based on step 320, the base station 101 can inform the remote UE 112 to make a connection adaptation, i.e. to set up additional paths or modify existing paths by sending a configuration message such as an RRC reconfiguration message 321 as defined in 3GPP TS 38.331 through the relay UE 110.

[0290] In one aspect of the application, the configuration message (for example, the RRC reconfiguration message 321) includes all or part of the following information elements or information:

[0291] - Multi-path information indicating that the RRC reconfiguration intends to set up a multi-path by adding a new path to an existing path. In a variant, the multi-path information indicates that the RRC reconfiguration intends to modify a multi-path configuration by updating or changing at least one of the existing indirect or direct paths. For example, the multi-path information included in the configuration message indicates that the configuration information included in the configuration message is associated with at least one other communication path to be configured between the remote UE 112 and the network to provide a multi-path between the remote UE 112 and the network, the multi-path including a first communication path already established between the remote UE 112 and the first base station 101.

[0292] - Relay list: This list contains at least one relay identified by its ID. This list indicates to the remote UE 112 which relay UE (e.g., relay node) the remote UE should connect to. If the RRC reconfiguration intends to set up several indirect paths, this list can carry several relay UEs. For example, the relay list provides relay identification information for identifying at least one relay node to establish a connection with the remote UE 112 for a respective at least one communication path of the multi-path. This relay list is associated with the primary relay UE(s) or main relay UE and is also referred to as target relay UE(s).

[0293] - Backup relay list: This list includes at least one backup relay identified by its ID. This list indicates to the remote UE 112 which relay UE the remote UE should connect to in case the primary or main relay UE is not available. If this list includes several relays, priority information can also be provided to indicate a priority order of the relays so that the remote UE can try to connect to the relays in the order indicated by the priority information.

[0294] - Primary cell for indicating the primary cell to connect to. This cell is identified by a cell ID (e.g., physCellld). For example, the configuration message can include primary cell information or main cell information for identifying a primary cell or main cell to establish a connection with the UE (e.g., for a direct path between the UE and the network) to provide a multi-path, and the primary cell information can include a cell ID.

[0295] - Secondary Cell List: This list includes at least one cell identified by its cell ID (e.g., sCellld). This list can be used as a backup list if the connection to the primary cell fails, or can be used to connect a second direct path. For example, the configuration message can include backup cell information (e.g., secondary cell list), and the backup cell information can include a cell ID for each of the at least one secondary cell, where the backup cell information (e.g., secondary cell list) is used to identify at least one secondary cell to establish a connection with the UE (e.g., for a direct path between the UE and the network) to provide a multi-path in the event that establishing a connection with the primary cell identified by the primary cell information fails.

[0296] - Path ID, used to identify each connection / path. If the RRCReconfiguration has included an identifier as part of the configuration of the UE, the UE considers the procedure as a path modification, otherwise the UE considers the procedure as a path addition.

[0297] The above two lists of relays can be concatenated into a single list, and an additional element can indicate the number of indirect paths to be established.

[0298] Similarly, an additional field can indicate the number of direct paths to be set up.

[0299] Each path is associated with a configuration that includes RLC, radio bearer configuration, and all configuration parts needed to establish and use the path.

[0300] In one aspect, the RRCReconfiguration message 321 includes only the configuration related to a new path or a path to be modified (and multi-path information). The remote UE 112 infers based on the multi-path information that the configuration is for multi-path setup. This multi-path information can be a multi-path bit or field set to 1 or enabled or true, or an information element that includes all information related to multi-path configuration, or the presence of SCell configuration or SpCell configuration in the CellGroupConfig information element carried in the RRCReconfiguration message (in addition to the relay UE identification(s) for new or modified indirect paths). In another aspect, the RRCReconfiguration message can include the configuration for all paths, existing path(s) and new (or to be modified) path(s). The full configuration can be included if a fullconfig flag carried in the RRCReconfiguration message is set to true.

[0301] In another aspect, if the new path to be setup involves another or second base station, then the mrdc-SecondaryCellGroup information element can also be included in the configuration message 321. This element included in the configuration message 321 includes the RRCReconfiguration message as generated by the second base station. This second RRCReconfiguration can also include the configuration for the direct path or indirect path or both as described above. For example, the remote UE 112 will be connected to the base station 101 through the relay UE 110 and directly to the second base station 102.

[0302] The selection of one or more cells by the base station 101 for adding the direct path can be based on the information included in the measurement reports from different UEs (e.g., from the remote UE 112 in the measurement report 311a and from the relay UE 110 in the measurement report 311b). The base station 101 evaluates the different cells included in the measurement reports. If the primary cell reported by the remote UE 112 suffers from unstable link quality and thus can be prone to connection failures, the RRCReconfiguration message 321 can include the primary cell and one or more secondary cells. In its cell selection, the base station 101 can prioritize the serving cell of the relay UE 110 in order to facilitate the management of the multiple paths. The selected cells can be cells controlled by the base station 101 or can be cells controlled by another or second base station such as the gNB 102.

[0303] Upon receiving the RRCReconfiguration message 321 including the multiple path information from the base station 101 as described above, the remote UE 112 proceeds to add the new direct path (or modify the existing path) according to the information elements or information carried in the RRCReconfiguration 321. The path addition process at the remote UE 112 starts with the initiation of the Path_Addition_Modification_failure timer in step 331. The remote UE 112 then attempts to establish a connection directly with the base station identified from the information in the RRCReconfiguration message 321. To this end, the remote UE 112 synchronizes with the base station and performs a random access procedure as specified in TS 38.300 clause 9.2.6. In the example shown, the base station is the first base station 101. The establishment of the connection with the base station 101 is exemplified by the message exchange 1210. In the example of this figure, the RACH procedure is successful and as a result, the remote UE 112 and the base station 101 can communicate directly with each other. Figure 12

[0304] ​Upon successful completion of the random access procedure, the remote UE 112 stops the Path_Addition_Modification_failure timer in step 332. At this point, the remote UE 112 has applied the configuration received in the RRCReconfiguration message 321 and thus the signal radio bearer (control plane) configuration (if any) for the new direct path. If SRB1 is configured for this new path, the remote UE 112 can transmit an RRCReconfigurationComplete message 501 to the base station 101 over the new direct path, otherwise the remote UE 112 transmits an RRCReconfigurationComplete message 323 to the base station 101 over the existing indirect path. In Figure 12 In the example shown, the remote UE 112 transmits the RRCReconfigurationComplete message to the base station 101 using the existing path (indirectly via the relay UE 110).

[0305] In a variant, the successful transmission of this RRCReconfigurationComplete message can trigger the remote UE to stop the Path_Addition_Modification_failure timer in step 332.

[0306] Upon reception of the RRCReconfigurationComplete message 323 (or RRCReconfigurationComplete message 501), the base station 101 considers that the multi-path setup has been completed (step 350). The base station 101 can inform the core network that the multi-path has been successfully set up (or modified) by sending a message MP Setup Ack (MP Modification Ack) 351 in response to the MP Setup Request 316.

[0307] As a result, the base station 101 and the remote UE 112 can communicate with each other via two paths (the direct path and the indirect path through the relay UE 110). In other words, the remote UE 112 transmits some uplink data or UL user data to the first base station 101 via either the direct path as shown by UL / DL user data 360a directly or via the indirect path as shown by UL / DL user data 360b through the relay UE, and / or the first base station 101 transmits some downlink data or DL user data to the remote UE 112.

[0308] Reference is now made to Figure 13 , Figure 13 is an example illustrating a method for managing a plurality of paths between a remote UE and a base station, such as Figure 1 aA simplified schematic diagram of an example of multi-path communication in a wireless communication system supporting relaying, such as the one shown above, in particular for managing the path addition procedure to enable multi-path, is shown in Figure 3. In this figure, remote UE 112 and base station 101 are connected through relay UE 110 and attempt to add a new direct or indirect path to setup multi-path. This figure presents a multi-path failure management case where the new path addition / modification fails and more particularly when the random access procedure fails. Figure 13 In the same way as Figures 3 to 12 The same elements (e.g., steps, messages, frames, entities, nodes, etc.) are denoted by the same reference signs. For simplicity of the description, here we will refer to Figure 13 The description of the same elements is omitted here Figures 3 to 12 but the details of these same elements can be found in the description above Figures 3 to 12 .

[0309] In one example, a remote UE, such as remote UE 112, is connected to a base station, such as base station 101, through a relay UE 110. Remote UE 112 and base station 101 communicate with each other through relay UE 110, in other words, remote UE 112 transmits some uplink data or UL user data 310 to first base station 101 through relay UE 110 and / or first base station 101 also transmits some downlink data or DL user data 310 to remote UE 112 through relay UE 110.

[0310] Remote UE 112 and relay UE 110 can also send some measurement report information to the first base station through MEASUREMENT REPORT messages 311a and 311b, respectively. In the example of this figure, message 311a is forwarded by relay UE 110 (the relay traffic or messages are indicated by the circles in the figure).

[0311] Based on the information carried by the received Measurement Report messages, first base station 101 can decide to adapt the connection of remote UE 112 to the network (step 320).

[0312] In other variants, step 320 can be performed upon detecting a QoS failure (latency, reliability) or a message from core network entity 140 (e.g., AMF 140). Figure 1 bThe request is triggered when the illustrated AMF entity, SMF entity, or UPF entity requests 316, or when the resources allocated to the remote UE 112 are insufficient to meet bandwidth requirements (BSRs reported continuously as the buffer size increases), or when requested by the remote UE 112 (e.g., through the use of a dedicated MAC control element), or when requested by a second base station during mobility operations by including multipath information, for example, in a handover (handover request / request confirmation) or (as defined in TS38.423) inter-gNB path handover message. In this case, base station 101 then requests measurement reports from the remote UE 112 to obtain information about its environment, particularly surrounding cells and relays.

[0313] Then, based on step 320, base station 101 can notify remote UE 112 to perform connection adaptation, that is, to set up an additional path or modify an existing path by sending a configuration message such as RRC reconfiguration message 321 as defined in 3GPP TS 38.331 via relay UE 110.

[0314] On the one hand, RRC reconfiguration message 321 includes Figures 3 to 12 The information elements or all or part of the information described above.

[0315] Upon receiving an RRC reconfiguration message 321 containing multipath information from base station 101 as described above, remote UE 112 continues to add new direct paths (or modify existing paths) based on the information elements or information carried in the RRC reconfiguration message 321. The path addition / modification process at the remote UE begins by starting the Path_Addition_Modification_failure timer in step 331. Then, remote UE 112 attempts to establish a direct connection with the base station identified from the information in the RRC reconfiguration message 321. For this purpose, the remote UE synchronizes with the base station and performs a random access procedure as specified in Clause 9.2.6 of TS38.300. Figure 13 In the example shown, the base station is the first base station 101. The establishment of a connection with base station 101 is illustrated by message exchange 1210. In this example, the RACH procedure fails.

[0316] When the remote UE 112 fails to establish a connection with the base station 101 indicated in the RRCReconfiguration message 321 and the Path_Addition_Modification_failure timer expires (e.g., at the expiration of a time period measured from the start of the timer) or reaches a predefined or certain value (step 333), the remote UE 112 enters a failure management procedure. In this procedure, the remote UE 112 can send a failure report message or failure message 900 to the base station 101. In the example of this figure, the failure report message 900 is sent to reach the base station 101 through an indirect path via the relay UE 110. This failure message 900 can include all or part of the following information:

[0317] - a failure cause (or failure type) indicating a multi-path setup (or modification) failure or a path addition / modification failure or a path failure timer expiration;

[0318] - a RelayUE-identity indicating an identity of the relay UE (if any) that the remote UE connected to fail;

[0319] - a Cell ID indicating an identity of the cell (if any) that the remote UE connected to fail;

[0320] - a new candidate relay list including a list of potential relay UEs that can be used for further path addition based on measurements collected up to the moment the UE detected the failure. Each input of the relay list can include a signal quality (SD-RSRP or SL-RSRP) measured by the remote UE and an ID to identify the relay. For example, the failure message can include candidate relay information (e.g., a new candidate relay list) for one or more relay nodes that are or can be considered as candidates to provide one or more new communication paths (e.g., to provide multi-path) to connect the UE to the network. The candidate relay nodes can be 3GPP nodes or non-3GPP relay nodes (e.g., WiFi nodes). The candidate relay information can include signal quality information for each candidate relay node and / or an identifier of each candidate relay node;

[0321] - the neighbor cell report includes the best measured cell, ordered such that the best cell is listed first and based on measurements collected up to the moment of UE detection failure. For example, the neighbor cell report can include neighbor cell information indicating one or more cells neighboring the remote UE that are or can be considered as candidates for providing one or more new direct paths (e.g., providing multipath) for connecting the UE to the network. For example, the candidate cell(s) can include suitable cells for establishing a new direct path (e.g., cells for which the signal quality measured up to the moment of UE detection failure is above a threshold). The neighbor cell report or neighbor cell information can include (one or more) identifiers of the cell(s) or of the respective base station(s) associated with the cell(s);

[0322] - a path ID for identifying each failed connection / path.

[0323] In an aspect, the failure report message 900 can be a MCGFailurelnformation as specified in TS 38.331.

[0324] In another aspect, the failure report message 900 can be a RRCRestablishmentRequest as specified in TS 38.331 clause 5.3.7. This second option can be particularly useful if the control plane and more specifically SRB0 and SRB1 configurations are released from the existing path and moved to the new path through the RRCReconfiguration message 321. In this case, the RRCRestablishmentRequest will allow to reestablish the control plane based on the previous configuration (i.e., based on the existing path) and thus will enable the remote UE 112 to communicate again with the base station 101.

[0325] At the same time, the remote UE 112 goes back to the previous configuration (before receiving the RRCReconfiguration 321) illustrated at step 920. From the remote UE’s perspective, this ends the path addition / modification failure management.

[0326] Upon receiving the failure report 900, the base station 101 also goes back to the previous configuration by cancelling the latest modification (step 910) and can optionally send an MP setup (or modification) failure message 352 to the core network as a response to the MP setup (or modification) request message 316.

[0327] As a result, the base station 101 and the remote UE 112 can communicate with each other via the previously existing path.

[0328] In a variant, the reception of the failure report message 900 can trigger the base station 101 to set or modify the multipath based on the measurements (neighboring cell report or / and candidate relay list) that can be included in the failure report message, by using another cell or another relay UE. Then, the base station 101 and the remote UE 112 can try to set or modify the multipath with this new configuration. For example, the remote UE 112 and the base station 101 can proceed as above with respect to Figure 10 the phase or process 1000 discussed (i.e., proceed with any one of the phases or processes 390-890). This new configuration can configure an inter-gNB path switch, and then the multipath setup can occur on the new base station.

[0329] In another variant, upon failure detection, the remote UE 112 can enter a path addition / modification recovery procedure, such as the one discussed above with respect to Figure 11 the recovery procedure. In this procedure, the remote UE 112 searches for a backup cell to connect to, instead of the primary cell it cannot connect to. The remote UE 112 can select the backup cell from the list provided in the RRCReconfiguration message 321 : for example, from the list of secondary cells, or as included as a conditional configuration that can include all the configuration information needed to connect to the backup cell(s) in case of primary cell connection failure. The remote UE 112 can also autonomously proceed with a cell reselection procedure based on its own measurements. The remote UE 112 can also consider a connection through a second relay to add another indirect path (e.g., based on the relay list provided in the RRCReconfiguration message 321).

[0330] Reference is now made to Figure 14 , Figure 14This is a flowchart illustrating the steps of a method 1400 for managing multipath communication in a wireless communication system supporting relay between a UE and a network, according to one or more embodiments of the present invention. The wireless communication system supports side-link relay and / or other peer-to-peer relay, such as via WiFi relay or Bluetooth relay. In the case where the wireless communication system supports side-link relay, the UE is referred to as a remote UE, and the relay node is referred to as a relay UE (e.g., a UE operating as a relay or used as a relay). The network of the wireless communication system includes at least a first base station. After a first communication path has been established between the UE and the first base station, method 1400 is performed at the first base station (i.e., method 1400 is performed at the base station of the network). The first communication path can be a direct path between the UE and the first base station, or an indirect path between the UE and the first base station via at least one relay node. The UE can be configured such that it can communicate with the network via the first base station on at least two separate paths or multiple paths (referred to as multipath). For example, the UE can be directly connected to the base station via a direct path, and can also be indirectly connected to the base station via at least one relay node (e.g., a relay UE) and thus via an indirect path. Alternatively or concurrently, the UE may connect to the base station via at least two indirect paths and / or at least two direct paths. The UE may also be configured to communicate with the network via a second base station on one or more direct and / or indirect paths. Regarding the example shown in Figure 1, the first base station performing method 1400 may be base station 101 (also referred to as gNB 101), and the UE may be a remote UE 112. The second base station may be base station 102. Figure 14 The image shown and about Figure 14 The described method 1400 can be performed by software elements and / or hardware elements. Therefore, for example, as... Figure 14 The image shown and about Figure 14 The described method can be performed by a device for a base station, which includes one or more processing units configured to perform the method. The base station can be, for example... Figure 17 The images and references shown Figure 17 The communication device 1700 described herein is implemented, wherein, as Figure 14 The image shown and about Figure 14 The described method is performed by one or more processing units (such as a central processing unit 1711, etc.).

[0331] In short, at step 1404, the base station 101 sends a configuration message to the remote UE 112, the configuration message comprising configuration information for configuring the remote UE 112 to communicate with or connect to the network. The configuration information (also referred to as multi-path (MP) configuration information) can comprise all or part of the information described above in relation to the RRCReconfiguration message 321. The configuration message can be the RRCReconfiguration message 321. The configuration message further comprises multi-path information or information indicating that multiple paths are to be configured, the multi-path information being for indicating that the configuration information is associated with at least one other communication path to be configured between the remote UE 112 and the network to provide multiple paths or multi-paths between the remote UE 112 and the network in conjunction with the first communication path. The configuration information can be for a new communication path to be added to provide the multiple paths, or in the case where multiple paths are already established, the configuration information is for modifying (or changing or updating) at least one of the multiple paths already established. In the latter case, the modification can comprise replacing one established or existing communication path between the UE and the network with another communication path between the UE and the network: for example, by releasing the established or existing communication path and adding at least one other communication path.

[0332] As discussed above, the multi-path information (or information indicating that multiple paths are to be configured) can be a bit or field set to 1 or enabled or true (e.g. a multi-path bit or field), or an information element comprising all information related to multi-path configuration, or the presence of an SCell configuration or SpCell configuration in the CellGroupConfig information element carried in the RRCReconfiguration message (in addition to the (one or more) relay UE identity for the new or modified indirect path).

[0333] By providing the multi-path information in the configuration message sent to the remote UE, the remote UE 112 is informed that multiple paths are to be set up or an existing multiple path configuration is to be changed / modified. This also means that only the configuration information for the new path or the path to be modified needs to be sent to the remote UE.

[0334] The first communication path can be a direct or indirect path (e.g. via a relay node such as the relay UE 110, etc.). The at least one other communication path can comprise at least one indirect path and / or at least one direct path. The at least one other communication path can be between the UE and a second base station of the network (such as the base station 102, etc.) (e.g. one or more direct paths to the second base station and / or one or more indirect paths to the second base station).

[0335] In an example, and as Figure 14As shown by the dashed line step 1402, the first base station 101 can determine to adapt (e.g., change, modify, update) the connectivity or connection of the remote UE 112 to the network and can transmit the configuration message after determining to adapt the connectivity of the UE 112. The determination by the first base station 101 can be based on the measurement report information received at the first base station 101. The measurement report information can include information received in one or more measurement reports (e.g., measurement report 311a) transmitted by the remote UE 112 and / or information received in one or more measurement reports (e.g., measurement reports 311b, 311c) received from other UEs in the wireless communication system, such as UE 110. These other UEs that are in the vicinity or surrounding of or adjacent to the remote UE 112 are potential candidates to operate as relay nodes for the remote UE 112. In addition, the first base station 101 can receive measurement report information associated with cells controlled by other base stations in the vicinity of or adjacent to the remote UE 112. The determination by the first base station 101 can be in response to a request received from a core network entity, such as entity 140, or after receiving a request received from a core network entity, such as entity 140, or after receiving a request received from a UE, or after receiving a request received from a second base station (e.g., 102), such as in a mobility procedure, by including the multi-path information, for example, in a handover (handover request / request acknowledge) or inter-gNB path switch message (as defined in TS 38.423). As mentioned above, the MP setup request 316 can be transmitted after transmitting information indicating that the QoS requirements are not satisfied (e.g., in the QoS monitoring report 315) by the first base station 101.

[0336] The determination by the first base station 101 to adapt the connectivity of the UE 112 to the network includes a determination to set multiple paths including the first communication path between the UE 112 and the network by adding at least one other communication path between the UE 112 and the network or a determination to modify the multiple paths or multi-path by changing at least the second communication path to at least one other communication path between the UE 112 and the network in case multiple paths including the first communication path and a second communication path (between the UE and the first base station or between the UE and a second base station) are already established (or exist) between the UE 112 and the network. Examples of such determination by the first base station 101 are described above with respect to the MP setup / modification decision step 320.

[0337] In an example, the first base station 101 can select at least one other communication path based on the measurement report information received at the first base station. For example, as discussed above, the received measurement report information can include information received in one or more measurement reports (e.g., measurement report 311a) sent by the remote UE 112 and / or information received in one or more measurement reports (e.g., measurement reports 311b, 311c) received from other UEs in the wireless communication system, such as UE 110, and / or measurement report information associated with cells controlled by other base stations in the vicinity of or in proximity to the remote UE 112. The selection can include selecting at least one relay node (such as relay UE 110) to which the remote UE 112 is to be connected based on the measurement report information or selecting at least one cell (e.g., a cell controlled by the second base station 102) to which the remote UE 112 is to be connected based on the measurement report information. For example, for an indirect other communication path including the second relay node 110, the second relay node 110 can be selected based on the measurement report information for the second relay node 110, and for a direct other communication path between the UE and the second base station 102, the second base station 102 can be selected based on the measurement report information for a cell served by the second base station 102. In relay selection, when one or more primary relay UEs are selected, the first base station 101 can prioritize relay UEs that are already in an RRC CONNECTED state to reduce latency of new path establishment.

[0338] In case at least one relay node is selected for at least one indirect path, the first base station 101 sends configuration information to each of the selected at least one relay node (e.g., relay UE 110) to configure the selected relay node for the respective indirect path between the UE and the network. As discussed above, the configuration information can be sent in an RRC reconfiguration message 341. If the selected relay node 110 is in a non-connected RRC state (e.g., RRC INACTIVE or RRC IDLE), the first base station 101 sends a trigger message to the selected relay node 110 to trigger the selected relay node 110 to enter an RRC connected state (e.g., RRC CONNECTED). The trigger message can be the message 400 sent after the first base station 101 checks the RRC state of the relay UE as described above in step 600. The trigger message can be a paging message or a system information block (e.g., SIB12)

[0339] The above description of how the base station 101 can trigger the relay UE to enter the RRC connected state has been made in relation to the configuration message including configuration information and multipath information. However, it will be appreciated that in the case where the configuration information does not include multipath information and includes configuration information for configuring the UE (e.g. remote UE 112) to communicate with the network, the base station 101 can trigger the relay UE to enter the RRC connected state based on the above description.

[0340] In the case where setting up the at least one other communication path fails, the first base station 101 can receive a failure message from the remote UE 112. The failure message can be the message 900 (e.g. MCGFailurelnformation message) and can include all or part of the information described above in relation to the message 900. After or in response to receiving the failure message, the first base station can cancel the configuration of the at least one communication path (e.g. as described above with reference to step 910). The first base station 101 can then send a multipath failure message to the core network, such as the message 352 or the like.

[0341] After receiving the failure message, in an example, the first base station 101 can then select at least one new communication path and send a configuration message to the remote UE 112, the configuration message including configuration information for configuring the at least one new communication path and multipath information for indicating that the at least one new communication path to be configured is for providing multiple paths or multipaths between the UE and the network. The first base station 101 can select the at least one new communication path based on the information provided in the failure message. The stage or process 1000 discussed above provides an example of how the first base station 101 can select a new path and send configuration information for the new path to the remote UE 112 to provide multiple paths.

[0342] Reference is now made to Figure 15 , Figure 15is a flowchart illustrating steps of a method 1500 for managing multipath communication in a wireless communication system that supports relaying between UEs and a network, according to one or more embodiments of the present application. The wireless communication system supports sidelink relaying and / or other peer-to-peer relaying, such as through WiFi relaying or Bluetooth relaying, etc. In case the wireless communication system supports sidelink relaying, a UE is referred to as a remote UE and a relay node is referred to as a relay UE (e.g., a UE that operates as or functions as a relay). The network of the wireless communication system includes at least a first base station. The method 1500 is performed at a UE after a first communication path has been established between the UE and the first base station. The first communication path can be a direct path between the UE and the first base station or an indirect path between the UE and the first base station via at least one relay node. The UE can be configured such that it can communicate with the network via the first base station over at least two separate paths or multiple paths, referred to as multipath. For example, the UE can be directly connected to the base station via a direct path and can also be indirectly connected to the base station via at least one relay node (e.g., a relay UE) and thus via an indirect path. Additionally or alternatively, the UE can be connected to the base station via at least two indirect paths and / or at least two direct paths. The UE can also be configured such that it can communicate with the network via a second base station over one or more direct and / or indirect paths. With respect to the example shown in FIG. 1, the UE performing the method 1500 can be the UE or remote UE 112 and the first base station can be the base station 101 (also referred to as gNB 101). The second base station can be the base station 102. As Figure 15 indicated and described with respect to Figure 15 the method 1500 can be performed by software elements and / or hardware elements. Thus, for example, the method as Figure 15 indicated and described with respect to Figure 15 may be performed by an apparatus for a base station, the apparatus comprising one or more processing units configured to perform the method. The base station can be implemented in a communication apparatus 1700 as Figure 17 indicated and described with respect to Figure 17 the method is performed by one or more processing units, such as the central processing unit 1711, etc. Figure 15 Figure 15

[0343] ​​In short, at step 1502, the remote UE 112 receives, from the base station 101, a configuration message including configuration information for configuring the remote UE 112 to communicate with or connect to the network. The configuration information (also referred to as multi-path (MP) configuration information) can include all or part of the information described above with respect to the RRC reconfiguration message 321. The configuration message can be the RRC reconfiguration message 321. The configuration message further includes multi-path information for indicating that the configuration information is associated with at least one other communication path to be configured between the remote UE 112 and the network to provide multiple paths or multi-paths between the remote UE 112 and the network along with the first communication path. The configuration information received at the remote UE 112 from the first base station 101 corresponds to the configuration information discussed above with respect to Figure 14 the configuration information sent by the first base station. Thus, for more details of the configuration information and the first communication path, see the description above with respect to Figure 14 .

[0344] Instead of the first base station 101 making a determination to adapt (e.g., change, modify, update) the connectivity or connection of the remote UE 112 to the network, the remote UE 112 can make the determination. For example, the remote UE 112 can determine an additional bandwidth requirement based on a steady increase of data held in its buffer(s) (e.g., when preparing a BSR) or receiving many negative acknowledgement messages (e.g., NACKs) from the relay UE to which it is connected. In this case, the remote UE 112 can send a request to the first base station 101 for establishing at least one other communication path between the UE and the network to provide multiple paths or multi-paths between the UE and the network.

[0345] In an example, and as shown by step 1504 in dashed lines in Figure 15 , the remote UE 112 can initiate connection adaptation to adapt (or modify or change or update) the connectivity of the UE to the network based on the information in the received configuration message.

[0346] The connection adaptation can include setting multiple paths between the UE 112 and the network by adding at least one other communication path between the UE 112 and the network to provide multiple paths or multi-paths between the UE and the network including the first communication path, or modifying the multiple paths or multi-paths by changing at least the second communication path to at least one other communication path between the UE 112 and the network in case multiple paths including the first communication path and the second communication path (between the UE and the first base station or between the UE and the second base station) are already established (or exist) between the UE 112 and the network.

[0347] In response to receiving or after receiving the configuration message, the remote UE 112 can start a path failure timer (e.g., a path addition / modification / failure timer). The remote UE 112 can stop the path failure timer in response to or after transmitting, by the remote UE 112, a message indicating a setup completion of at least one other communication path at the remote UE 112. The message transmitted by the remote UE 112 can be the RRC reconfiguration message 323 or the RRCReconfigurationComplete message 501. The remote UE 112 can stop the path failure timer in response to or after a successful transmission of the message. In an example, the message 323 or 501 is transmitted by the remote UE 112 when a signaling radio bearer (e.g., SRB1) is configured on the indirect path between the remote UE 112 and the network. In another example, the remote UE 112 can stop the path failure timer in response to or after receiving a relay message indicating that a relay node (e.g., the relay UE 110) is configured (e.g., configuration of PC5 RRC AS has completed) or active. The relay message can also indicate that the relay node 110 is connected to the first base station 101. In an example, the relay message is transmitted when no signaling radio bearer (e.g., SRB1) is configured on the indirect path between the remote UE 112 and the network. For example, the relay message includes information indicating that the relay UE 110 is in an RRC connected state (RRC CONNECTED). The relay message can be the feedback message 500, the NotificationMessageSidelink message, the RRCReconfigurationCompleteSidelink 812, the MeasurementReportSidelink 831, as discussed above.

[0348] When the path failure timer reaches a certain value (e.g., at timer expiry), the remote UE 112 transmits a failure message to the first base station 101 indicating a failure to setup at least one other communication path. The failure message can be the message 900 (e.g., a MCGFailureInformation message) and can include all or part of the information described above for the message 900.

[0349] In the example case where at least one other communication path includes an indirect path that includes a relay node, the remote UE 112 initiates connection adaptation by sending configuration information to the relay node for configuring the relay node for the indirect path. The configuration information can be sent in an RRCReconfigurationSidelink message 811. In response to sending the configuration information, the remote UE 112 can receive an acknowledgement indicating completion of the configuration at the relay UE 110 (e.g., in an RRCReconfigurationCompleteSidelink message 812).

[0350] After sending the configuration information, the remote UE 112 can send a message (e.g., RRCReconfigurationSidelink 811 or RemoteUEInformationSidelink 700) to the relay UE 110 to trigger the relay node to enter an RRC connected state. The RRCReconfigurationSidelink sent by the remote UE 112 can include a new IE Sl_RelayUE_RRCConnected_Req that, if present, requests the relay UE 110 to enter an RRC CONNECTED state.

[0351] The remote UE 112 can receive information from the relay UE 110 indicating whether the relay UE 110 supports being triggered by the UE to enter an RRC connected state. The information can be sent as part of a UECapabilityInformationSidelink message 822 in response to a request from the UE UECapabilityEnquirySidelink message 821 or automatically according to its own volition. The capability exchange can occur prior to the RRCReconfigurationSidelink as long as the direct communication is established. The remote UE 112 can determine whether the relay UE 110 supports being triggered by the remote UE 112 based on the information received from the relay UE 100 and can then send the trigger message after determining that the relay UE 110 supports being triggered by the remote UE 112.

[0352] The above description of how the remote UE 112 can trigger the relay UE to enter an RRC connected state has been made with respect to receiving a configuration message that includes configuration information and multipath information. However, it should be understood that in the case where the configuration information does not include multipath information and includes configuration information for configuring the UE (e.g., remote UE 112) to communicate with the network, the remote UE 112 can trigger the relay UE to enter an RRC connected state based on the above description.

[0353] In an example, the remote UE 112 transmits, to the first base station 101, at least one of: information indicating whether the UE prefers the relay node to be in a connected RRC state or in an unconnected RRC state in case an indirect path is to be configured; information indicating whether the UE prefers triggering the relay node to enter a connected RRC state or not in case an indirect path is to be configured and the relay node of the indirect path is in an unconnected RRC state. Such information can be transmitted in a UEAssistanceInformation message 610.

[0354] As discussed above, in response to receiving the configuration message or after receiving the configuration message, the remote UE 112 can start a path failure timer (e.g., a path addition / modification / failure timer). In an example, after the path failure timer reaches a certain value indicating a failure of setting at least one other communication path (e.g., at the expiration of the timer), the remote UE 112 selects at least one new communication path (e.g., at least one direct path and / or at least one indirect path). After selecting the at least one new communication path, the remote UE 112 starts a path recovery timer (e.g., a path addition / modification / recovery timer), and after starting the timer, the remote UE 112 attempts to establish at least one connection to set the at least one communication path.

[0355] The remote UE 112 can start a path recovery timer in response to sending the RRCReestablishment message, such as message 1112, or after sending the RRCReestablishment message, such as message 1112, or in response to selecting the at least one new communication path. The remote UE 112 can stop the path recovery timer in response to sending, by the remote UE 112, a message indicating a setup completion of the at least one new communication path. The message can be the RRCRestablishmentComplete message 1114 or the RRC reconfiguration complete message 323 / 501. The remote UE 112 can stop the path recovery timer in response to or after a successful transmission of the message. In an example case where the at least one new communication path comprises a new indirect path including a relay node, the remote UE 112 stops the path recovery timer in response to receiving a relay message: such as a message indicating that the relay UE 110 is configured or active, and the message can further indicate that the relay UE 110 is connected to the first base station 101. For example, the relay message comprises information indicating that the relay UE 110 is in an RRC connected state (RRC_CONNECTED). The relay message can be the feedback message 500, the NotificationMessageSidelink message, the RRCReconfigurationCompleteSidelink 812, the MeasurementReportSidelink 831 as discussed above.

[0356] The remote UE 112 can receive, from the first base station 101, backup identification information identifying at least one backup communication path. The backup identification information can comprise backup relay identification information, such as the backup relay list discussed above with reference to the configuration message 321, and / or backup cell information, such as the cell list discussed above with reference to the configuration message 321. After the path failure timer reaches a certain value, the remote UE 112 can select at least one relay node identified in the backup relay identification information, and in this case the at least one new communication path comprises at least one new indirect path through the selected one of the at least one relay node, and / or the remote UE 112 can select at least one secondary cell identified in the backup cell information, in which case the at least one new communication path comprises at least one new direct path to the selected one of the at least one secondary cell.

[0357] In another example, after the path failure timer reaches a certain value, the remote UE 112 can select the at least one new communication path based on measurements made at the UE.

[0358] After the remote UE 112 determines that the setup of the at least one new communication path is complete, the remote UE 112 can then proceed with an RRC reestablishment procedure to continue the RRC connection for the remote UE 112. As discussed above with reference to FIG. 11, the RRC reestablishment procedure can include sending an RRC reestablishment request message (such as message 1112), receiving an RRC reestablishment message (such as message 1113), and sending an RRC reestablishment complete message (such as message 1114). Figure 11 As discussed above, the RRC reestablishment procedure can include sending an RRC reestablishment request message (such as message 1112), receiving an RRC reestablishment message (such as message 1113), and sending an RRC reestablishment complete message (such as message 1114).

[0359] With respect to receiving the configuration message including configuration information and multipath information, the above description of the behavior of the Path_Addition_Modification_failure timer (also referred to as the path failure timer) and the behavior of the Path_Addition_Modification_recovery timer (also referred to as the path recovery timer) has been made. However, it should be understood that the behavior of these timers can also apply in the case where the configuration information does not include multipath information and includes configuration information for configuring the UE (e.g., remote UE 112) to communicate with the network.

[0360] Reference is now made to Figure 16 , Figure 16This is a flowchart illustrating the steps of a method 1600 for managing multipath communication in a wireless communication system supporting relay between a UE and a network, according to one or more embodiments of the present invention. The wireless communication system supports side-link relay and / or other peer-to-peer relay, such as via WiFi relay or Bluetooth relay. In the case where the wireless communication system supports side-link relay, the UE is referred to as a remote UE, and the relay node is referred to as a relay UE (e.g., a UE operating as a relay or used as a relay). The network of the wireless communication system includes at least a first base station. Method 1600 is performed at the relay UE after a first communication path has been established between the UE and the first base station. The first communication path may be a direct path between the UE and the first base station, or an indirect path between the UE and the first base station via at least one other relay node. The UE may be configured such that it can communicate with the network via the first base station on at least two separate paths or multiple paths (referred to as multipath). For example, the UE may be directly connected to the base station via a direct path, and may also be indirectly connected to the base station via at least one relay node (e.g., a relay UE) and thus via an indirect path. Alternatively or additionally, the UE may be connected to the base station via at least two indirect paths and / or at least two direct paths. The UE can also be configured to communicate with the network via a second base station on one or more direct and / or indirect paths. Regarding the example shown in Figure 1, the relay UE performing method 1600 could be UE 110 operating as a relay UE, the UE could be a remote UE 112, and the first base station could be base station 101 (also referred to as gNB 101). The second base station could be base station 102. As... Figure 16 The image shown and about Figure 16 The described method 1600 can be performed by software elements and / or hardware elements. Therefore, for example, as... Figure 16 The image shown and about Figure 16 The described method can be performed by a device for a base station, which includes one or more processing units configured to perform the method. The base station can be, for example... Figure 17 The images and references shown Figure 17 The communication device 1700 described herein is implemented, wherein, as Figure 16 The image shown and about Figure 16 The described method is performed by one or more processing units (such as a central processing unit 1711, etc.).

[0361] Briefly, at step 1602, the relay UE 110 receives configuration information from a base station 101 (e.g., in an RRCReconfiguration message 341, or from a remote UE 112 (e.g., in an RRCReconfigurationSidelink message 811) to configure the relay node for an indirect communication path between the UE and the network to provide multiple paths between the UE and the network along with the first communication path.

[0362] At step 1604, the relay UE 110 sends information to the remote UE 112 indicating the current RRC state of the relay UE 110 (e.g., whether the relay node is in an RRC connected state (e.g., RRC CONNECTED)). The information can be sent in any of the feedback message 500, NotificationMessageSidelink message, MeasurementReportSidelink 831, RRCReconfigurationCompleteSidelink 812, or any other PC5_RRCReconfigurationComplete message as described above. For example, the relay UE 110 can send a relay message indicating that the relay node is configured or active, and the message can also indicate that the relay UE 110 is connected to the first base station, and can include information indicating that the relay UE 110 is in an RRC connected state (RRC CONNECTED). The relay message can be the feedback message 500, NotificationMessageSidelink message, RRCReconfigurationCompleteSidelink 812, MeasurementReportSidelink 831 as discussed above.

[0363] The configuration information can include measurement report configuration information to configure the relay node to send measurement report information after a change in RRC state. After determining a change in RRC state at the relay UE 110, the relay UE 110 can send measurement report information to the remote UE 112 including information indicating the current RRC state of the relay UE. The measurement report information can be sent in the MeasurementReportSidelink 831.

[0364] In an example, the relay UE 110 sends information to the remote UE 112 indicating whether the relay node supports being triggered by the UE to enter the RRC connected state. The information can be sent as part of the UECapabilitylnformationSidelink message 822 in response to a request from the UE UECapabilityEnquirySidelink message 821 or automatically according to its own volition. In the example case where the relay UE 110 does support being triggered by the remote UE 112 to enter the RRC connected state and the current RRC state of the relay UE 110 is the non-connected RRC state, the relay UE 110 enters the RRC connected state in response to receiving the trigger message (e.g., RRCReconfigurationSidelink 811 or RemoteUEInformationSidelink 700) from the remote UE 112.

[0365] In another example, the relay UE 110 can receive a message from the first base station 101 to trigger the relay UE 110 to enter the RRC connected state. Such a message can be the message 400.

[0366] Figure 17 A schematic representation of an example communication apparatus or station according to one or more example embodiments of the disclosure is shown.

[0367] The communication apparatus 1700 can be an apparatus such as a microcomputer, a workstation or a light portable apparatus. The communication apparatus 1700 comprises a communication bus 1713, preferably connected with:

[0368] - a central processing unit 1711, denoted CPU, such as a microprocessor or the like;

[0369] - a memory for storing data and computer programs containing instructions for the operation of the communication apparatus 1700. The computer programs can contain a plurality of different program elements or subroutines containing instructions for various operations and for implementing the present application. For example, the program elements include at least one element for managing the multi-path communication as described above. The at least one element, when executed by the central processing unit 1711, configures one or more processing units (e.g., functioning as the CPU 1711 or as part of the CPU 1711) to perform the method(s) as described above.

[0370] The communication device 1700 can also comprise at least one communication interface 1702 connected to a radio communication network 1703 (for example a 5G NR wireless communication network) transmitting digital data packets or frames or control frames. Under the control of a software application running in the CPU 171 1, frames are written from the FIFO sending memory in the RAM 1712 to the communication interface 1702 for transmission, or read from the communication interface 1702 for reception and written into the FIFO receiving memory in the RAM 1712.

[0371] The UE and the base station can each comprise such a communication device 1700.

[0372] The central processing unit 171 1 can be a single processing unit or processor, or can comprise two or more processing units or processors operating in coordination. The number of processing units or processors and the allocation of function among them are a design choice to achieve the desired balance between complexity and function.

[0373] The memory can comprise:

[0374] - a read only memory 1707, denoted ROM, for storing a computer program for implementing the method according to an embodiment of the application;

[0375] - a random access memory 1712, denoted RAM, for storing the executable code of the method according to an embodiment of the application, and registers adapted to record the variables and parameters required to implement the method according to an embodiment of the application.

[0376] Optionally, the communication device 1700 can also comprise the following components:

[0377] - a data storage means 1704, such as a hard disk, for storing a computer program for implementing the method according to one or more embodiments of the application;

[0378] - a disk drive 1705 for a disk 1706, the disk drive being adapted to read data from the disk 1706 or to write data on the disk;

[0379] - a screen 1709 for displaying decoded data and / or for use as a graphical interface with the user with the keyboard 1710 or any other user input means.

[0380] Preferably, the communication bus 1713 provides communication and interoperability between the various elements comprised in the communication device 1700 or connected to the communication device 2100. The representation of the bus 1713 is not limiting and in particular the central processing unit is operable to communicate instructions to any element of the communication device 1700, directly or through other elements of the communication device 1700.

[0381] The disk 1706 can optionally be replaced by any information medium, for example a rewritable or non-rewritable compact disk (CD-ROM), a ZIP disk, a USB key or a memory card, etc., and in general by an information storage component that is readable by a microcomputer or microprocessor, integrated or not into the device, possibly removable, and adapted to store one or more programs whose execution makes it possible to carry out the method according to the embodiments of the application.

[0382] The executable code can optionally be stored in the read-only memory 1707, on the hard disk 1704 or on a removable digital medium, for example the disk 1706, etc., as mentioned previously. According to an optional variant, the executable code of the program can be received via the communication interface 1702, through the communication network 1703, to be stored in one of the storage components of the communication device 1700, such as the hard disk 1704, etc., before being executed.

[0383] The central processing unit 1711 is preferably adapted to control and direct the execution of the instructions or partial software code of one or more programs according to the application, stored in one of the storage components mentioned above. Upon power-up, the one or more programs stored in non-volatile memory, for example in the hard disk 1704 or in the read-only memory 1707, are transferred into the random access memory 1712, which then contains the executable code of the one or more programs as well as registers for storing variables and parameters required for implementing the application.

[0384] In an embodiment, the device is a programmable device that implements the application using software. However, alternatively, the application can be implemented in hardware, for example in the form of an application-specific integrated circuit or ASIC. In this case, the logic unit is configured to carry out the steps of the method(s) according to the application described above.

[0385] While the application has been described with reference to the examples, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the application as defined in the appended claims. The various features disclosed in the specification (including any accompanying claims, abstract and drawings), and / or the methods or processes described herein can be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive, provided such combinations are not expressly disclosed. Unless otherwise expressly stated, the various features disclosed in the specification (including any accompanying claims, abstract and drawings) can be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, the disclosed features are merely exemplary of the generic series of equivalent or similar features.

[0386] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

[0387] In the foregoing embodiments, the functions described can be implemented in hardware, software, firmware or any combination thereof. If implemented in software, the functions can be stored or transmitted over as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit.

[0388] Computer-readable media can include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another, e.g., according to a communication protocol. In this manner, computer- readable media generally can correspond to (1) tangible computer-readable storage media which is non-transitory or (2) a communication medium such as a signal or carrier wave. Data storage media can be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and / or data structures for implementation of the techniques described in this disclosure. A computer program product can include a computer-readable medium.

[0389] By way of example, and not limitation, such computer-readable storage media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other storage 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. Also, any connection is properly termed a computer-readable medium. For example, if the instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. It should be understood, however, that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but are instead directed to non-transient, tangible storage media. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

Claims

1. A method for managing multipath communication in a wireless communication system that supports relaying between a user equipment (UE) and a network comprising at least a first base station, wherein, A first communication path has been established between the UE and the first base station, and the method at the first base station includes: A configuration message is sent to the UE, the configuration message including configuration information for configuring the UE to communicate with the network. The configuration message includes information indicating that at least one other communication path should be configured between the UE and the network in addition to the first communication path to provide multiple paths between the UE and the network.

2. The method of claim 1, wherein, Sending the configuration message includes: after determining that the connectivity of the UE to the network should be adapted to provide multiple paths between the UE and the network, sending the configuration message to the UE.

3. The method of claim 2, further comprising: The connectivity of the UE to the network is determined based on the measurement report information received at the first base station.

4. The method of claim 2, further comprising: Upon receiving a request from a core network entity, or upon receiving a request from the UE, or upon receiving a request from a second base station, it is determined that the UE's connectivity to the network should be adapted.

5. The method according to claim 2, further comprising: Send information to the core network entity indicating that the first communication path does not meet the Quality of Service (QoS) requirements. After sending information indicating that QoS requirements are not met, a multipath setting request is received from the core network entity; Upon receiving the multipath setting request, it is determined that the connectivity of the UE to the network needs to be adapted.

6. The method of any one of claims 2 to 5, wherein, Determining the connectivity to be adapted for the UE to the network includes: determining to set up multiple paths between the UE and the network, including the first communication path, by adding at least one other communication path between the UE and the network, wherein the configuration message includes path configuration information for configuring the UE for the at least one other communication path.

7. The method of any one of claims 2 to 5, wherein, In the case where multiple paths, including the first communication path and the second communication path, have been established between the UE and the network, determining to adapt the connectivity of the UE to the network includes: determining to modify the multiple paths by changing at least the second communication path to at least one other communication path between the UE and the network, wherein the configuration message includes path configuration information for configuring the UE for the at least one other communication path.

8. The method according to any one of the preceding claims further comprises: The at least one other communication path is selected based on the measurement report information received at the first base station.

9. The method of claim 8, wherein, Selecting the at least one other communication path includes: selecting at least one relay node to which the UE should connect based on the measurement report information, in which case the at least one other communication path includes at least one indirect path through the selected at least one relay node.

10. The method according to claim 8, wherein, Selecting the at least one other communication path includes: selecting at least one cell to which the UE should connect based on the measurement report information, in which case the at least one other communication path includes at least one direct path to the selected at least one cell.

11. The method of claim 9, further comprising: Configuration information for configuring the selected relay nodes for the corresponding indirect path between the UE and the network is sent to each of the at least one selected relay nodes.

12. The method according to any one of claims 1 to 9 and 11, further comprising: The system receives capability information, which indicates whether a relay node, as a candidate relay node for providing an indirect communication path between the UE and the network, supports PC5 triggering, in which the relay node can be triggered to enter the RRC connection state using PC5 messages.

13. The method according to any one of claims 1 to 12, wherein, Sending the configuration message includes sending a configuration message to the UE, the configuration message including configuration information for configuring a signaling radio bearer (SRB) on the at least one other communication path for use by the UE when triggering a relay node to enter an RRC connection state.

14. The method of claim 12, further comprising: After determining that the relay node does not support PC5 triggering based on the received capability information, the base station determines that it needs to send a trigger message to trigger the relay node to enter the RRC connection state.

15. The method according to claim 9, 11, or 14, further comprising: After determining that the selected relay node is in a disconnected RRC state, a trigger message is sent to the selected relay node to trigger it to enter the RRC connected state.

16. The method according to claim 15, wherein, The trigger message is one of the following: The paging message includes the identifier of the selected relay node and paging reason information indicating that the selected relay node wants to initiate a connection process; A paging message is used to indicate that the first base station has data to be sent to the relay node for use by the UE.

17. The method according to any one of the preceding claims further comprises: The UE receives a failure message indicating that setting at least one other communication path has failed.

18. The method according to claim 17, wherein, The failure message includes at least one of the following: Failure type information, which indicates the type of failure in setting up the at least one other communication path; Identification information is used to identify the relay node that the UE cannot connect to in the event that the indirect path setup fails; Cell information is used to identify cells that the UE cannot connect to when setting up a direct path fails; Candidate relay information for one or more relay nodes, wherein the one or more relay nodes are candidates for providing one or more new communication paths to connect the UE to the network; Neighboring cell information, used to indicate one or more cells adjacent to the UE, wherein the one or more cells are candidates for providing one or more new communication paths to connect the UE to the network; Path identification information is used to identify at least one communication path that has failed to be configured, or to identify each connection of at least one communication path that has failed to be configured.

19. The method according to claim 17 or 18, further comprising: Upon receiving the failure message, the configuration of at least one other communication path is cancelled.

20. The method according to claim 17 or 18, further comprising: Upon receiving the failure message, the configuration of at least one other communication path is cancelled and a multipath failure message is sent to the core network entity.

21. The method according to claim 17 or 18, further comprising: Upon receiving the failure message, select at least one new communication path; A configuration message is sent to the UE, the configuration message including configuration information for configuring the at least one new communication path and information for indicating that the at least one new communication path to be configured should provide multiple paths between the UE and the network.

22. The method according to any one of the preceding claims, wherein, The configuration message also includes at least one of the following: Relay identification information is used to identify at least one relay node, wherein the UE is to establish a connection with the at least one relay node for the at least one other communication path to provide multiple paths; Backup relay identification information is used to identify at least one relay node, wherein in the event that a connection to the first relay node fails, the UE shall establish a connection with the at least one relay node to provide multiple paths; Primary cell information is used to identify the primary cell, wherein the UE needs to establish a connection with the primary cell for the at least one other communication path to provide multiple paths; Backup cell information is used to identify at least one secondary cell, wherein in the event that the UE fails to establish a connection with the primary cell, it needs to establish a connection with the at least one secondary cell to provide multiple paths; Path identification information, used to identify the at least one other communication path or to identify each connection of the at least one other communication path; Configuration information is used to configure at least one communication path between the UE and the second base station to provide multiple paths.

23. A method for managing multipath communication in a wireless communication system, said wireless communication system supporting relay between a user equipment (UE) and a network including a first base station, wherein, A first communication path has been established between the UE and the first base station, and the method includes the following at the UE: The UE receives a configuration message from the first base station, the configuration message including configuration information for configuring the UE to communicate with the network. The configuration message includes information indicating that at least one other communication path should be configured between the UE and the network in addition to the first communication path to provide multiple paths between the UE and the network.

24. The method of claim 23, further comprising: A request is sent to the first base station to establish at least one other communication path between the UE and the network, thereby providing multiple paths between the UE and the network.

25. The method according to claim 23 or 24, further comprising: Based on the information in the received configuration message, a connection adaptation is initiated to adapt the UE to the network connectivity.

26. The method according to any one of claims 23 to 25, further comprising: Upon receiving the configuration message, a path failure timer is started.

27. The method according to claim 26, wherein, Initiating connection adaptation includes initiating connection adaptation after starting the path failure timer.

28. The method according to claim 26 or 27, further comprising: In response to a message sent by the UE indicating that the setup of at least one other communication path at the UE is complete, the path failure timer is stopped.

29. The method according to claim 26 or 27, further comprising: After a signaling radio bearer (SRB) is configured on at least one other communication path, the path failure timer is stopped in response to a message sent by the UE indicating that the configuration of the at least one other communication path at the UE is complete.

30. The method according to claim 26 or 27, further comprising: When no signaling radio bearer (SRB) is configured on the at least one other communication path, the path failure timer is stopped in response to receiving a message indicating that the configuration of the at least one other communication path at the UE is complete.

31. The method according to claim 26 or 27, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes: In response to receiving a relay message indicating that the relay node is configured, the path failure timer is stopped.

32. The method according to claim 26, 27, or 30, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes: In response to receiving the RRCReconfigurationcompleteSidelink message, the path failure timer is stopped.

33. The method according to claim 31, wherein, The relay message includes information indicating that the relay node is in an RRC connection state.

34. The method according to any one of claims 25 to 33, wherein, Connection adaptation includes adding the at least one other communication path to provide multiple paths including the first communication path between the UE and the network, or, if multiple paths including the first and second communication paths have already been established between the UE and the network, connection adaptation includes modifying multiple paths by changing at least the second communication path to at least one other communication path between the UE and the network.

35. The method according to any one of claims 25 to 34, wherein, In the case that at least one other communication path includes an indirect path containing a relay node, initiating connection adaptation includes: Initiate the establishment of a PC5 connection with the relay node for the indirect path.

36. The method of claim 35, further comprising: After initiating the establishment of the PC5 connection, receive from the relay node an acknowledgment indicating that the establishment of the PC5 connection at the relay node is complete.

37. The method according to any one of claims 35 to 36, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes: after initiating the establishment of a PC5 connection, receiving information from the relay node indicating whether the relay node is in an RRC connection state.

38. The method according to any one of claims 35 to 37, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes sending a message to the relay node to trigger the relay node to enter an RRC connection state.

39. The method according to any one of claims 23 to 37, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes sending a RemoteUEInformationSidelink message to the relay node to trigger the relay node to enter an RRC connection state.

40. The method according to any one of claims 23 to 37, wherein, If at least one other communication path includes an indirect path containing a relay node and the UE is in an RRC connection state, the method further includes: sending a message to the relay node to trigger the relay node to enter the RRC connection state.

41. The method according to any one of claims 38 to 40, wherein, The message includes information for triggering the relay node to enter the RRC connection state.

42. The method according to any one of claims 23 to 41, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes: receiving information indicating whether the relay node supports being triggered by the UE to enter an RRC connection state.

43. The method according to any one of claims 23 to 41, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes: receiving capability information indicating whether the relay node supports PC5 triggering, in which the UE can trigger the relay node to enter an RRC connection state using a PC5 message.

44. The method according to any one of claims 23 to 43, wherein, If the at least one other communication path includes an indirect path containing a relay node, the method further includes: receiving preference information indicating whether the relay node prefers to be triggered via PC5 or RRC, wherein in PC5 triggering, the UE can trigger the relay node to enter an RRC connection state using a PC5 message, and in RRC triggering, the UE can trigger the relay node to enter an RRC connection state using an RRC message.

45. The method according to claim 42, 43, or 44, further comprising: The relay node sends capability information and / or preference information to the first base station. The capability information indicates whether the relay node supports PC5 triggering, which allows the UE to trigger the relay node into an RRC connection state using a PC5 message. The preference information indicates whether the relay node prefers to trigger via PC5 triggering, which allows the UE to trigger the relay node into an RRC connection state using a PC5 message, or via RRC triggering, which allows the UE to trigger the relay node into an RRC connection state using an RRC message.

46. ​​The method according to claim 38 or 39 or 40 and 42, or claim 38 or 39 or 40 and 43, wherein, Sending a message to the relay node to trigger the relay node includes: after determining that the relay node supports being triggered by the UE, sending a message to the relay node to trigger the relay node to enter the RRC connection state.

47. The method according to any one of claims 23 to 38, wherein if the at least one other communication path includes an indirect path comprising a relay node, the method further comprises: When the configuration information does not include the signal radio bearer configuration (SRB) for the indirect path, the UE determines that it wants to trigger the relay node to enter the RRC connection state by using a PC5 message.

48. The method according to any one of claims 23 to 38, wherein if the at least one other communication path includes an indirect path comprising a relay node, the method further comprises: The UE determines, based on the configuration message, that it will trigger the relay node to enter the RRC connection state by using the PC5 message.

49. The method according to any one of claims 23 to 48, further comprising sending at least one of the following to the first base station: Information used to indicate whether the UE prefers the relay node to be in a connected RRC state or a disconnected RRC state when configuring an indirect path; Information used to indicate whether the UE prefers to trigger the relay node into a connected RRC state when an indirect path is to be configured and the relay node of the indirect path is in a non-connected RRC state.

50. The method according to any one of claims 23 to 49, further comprising: In response to receiving the configuration message, a path failure timer is started; When the path failure timer reaches a certain value, a failure message and / or an RRCReestablishment message are sent to indicate that the setting of at least one other communication path has failed.

51. The method according to claim 50, wherein, The failure message includes at least one of the following: Failure type information, which indicates the type of failure in setting up the at least one other communication path; Identification information is used to identify the relay node that the UE cannot connect to in the event that the indirect path setup fails; Cell information is used to identify cells that the UE cannot connect to when setting up a direct path fails; Candidate relay information for one or more relay nodes, wherein the one or more relay nodes are candidates for providing one or more new communication paths to connect the UE to the network; Neighboring cell information, used to indicate one or more cells adjacent to the UE, wherein the one or more cells are candidates for providing one or more new communication paths to connect the UE to the network; Path identification information is used to identify at least one communication path that has failed to be configured, or to identify each connection of at least one communication path that has failed to be configured.

52. The method according to any one of claims 23 to 51, further comprising: After the failure to set up at least one other communication path, a path recovery timer is started after sending an RRCReestablishment message to initiate the RRC reconstruction process.

53. The method according to any one of claims 23 to 51, wherein, in the case that the first communication path is a suspended direct path, and after setting the indirect path as the at least one other communication path has failed, the method further comprises: After sending the RRCReestablishment message to initiate the RRC reconstruction process to rebuild the direct path, a path recovery timer is started; In response to a message sent by the UE indicating that the reconstruction of the direct path is complete, the path recovery timer is stopped.

54. The method according to any one of claims 23 to 51, further comprising: Upon receiving the configuration message, start the path failure timer; After the path failure timer reaches a certain value indicating that at least one other communication path has failed, at least one new communication path is selected. After selecting at least one new communication path, start the path recovery timer; After starting the path recovery timer, attempt to establish at least one connection to set up the at least one new communication path.

55. The method of claim 54, further comprising: In response to a message sent by the UE indicating that the setup of the at least one new communication path is complete, the path recovery timer is stopped.

56. The method of claim 54, further comprising: If the at least one new communication path includes a new indirect path containing a relay node, the path recovery timer is stopped in response to receiving a relay message indicating that the relay node is configured.

57. The method according to claim 56, wherein, The relay message includes information indicating that the relay node is in an RRC connection state.

58. The method according to any one of claims 54 to 57, further comprising: The system receives backup identification information from the first base station for identifying at least one backup communication path, wherein the selection includes selecting one of the at least one backup communication path as the at least one new communication path.

59. The method according to claim 58, wherein, The backup identification information includes backup relay identification information for identifying at least one relay node, to which the UE can establish a connection to provide multiple paths. The selection includes selecting one of the at least one relay node identified in the backup relay identification information. In this case, the at least one new communication path includes at least one new indirect path through the selected relay node among the at least one relay node.

60. The method according to claim 59, wherein, Attempting to establish at least one connection includes performing connection establishment to establish a connection with a selected relay node among the at least one relay nodes.

61. The method according to claim 58, wherein, The backup identification information includes backup cell information for identifying at least one secondary cell, and the UE is able to establish a connection with the at least one secondary cell to provide multiple paths, wherein selection includes selecting one of the at least one secondary cell identified in the backup cell information, in which case the at least one new communication path includes at least one new direct path to the selected secondary cell among the at least one secondary cells.

62. The method according to any one of claims 54 to 57, wherein, Selecting the at least one new communication path includes selecting the at least one new communication path based on measurements performed at the UE.

63. The method according to claim 55 or 56, wherein, After the setup of the at least one new communication path is completed, an RRC reconstruction procedure is initiated to continue the RRC connection for the UE.

64. The method according to claim 52, 53, or 63, wherein, Initiating the RRC reconstruction process includes: Send an RRC reconstruction request message to the first base station, the RRC reconstruction request message including identification information for identifying the UE; Receive an RRC reconstruction message from the first base station, the RRC reconstruction message including information associated with an RRC procedure for continuing the RRC connection for the UE; In response to the RRC reconstruction message, an RRC reconstruction completion message indicating that the RRC connection associated with the RRC process has been completed is sent to the first base station.

65. The method according to claim 64, wherein, The RRC reconstruction request message also includes at least one of the following: The cause information indicates the reason why setting up at least one other communication path failed; Identification information is used to identify the relay node that the UE cannot connect to in the event that the indirect path setup fails; Cell information is used to identify cells that the UE cannot connect to when setting up a direct path fails; Path identification information is used to identify at least one communication path that has failed to be configured, or to identify each connection of at least one communication path that has failed to be configured.

66. The method according to claim 64 or 65, wherein, Information associated with the RRC process includes at least one of the following: Security information regarding the RRC process; UE configuration information, which includes SRAP configuration information and an identifier specific to the UE; The identifier for the RRC procedure.

67. The method according to any one of claims 64 to 66, wherein, The RRC reconstruction completion message includes at least one of the following: Identifier for the RRC procedure; Candidate relay information for one or more relay nodes, wherein the one or more relay nodes are candidates for providing one or more new communication paths to connect the UE to the network; Neighboring cell information, used to indicate one or more cells adjacent to the UE, wherein the one or more cells are candidates for providing one or more new communication paths to connect the UE to the network; Information associated with the failure of the UE to connect to the relay node in the event that the indirect path setup fails.

68. The method according to any one of claims 23 to 51, further comprising: In response to receiving the configuration message, a path failure timer is started; After the path failure timer reaches a certain value indicating that at least one other communication path has failed, a relay (re)selection is performed.

69. The method according to any one of claims 23 to 68, wherein, The configuration message also includes at least one of the following: Relay identification information is used to identify at least one relay node, wherein the UE is to establish a connection with the at least one relay node for the at least one other communication path to provide multiple paths; Backup relay identification information is used to identify at least one relay node, wherein in the event that a connection to the first relay node fails, the UE shall establish a connection with the at least one relay node to provide multiple paths; Primary cell information is used to identify the primary cell, wherein the UE needs to establish a connection with the primary cell for the at least one other communication path to provide multiple paths; Backup cell information is used to identify at least one secondary cell, wherein in the event that the UE fails to establish a connection with the primary cell, it needs to establish a connection with the at least one secondary cell to provide multiple paths; Path identification information, used to identify the at least one other communication path or to identify each connection of the at least one other communication path; Configuration information is used to configure at least one communication path between the UE and the second base station to provide multiple paths.

70. A method for managing multipath communication in a wireless communication system, the wireless communication system supporting relay between a user equipment (UE) and a network including a first base station, wherein, A first communication path has been established between the UE and the first base station, and the method includes the following at the relay node: The system receives configuration information, which is used to configure the relay node for the indirect communication path between the UE and the network to provide multiple paths between the UE and the network together with the first communication path.

71. The method of claim 70, further comprising: Send information to the UE indicating whether the relay node supports entering the RRC connection state triggered by the UE.

72. The method according to claim 70 or 71, further comprising: The UE receives a message to trigger the relay node to enter the RRC connection state.

73. The method of claim 72, further comprising: If the relay node does indeed support being triggered by the UE to enter the RRC connected state and the current RRC state of the relay node is the disconnected RRC state, it enters the RRC connected state in response to receiving a trigger message from the UE.

74. The method according to any one of claims 70 to 73, further comprising: Send information to the UE indicating the current RRC status of the relay node.

75. The method according to any one of claims 70 to 73, further comprising: Send a relay message to the UE indicating that the relay node is configured.

76. The method according to claim 75, wherein, The relay message includes information indicating the current RRC status of the relay node.

77. The method according to any one of claims 70 to 76, wherein, The configuration information includes measurement report configuration information for configuring the relay node to send measurement report information after an RRC status change.

78. The method of claim 77, further comprising: After determining that the RRC status at the relay node has changed, a measurement report is sent to the UE. The measurement report includes information indicating the current RRC status of the relay node.

79. A method for managing multipath communication in a wireless communication system, the wireless communication system supporting relay between a user equipment (UE) and a network including a first base station, wherein, A first communication path has been established between the UE and the first base station, and a second UE is capable of establishing a non-3GPP connection with the UE and supports relaying between the UE and the network. The method at the UE includes: A measurement report message is sent to the first base station, the measurement report message being used to indicate that a non-3GPP connection can be established between the UE and the second UE.

80. The method according to claim 79, wherein, The measurement report message includes information elements indicating that a non-3GPP connection can be established between the UE and the second UE.

81. The method according to claim 79 or 80, wherein, The measurement report message includes at least one of the following: Identification information, used to identify the second UE; Serving cell identification information, used to identify the cell serving the second UE; Link measurement information, which is associated with non-3GPP connections.

82. The method according to claim 79, wherein, The measurement report message includes link measurement information associated with a non-3GPP connection, and wherein a certain value of the link measurement information identifies that the connection that can be established between the UE and the second UE is a non-3GPP connection.

83. The method according to any one of claims 79 to 82, wherein, The measurement report message includes at least one of the following: Identification information is used to identify one or more other UEs that can use a 3GPP connection with the UE to support relaying between the UE and the network; Serving cell identification information for each of one or more other UEs that can use a 3GPP connection with the UE to support relay between the UE and the network, for identifying the cell serving the corresponding other UE; Link measurement information associated with the respective 3GPP connection for each of one or more other UEs that can use the 3GPP connection of the UE to support relay between the UE and the network.

84. The method according to any one of claims 79 to 83, further comprising: The UE receives a measurement report configuration from the first base station, the measurement report configuration including information indicating that the UE is authorized to report information associated with non-3GPP connections.

85. The method according to any one of claims 79 to 84, wherein, Sending includes: After determining that the non-3GPP connection that can be established between the second UE and the first UE meets certain requirements, the measurement report message is sent to the first base station.

86. The method according to claim 85, wherein, The measurement report configuration includes information for indicating certain requirements, which is used by the UE to determine whether to report non-3GPP connections to the first base station.

87. The method according to any one of claims 79 to 83, further comprising: The first base station receives a configuration indicating that the UE is not authorized to establish a non-3GPP connection with another UE.

88. An apparatus for a base station in a wireless communication system supporting relay, the apparatus comprising: One or more processing units are configured to perform the method according to any one of claims 1 to 22.

89. A device used by a user equipment (UE) in a wireless communication system supporting relay, the device comprising: One or more processing units are configured to perform the method according to any one of claims 23 to 69, 79 to 87.

90. An apparatus for a relay node in a wireless communication system supporting relay, the apparatus comprising: One or more processing units are configured to perform the method according to any one of claims 70 to 78.

91. A computer program comprising instructions that, when executed by a computer, cause the computer to perform the control method according to any one of claims 1 to 87.

92. A computer-readable medium carrying a computer program according to claim 91.

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