Methods and apparatus for managing relay communication in multi-hop relay

Abstract

Managing relay communication in a wireless communication system that comprises User Equipment (UE) 111, 112, 113, and a network including a base station, e.g. gNB 101. Remote UE 113 may send a reques

Description

Field of the Invention The present invention generally relates to managing relay communication in a wireless communication system supporting relaying. For example, the present invention relates to a multi-hop relaying in a communication system supporting sidelink (SL) relaying. In particular, the present invention relates to methods for managing the establishment of relay communication involving multiple relays. Background ....................................................w—'1.......................................................... The 3rd Generation Partnership Project (3GPP) has initiated the development of new radio access technology known as fifth-generation New Radio (5G NR) to respond to requirements related to very high reliability and very low latency. The 5G NR is not referred only to the enhancement of radio access technology but also to address a wide range of new services to be enabled by future mobile communication. Three distinctive categories of use cases are defined in NR from enhanced mobile broadband (eMBB), massive machine type communication (mMTC) to Ultra-Reliable and Low Latency communication (URLLC). A first version of Sidelink for 5G, 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 and commercial applications and services in addition to complement former basic safety services. NR V2X addresses advanced driving use cases where vehicles are exchanging large amount of data while respecting a low latency requirement. NR Sidelink is designed to provide three basic transmission scenarios: broadcast, groupcast and unicast communications, while considering both out-of-coverage and in-network coverage deployment scenarios. Based on the NR sidelink technology, 3GPP introduced the sidelink-based relaying functionality as part of the 3GPP Release 17 framework, where a relay UE may provide User Plane (UP) and Control Plane (CP) data relaying between a set of served remote UEs and the network (UE-to-network, or U2N, relay) or between a source remote UE, or source UE, and a target remote UE, or target UE (UE-to-UE, or U2U relay). The purpose of the Release 17 sidelink relaying functionality was to both extend sidelink / network coverage and improve power efficiency, while considering a wider range of applications and services, including V2X, Public Safety and commercial applications and services. Some of these new V2X scenarios require ultra-reliability and low latency (URLLC) performance, in order to meet high-speed and high-density constraints, while requiring some network coverage extension, which may be achieved through sidelink relaying. This first version of the sidelink relaying functionality, as defined in the Release 17 specification, mainly aimed at supporting the UE-to-network (U2N) relaying with basic functionalities and limited features. For better support of the use cases requiring sidelink relay, further enhancements are necessary in order to introduce the potential solutions identified during the Rel-17 study item. The follow-up 3GPP Release 18 work item “NR Sidelink Relay (SLR) Enhancements” has addressed several solutions considered as enhancement areas needed in NR Sidelink Relay system for the V2X, public safety and commercial use cases. In this respect, the Release 18 introduced some new features aiming at supporting the UE-to-UE (U2U) relaying, while introducing some service continuity enhancements for the UE-to-network (U2N) relaying, while some further enhancements to support multi-hop relaying are foreseen for Release 19. So far, the establishment procedure for establishing a connection considered in 3GPP is intended for “direct” relaying and does not support multi-hop relaying scenarios where a UE would be connected to the Network (multi-hop U2N) through more than one Relay UE. Therefore, it is desirable to provide solutions to manage or facilitate relay communication in a wireless communication system supporting multi-hop relaying. Summary In accordance with an aspect of the present invention, there is provided a method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network, the method at a UE of the plurality of UEs including: sending a request to establish a connection (e.g. RRC connection) between the UE and the network for establishing multi-hop communication between a first UE of the plurality of UEs and the network via at least two relay UEs of the plurality of UEs. In accordance with another aspect of the present invention, there is provided a method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network, the method at a first UE of the plurality of UEs including: sending a request to establish a connection (e.g. RRC connection) between the first UE and the network for establishing multi-hop communication between the first UE and the network via at least two relay UEs of the plurality of UEs. In accordance with another aspect of the present invention, there is provided a method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network, the method at a relay UE of the plurality of UEs including: sending, by the relay UE to the network, a request to establish a connection (e.g. RRC connection) between the relay UE and the network for establishing multi-hop communication between a first UE of the plurality of UEs and the network via at least two relay UEs, including the relay UE which is a root relay UE to be connected to the network. In accordance with another aspect of the present invention, there is provided a method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network including a base station, the method at the base station including: establishing multihop communication between a first UE of the plurality of UEs and the network via at least two relay UEs. In accordance with another aspect of the present invention, there is provided an apparatus for a UE as recited in claim 68 of the accompanying claims. In accordance with another aspect of the present invention, there is provided an apparatus for a base station as recited in claim 69 of the accompanying claims. The methods and apparatus in accordance with the present invention provide mechanisms and signalling that enables connections to the network to be set up efficiently for a remote UE and multiple relay UEs which results in managing efficient End-to-End connection establishment (e.g. RRC connection establishment) between a remote UE and a network (e.g. a network entity such as a gNB or AMF) involving or over at least two relay UEs. In an example, a message for requesting establishment of a PC5 connection (e.g. a Direct Communication Request message) is used to trigger a UE (e.g. remote UE, intermediate relay UE or a root relay UE) to establish a connection, e.g. RRC connection, with the network. Since the message for requesting establishment of a PC5 connection (e.g. a Direct Communication Request message) is sent early on in the process for establishing an End-to-End connection, the latency of establishing the different hops can be minimised. Other mechanisms as also described help to minimise latency and improve the bandwidth consumption. Other mechanisms as also described help to minimize the number of UE connected to the base station which is really advantageous as a base station can only accept a finite number of UEs and each UE connected requires memory for example to store the UE context retrieved from the core network. Further example features of the invention are described in other independent and dependent claims. In the following reference will be a relay UE and other relay UE. It will however be appreciated that instead the terms first relay UE and second relay UE could be used in place of relay UE and other relay UE. Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus / device / unit aspects, and vice versa. Furthermore, features implemented in hardware may be implemented in software, and vice versa. Any reference to software and hardware features herein should be construed accordingly. For example, in accordance with other aspects of the invention, there are provided a computer program comprising instructions which, when the program is executed by one or more processing units, cause the one or more processing units to carry out the method of any aspect or example described above and a computer readable storage medium carrying the computer program. Brief Description of the Drawings Different aspects of the invention will now be described, by way of example only, and with reference to the following drawings in which: Figure 1 is a schematic diagram illustrating an example wireless communication system in which the present invention may be implemented according to one or more embodiments; Figure 2 is a schematic diagram illustrating a typical 5G Proximity-based Services (ProSe) Relay reference architecture; Figure 3 is a schematic diagram illustrating user plane stacks of some protocol layers involved in Sidelink relay operations for UE-to-network (U2N) based relaying; Figure 4 is a block schematic diagram of an example wireless communication device in accordance with embodiments of the present invention; Figures 5 to 7 are schematic and simplified diagrams illustrating example of message flows for managing a UE-to-network establishment procedure between a remote UE and a gNB involving several Relay UEs in a wireless communication system in accordance with one or more embodiments of the invention; Figures 8 to 11 are simplified flowcharts of methods for managing relay communication in a wireless communication system supporting relaying in accordance with one or more embodiments of the present invention. Detailed Description Figure 1 represents an example of a wireless communication system 100 capable of supporting relaying between a User Equipment (UE) and a base station, or between two User Equipment (UE) and shows a relay arrangement or system (or network) including a plurality of nodes including one or more relay nodes (e.g., relay User Equipment (UE)) serving one or more remote User Equipment (UE). In the following description reference is made to a wireless communication system 100 capable of supporting Sidelink Relay where a path between a remote UE and a base station includes a sidelink connection (also known as a PC5 link) between the remote UE and a relay UE and a network connection (also known as a Uu link) between a relay UE and the base station. However, it is not intended that the present invention is limited to a PC5 link between the remote UE and the relay UE and could apply to relaying configurations where the link between the remote UE and the relay UE is via another type of connection (e.g., a non-3GPP connection), such as a WiFi or Bluetooth. With reference to Figure 1, UE node Illis served by network node 101 and may operate as a relay UE node relaying data between one of the UE nodes 112, 121 (referred to as remote UE nodes) and the network node 101, hence performing UE-to-network (U2N) relaying. In its turn, UE 112 may operate as a relay UE node relaying data between the UE node 113 and the network node 101 through the other relay node 111. Some multi-hop UE-to-Network relaying (multi-hop U2N) may thus be performed between network node 101 and UE 113 through relay UEs 111 and 112. In the example of the figure 1, the UE 111 may act as a remote UE and as a relay UE. In an example where the network node 101 is part of a cellular network, the relay UE Illis served by a cell 101a controlled by the network node 101. UE node 131 is served by network node 101 and may operate as a relay UE node relaying data between the UE node 132 (referred to as a remote UE node) and the network node 101, hence performing UE-to-network (U2N) relaying. In its turn, UE 132 may operate as a relay UE node relaying data between the UE node 133 or 134 and the network node 101 through the other relay node 131. Some multi-hop UE-to-Network relaying (multi-hop U2N) may thus be performed between network node 101 and UEs 133 or 134 through relay UEs 131 and 132. In an example where the network node 101 is part of a cellular network, the relay UE 131 is served by cell 101a controlled by the network node 101. In an example where the network node 101 is part of a cellular network, the relay UE 131 and 132 are served by a cell 101a controlled by the network node 101, while remote UE 133 and 134 are out of coverage (OOC) as they are not served by any cell. UE node 121 is served by network node 101 and may operate as a relay UE node relaying data between the UE nodes 122 (referred to as remote UE node) and the network node 101, hence performing UE-to-network (U2N) relaying. In its turn, UE 122 may operate as a relay UE node relaying between the UE node 123 and the network node 101 through the other relay node 121. In the example of the figure 1, the UE 121 may act as a remote UE and as a relay UE. In its turn, UE 123 may operate as a relay UE node relaying between the UE node 124 and the network node 101 through the other relay nodes 121 and 122. Some multi-hop UE-to-Network relaying (multi-hop U2N) may thus be performed between network node 101 and UE 123 or 124 through relay UEs 122 and 121 or through relay UEs 123, 122 and 121. In an example where the network node 101 is part of a cellular network, the relay UE 121, 122 and 123 are served by a cell 101a controlled by the network node 101, while remote UE 124 is out of coverage (OOC) as it is not served by any cell. UE node 151 is served by network node 102 and may operate as a relay UE node relaying data between one of the UE nodes 152, 153, 141 (referred to as remote UE nodes) and the network node 102, hence performing UE-to-network (U2N) relaying. In its turn, UE 152 may operate as a relay UE node relaying between the UE node 154 and the network node 102 through the other relay node 151. Some multi-hop UE-to-Network relaying (multi-hop U2N) may thus be performed between network node 102 and UE 154 through relay UEs 152, and 151 (and 141). In the example of the figure 1, the UE 141 may act as a remote UE and / or as a relay UE for UE 151. In an example where the network node 102 is part of a cellular network, the UEs 151, 152 and 141 are served by a cell 102a controlled by the network node 102, while remote UEs 153 and 154 are out of coverage (OOC) as they are not served by any cell. The network nodes 101 and 102 may 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. Figure 1 only shows the base stations of the wireless network for clarity. Base stations 101 and 102 are interconnected such as through a wired link infrastructure 180, preferably based on optical fiber or any other wired means. As shown in figure 1, the base stations are also connected to a core network 170 through a wired link infrastructure 190, preferably based on optical fiber or any other wired means. For a 5G NR network, the network nodes 101, and 102, are referred to as gNBs and are part of the NG-RAN. UEs 161, 162, 163 and 164 are not served by any network node. Still, UE node 162 may operate as a relay UE node relaying data between the UE node 161 (referred to as a remote UE node) and the UE node 163, hence performing UE-to-UE (U2U) relaying. In its turn, UE 163 may operate as a relay UE node relaying data between the UE node 164 and the UE node 161 through the other relay node 162. Some multi-hop UE-to-UE relaying (multi-hop U2U) may thus be performed between UE 161 and UE 164 through relay UEs 162 and 163. Similarly, some multi-hop UE-to-UE relaying (multi-hop U2U) may be performed between UE 121 and UE 124 through relay UEs 122 and 123. In general, the wireless communication system 100 is capable of supporting multi-hop relaying between a remote UE node (or remote UE) and a target or target node. The target node may be a base station of the network in the case of U2N relaying or another UE in the case of U2U relaying. Some examples of UEs include smartphones / tablets (such as UEs 121, 122, 123, 141 and 161), XR headsets (such as UEs 111, 112, 113), cameras (such as UEs 124 and 153), fixed video cameras (such as UEs 131, 132, 133), mobile / wearable video cameras (such as UEs 134, 162, 163, 164, 152 and 154) or Unmanned Aerial Vehicle (UAV) 151, which may also embed one or more video cameras. In general, the UE may be any portable or handheld or mobile telephone, a smartphone, a tablet, a portable or fixed computer, fixed or mobile camera, portable television, other smart devices or other similar wireless communication device. In the following description, the term UE will be used and it is not intended to limit the description to any particular type of wireless communication device. In the following, a relay UE node will also be referred to as a relay UE, a remote UE node will also be referred to as a remote UE and a network node will be referred to as a base station or as a gNB. It will however be appreciated that the terms first and second UEs may be used instead of remote UE and relay UE. Although in the following description, embodiments and examples of embodiments of the present invention will be described with respect to a 5G NR network, it will be appreciated that it is not intended that the present invention is limited to 5GNR systems and may be used in any wireless communication systems supporting sidelink (or peer to peer) relay communications and multi-hop relaying. In an example shown in Figure 1, in a UE-to-Network (or U2N) scenario with the UE 111 (or UE 131) operating as UE-to-Network relay UE, the UE-to-Network relay UE 111 (or relay UE131) connects the UEs 112 and 121 (or UE 132), operating as remote UEs, to the gNB 101 (or gNB 102). The remote UE 112 is connected to the relay UE 111 via or through a sidelink 112a which may be referred to as a PC5 hop or link or connection or interface 112a. Similarly, remote UE 121, and remote UE 132 have PC5 hops, or links or connections or interfaces 121b, and 132b respectively with the relay UE 111, and relay UE 131. AUu hop or link or connection or interface Illa connects the relay UE 111 to the gNB 101, while a Uu hop or link or connection or interface 131a and 131b respectively connect the relay UE 131 to the gNB 101 and the UE 131 to the gNB 102. PC5 connections are used for the relayed traffic of the remote UEs (112, 113, 121 and 132) and the non-relayed traffic specific to the relay UE 111, 131, i.e. for the direct communications between relay UE 111, 131 and the other remote UEs (112, 121 and 132). Therefore, the remote UE 112 is connected to the gNB 101 through the relay UE 111 with a PC5 hop 112a and a Uu hop 1 Ila. For uplink communication, the remote UE 112 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 112 and the gNB 101 with a PC5 hop 112a and a second Uu hop 11 la and for downlink communication, the remote UE 112 is the destination or target node (or receiver node) and the gNB 101 is the source node (or transmitter node). Similarly, the remote UE 132 is connected to the gNB 102 through the relay UE 131 with a PC5 hop 132b and a Uu hop 131b. The remote UE 113 for its part is connected to the gNB 101 through the relay UE 112 with a 1st PC5 hop 113a and then through the relay UE 111 with a 2nd PC5 hop 112a and a Uu hop Illa. It will be appreciated that the terms first and second could be used in place of source and target. At some point, the gNB 101 may decide to setup a multi-path to the UE 132. For example, to maintain the QoS despite an increase of the applicative traffic to transmit / receive from / to the UE 132. Then, based on some information such as measurement information received from the different UEs (relay, remote) in, for example, measurement reports and / or measurements made by the gNB 101 itself, the source gNB 101 may decide to add an additional path either a direct path (link 132c) or a new indirect path through the relay UE 111 (links 132a and Illa) so as to set up a multi-path between the remote UE 132 and the network. At some other point, the gNB 101, acting as a source gNB, may decide to hand over the relay UE 131 to the gNB 102, which would then act as a target gNB. For example, in the case where the radio conditions in the serving cell 101a controlled by the source gNB 101 deteriorate such that the radio conditions in the target cell 102a controlled by the target gNB 102 are better than the serving cell 101a, the source gNB 101 may decide to handover the relay UE 131 to the target gNB 102. In such a case, the relay UE 131 would detach from the source gNB 101, thereby releasing the Uu link 131a to further connect to the target gNB 102 through Uu link 131b established as part of a re-establishment procedure. As mentioned earlier, the remote and relay UEs are attached to the core network 170 through their serving gNB (101 or 102 in figure 1). Figure 2 represents a typical 5G Proximitybased Services (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. base station or gNB). The 5G ProSe Remote UE and 5G ProSe Relay may be served by the same or different PLMNs (Public Land Mobile Network). If the serving PLMNs of the 5G Remote UE and the 5G ProSe Relay are different then the NG-RAN is shared by the serving PLMNs. In order to set up a relayed traffic between a first node (remote UE) and a second node (gNB or remote UE), a Sidelink relay architecture may be used, based on the 3GPP TR 38.836. The user plane architecture or protocol stack is shown in Figure 3 and represents the Sidelink Relay adaptation layer called SRAP that is introduced between the PDCP layer and the RLC layer at the extreme nodes and above the RLC layer in the relay UE. This architecture was first documented in the TR 38.836 and finally refined in 3GPP TS 38.300 while the SRAP layer is defined in 3GPP TS 38.351. This architecture shown in Figure 3 shows the Sidelink relay architecture 300 for the multi-hop UE-to-Network relay scenario. As shown in Figure 3 illustrating a multi-hop UE-to-Network relay scenario, a remote UE 301, such as remote UE 113 of figure 1, has a PC5 SRAP layer or entity 311 between its Uu PDCP layer 312 and its PC5 RLC layer 313. Similarly, the gNB 304, such as gNB 101 of figure 1, has a Uu SRAP layer or entity 341 between its Uu PDCP layer 342 and its Uu RLC layer 343. As shown in Figure 3 related to a multi-hop UE-to-Network relay scenario, at the relay UE 303, such as relay UE 111, there are two SRAP layers to interface with the PC5 hop 112a and the Uu hop Illa: the PC5 SRAP layer or entity 331 is connected to the PC5 SRAP 322 of a second relay UE 302 such as relay UE 112 through the PC5 hop 112a; and the Uu SRAP layer or entity 332 is connected to the Uu SRAP layer 341 at the gNB side 101 through the Uu link Illa. The second relay UE 302 such as relay UE 112 has also two SRAP layers to interface with the PC5 hop 112a and the PC5 hop 113a: the PC5 SRAP layer or entity 322 is connected to the PC5 SRAP 331 of a first relay UE 303 such as relay UE 111 through the PC5 hop 112a; and the PC5 SRAP layer or entity 321 is connected to the PC5 SRAP layer 311 at the remote UE 303, such as remote UE 113 through the PC5 link 113a. A remote UE 301 / 113 establishes End-to-End radio bearers 305 with the gNB 304 / 101. These radio bearers could be a Signalling Radio Bearer SRB or Data Radio Bearer DRB. Figure 3 shows an E2E Uu DRB / SRB 305 between the remote UE 113 and the gNB 101 by way of example. The PC5 SRAP layer 331 of the UE-to-Network relay UE 303 / 111 receives data or packets (traffic data or signalling) over or via ingress PC5 Relay RLC channels 352 through the PC5-RLC layer from remote UE 113 (at PC5 hop 112a) through a UE-to-UE relay UE 302 / 112 in an uplink direction and transmits the packets to the Uu SRAP entity 332 of the same relay UE 303 / 111. The Uu SRAP 332 entity will map the corresponding ingress PC5 Relay RLC channels 352 to egress Uu Relay RLC channels 353a and / or 353b at Uu link Illa. Thus, a mapping table is required for uplink and it is configured by gNB 101 at the Uu SRAP entity 332 of the relay UE 303 / 111. The mapping table takes at its input an identifier of the remote UE 113 (e.g. L2-ID), an identifier of the E2E radio bearer 305 (e.g. the E2E Uu DRB ID) and an identifier of the ingress PC5 Relay RLC channel (or bearer) 352 and identifies the egress Uu Relay RLC bearer ID where the E2E radio bearers are mapped. For example, the UE E2E bearer ID and remote UE ID can be obtained from the header of a data packet received at the Uu SRAP entity 332 via the PC5-SRAP entity 331. An example of an entry for an uplink mapping table with one entry configured at the Uu SRAP entity 332 is shown in Table 1 below. It will be appreciated that the mapping table will be configured so that it has an entry for each remote UE connected to the relay UE 303 / 111. UE ID E2E Uu DRB ID Ingress PC5 RLC channel ID Egress Uu RLC channel ID xl yi zl wl Table 1 At the Uu side or link Illa, different radio bearers of the same remote UE or different remote UEs can be subject to N: 1 mapping and data multiplexing over Uu RLC channels 353a and 353b. In the downlink direction, data or packets transmitted from gNB 101 arrive at the relay UE 303 / 111 through the Uu link Illa. The Uu SRAP layer 332 of the UE-to-Network relay UE 111 receives data or packets (traffic data or signalling) over or via ingress Uu Relay RLC channels 353a and 353b through the Uu-RLC layer 343 from gNB 101 and transmits the packet to the PC5 SRAP entity 331 of the same relay UE 111. Those ingress Uu Relay RLC channels 353a and 353b will be mapped at the PC5 SRAP entity 331 of the relay UE 111 to the egress PC5 Relay RLC channels 352 at PC5 hop 112a. Thus, a mapping table is required for downlink and it is configured by the gNB 101 at PC5 SRAP entity 331 of the relay UE 111. The mapping table requires at its input the remote UE 113 L2-ID, the End-to-End radio bearer 305 ID and the ingress Uu Relay RLC channel (or bearer) 353a and 353b ID and identifies the egress PC5 Relay RLC channels (or bearer) 352 ID of the PC5 hop 112a. The End-to-End Radio bearer 305 is then mapped at the PC5 hop 112a to the egress PC5 Relay RLC channels 352. For example, the UE E2E bearer ID and remote UE ID can be obtained from the header of a packet received at the PC5 SRAP entity 331 via the Uu SRAP entity 332. An example of a downlink mapping table with one entry configured at the PC5 SRAP entity 331 is shown in Table 2 below. It will be appreciated that the mapping table will be configured so that it has an entry for each remote UE connected to the relay UE 303 / 111. UE ID E2E Uu DRB ID Egress PC5 RLC channel ID Ingress Uu RLC channel ID x2 y2 z2 w2 Table 2 Similarly, the UE-to-UE relay UE 302 / 112 maps the ingress PC5 RLC channel 351 to the egress PC5 RLC channel 352 and vice versa. Thereby, mapping tables is also required to determine the egress RLC channel based on the ingress RLC channel, the Bearer ID and the UE ID. The mapping tables at the UE-to-UE relay UE 302 / 112 may be configured by the network. It is noted that in the case of multi-hop UE-to-Network, the mapping table at the UE-to-Network relay may map the ingress Uu Relay RLC channel to the egress End-to-End PC5 RLC channel used by the UE-to-Network relay UE 303 / 111 to connect to the remote UE 301 / 113 through the UE-to-UE relay UE 302 / 112. As mentioned in 3GPP TS 38.351, each SRAP entity has a transmitting part and a receiving part. Across the PC5 interface 113a and 112a, the transmitting part of the PC5 SRAP entity 311 at the remote UE 301 / 113 and the transmitting part of the PC5 SRAP entity 322 at the relay UE 302 / 112 has a corresponding receiving part respectively at PC5 SRAP entity 321 at the UE-to-UE relay 302 / 112 and at PC5 SRAP entity 331 at the UE-to-Network Relay UE 303 / 111, and vice-versa. Across the Uu interface Illa, the transmitting part of the Uu SRAP entity 332 at the UE-to-Network Relay UE 303 / 111 has a corresponding receiving part at Uu SRAP entity 341 at the gNB 304 / 101, and vice-versa. To summarize, the transmitting part of each SRAP entity at the UE-to-Network Relay UE 111 receives the data packet with its SRAP header from its corresponding receiving part (receiving part of the SRAP entity 332 forwards the data to the transmitting part of the SRAP entity 331 and vice-versa). The transmitting part of each SRAP entity owns a mapping table configured by the gNB 101 which allows the identification of the egress RLC channel (at Uu or PC5 link) based on the ingress RLC channel where the data packet is received and the UE and Bearer IDs carried in the SRAP header. Specific mapping rules may be applied for SRB0 and SRB1 as specified in TS38.351 and TS38.331. In the case of the multi-path with one indirect and one direct path, the remote UE 113 and the gNB 101 may communicate with each other through both paths. Thereby, each node has two protocol stacks: one for the indirect path such as described above and one for the direct path. The split between the direct and / or the indirect path is performed at the PDCP layer of each node. For the direct path, in the downlink direction, data or packets transmitted from gNB 101 through the direct path arrive at the remote UE 113 via ingress Uu Direct Path RLC channel 354 of the Uu link 113b. On the other hand, in the uplink direction, data or packets transmitted from the remote UE 113 through the direct path arrive at the gNB 101 via ingress Uu Direct Path RLC channel 354 of the Uu link 113b. Figure 4 shows a schematic representation of an example communication device or station, in accordance with one or more example embodiments of the present disclosure. The communication device 400 may be a device such as a micro-computer, a workstation or a portable or mobile device. The communication device 400 comprises a communication bus 413 to which there are preferably connected: a central processing unit 411, such as a microprocessor, denoted CPU; memory for storing data and computer programs containing instructions for the operation of the communication device 400. The computer programs may contain a number of different program elements or sub-routines containing instructions for a variety of operations and for implementing the invention. For example, the program elements include at least one element for managing multi-path or multi-hop communication (for example, managing the establishment of relay communication involving or over multiple relays) as discussed above. The at least one element when executed by the central processing unit 411 configure one or more processing units (e.g. functioning as or part of the CPU 411) to perform the method(s) as described above. The communication device 400 may further comprise at least one communication interface 402 connected to the radio communication network 403 over which digital data packets or frames or control frames are transmitted, for example a 5G NR wireless communication network. The frames are written from a FIFO sending memory in RAM 412 to the communication interface 402 for transmission or are read from the communication interface 402 for reception and writing into a FIFO receiving memory in RAM 412 under the control of a software application running in the CPU 411. Each of a UE and base station may comprise such a communication device 400. The central processing unit 411 may be a single processing unit or processor or may comprise two or more processing units or processors carrying out the processing required for the operation of the communication device 400. The number of processing units or processors and the allocation of processing functions to the processing unit(s) is a matter of design choice for a skilled person. The memory may include: a read only memory 407, denoted ROM, for storing computer programs for implementing methods according to embodiments of the invention; a random-access memory 412, denoted RAM, for storing the executable code of methods according to embodiments of the invention as well as the registers adapted to record variables and parameters necessary for implementing methods according to embodiments of the invention. Optionally, the communication device 400 may also include the following components: a data storage means 404 such as a hard disk, for storing computer programs for implementing methods according to one or more embodiments of the invention; a disk drive 405 for a disk 406, the disk drive being adapted to read data from the disk 406 or to write data onto said disk; a screen 409 for displaying decoded data and / or serving as a graphical interface with the user, by means of a keyboard 410 or any other user input means. Preferably the communication bus 413 provides communication and interoperability between the various elements included in the communication device 400 or connected to it. The representation of the bus 413 is not limiting and in particular, the central processing unit is operable to communicate instructions to any element of the communication device 400 directly or by means of another element of the communication device 400. The disk 406 may optionally be replaced by any information medium such as for example a compact disk (CD-ROM), rewritable or not, a ZIP disk, a USB key or a memory card and, in general terms, by an information storage means that can be read by a microcomputer or by a microprocessor, integrated or not into the apparatus, possibly removable and adapted to store one or more programs whose execution enables a method according to embodiments of the invention to be implemented. The executable code may optionally be stored either in read only memory 407, on the hard disk 404 or on a removable digital medium such as for example a disk 406 as described previously. According to an optional variant, the executable code of the programs can be received by means of the communication network 403, via the communication interface 402, in order to be stored in one of the storage means of the communication device 400, such as the hard disk 404, before being executed. The central processing unit 411 is preferably adapted to control and direct the execution of the instructions or portions of software code of the program or programs according to the invention, which instructions are stored in one of the aforementioned storage means. On powering up, the program or programs that are stored in a non-volatile memory, for example on the hard disk 404 or in the read only memory 407, are transferred into the random-access memory 412, which then contains the executable code of the program or programs, as well as registers for storing the variables and parameters necessary for implementing the invention. In an example implementation, the communication device may be or may include an apparatus comprising one or more processing units or processors for performing or implementing the methods in accordance with one or more embodiments of the invention. In other words, the apparatus is capable of performing one or more functions of the communication device including performing the methods in accordance with one or more embodiments of the invention by means of the one or more processing units. For example, the one or more processing units uses software to implement the one or more embodiments of the invention as described above with reference to the central processing unit 411 of figure 4. Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, a CPU of a microcontroller Unit (MCU), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other equivalent integrated (e.g. on an Integrated Circuit) or discrete logic circuitry. In an embodiment, the apparatus is a programmable apparatus which uses software to implement the invention. However, alternatively, the one or more processing units for performing or implementing the methods in accordance with embodiments of the present invention may be implemented in hardware: for example, in the form of an Application Specific Integrated Circuit or ASIC or other hardware comprising logic element (s). In such a case, logic units or logic elements or means are configured to perform the steps of the method(s) in accordance with the present invention described above. Accordingly, the term “processing unit” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. Referring now to figure 8 which is a flow chart showing steps of a method 800 for managing or facilitating relay communication (or a method for managing establishment of relay communication) in a wireless communication system supporting relaying, in accordance with one or more embodiments of the invention. Method 800 can be used to manage End-to-End connection establishment between a remote UE and a network (e.g. a network entity such as a gNB or AMF) involving or over at least two relay UEs, in accordance with one or more embodiments of the invention. The wireless communication system includes a plurality of User Equipment, UE and a network. The method is performed at a UE (e.g. a UE that is first or remote UE, a UE that can operate / act as a relay UE or is a root / target / end UE connected or to be connected to the network) of the plurality of UEs. The network includes a number of entities, such as a base station or gNB of the RAN, the Access and Mobility Management Function (AMF) entity of the core network. At least one of these entities (e.g. base station or AMF) may send or receive messages / information and / or establish connections as discussed below with references to messages / information being sent to the network and connections being established with the network. The wireless communication system may be, for example, the wireless communication system 100 of Figure 1. With respect to the example shown in Figure 1 (and the messages flows discussed with reference to figures 5-7), the UE may be UE 113, 112 or 111 in the case where multi-hop communication is to be established between first UE 113 (source / initiating remote UE) and the network. The method 800 as shown in and described with respect to figure 8 may be performed by software elements and / or hardware elements. Thus, for example, the method as shown in and described with respect to figure 8 may be performed by an apparatus for the UE comprising one or more processing units configured to carry out the method. The UE may be implemented in a communication device 400 as shown in and described with reference to figure 4 with the method as shown in and described with respect to figure 8 being performed by one or more processing units, such as the central processing unit 411. For the method described with reference to figure 8, the intermediate relay UE (e.g. UE 112) acts as a relay UE for the remote UE (e.g. 113) and as a remote or child UE to get the connection to the network through the root relay UE (e.g. 111) acting as a UE-to-Network (U2N) relay. Although the following description relates to there being only one intermediate relay UE (relay UE 112), the method described below with reference to figure 8 (as with the figures 5-6) could be extended to several intermediate relay UEs. Therefore, an intermediate relay UE would act as a U2N relay UE for its child relay UE or for a remote UE and as remote UE for its parent relay UE or for the root U2N relay UE. A hop is a link or connection between two UEs in which case the hop is a PC5 hop or between a UE and a base station in which case the hop is a Uu hop. Briefly, at step 801, the UE, sends a request to establish a connection, such as a RRC connection, between the UE and the network (e.g. base station or AMF) for establishing multihop communication between a first UE of the plurality of UEs and the network via at least two relay UEs of the plurality of UEs. In other words, a request to initiate establishment of a connection is sent by the UE and in the case of a RRC connection is a request to enter in a connected RRC state (RRC CONNECTED). The request may be the RRCSetupRequest 541 or 641 in the case the UE sending the request is the first or remote UE 113 as discussed below with reference to figures 5-6. The request may be the RRCSetupRequest 531 in the case the UE sending the request is a relay UE or intermediate relay UE, such as relay UE 112, as discussed below with reference to figures 5-6. The request may be a RRCSetupRequest (as part of the RRC Setup procedure) or a RRCResumeRequest or RRCResumeRequest 1 (as part of the RRC resume procedure defined in TS 38 331) in the case the UE sending the request is the root / last / target relay UE to be connected to the network. In this case, the root relay UE 111 sends a request, RRCSetupRequest or RRCResumeRequest / RRCResumeRequestl, to the network to respectively establish or resume a connection between the root relay UE and the network for establishing multi-hop communication between the remote UE 113 and the network via the root relay UE 111. Such a request sent by the root relay UE Illis mentioned below but is not shown in the figures. The request sent by the root relay UE 111 may include cause information (cause IE) to indicate that the connection aims to be used for multi-hop relaying. The root relay UE 111 may also combine or aggregate the RRCSetupRequests of the remote UE and child or intermediate relay UE(s) into the parent RRCSetupRequest. At the end of the combining or aggregation, the RRCSetupRequest (or similarly in the RRCResumeRequest) of the root relay UE 111 includes the RRCSetupRequest of all the child and the remote UEs. In case of the inclusion of RRCSetupRequest command in the Direct Communication Request, the root relay UE 111 may include the RRCSetupRequest of the remote UE in its RRCSetupRequest or RRCResumeRequest. Based on this aggregated RRCSetupRequest sent to the network by the root relay UE, the network (e.g. gNB) sends a response to each UE to continue the establishment procedure or sends an aggregated RRCSetup including the configuration of all UEs. Each intermediate UE forwards the message after removing its own configuration. The RRCSetup combination or aggregation may also be performed by each intermediate UE. In an example, the UE, sending the request, establishes a PC5 connection with a relay UE of the at least two relay UEs, which may be an intermediate relay UE or one of the intermediate relay UEs if there are more than three relay UEs or the root relay UE. In this example, the request is sent after the PC5 connection is established with the relay UE. For example, in the case where the UE sending the request is the remote UE 113, the remote UE 113 establishes a PC5 connection with the relay UE (intermediate relay UE) 112 and sends the request 541, 641 to the network via the relay UE 112 after the PC5 connection is established. In another example, in the case where the UE sending the request is the relay UE 112 (intermediate relay UE acting as a remote UE or child UE), the relay UE 112 establishes a PC5 connection with a next relay UE, which in the case of figures 5-6 is the root relay UE 111 (acting as a U2N relay UE or parent relay UE) and sends the request 531 to the network via the root relay UE 111 after the PC5 connection is established. When there are three or more relay UEs, the relay UE 112 (intermediate relay UE acting as a remote UE or child UE) establishes a PC5 connection with another relay UE (intermediate relay UE acting as a U2N relay UE or parent relay UE). The UE sending the request selects the relay UE with which to establish a PC5 connection based on information received at the UE associated with neighbouring UEs e.g. in discovery message or in measurements reports on neighbouring UEs received at the UE. The information may include capability information of the neighbouring UEs, which capability information indicates whether the neighbouring UE is capable of acting as a relay UE for multihop communication. Establishing a PC5 connection may include sending, to the relay UE, a request to establish a PC5 connection between the UE (e.g. the UE sending the RRCSetupRequest) and the relay UE and configuration information for configuring the PC5 connection between the UE and the relay UE and receiving, from the relay UE, a response indicating the request has been accepted and configuration at the relay UE has been completed: the PC5 connection between the UE and the relay UE being established after configuration has been completed. The request may be a Direct Communication Request, such as the Direct Communication Request 611 described below. The Direct Communication Request 611 requesting establishing a PC5 connection may include the configuration information for configuring the PC5 connection or the configuration information may be sent separately, such as in a RRCReconfigurationSidelink message 613 as discussed below. The response indicating the request has been accepted and the configuration at the relay UE has been completed (i.e. indicating the PC5 connection has been established) may be a Direct Communication Accept, such as the Direct Communication Accept 612, or a RRC message, such as the RRCReconfigurationCompleteSidelink 614, as described below. In another example, the response may include the Direct Communication Accept 612 indicating the request has been accepted and a RRC message such as the RRCReconfigurationCompleteSidelink 614 indicating the configuration at the relay UE has been completed. In the case where a PC5 connection is established between the first or remote UE 113 and a relay UE, such as relay UE 112, the relay UE 112 receives, from the remote UE 113, a request (e.g. RRCSetupRequest 541, 641) to establish a connection between the remote UE 113 and the network for establishing multi-hop communication between the remote UE 113 and the network via the relay UE 112. In the case where a PC5 connection is established between the relay UE 112 (child relay UE) and another relay UE (parent relay UE), such as root relay UE 111, the relay UE 112 forwards the request (541, 641) received from the remote UE 113 to the network. In the case where a PC5 connection is established between one relay UE, such as relay UE 112 and a root relay UE, such as relay UE 111, the relay UE 111 receives, from the relay UE 112, a request (e.g. RRCSetupRequest 531) to establish a connection between the relay UE 112 and the network for establishing multi-hop communication between the remote UE 113 and the network and receives, from the remote UE 113 via the relay UE 112, a request (e.g. RRCSetupRequest 541, 641) to establish a connection between the remote UE 113 and the network for establishing multi-hop communication between the remote UE 113 and the network. In the case where the root relay UE Illis connected to the network, the root relay UE 111 forwards the request 541 received from the remote UE 113 and the request 531 received from the relay UE 112 to the network. The UE (e.g. the UE sending the RRCSetupRequest) may send to the relay UE a trigger to trigger the relay UE to send a request (e.g. RRCSetupRequest) to establish a connection between the relay UE and the network for establishing multi-hop communication between the remote UE and the network via at least two relay UEs, including the relay UE. For example, the UE (remote UE 113 or child relay UE 112) sends a trigger to the relay UE (parent relay UE 112 or parent relay UE 111) to send a request (e.g. RRCSetupRequest) to enter in the connected RRC state. The trigger sent to the relay UE may be included in a Direct Communication Request, such as Direct Communication Request 611, a RRCReconfigurationSidelink, such as RRCReconfigurationSidelink 613, or a RRC or PC5 message such as that indicated by 618 in figure 6. The trigger may also be included in SRBO or SRB1 or a discovery message. The trigger may be sent before or after PC5 establishment. For example, when the trigger is included in a Direct Communication Request, the trigger is sent before PC5 establishment and when the trigger is included in a RRCReconfigurationSidelink 613 and a RRC or PC5 message such as that indicated by 618, the trigger is sent after PC5 establishment. The trigger may be trigger information for triggering the relay to request establishment of a connection to the network, which trigger information is included in a message. The message may include one of a message for requesting establishment of a PC5 connection between the UE and the relay UE (e.g. Direct Communication Request message 611); a message including configuration information for configuring the PC5 connection between the UE and the relay UE (e.g. RRCReconfigurationSidelink message 613); a new trigger message 618 (e.g. a new PC5 RRC message such as RemoteUETriggerSidelinkForMulti-HopConnection as discussed below); a Link Modification Request message which is an example of a PC5-S message as described below. The information may include at least one of: information for indicating the connection to be established is a multi-hop connection for use in multi-hop communication, such as the connectionForMultiHop information described below; information for indicating the number of hops from the first or remote UE to the UE, such as the hop count as discussed below (if the UE is the first UE, the hop count will indicate zero hops); information for identifying the network, such as an identifier of the cell (cell ID) served by a base station and / or an identifier of a serving Public Land Mobile Network (PLMN ID). In the case the trigger is sent to the root relay UE, this could help the root relay UE, which is not connected, to select a cell if the root relay UE is in coverage of several cells. The UE (e.g. the UE sending the RRCSetupRequest) may send the trigger irrespective of the current RRC state of the relay UE (e.g. the relay UE could already be in a connected RRC state or could be in a non-connected RRC state, such as RRCINACTIVE or RRC IDLE). Alternatively, the UE receives information from the relay UE indicating the current connection state of the relay UE and sends the trigger when the relay UE is determined to be in a nonconnected state based on the received information. It is noted that, based on the RRC state of a UE, the remote UE or child UE may also give priority to a parent relay UE or root relay UE which is already connected over a UE which is not connected, so as to speed up the establishment process. This implies that the RRCstate is shared before the PC5 establishment for example, in a discovery message, to help the relay selection. In an example where the UE sending the request for establishing a connection to the network is a first or remote UE, such as UE 113 sending the RRCSetupRequest 541, after the UE 113 sends the request (e.g. upon or on sending the request), the UE 113 starts a timer, which is implemented in the UE 113 (e.g. by a particular program element), set with a value of a time period for connection failure determination for multi-hop. The timer may be the t300 timer associated with establishing a RRC connection with the network and the time period may be the value t300-RemoteUEForMultiHop-rl9 provided to the remote UE 113 from SIB 12 or a pre-configured value for multi-hop. The value of the time period for connection failure determination for multi-hop is greater than a value of a time period for connection failure determination for one hop or non-multi-hop. As the timer value is increased compared to the non-multi-hop case, the additional time required to establish a connection due to the establishment procedures having to take place at the at least two relay UEs can be accounted for to avoid wrong connection failure determination or detection. In an example where the UE sending the request for establishing a connection to the network is a relay UE, such as relay UE 112 sending the RRCSetupRequest 531, the relay UE 112 updates a value of a time period for connection failure determination for multi-hop based on information indicating a number of hops from the first or remote UE 113 to the relay UE 112 (e.g. hop count) and on information indicating a maximum number of hops (e.g. hop limit information) or information indicating the actual number of hops (e.g. max hop) between the first or remote UE 113 and a root relay UE (e.g. relay UE 111) of the at least two relay UEs connected or to be connected to the network for establishing multi-hop communication. As discussed below, the hop limit information indicates the maximum number of hops supported or permitted by the remote UE 113 or by the network. The max hop information indicates the actual number of hops between the remote UE and the root relay (or gNB) determined or provided during a discovery process. The maxjiop could be configured by the network for instance through SIB 12 or during authorization procedures or be pre-configured. After the relay UE 112 sends the request (e.g. upon or on sending the request), the UE 112 starts a timer, which is implemented in the UE 112 (e.g. by a particular program element), set with the updated value of the time period for connection failure determination for multi-hop. The timer may be the t300 timer associated with establishing a RRC connection with the network and the time period may be the value t300-RemoteUEForMultiHop-r 19 provided to the relay UE 112 from SIB12 or a pre-configured value for multi-hop. The max hop information and / or hop limit and / or hop count may be determined at the relay UE 112 during discovery (e.g. such as that described with reference to step 501 and 601) or during establishing a PC5 connection to the relay UE 112. For example, the max hop information and / or hop limit and / or hop count may be provided in a Direct Communication Request, such as message 611, a RRCReconfigurationSidelink, such as message 613, or in a Link Modification Request message. The same process applies for other intermediate relay UEs and the root relay UE 111. The timer is stopped after receiving, from the network, configuration information for configuring the UE for connection to the network to support multi-hop relay communication between the remote or first UE and the network. The configuration information may be provided in a RRCSetup message, such as message 542 or 643 for remote UE 113, message 532 for relay UE 112, and a RRCSetup message not shown for the root relay UE 111. As discussed below, the expiry of the time period (timer expiry) indicates to the UE (remote UE or child UE) a connection failure to a relay UE. In an example, after expiry of the time period, the UE initiates the establishment of a connection to another relay UE selected by the UE. For example, the expiry of the time period at the remote UE 113 indicates that the connection to one of the parent relay UEs (e.g. the relay UE 112) has failed and the remote UE 113 may then try to reconnect through another relay UE (another parent UE). The expiry of the time period at the relay UE 112 indicates that the connection establishment to the relay UE 111 has failed and the relay UE 112 may then try to reconnect through another relay UE (another parent UE). Alternatively or in addition, the relay UE 112 may send, to the remote UE 113 (or child UE), a notification indicating the connection failure with the notification including an identifier of the parent relay UE (e.g. root relay UE 111) through which the connection failed. Such a notification may help the UE to select a new path connection excluding the UE that failed to connect. The notification may include information indicating the cause for the failed connection. Such cause (of failure) information can help the UE to know what prevented the connection. A relay UE, such as relay UE 112 or relay UE 111, may send to the network, information associated with at least the relay UE for use by the network to configure the at least two relay UEs (e.g. relay UEs 112, 111) and first or remote UE (e.g. remote UE 113) to support multihop relay communication between the remote UE and the network. The relay UE may send the information in a SidelinkUEInformation NR 642 as discussed below. The UE, such as each of remote UE 113, relay UE 112, relay UE 111, may receive, from the network, configuration information for configuring the UE (e.g. configuring SRB1, SRB2 and DRB) for connection to the network to support multi-hop relay communication between the remote or first UE and the network. For example, configuration information for SRB1 may be sent in RRCSetup 532, 542, 642. RRCSetup may also include SRAP configuration such as mapping table, locallD as discussed below. Configuration information for SRB2 and DRB may be sent in RRCReconfiguration 535. RRCReconfiguration may also include PDCP configuration, RLC configuration as discussed below. After SRBI is configured, the UE is in RRC connected state and the UE (e.g. UE 113, 112) sends a RRCSetupComplete 534, 544. After SRB2 / DRB is configured, the first or remote UE 113 is End-to-End connected for multihop communication and the first or remote UE sends a RRCReconfigurationComplete (e.g. as discussed below for the RRCReconfigurationComplete 536 sent by the relay UE 112). A relay UE, such as relay UE 111 or relay UE 112, may receive from the network configuration information. The configuration information including information for configuring another relay UE and / or a first UE for connection to the network to support multihop relay communication between the first UE and the network. Further, the relay UE which receives the configuration information from the network may send to an other relay UE or to the first UE, the configuration information from the network for configuring the other relay UE and a first UE for connection to the network to support multi-hop relay communication between the first UE and the network. For example, the configuration information may combine or aggregate the RRCReconfiguration of the remote UE and child or intermediate relay UE(s) into the parent RRCReconfiguration. After completion of the combining or aggregation, the RRCReconfiguration for the root relay UE 111 includes the RRCReconfiguration of all the child and the remote UEs. In a variant, the RRCReconfiguration 535 sent to the root relay UE 111 includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the intermediate Relay UE 112 which also includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the remote UE 113. Each intermediate UE performs its own configuration based on the received RRCReconfiguration message and extracts the RRCReconfiguration message embedded in the Multi-HopConfigurationCommand and sends it to its child relay UE or to the remote UE (for the last intermediate relay UE). In response, each UE sends a message (RRCReconfigurationComplete) to the base station to acknowledge the configuration and complete the RRCReconfiguration procedure. It is noted that the combination or aggregation could be partial meaning that the base station 101 could send combined RRCReconfiguration message including the configuration of a subset of the UEs involved in the multi-Hop establishment and send a RRCReconfiguration directly to the other UEs. A relay UE, such as relay UE 112, may receive from the network configuration information including the configuration information for configuring the relay UE for communication with the network and configuration information for configuring the relay UE for communication with another relay UE or a first UE. For example, as the relay UE 112 acts in the same time as a remote UE and as a relay UE, this RRCReconfiguration message may include a multi-HopUEconfiguration IE including the configuration for the relay part as well as the configuration for the remote part. Referring now to figure 9 which is a flow chart showing steps of a method 900 for managing or facilitating relay communication (or a method for managing establishment of relay communication) in a wireless communication system supporting relaying, in accordance with one or more embodiments of the invention. Method 900 can be used to manage End-to-End connection establishment between a remote UE and a network (e.g. a network entity such as a gNB or AMF) involving or over at least two relay UEs, in accordance with one or more embodiments of the invention. The wireless communication system includes a plurality of User Equipment, UE and a network. The method is performed at a first or remote UE. The network includes a number of entities, such as a base station or gNB of the RAN, the Access and Mobility Management Function (AMF) entity of the core network. At least one of these entities (e.g. base station or AMF) may send or receive messages / information and / or establish connections as discussed below with references to messages / information being sent to the network and connections being established with the network. The wireless communication system may be, for example, the wireless communication system 100 of Figure 1. With respect to the example shown in Figure 1 (and the messages flows discussed with reference to figure 7), the UE may be UE 113 in the case where multi-hop communication is to be established between first or remote UE 113 (source / initiating remote UE) and the network. The method 900 as shown in and described with respect to figure 9 may be performed by software elements and / or hardware elements. Thus, for example, the method as shown in and described with respect to figure 9 may be performed by an apparatus for the UE comprising one or more processing units configured to carry out the method. The UE may be implemented in a communication device 400 as shown in and described with reference to figure 4 with the method as shown in and described with respect to figure 9 being performed by one or more processing units, such as the central processing unit 411. For the method described with reference to figure 9, each of the intermediate relay UEs acts as UE-to-UE relay UEs (e.g. 112) to connect the remote UE (e.g. 113) with the (root) UE-to-Network, U2N, relay UE (e.g. 111). The U2N relay UE connects the remote UE to the network (e.g. gNB). Although the following description relates to there being only one intermediate relay UE (relay UE 112), the method described below with reference to figure 9 (as with the figure 7) could be extended to several intermediate relay UEs. It is noted that when the intermediate relay UEs are UE-to-UE relay, they do not require to be RRCCONNECTED, only the root U2N relay UE has to be RRC COWECTED. This could be advantageous as it decreases the number of UEs connected to the network (e.g. to the gNB) and the traffic burden at gNB. Briefly, at step 901, the first or remote UE, such as UE 113, sends a request to establish, or to initiate establishment of, a connection, such as a RRC connection, between the remote UE 113 and the network (e.g. base station or AMF) for establishing multi-hop communication between the first UE and the network via at least two relay UEs of the plurality of UEs. In other words, a request to initiate establishment of a connection is sent by the remote UE 113 and in the case of a RRC connection is a request to enter in a connected RRC state (RRC CONNECTED). The request may be the RRCSetupRequest 741 as discussed below with reference to figure 7. In an example, the remote UE 113 establishes a PC5 connection with a first relay UE (e.g. first intermediate relay UE acting as a UE-to-UE (U2U) relay UE), such as relay UE 112, of the at least two relay UEs. In one aspect, the remote UE 113 establishes an End-to-End PC5 connection between the remote UE 113 and a root relay UE, such as relay UE 111, via at least one intermediate relay UE (e.g. relay UE 112). The root relay UE 111 is connected or is to be connected to the network. The End-to-End PC5 connection is established after a PC5 connection is established between the remote UE and a first relay UE (first intermediate relay UE), such as in step 710, after a PC5 connection is established between the first relay UE and a second relay UE (second intermediate relay UE if there is more than one intermediate relay or the root relay UE if there is only one intermediate relay UE), such as in step 720 where the second relay UE is the root relay UE 111, after a PC5 connection is established between the second relay UE (second intermediate relay UE if there is more than one intermediate relay) and a third relay UE (third intermediate relay UE if there is more than two intermediate relay or the root relay UE if there is only two intermediate relay UEs), and so on depending on the number of relay UEs. The request (e.g. RRCSetupRequest 741) to establish a connection, such as a RRC connection, between the remote UE 113 and the network is sent after the End-to-End PC5 connection is established with the root relay UE 111. The remote UE 113 may establish an End-to-End PC5 connection between the remote UE 113 and a root relay UE 111 by sending, to the root relay UE 111 via the intermediate relay UE(s) such as relay UE 112, a message for establishing an End-to-End PC5 connection. The message may be a Direct Communication Request, such as Direct Communication Request 611 or a Link Modification Request message. The message may include information for use in establishing a connection, such as a RRC connection, between the remote UE 113 and the network. The information may be in addition to the information described below for the Direct Communication Request 611 and may include at least one of: RRCcontainer information as discussed below; SetupRequestCommand as discussed below. The message may include information to trigger the root relay UE 111 to request establishment of a connection (e.g. RRC connection) to the network. The information may include at least one of: information for indicating the connection to be established is a multihop connection for use in multi-hop communication, such as the connectionForMultiHop information described below; information for indicating the number of hops from the first or remote UE to the root relay UE, such as the hop count as discussed below; information for identifying the network, such as an identifier of the cell (cell ID) served by a base station and / or an identifier of a serving Public Land Mobile Network (PLMN ID). As discussed above, the trigger sent to the root relay UE can help the root relay UE, which is not connected, to select a cell if the root relay UE is in coverage of several cells. The request (RRCSetupRequest 741) sent by the UE 113 may also trigger the root relay UE 111 to initiate establishment of a connection to the network e.g. through the RRC Resume or RRC setup procedures. The UE 113 may receive identification information for identifying each of the at least two relay UEs, such as the one or more intermediate relay UEs and the root relay UE. The identification information for each relay UE may include its local ID and L2 ID. For example, the remote UE 113 may receive the local IDs and L2 IDs of the relay UEs 112 and 111. In one aspect, the remote UE 113 may send to the network, for example in a RemoteUEInformationSidelink 751, information associated with the remote UE 113 for use by the network to configure the remote UE 113, the intermediate relay UE(s), such as 112, and the root relay UE 111 to support multi-hop communication between the remote UE 113 and the network. The root relay UE 111 adds the information received from the remote UE 113 and information received from the intermediate relay UE(s), such as 112, to provide information, such as the intermediate relay UE(s) ID list and / or hop count, which is sent to the network in the SidelinkUEInformationNR 752. The remote UE 113 may receive, from the network, configuration information for configuring the remote UE 113 (e.g. configuring SRB1, SRB2 and DRB) for connection to the network to support multi-hop relay communication between the remote or first UE and the network. For example, configuration information for SRB1 may be sent in RRCSetup 742. RRCSetup may also include SRAP configuration such as mapping table, locallD as discussed below. Configuration information for SRB2 and DRB may be sent in RRCReconfiguration 761. RRCReconfiguration may also include PDCP configuration, RLC configuration as discussed below. After SRB1 is configured, the remote UE 113 is in RRC connected state and the remote UE 113 sends a RRCSetupComplete 743. After SRB2 / DRB is configured, the first or remote UE 113 is End-to-End connected for multi-hop communication and the first or remote UE sends a RRCReconfigurationComplete 762 (e.g. as discussed below for the RRCReconfigurationComplete 536 sent by the relay UE 112). Referring now to figure 10 which is a flow chart showing steps of a method 1000 for managing or facilitating relay communication (or a method for managing establishment of relay communication) in a wireless communication system supporting relaying, in accordance with one or more embodiments of the invention. Method 1000 can be used to manage End-to-End connection establishment between a remote UE and a network (e.g. a network entity such as a gNB or AMF) involving or over at least two relay UEs, in accordance with one or more embodiments of the invention. The wireless communication system includes a plurality of User Equipment, UE and a network. The method is performed at a root relay UE i.e. the relay in coverage of the network managing the Uu link connected with a base station: e.g. the relay UE connected or to be connected to the network. The network includes a number of entities, such as a base station or gNB of the RAN, the Access and Mobility Management Function (AMF) entity of the core network. At least one of these entities (e.g. base station or AMF) may send or receive messages / information and / or establish connections as discussed below with references to messages / information being sent to the network and connections being established with the network. The wireless communication system may be, for example, the wireless communication system 100 of Figure 1. With respect to the example shown in Figure 1 (and the messages flows discussed with reference to figure 7), the root relay UE may be root relay UE 111. The method 1000 as shown in and described with respect to figure 10 may be performed by software elements and / or hardware elements. Thus, for example, the method as shown in and described with respect to figure 10 may be performed by an apparatus for the UE comprising one or more processing units configured to carry out the method. The UE may be implemented in a communication device 400 as shown in and described with reference to figure 4 with the method as shown in and described with respect to figure 10 being performed by one or more processing units, such as the central processing unit 411. The methods described with reference to figures 9 and 10 are related in that the method described with reference to figure 9 relates to step(s) performed at the remote UE and the method described with reference to figure 10 relates to step(s) performed at the root relay UE of the same arrangement. In other words, for both methods each of the intermediate relay UEs acts as U2U relay UEs (e.g. 112) to connect the remote UE (e.g. 113) with the (root) UE-to-Network, U2N, relay UE (e.g. 111). The root U2N relay UE connects the remote UE to the network (e.g. gNB) as discussed above (see also the discussion with respect to figure 8 of how the root relay UE connects to the network). Briefly, at step 1001, the root relay UE, such as UE 111, sends, to the network, a request to establish, or to initiate establishment of, a connection, such as a RRC connection, between the root relay UE 111 and the network (e.g. base station or AMF) for establishing multi-hop communication between a first or remote UE 113 and the network via at least two relay UEs of the plurality of UEs, including the root relay UE which is to be connected to the network. In other words, a request to initiate establishment of a connection is sent by the root relay UE 111 and in the case of a RRC connection is a request to enter in a connected RRC state (RRC CONNECTED). The request may be the RRCSetupRequest of a RRCSetup procedure or a RRCresume request of a RRC resume procedure as discussed below with reference to figure 7. In an example, the root relay UE 111 establishes a PC5 connection with another relay UE (e.g. an intermediate relay UE), such as relay UE 112, of the at least two relay UEs. In one aspect, the root relay UE 111 establishes an End-to-End PC5 connection between the remote UE 113 and the root relay UE 111, via at least the other relay UE 112 (depending on how many intermediate relay UE(s)). The request to establish, or to initiate establishment of, a connection, such as a RRC connection, between the root relay UE 111 and the network is sent after the End-to-End PC5 connection is established. The End-to-End PC5 connection is established after a PC5 connection is established between the remote UE and a first relay UE (first intermediate relay UE), such as in step 710, after a PC5 connection is established between the first relay UE and a second relay UE (second intermediate relay UE if there is more than one intermediate relay or the root relay UE if there is only one intermediate relay UE), such as in step 720 where the second relay UE is the root relay UE 111, after a PC5 connection is established between the second relay UE (second intermediate relay UE if there is more than one intermediate relay) and a third relay UE (third intermediate relay UE if there is more than two intermediate relay or the root relay UE if there is only two intermediate relay UEs), and so on depending on the number of relay UEs. After a PC5 connection is established between the root relay UE 111 and the other relay UE 112, the root relay UE may receive, from the remote UE 113, a request (such as the RRCSetupRequest 741) to establish, or to initiate establishment of, a connection, such as a RRC connection, between the remote UE 113 and the network for establishing multi-hop communication between the remote UE 113 and the network. In the case where a connection is established between the root relay UE 111 and the network UE, the root relay UE 111 forwards, to the network, the request, from the remote UE 113, to establish a connection between the remote UE 113 and the network for establishing multi-hop communication. The root relay UE 111 may also receive, from each intermediate relay UE(s) , such as the other relay UE 112, a request (such as the RRCSetupRequest) to establish, or to initiate establishment of, a connection, such as a RRC connection, between the respective intermediate relay UE, such as relay UE 112, and the network for establishing multi-hop communication between the remote UE 113 and the network. The root relay UE 111 may then combine or aggregate the RRCSetupRequests of the remote UE and child or intermediate relay UE(s) into the parent RRCSetupRequest. At the end of the combining or aggregation, the RRCSetupRequest of the root relay UE 111 includes the RRCSetupRequest of all the child and the remote UEs. In case of the inclusion of RRCSetupRequest command in the Direct Communication Request, the root relay UE 111 may include the RRCSetupRequest of the remote UE in its RRCSetupRequest or RRCResume. Based on this aggregated RRCSetupRequest sent to the network by the root relay UE, the network (e.g. gNB) sends a response to each UE to continue the establishment procedure or sends an aggregated RRCSetup including the configuration of all UEs. Each intermediate UE forwards the message after removing its own configuration. In an example, the root relay UE 111, sends, to the network, a request to establish, or to initiate establishment of, a connection, such as a RRC connection, between the root relay UE 111 and the network after receiving a trigger at the root relay from another relay UE (e.g. from an intermediate relay UE), such as relay UE 112. The root relay UE 111 may receive a message including information to trigger the root relay UE 111 to request establishment of a connection (e.g. RRC connection) to the network. The message may be a Direct Communication Request, such as Direct Communication Request 611 or a Link Modification Request message. The information may be in addition to the information described below for the Direct Communication Request 611 and may include at least one of: RRCcontainer information as discussed below; SetupRequestCommand as discussed below. The information may include at least one of: information for indicating the connection to be established is a multi-hop connection for use in multi-hop communication, such as the connectionForMultiHop information described below; information for indicating the number of hops from the first or remote UE to the root relay UE, such as the hop count as discussed below; information for identifying the network, such as an identifier of the cell (cell ID) served by a base station and / or an identifier of a serving Public Land Mobile Network (PLMN ID). As discussed above, the trigger sent to the root relay UE can help the root relay UE, which is not connected, to select a cell if the root relay UE is in coverage of several cells. The request (RRCSetupRequest 741) sent by the UE 113 may also trigger the root relay UE 111 to initiate establishment of a connection to the network e.g. through the RRC Resume or RRC setup procedures. In one aspect, the root relay UE 111 may receive from the remote UE 113, for example in a RemoteUEInformationSidelink 751, information associated with the remote UE 113 for use by the network to configure the remote UE 113, the intermediate relay UE(s), such as 112, and the root relay UE 111 to support multi-hop communication between the remote UE 113 and the network. The root relay UE 111 may also receive information associated with each of the intermediate relay UE(s) for use by the network to configure the remote UE 113, the intermediate relay UE(s), such as 112, and the root relay UE 111 to support multi-hop communication. The root relay UE 111 adds the information received from the remote UE 113 and information received from the intermediate relay UE(s), such as 112, to provide information, such as the intermediate relay UE(s) ID list and / or hop count, which is sent to the network in the SidelinkUEInformationNR 752. The root relay UE 111 may receive, from the network, configuration information for configuring the root relay UE 111 (e.g. configuring SRB1, SRB2 and DRB) for connection to the network to support multi-hop relay communication between the remote or first UE and the network. For example, configuration information for SRB1 may be sent in RRCSetup 742. Configuration information for SRB2 and DRB may be sent in RRCReconfiguration 761. For example, the configuration information may include SL-SRAP-Config for the remote UE 113 sent to the remote UE 113 via the relay UEs 111 and 112 and potentially SL-SRAP-ConfigU2U for the intermediate relay UE(s), to setup the End-to-End SRB2 / DRBs of the remote UE 113. Referring now to figure 11 which is a flow chart showing steps of a method 1100 for managing or facilitating relay communication (or a method for managing establishment of relay communication) in a wireless communication system supporting relaying, in accordance with one or more embodiments of the invention. Method 1100 can be used to manage End-to-End connection establishment between a remote UE and a network (e.g. a network entity such as a gNB or AMF) involving or over at least two relay UEs, in accordance with one or more embodiments of the invention. The wireless communication system includes a plurality of User Equipment, UE and a network including a base station or gNB. The method is performed at the base station. The wireless communication system may be, for example, the wireless communication system 100 of Figure 1. With respect to the example shown in Figure 1 (and the messages flows discussed with reference to figures 5-7), the base station may be gNB 101. The method 1100 as shown in and described with respect to figure 11 may be performed by software elements and / or hardware elements. Thus, for example, the method as shown in and described with respect to figure 11 may be performed by an apparatus for the gNB or base station comprising one or more processing units configured to carry out the method. The base station may be implemented in a communication device 400 as shown in and described with reference to figure 4 with the method as shown in and described with respect to figure 11 being performed by one or more processing units, such as the central processing unit 411. Briefly, at step 1101, the base station establishes multi-hop communication between a first or remote UE, such as remote UE 113, of the plurality of UEs and the network via at least two relay UEs, such as relay UE 112 and relay UE 111. In an example, the base station 101 sends a message, such as SIB 12, including information indicating a value of the time period for connection failure determination for multihop. UEs receiving the information may use the value of the time period for connection failure determination for multi-hop in the received information to set a timer associated with establishing a RRC connection with the network. For example, the timer may be the t300 timer and the time period may be the value t300-RemoteUEForMultiHop-rl9 as discussed below. The value of the time period for connection failure determination for multi-hop is greater than a value of a time period for connection failure determination for one hop or non-multi-hop. As the timer value is increased compared to the non-multi-hop case, the additional time required to establish a connection due to the establishment procedures having to take place at the at least two relay UEs can be accounted for to avoid wrong connection failure determination or detection. The base station 101 may also provide hopjimit and / or max hop to the UEs, for example, through the SIB 12. In an example, the base station 101 combines or aggregates the RRCReconfiguration of the remote UE and child or intermediate relay UE(s) into the parent RRCReconfiguration. Once combined or aggregated, the RRCReconfiguration for the root relay UE 111 includes the RRCReconfiguration of all the child and the remote UEs. In a variant, the RRCReconfiguration 535 sent to the root relay UE 111 includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the intermediate Relay UE 112 which also includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the remote UE 113. Each intermediate UE performs its own configuration based on the received RRCReconfiguration message and extract the RRCReconfiguration message embedded in the Multi-HopConfigurationCommand and sends it to its child relay UE or to the remote UE (for the last intermediate relay UE). In response, each UE sends a message (RRCReconfigurationComplete) to the base station to acknowledge the configuration and complete the RRCReconfiguration procedure. It is noted that the combination or aggregation could be partial meaning that the base station 101 could send combined RRCReconfiguration message including the configuration of a subset of the UEs involved in the multi-Hop establishment and send a RRCReconfiguration directly to the other UEs. In an example, the base station 101 sends configuration information including the configuration information for configuring a relay UE for communication with the network and configuration information for configuring the relay UE for communication with another relay UE or a first UE. For example, where the relay UE 112 acts both as a remote UE and as a relay UE, the RRCReconfiguration message may include a multi-HopUEconfiguration IE including the configuration for the relay part as well as the configuration for the remote part. It is noted that features of the method described with respect to figure 8 and 11 as discussed above may be used in the method described with respect to figures 9 to 11 and vice versa. For example, part or some of the intermediate relay UE(s) could be RRCCONNECTED acting as U2N relay while others could be unconnected acting as U2U relay. It may also be the case that all UE in RRC CONNECTED state could be connected to different base stations. It may also be the case that one hop between UEs is not provided by a PC5 connection but with a non-3GPP connection (N3C), such as wifi or Bluetooth. All or part of the above could be supported based on capability of the different UEs and network entities and authorization provided by the network. Referring now to Figures 5, 6 and 7 which are schematic and simplified diagrams illustrating examples of message flows for managing a UE-to-network establishment procedure in a wireless communication system supporting relaying, such as that shown in figure 1. More particularly, these figures illustrate examples of message flows for managing an End-to-End connection establishment between a remote UE and a network (e.g. a network entity such as a gNB or AMF) involving or over several Relay UEs, in accordance with one or more embodiments of the invention. In the example of the following figures, a remote UE maybe out-of-coverage of any gNB or at the edge of a cell with a poor-quality connection which does not give the opportunity for the remote UE to directly connect to a gNB or the remote UE wants or is directed by gNB to establish an indirect path in addition to a direct connection with the gNB in order to get a more stable connection or to achieve a better QoS (e.g. more bandwidth or more reliable connection). Among the relay UEs, at least one should be in-coverage for ensuring the connection to the gNB by acting as a UE-to-Network relay UE. This relay UE ensuring the connection for the last hop through the Uu link could be called a root U2N relay: that is, a relay UE or U2N relay UE that connects to the network. It will be appreciated that a descriptor other than ‘root’ may be used, e.g. last, target, base relay UE etc.. The other relay UEs could be indifferently incoverage or out-of-coverage. These relay UEs could be called intermediate relay UEs. By considering the connection path or map or graph connecting the remote UE to the gNB through the different relay UEs, a particular relay UE is connected on one side to a child relay UE (in the direction of the remote UE) or to a remote UE and on the other side is connected to a parent relay UE (in the direction of the gNB) or to a gNB. The figures 5 and 6 presents two examples of embodiments of the present invention wherein the intermediate relay UE (e.g. UE 112) acts as a relay UE for the end remote UE (e.g. 113) and as a remote UE to get the connection to the network through the root UE-to-Network relay UE (e.g. 111). For sake of clarity, these figures depict only one intermediate relay UE (relay UE 112), however, the multi-hop network establishment procedure could be extended to several intermediate relay UEs. Therefore, an intermediate relay UE would act as a UE-to-Network relay UE for its child relay UE or for an end remote UE and as remote UE for its parent relay UE or for the root UE-to-Network relay UE. The figure 7 presents an example of embodiments of the present invention wherein each of the intermediate relay UEs acts as UE-to-UE relay UEs (e.g. 112) to connect the remote UE (e.g. 113) with the (root) UE-to-Network relay UE (e.g. 111). This latter connecting the remote UE to the gNB. For sake of clarity, this figure depicts only one intermediate relay UE (relay UE 112), however, the multi-hop network establishment procedure could be extended to several intermediate relay UEs. It is noted that when the intermediate relay UEs are UE-to-UE relay, they do not require to be RRCCONNECTED, only the root UE-to-Network needs to be RRCCONNECTED. This could be advantageous as it decreases the number of UE connected to the gNB and the traffic burden at gNB. The reduction of the number of UE(s) connected to a gNB is particularly advantageous as a base station can only accept a finite number of UEs and each UE connected requires memory for example to store the UE context retrieved from the core network. Moreover, in the example of the figure 7, the mapping table at the root UE-to-Network UE and at the remote UE point to the end-to-end PC5 connection while for the figures 5 and 6, the mapping table point to the next UE i.e. the parent relay UE for the Uplink traffic and the child relay UE for the Downlink traffic. Based on the current 3GPP specifications, unconnected (RRCIDLE or RRCINACTIVE) relay UEs are triggered to enter in RRCCONNECTED when they receive a message from a remote UE (or a child relay acting as a remote UE) via SRBO or SRB1. This is the usual method to “wake up” a relay UE to go into RRC CONNECTED mode (which is mandatory to ensure its role of L2 relay UE). What is suitable for a 1-hop connection, becomes unsuitable and not scalable when considering a multi-hop establishment procedure. Indeed, if the selected parent relay is RRC IDLE or RRC INACTIVE, it must establish its own connection before relaying the connection request from its remote UE (or a child relay UE acting as a remote UE). Thus, in the multi-hop case in the example of figures 5 and 6, as each relay UE in the multi-hop path between the remote UE and the network performs connection establishment before the connection request from the remote UE can be relayed, such nested establishment procedures can introduce latency in the establishment procedure for the remote UE. As the establishment procedure is managed by a timer that allows the detection of failure (e.g. on expiry of a certain time period measured by the timer, connection failure is detected), this timer is started upon the transmission of RRCSetupRequest and is stopped upon reception of the RRCSetup or RRCReject message. At expiry of the time period (e.g. timer expiry), the UE informs upper layers about the failure to establish the RRC connection, upon which the procedure ends. However, in the case of multi-hop relaying, the timer expiry could be interpreted incorrectly as a failure to establish the connection as the delay could be caused by the duration or time taken to establish a connection performed by each of the subsequent relays in the multi-hop communication path. Besides, even in the example of the figure 7 where only the remote and the root relay UEs need to establish the RRC connection similar to the legacy UE-to-Network behavior, the time to transmit the message from hop-to-hop can be longer than in the legacy UE-to-Network as there are multiple hops to cross and the transmission opportunities of each relay are not necessarily synchronized i.e. the message is not instantaneously forwarded when it is received in a relay. Therefore, in the example of the figures 5-6, it is proposed to adapt the timer behaviour for this new multi-hop establishment procedure in order to have specific timer value before expiration in the case of multi-hop establishment. In the example of figure 7, only the remote and the root relay UEs need to be connected to the network and in such a case the behaviour for establishing connections to the network is close to the behaviour of that of a U2N relay UE. However, the time to transmit the messages from hop-to-hop is longer as there are multiple hops and as the transmission opportunities are not necessarily synchronized: i.e. the message is not instantaneously forwarded when it is received in a relay. As a result, it could also be useful to adapt the timer as described below for the U2U case as described with reference to figure 7. For example, a message (e.g. configuration message) received at a UE may include information for indicating a value for a time period (e.g timer value) to be used by the UE, such as to be used by a timer (e.g. T300) of the UE, in the case of a multi-hop connection (e.g. in the case of multi-hop for a Release 19 UE) to determine whether the establishment of a connection to the network has failed or not. The UE may be a remote UE or a child relay UE acting as a remote UE and is used by the UE when the UE is capable of supporting multi-hop communication. The value for the time period in the multi-hop case will be different to (e.g. greater than) the value for non multi-hop case e.g. for a one hop connection. For instance, the SIB 12 may carry a new IE indicating the timer value of T300 used by L2 U2N Remote UE in the case of a Multi-Hop connection. If the new IE or field is absent, the timer value indicated in t300-RemoteUE-rl7 applies to L2 U2N Remote UE. The new IE could be, for example, as follow: UE-TimersAndConstantsRemoteUEForMultiHop-rl9 ::= SEQUENCE { t300-RemoteUEForMultiHop-rl9 ENUMERATED {mslOO, ms200, ms300, ms400, ms600, ms 1000, ms 1500, ms2000} OPTIONAL, - Need S In addition, each intermediate relay UE when acting as a remote UE (in the example of the figures 5 and 6) to establish its own connection could use the value from the SIB 12 or the value from the SIB 12 moderated or updated according to the position of the relay UE in the connection path or map or graph of connectivity. For example, the value for the time period (such as the timer value in the SIB 12) in the multi-hop case may be updated or moderated based on the hop count, the max hop and hop limit information obtained from the discovery or during PC5 establishment. The hop limit information could be also obtained from the SIB 12 or may be pre-configured. Hop count information (e.g. hop count) indicates the number of hops (e.g. relay UEs or relay UEs crossed) from the remote UE to the relay UE and the maximum hop information (e.g. hop limit information) indicates a maximum number of hops between the remote UE and the root UE (i.e. the relay UE that is connected or is to be connected to the network) which maximum number of hops is permitted, allowed or supported by the remote UE. The max hop information indicates the actual number of hops between the remote UE and the root relay (or gNB) determined or provided during discovery process. As explained above, in the case of multi-hop establishment, the timer value needs to be increased compared to the non-multi-hop case (e.g. one-hop case such as described in Release 17), to handle the potential nested establishment procedures from the intermediate relay UEs to avoid wrong failure detection. However, this does not help to solve a drawback of the latency introduced by the nested establishment procedures from the intermediate relay UEs. To help to overcome this problem and reduce latency, in an example, as further illustrated in the example of figure 6, a new message is sent by the remote UE to the intermediate relay UE (or by a child relay UE acting as remote UE to its parent relay UE) that triggers the relay UE to enter in RRCCONNECTED state. The figure 6 shows different signalling that could be used as trigger. These different messages occur at different time points of the procedure (e.g. the procedure to establish a connection between a remote UE and the network over or involving multiple relay UEs or to establish multi-hop communication between a remote UE and the network). The sooner the triggering occurs in the procedure allows to optimise (e.g. by allowing the establishment of the different hops to occur in parallel as much as possible) the establishment of the different hops and so minimize the latency of the overall establishment. In a variant, the embodiments of figures 5 / 6 and 7 can be mixed. That is to say part or some of the intermediate relays UE could be RRC CONNECTED acting as U2N relay UE(s) while others could be unconnected acting as U2U relay UE(s). It may also be the case that all UE in RRC CONNECTED state could be connected to different base stations. It may also be the case that one hop between UEs is not ensured by a PC5 connection but with a non-3GPP connection (N3C), such as wifi or Bluetooth. All or part of the above could be supported based on capability of the different UEs and network entities and authorization provided by the network. Back to the figure 5, a remote UE, like remote UE 113, wants to establish a communication with the network, like the gNB 101. The remote UE begins a discovery procedure 501 so as to discover the relay UE(s) in its surroundings. The discovery process can follow for example the discovery model A or model B such as described in the TS23.304. At the end of the discovery procedure 501, the remote UE has a list of the potential relay UEs around it and may select one of these relay UEs to establish a PC5 connection in view of reaching a gNB or in other words establishing a connection with the network. To participate in the discovery procedure, each of the UEs checks whether it supports remote functions for the remote UE 113 or relay functions for the relays 112 and 111, and / or multi-hop capabilities, and whether it is authorized to act as a remote UE and / or relay UE in multi-hop connection. This authorization may be provided by the network before the step 501 (not shown in the figure). For example, this authorization may be provided as part of a service authorization and parameter provisioning procedure such as that described in 3GPP TS23.304 clause 6.2. The discovery procedure may be the discovery procedure described in GB2406657.3 filed on 10 May 2024 or in GB2406656.5 filed on 10 May 2024, both of which are incorporated herein by reference in its entirety. Then the remote UE 113 and the relay UE 112 establish a PC5 connection 510. The details of establishing the PC5 connection are ignored in this figure 5 and are shown in detail in the figure 6 with respect to the PC5 connection establishment 610. The PC5 connection establishment 510 starts with a PC5-S frame exchange. The remote UE 113 sends a Direct Communication Request, such as the Direct Communication Request message 611 shown in figure 6, to the relay UE 112 to initiate the PC5 connection establishment. The Direct Communication Request message 611 includes at least one of: - Source User Info: the initiating UE's Application Layer ID (i.e. Remote UE's Application Layer ID). For example, this information includes an identifier for identifying the UE that initiates the PC5 connection establishment (such as the remote UE 113 or a relay UE acting as a remote UE); - Target User Info: the target UE's Application Layer ID (i.e. Relay UE's Application Layer ID). This information may be supplied by upper layer of the remote UE 113 e.g. ProSe application. For example, this information includes an identifier for identifying the relay UE (such as relay UE 112) that is a target for establishing a PC5 connection with the initiating UE (such as the remote UE 113); - ProSe Service Info: the information about the ProSe identifier(s) requesting link establishment; This information is a global unique identifier used to identify the ProSe Application such as described in TS23.304. - Relay Service Code: information for indicating the connectivity service (which may be non-emergency or emergency) provided by the 5G ProSe UE-to-Network Relay (such as the relay UE 112) as requested by the 5G ProSe Remote UE (such as the remote UE 113 or a relay UE acting as a remote UE); - Security Information: the information for the establishment of security for the PC5 link establishment. Two types of link establishment (as specified in TS23.287) may be used either UE oriented link establishment based on the Target User Info if included in the Direct Communication Request or ProSe Service oriented link establishment if the Target User Info is not included in the Direct Communication Request. In addition, the Direct Communication Request message 611 may also include at least one of: - A Hop-Count: This information is used to control the number of hops to be supported for multi-hop Relay operations. For example, hop count information (e.g. hop count) indicates the number of hops (relay UEs) to the relay UE (as specified in TR23.700-03); - Hop-Limit information. For example, a separate Hop-Limit (or max hop) IE is used for controlling the maximum hops and is provided to the 5G ProSe Remote UE and UE-to-Network Relays per RSC using the Policy / Parameter provisioning as described in clause 5.1.5 of TS 23.304. The hop-Limit IE may also be received in the SIB12. As discussed above, the hop-limit information indicates a maximum number of hops between the remote UE and the root or last relay UE (i.e. the relay UE that connects to the network) that is permitted, allowed or supported by the remote UE; - Max hop information: This information indicates the actual number of hops between the remote UE and the root relay (or gNB) determined or provided during discovery process. - Accumulated QoS for PC5 link: information to inform the QoS information for or requested by the initiating UE, such as the remote UE 113 or Intermediate UE, to select the path to the network (as specified in TR23.700-03); - connectionForMultiHop: information to trigger the connection of relay UE to gNB and so trigger the relay UE to enter in RRC CONNECTED state. A Direct Communication Accept message, such as the Direct Communication Accept 612 shown in figure 6, is sent to remote UE 113 by the relay UE 112 that has successfully established security with the remote UE 113 (security establishment is voluntarily not shown in the figure for the sake of clarity), if the Target User Info included matches the Relay UE's Application Layer ID or if the relay UE 112 is interested by the ProSe services announced for instance with ProSe Service Info (e.g. is interested in establishing a PC5 connection to provide the ProSe services announced). The Direct Communication Accept message 612 includes at least one of: - Source User Info: Application Layer ID of the UE sending the Direct Communication Accept message (i.e. Relay UE). For example, this information includes an identifier for identifying the relay UE that sends the message accepting the Direct Communication request (such as the relay UE 112); - QoS Info: the information about PC5 QoS Flow(s). For each PC5 QoS Flow, the PC5 QoS Flow Identifier (PFI) and the corresponding PC5 QoS parameters requested by the initiating UE, such as remote UE 113: i.e. PC5 5G QoS Identifier (PQI) and conditionally other 37 parameters such as Maximum Flow Bit Rate (MFBR) / Guaranteed Flow Bit Rate (GFBR), etc., and optionally the associated ProSe identifiers(s); - Optional PC5 QoS Rule(s) (as defined in TS23.304). At the end of this Direct Communication Request / Accept exchange, the remote UE 113 and relay UE 112 may use the PC5 link to communicate with each other. Then, the remote UE 113 may initiate a RRCReconfigurationSidelink procedure. The purpose of this procedure is to modify a PC5-RRC connection, e.g. to establish / modify / release sidelink DRBs or PC5 Relay RLC channels, to (re-)configure NR sidelink measurement and reporting, and so on. The remote UE 113 sends to the relay UE 112 a RRCReconfigurationSidelink message, such as the RRCReconfigurationSidelink 613 shown in figure 6, which includes the parameters or configuration information to configure the relay UE 112. Upon the reception of the RRCReconfigurationSidelink message 613, the relay UE 112 may apply the received configuration and send as a response a RRCReconfigurationCompleteSidelink message, such as the RRCReconfigurationCompleteSidelink 614 shown in figure 6, to the remote UE 113 to acknowledge the configuration procedure. If the relay UE 112 is unable to support the configuration notified by the remote UE 113, the relay UE 112 sends a RRCReconfigurationFailureSidelink (not shown). As shown in figure 5, then, the remote UE 113 sends the first RRCSetupRequest message 541 for its connection establishment with the gNB 101 via the relay UE 112, using a specified PC5 Relay RLC channel configuration. Upon sending the RRCSetupRequest 541, the remote UE 113 starts the associated timer for establishing a RRC connection with the gNB 101 (e.g. t300). The expiry timer value being set with the value or value of a time period dedicated to multi-hop: for example, as described above the expiry timer value may be set with the value of the t300-RemoteUEForMultiHop-rl9 from the SIB 12 or a pre-configured value for multi-hop. The remote UE 113 is aware of the multi-hop nature of the connection based on the information exchanged during the discovery procedure performed at the remote UE 113 (such as the discovery procedure discussed above with respect to procedure 501) or during the PC5 establishment (e.g. with the remote UE 113). As the relay UE 112 is not in RRC CONNECTED, it needs to do its own Uu RRC connection establishment which is triggered by the reception of the RRCSetupRequest 541 from the remote UE 113 on the specified PC5 Relay RLC channel. Then, the relay UE 112 intends or decides to establish a PC5 connection with the relay UE 111 which has been formerly discovered in 501. The details of the PC5 connection 520 are not shown in figure 5 and are shown in detail in the figure 6 with respect to the PC5 connection establishment 620. The PC5 connection establishment 520 starts with a PC5-S frame exchange. The relay UE 112 sends a Direct Communication Request message, such as the message described above with respect to the Direct Communication Request message 611 sent by the remote UE 113, to the relay UE 111 to initiate the PC5 connection establishment. The Direct Communication Request, sent to the relay UE 111, may include in addition to the information described above for the Direct Communication Request message 611, sent to the relay UE 112, at least one of: Remote UE information (and child relay information in the case where the relay UE sending the Direct Communication Request has established a PC5 connection with a child relay UE) including the remote UE identifier and the remote UE User Info (Target / Source User Info) and the QoS flow for the remote UE (and similar information for the child relay information). This additional information indicates to the relay UE 111 that the connection will serve another UE (e.g. UE 113) and includes the QoS Flow requested for the remote UE 113. In the case of relay UE 112 serving several remote UEs, the Direct Communication Request may include Remote UE information per remote UE or in other words a list of remote UE info. It is noted that QoS Info in the Direct Communication Accept or Link Modification Accept indicates the QoS available for the connection or link: i.e. the QoS accepted by the target UE. In the Direct Communication Request or Link Modification Request, the QoS Info indicates the QoS requested by the initiating UE. The accumulated QoS is the QoS of the remote UE and all of the child relay UEs for a parent relay UE. For the remote UE, the QoS Info is the Accumulated QoS, for the relay UE 112, the Accumulated QoS is the QoS Info of remote UE and the QoS Info of the relay UE 112. A Direct Communication Accept message, such as the message described above with respect to the Direct Communication Accept message 612 sent by the relay UE 112, is sent to relay UE 112 by the relay UE 111 that has successfully established security with the relay UE 112. At the end of this Direct Communication Request / Accept exchange, the relay UE 112 and relay UE 111 may use the PC5 link to communicate with each other. In one variant not shown, the Direct Communication is already established between the relay UE 112 and the relay UE 111 (or only the legacy Direct Communication Request is supported by the UEs), a subsequent Link Modification Request message, sent by the relay UE 112 to the relay UE 111, is used to change the PC5 connection and indicate to the relay UE 111 that the connection will serve for the remote UE 113 (e.g. is for multi-hop communication) and also provide the QoS flows for the remote UE 113. This link modification request may also include a new value for its link modification operation code such as “Add new 5G ProSe UE to the existing 5G ProSe direct link for multi-hop”. This operation code could be generic to add a child relay or the end remote UE for multi-hop communication or one operation code could be used specifically for each case. For the opposite case to change from multi-hop to non multihop, another operation code could be used to “remove a 5G ProSe UE from the existing 5G ProSe direct link for multi-hop”. When receiving a Link Modification Request message, the relay UE 111 may accept the modification to the PC5 connection by sending a Link Modification Accept or may reject the modification by sending a Link Modification Reject. It is noted that the Link Modification Request message may be sent by a remote UE, for example in the case where a PC5 connection is already established between the remote UE 113 and the relay UE 112. In this case, a target relay UE may accept the modification to the PC5 connection by sending a Link Modification Accept or may reject the modification by sending a Link Modification Reject. The relay UE 112 may initiate a RRCReconfigurationSidelink procedure. The purpose of this procedure is to modify a PC5-RRC connection, e.g. to establish / modify / release sidelink DRBs or PC5 Relay RLC channels, to (re-)configure NR sidelink measurement and reporting, and so on. The relay UE 112 sends to the relay UE Illa RRCReconfigurationSidelink message, such as the message described above with respect to the RRCReconfigurationSidelink message 613 sent by the remote UE 113, which includes the parameters or configuration information to configure the relay UE 111. Upon the reception of the RRCReconfigurationSidelink message, the relay UE 111 may apply the received configuration and send as a response a RRCReconfigurationCompleteSidelink message, such as the message described above with respect to the RRCReconfigurationCompleteSidelink message 614 sent by the remote UE 113, to the relay UE 112 to acknowledge the configuration procedure. If the relay UE 111 is unable to support the configuration notified by the relay UE 112, the relay UE 111 sends a RRCReconfigurationFailureSidelink. Then, the relay UE (acting as a remote UE) 112 sends the first RRCSetupRequest message 531 for its connection establishment with gNB 101 via the relay UE 111, using a specified PC5 Relay RLC channel configuration. In a variant, relay UE 112 may also combine or aggregate the RRCSetupRequests of the remote UE 113 (and child or intermediate relay UE(s)) into its RRCSetupRequest. This allows to decrease the latency of the overall establishment procedure and save bandwidth that is normally used to forward the RRCSetupRequest of the remote UE 113. Upon sending the RRCSetupRequest 531, the relay UE 112 (acting as a remote UE) starts the associated timer for establishing a RRC connection with the gNB 101 (e.g. t300). The expiry timer value being set with the value or value of a time period dedicated to multi-hop: for example, as described above the expiry timer value may be set with the value of the t300-RemoteUEForMultiHop-rl9 from the SIB 12 or a pre-configured value for multi-hop. The remote UE 113 is aware of the multi-hop nature of the connection based on the information exchange during the discovery or during the PC5 establishment. The relay UE 112 (acting as a remote UE) can moderate or update the t300-RemoteUEForMultiHop-rl9 based on the hop count and the hop limit (or max hop if available) information obtained from a discovery procedure performed at the relay UE 112 (such as the discovery procedure discussed above with respect to procedure 501) or during PC5 establishment (e.g. with the remote UE 113 and / or with the relay UE 111). The hop limit could be also obtained from the SIB 12 or pre-configured. For instance, the relay UE 112 may use the value provided by or calculated from (hopjimit - hop_count) / hopjimit of the value used by the remote UE 113 (e.g. the t300-RemoteUEForMultiHop-rl9 value) to update or moderate the value used by the remote UE 113 (e.g. the t300-RemoteUEForMultiHop-rl9 value) to provide an updated value and set the updated value as the expiry timer value for the timer (e.g. t300) of the relay UE 112. In the example arrangement shown in figure 6 where there are two relay UEs, the value used to set the expiry timer value for the timer (e.g. t300) of the relay UE 112 is 2 / 3 of t300-RemoteUEForMultiHop-rl 9 as the relay UE 112 is the initiator of the second hop and assuming the hop limit is set to 3. When available, the max hop may advantageously replace the hop limit as the max hop reflects the real number of hops between the remote UE and the root relay UE while the hop limit indicates a maximum number of hops supported. In the example of the figure 5, the relay UE 111 (root UE-to-Network relay) is already connected to the gNB 101 when it receives the RRCSetupRequest 531 from the relay UE (acting as a remote UE) 112. Otherwise, the root UE-to-Network relay 111 may connect to the gNB 101 through the RRC Resume or RRC setup procedures as defined in the TS 38.331. Once connected, then, relay UE 111 forwards the RRCSetupRequest 531 from the relay UE (acting as a remote UE) 112 to the gNB 101. In addition, the root UE-to-Network relay UE 111 may send to the gNB 101 the SidelinkUEInformationNR message (not shown) to request for the dedicated configurations required to support the relay operation for the relay UE (acting as a remote UE) 112. Based on the information provided by the relay UE 111 through the SidelinkUEInformationNR, the gNB 101 configures the relay UE 111, (RLC channels for the SRBO allowing to transmit the RRCSetup message...) and responds with a RRCSetup message 532 to the relay UE (acting as a remote UE) 112 through the relay UE 111. Upon reception of the RRCSetup 532 from the gNB 101, the relay UE (acting as a remote UE) 112 stops the timer t300. In case of timer expiry, meaning that the RRC connection establishment failed through the UE 111, the relay UE 112 may inform the remote UE about this failure and indicate the ID of the root or parent relay UE through which the connection failed. Based on the reception of this failure message, the remote UE 113 may try to connect through a new path avoiding the UE that failed to connect. In one variant, the remote UE 113 receiving the failure message may reset its t300 timer while the relay UE 112 tries a reconnection through the same or a different root or parent relay. If the failure occurs at a relay not connected to the remote UE 113, the failure message could be propagated up to the remote UE 113. The failure could be carried for instance in the NotificationMessageSidelink message. In one variant, the root UE-to-Network relay 111 may include information about all the child relay UE(s), such as relay UE 112, and about the remote UE 113 (at least their IDs) in the SidelinkUEInformationNR. The information about all the child relay UE(s) and about the remote UE 113 may also include, in addition to identifiers for each UE, at least one of: hop count, the remote UE User Info (Target / Source User Info) and the QoS flow for the remote UE, the child relay UE Source User Info, the capability of the remote UE and child relay UEs, the power save information (DRX), UE type (intermediate U2N relay or intermediate U2U relay or remote UE), interested frequency for Transmission, for Reception and for Discovery, the End-to-end PC5 information in case of U2U relay UE being involved in the multihop connection (including per Hop info and end-to-end info). Based on this additional information, the gNB 101 may prepare the configuration of the whole path rather than modifying the configuration after the reception of the SidelinkUEInformationNR from each intermediate relay. For example, this information about all the child relay UE(s) and about the remote UE could be added in a new IE dedicated to multi-hop transmission or as an enhancement of an existing IE such as TxResourceReqL2U2N-Relay or TxResourceReqL2-U2U which would include a new input to indicate the hop count and a pointer to another TxResourceReqL2U2N-Relay IE (or TxResourceReqL2-U2U IE depending on the type of the intermediate relay UE) corresponding to a subsequent child relay. In step 533, the gNB 101 completes the configuration of the relay UE 111 and relay UE (acting as a remote UE) 112. Based on the configuration supplied by the gNB 101 (SRAP and RLC configuration for SRB1), both UEs 112 and 111 prepare a PC5 Relay RLC channel and relay UE 111 and gNB prepares a Uu Relay RLC channel for SRB1 which is used to send RRCSetupComplete, RRCReconfiguration and RRCReconfigurationComplete. Then, the relay UE (acting as a remote UE) 112 completes the RRCSetup by sending the RRCSetupComplete message 534 to the gNB 101 though the relay UE 111. The relay UE (acting as a remote UE) 112 is in RRC CONNECTED state. Then, gNB 101 sends an RRCReconfiguration message 535 to the relay UE (acting as a remote UE) 112 via the relay UE 111, to setup the end-to-end SRB2 / DRBs of the UE 112. In a variant, as the relay 112 acts as both a remote UE and as a relay UE. In said variant the RRCReconfiguration message may include a multi-HopUEconfigurati on IE including the configuration for the relay part as well as the configuration for the remote part. The relay UE (acting as a remote UE) 112 sends an RRCReconfigurationComplete message 536 to the gNB 101 via the root relay UE 111 as a response. In step 537, according to the configuration exchanged through the RRCReconfiguration messages 535, the gNB 101 and the relay UE (acting as a remote UE) 112 prepare PC5 and Uu Relay RLC channel for the SRB2 and DRB. In a variant, the gNB 101 may also combine or aggregate the RRCReconfiguration of the remote UE and child or intermediate relay UE(s) into the parent RRCReconfiguration. Upon completion of the combining or aggregation, the RRCReconfiguration for the root relay UE 111 includes the RRCReconfiguration of all the child and the remote UEs. In an embodiment, the RRCReconfiguration 535 sent to the root relay UE 111 includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the intermediate Relay UE 112 which also includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the remote UE 113. Each intermediate UE performs its own configuration based on the received RRCReconfiguration message and extract the RRCReconfiguration message embedded in the Multi-HopConfigurationCommand and sends it to its child relay UE or to the remote UE (by the last intermediate relay UE). This allows to decrease the latency of the overall establishment and configuration procedure and save some bandwidth. It is noted that the combination or aggregation could be partial, meaning that the base station 101 could send a combined RRCReconfiguration message including the configuration of a subset of the UEs involved in the multi-Hop establishment and send a RRCReconfiguration directly to the other UEs. Once in RRC CONNECTED state (any time after the sending of the RRCSetupComplete 534), the relay UE 112 resumes the sending of the RRCSetupRequest message 541 from the remote UE 113. The relay UE 112 also sends the SidelinkUEInformationNR message (not shown in figure 5) to request for the dedicated configurations required to support the relay operation for the remote UE 113. The SidelinkUEInformationNR may include all or part of the following: - Destinationidentity which indicates the destination for which the TX resource request and allocation from the network are concerned, in other word the remote UE identity; - TxInterestedFreqList: this information indicates on which frequency the remote UE wants to transmit; - LocallD-Request which indicates if the relay UE request a local ID for the remote UE; - PagingldentityRemoteUE indicates the UE ID to be used by the gNB to send paging information to the remote UE. This ID is provided by the relay UE; - Capabilityinformation indicates the sidelink capability of the remote UE. The SidelinkUEInformationNR may also include identifiers for each UE, hop count, the remote UE User Info (Target / Source User Info) and the QoS flow for the remote UE, the power save information (DRX), UE type (intermediate U2N relay intermediate U2U relay or remote UE), interested frequency for Discovery, the End-to-end PC5 info in case of U2U relay UE involved in the multihop connection (including per Hop info and end-to-end info). Based on the information provided by the relay UE 112 through the SidelinkUEInformationNR, the gNB 101 configures the relay UE 112, (RLC channels for the SRBO allowing to transmit the RRCSetup message...) and responds with a RRCSetup message 542 to the remote UE 113 through the relay UEs 111 and 112. Upon reception of the RRCSetup 542 from the gNB 101, the remote UE 113 stops the timer t300. In case of timer expiry, meaning that the RRC connection establishment failed through the UE 112, the remote UE 113 may try to connect through a new relay UE. In step 543, the gNB 101 completes the configuration of the relay UE 112 and remote UE 113. Based on the configuration supplied by the gNB 101 (SRAP and RLC configuration for SRB1), both UEs 112 and 113 prepare a PC5 Relay RLC channel and relay UE 112 and gNB prepare Uu Relay RLC channel for SRB1 which is used to send RRCSetupComplete, RRCReconfiguration and RRCReconfigurationComplete. Then, the remote UE 113 completes the RRCSetup by sending the RRCSetupComplete message 544 to the gNB 101 though the relay UEs 111 and 112. The remote UE 113 is in RRC CONNECTED state. The gNB 101 continues the configuration of the remote UE’s SRB2 and DRB through RRCReconfiguration procedure (as described for messages 535, 536 and the step 537). Referring now to Figure 6 which is a schematic and simplified diagram illustrating an example of message flows for managing a UE-to-network establishment procedure in a wireless communication system, such as that shown in figure 1. More particularly, this figure 6 illustrates an example of message flows for managing an End-to-End connection establishment between a remote UE and a gNB involving several Relay UEs, in accordance with one or more embodiments of the invention. In one example, a remote UE, like remote UE 113, wants to establish a communication with the network, like the gNB 101. The remote UE 113 begins a discovery procedure 601 so as to discover the relay UE(s) in its surroundings. The discovery process can follow for example the discovery model A or model B such as described in the TS23.304. At the end of the discovery procedure 601, the remote UE 113 has a list of the potential relay UEs around it and may select one of these relays to establish a PC5 connection in view of reaching a gNB or in other words establishing a connection with the network. Among the information exchanged via the discovery signalling, the relays 112 and 111 may indicate they support RRC connection establishment / resume for Multi-Hop operation, which RRC connection establishment / resume is triggered by receiving a PC5 trigger. This RRC connection could be direct or indirect; i.e. the reporting relay acts as a UE-to-Network relay with a direct connection to the gNB or as an intermediate UE-to-Network relay requiring the connection through another relay to reach the gNB (e.g. an indirect connection). To participate in the discovery procedure, each of the UEs checks whether it supports remote functions for the remote UE 113 or relay functions for the relays 112 and 111, and / or multi-hop capabilities, and whether it is authorized to act as a remote and / or relay in multi-hop connection. This authorization may be provided by the network before the step 601 (not shown in the figure). For example, this authorization may be provided as part of a service authorization and parameter provisioning procedure such as that described in 3GPP TS23.304 clause 6.2. The discovery procedure may be the discovery procedure described in GB2406657.3 filed on 10 May 2024 or in GB2406656.5 filed on 10 May 2024, both of which are incorporated herein by reference in its entirety. The PC5 connection establishment 610 starts with a PC5-S frame exchange. The remote UE 113 sends a Direct Communication Request 611 to the relay UE 112 to initiate the PC5 connection establishment. The Direct Communication Request message 611 includes at least one of - Source User Info: the initiating UE's Application Layer ID (i.e. Remote UE's Application Layer ID) For example, this information includes an identifier for identifying the UE that initiates the PC5 connection establishment (such as the remote UE 113 or a relay UE acting as a remote UE); - Target User Info: the target UE's Application Layer ID (i.e. Relay UE's Application Layer ID). This information may be supplied by upper layer of the remote UE 113, e.g. ProSe application. For example, this information includes an identifier for identifying the relay UE (such as relay UE 112) that is a target for establishing a PC5 connection with the initiating UE (such as the remote UE 113); - ProSe Service Info: the information about the ProSe identifier(s) requesting link establishment; - Relay Service Code: information indicating the connectivity service (which may be non-emergency or emergency) provided by the 5G ProSe UE-to-Network Relay (such as the relay UE 112) as requested by the 5G ProSe Remote UE (such as the remote UE 113 or a relay UE acting as a remote UE); - Security Information: the information for the establishment of security for the PC5 link establishment. Two types of link establishment (as specified in TS23.287) may be used either UE oriented link establishment based on the Target User Info if included in the Direct Communication Request or ProSe Service oriented link establishment if the Target User Info is not included in the Direct Communication Request. In addition, the Direct Communication Request message 611 may also include: - A Hop-Count: This information is used to control the number of hops to be supported for multi-hop Relay operations. For example, hop count information (e.g. hop count) indicates the number of hops (relay UEs) to the relay UE (as specified in TR23.700-03); - Hop-Limit information. For example, separate Hop-Limit IE is used for controlling the maximum hops and is provided to the 5G ProSe Remote UE and UE-to-Network Relays per RSC using the Policy / Parameter provisioning as described in clause 5.1.5 of TS 23.304. The hop-Limit IE may also be received in the SIB 12. As discussed above, the hop-limit information indicates a maximum number of hops between the remote UE and the root or last relay UE (i.e. the relay UE that connects to the network) that is permitted, allowed or supported by the remote - Max hop information: This information indicates the actual number of hops between the remote UE and the root relay (or gNB) determined or provided during discovery process. - Accumulated QoS for PC5 link: information to inform the QoS information for or requested by the initiating UE, such as remote UE 113, or Intermediate UE to select the path to the network (as specified in TR23.700-03); - connect!onForMultiHop: information to trigger the connection of relay UE to gNB and so trigger the relay UE to enter in RRCCONNECTED state. A Direct Communication Accept message 612 is sent to remote UE 113 by the relay UE 112 that has successfully established security with the remote UE 113 (security establishment is voluntarily not shown in the figure for the sake of clarity), if the Target User Info included matches the Relay UE’s Application Layer ID or if the relay UE 112 is interested by the ProSe services announced for instance with ProSe Service Info (e.g. is interested in establishing a PC5 connection to provide the ProSe services announced). The Direct Communication Accept message 612 includes at least one of: - Source User Info: Application Layer ID of the UE sending the Direct Communication Accept message (i.e. Relay UE). For example, this information includes an identifier for identifying the relay UE that sends the message accepting the Direct Communication request (such as the relay UE 112); - QoS Info: the information about PC5 QoS Flow(s). For each PC5 QoS Flow, the PC5 QoS Flow Identifier (PFI) and the corresponding PC5 QoS parameters requested by the initiating UE, such as remote UE 113, (i.e. PC5 5G QoS Identifier (PQI) and conditionally other parameters such as Maximum Flow Bit Rate (MFBR) / Guaranteed Flow Bit Rate (GFBR), etc.) and optionally the associated ProSe identifiers(s); - Optional PC5 QoS Rule(s). At the end of this Direct Communication Request / Accept exchange, the remote UE 113 and relay UE 112 may use the PC5 link to communicate with each other. Then, the remote UE 113 may initiate a RRCReconfigurati on Si delink procedure. The purpose of this procedure is to modify a PC5-RRC connection, e.g. to establish / modify / release sidelink DRBs or PC5 Relay RLC channels, to (re-)configure NR sidelink measurement and reporting, and so on. The remote UE 113 sends to the relay UE 112 a RRCReconfigurationSidelink message 613 which includes the parameters or configuration information to configure the relay UE 112. In one aspect, the RRCReconfigurationSidelink sent by the remote UE 113 may include a connectionForMultiHop IE which if present, requests the relay UE 112 to enter in RRC CONNECTED state. In other words, the RRCReconfigurationSidelink 613 sent by the remote UE 113 may include information, such as the connect!onForMultiHop IE, as a trigger for triggering the relay UE 112 to request establishment of a connection (e.g. RRC connection) to the gNB 101 and so to enter the RRC CONNECTED state. Upon the reception of the RRCReconfigurationSidelink message 613, the relay UE 112 may apply the received configuration and send as a response a RRCReconfigurationCompleteSidelink 614 to the remote UE 113 to acknowledge the configuration procedure. In one aspect, the relay UE 112 may include its RRC state to inform the remote UE 113 if the relay UE 112 is RRCCO WECTED or not. This information may be used by the remote UE 113 to know if it has to trigger the relay UE 112 to enter in RRCCONNECTED state. If the relay UE 112 is unable to support the configuration notified by the remote UE 113, the relay UE sends a RRCReconfigurationFailureSidelink (not shown in the figure). In another aspect, the remote UE 113 may configure the sidelink measurement reporting so that the relay UE 112 sends a MeasurementReportSidelink 617 when it enters in RRC CONNECTED or more generally if its RRC state changes. In this variant, a new event(s) based on the RRCstate is defined to trigger sidelink measurement reporting in addition to the existing ones (such as, when the link quality level, or the signal strength, of the serving cells of the relay UE 112 is lower than a predefined low threshold or is higher than a predefined high threshold). In other words, a new event is defined to trigger the sending of a Sidelink measurement report including the relay UE RRC state and so inform the remote UE 113 about the relay UE 112 RRC state change. In addition, the MeasurementReportSidelink 617 includes the RRC state as a new Information Element. Thereby, the relay UE 112 may inform the remote UE 113 about its current RRC state when the measurement report sidelink is configured (after the sending of the RRCReconfigurationCompleteSidelink 614) for example, through the MeasurementReportSidelink message 617. The MeasurementReportSidelink may further or alternatively include information indicating if the relay UE supports the multi-hop relay operations or multi-hop communication. More especially, the relay UE 112 may indicate to the remote UE 113 that it supports RRC connection establishment / resume for Multi-Hop operation triggered by receiving a PC5 trigger. This RRC connection could be direct or indirect: i.e. the reporting relay acts as a UE-to-Network relay connected directly to the network or as an intermediate UE-to-Network relay requiring the connection through another relay to reach the gNB (e.g. indirect connection). The PC5 trigger could be the reception by the relay UE of the connectionForMultiHop Information Element in the Direct Communication Request 611, or in the RRCReconfigurationSidelink 613, or in the RemoteUEInformati on Sidelink (as an example of the message 618). Similarly, the Direct Communication Request 611 including a connectionForMultiHop may be used to trigger the relay UE to enter in RRC CONNECTED state. In other words, a message sent by the remote UE 113 to the relay UE 112, such as at least one of the Direct Communication Request 611, the RRCReconfigurationSidelink 613, the Rem oteUEInformationSi delink 618, may include information, such as the connectionForMultiHop IE, as a trigger for triggering the relay UE 112 to request establishment of a connection (e.g. RRC connection) to the gNB 101 and so to enter the RRCCONNECTED state for multi-hop communication. In one aspect, the relay UE may also infer that it needs to enter in RRC CONNECTED for the multi-Hop purpose when a message, such as the Direct Communication Request 611, carries information about the hop count. In one aspect, the remote UE 113 may ask the relay UE 112 about its capability by sending a UECapabilityEnquirySidelink message 615. This message may optionally include the capability of the remote UE 113 in the UECapabilitylnformationSidelink Information Element. This capability can carry information to notice or inform the relay UE 112 that the remote UE 113 supports the sending of or has the capability to send the message that triggers the relay UE to enter in RRCCONNECTED (e.g. message 618) for multi-hop connection and that the remote UE 113 supports the multi-hop operations or multi-hop communication. As a response, the relay UE 112 sends a UECapabilitylnformationSidelink message 616 including the capability of the relay UE 112 and more especially if the relay UE 112 supports to be triggered by the remote UE 113 to enter in RRC CONNECTED: for example, the relay UE 112 sends to the remote UE 113 information indicating the relay UE 112 supports a PC5 trigger to enter in RRC CONNECTED for a multi-hop connection to the gNB 101. The relay UE 112 may also inform about its capability to support multi-hop relay operations or multi-hop communication. In a variant, this feature(s) may be mandatory for a Releasel9 sidelink relay UE and so a relay UE or remote UE with the AccessStratumReleaseSidelink field set to rell9 in the UECapabilitylnformationSidelink should support these functionalities (e.g. supporting PC5 trigger to enter RRCCONNECTED and multi-hop communication). This message 616 may also be sent autonomously by the relay UE 112 to inform the remote UE 113 about its capabilities. The UE Capability may also be exchanged prior to the RRCReconfigurationSidelink procedure (frame exchange 613 / 614) as long as the Direct Communication is established (e.g. over PC5 link). Once the PC5 connection is established, the remote UE 113 may send a message 618 to trigger the relay UE 112 to enter in RRC CONNECTED state. This message could be sent whatever the RRC state of the relay UE 112. In another variant, the relay UE 112 may inform the remote UE 113 on its RRC state before the remote UE 113 sends the triggering message 618, for example as aforementioned through a message such as the RRCReconfigurationCompleteSidelink 614 or through the MeasurementReportSidelink 617 or UECapabilitylnformationSidelink message 616. The trigger message 618 may be conditioned to the remote UE 113 and relay UE 112 capabilities shared through the messages 613 and 614 or 615 and 616 or in some point through the MeasurementReportSidelink 617 or the discovery message (included in the step 601): i.e. if the relay UE supports or not a PC5 Jrigger to enter in RRCCONNECTED and the multi-hop operations or multi-hop communication. The triggering message 618 could be a new message RemoteUETriggerSidelinkForMulti-HopConnection. In a variant, this triggering message 618 could be a RemoteUEInformationSidelink as specified in TS38.331. However, in this new usage, the RemoteUEInformationSidelink message will be sent when the remote UE 113 is in RRCCONNECTED. In this case the RemoteUEInformationSidelink message includes a new IE connectionForMultiHop which if present, requests the relay UE 112 to enter in RRC CONNECTED state. In another variant, triggering message 618 could be a RRCReconfigurationSidelink including a new IE connectionForMultiHop which if present, requests the relay UE 112 to enter in RRC CONNECTED state. In another variant, the relay UE 112 may infer that it needs to enter in RRC CONNECTED for the multi-Hop purpose from the reception of a RRC message including information about the hop count which is related to the multi-Hop feature. For the intermediate relay UE 112, a trigger to enter in RRC CONNECTED state implies to use another relay to reach the gNB 101. In that case, the relay UE 112 may act as a remote UE. Therefore, after the reception of a trigger as described above, the relay UE 112 intends or decides to establish a PC5 link / connection with a relay UE in gNB coverage having UE-to-Network capability or with another intermediate relay UE closer to the gNB or closer to a UE-to-Network relay (in gNB coverage and with relay capabilities). In the example of the figure 6, the relay UE 112 means or decides to establish a PC5 link / connection with the relay UE 111 (formerly discovered during the step 601). The procedure to establish a PC5 link / connection with the relay UE 111 primarily gathers or uses the Direct Communication Request / Direct Communication Accept (respectively 611 and 612) and the RRCReconfigurationSidelink / RRCReconfigurationSidelinkComplete (respectively 613 and 614) message exchanges as described above. In the procedure 620, the Direct Communication Request, sent to the relay UE 111, may further include, in addition to the information described above for the Direct Communication Request message 611, sent to the relay UE 112, at least one of Remote UE information (and child relay information in the case where the relay UE sending the Direct Communication Request has established a PC5 connection with a child relay UE) including the Remote UE identifier and the remote UE User Info (Target / Source User Info) and the QoS flow for the remote UE (and similar information for the child relay information). This additional information indicates to the relay UE 111 that the connection will serve another UE (e.g. UE 113) and includes the QoS Flow requested for the remote UE 113. In the case of relay UE 112 serving several remote UEs, the Direct Communication Request may include Remote UE information per remote UE or in other words a list of remote UE info. In one variant not shown, where the Direct Communication Request does not carry the remote and child relay information as described above or if a Direct Communication has already been established between the relay UE 112 and the relay UE 111, a subsequent Link Modification Request message, sent by the relay UE 112 to the relay UE 111, is used to change the PC5 connection and indicate to the relay UE 111 that the connection will serve for the remote UE 113 and also provide the QoS flows for the remote UE 113. Therefore, the link modification request may include the following information: - Remote UE information (and child relay information in the case where the relay UE sending the Direct Communication Request has established a PC5 connection with a child relay UE) including the Remote UE identifier and the remote UE User Info (Target / Source User Info) and the QoS flow for the remote UE (and similar information for the child relay information). This information indicates to the relay UE 111 that the connection will serve another UE (e.g. UE 113) and includes the QoS Flow requested for the remote UE 113. This link modification request may also include a new value for its link modification operation code such as “Add new 5G ProSe UE to the existing 5G ProSe direct link for multihop”. This operation code could be generic to add a child relay or the end remote UE for multihop communication or one operation code could be used specifically for each case. For the opposite case to change from multi-hop to non multi-hop, another operation code could be used to “remove a 5G ProSe UE from the existing 5G ProSe direct link for multi-hop”. When receiving a Link Modification message, the relay UE 111 may accept the modification by sending a Link Modification Accept or reject the modification by sending a Link Modification Reject. Then, once the PC5 connection has been established through the step 620, the relay UE 111 starts the procedure for the UE-to-Network connection 630 as described in TS38.300 section 16.12.5. This procedure is described in more detail with reference to the figure 5 in the step 530. The steps 620 and 630 could be started any time after the reception of the trigger by the relay UE 112 and depending in which message the trigger is carried (e.g. 611, 613 or 618 or during discovery 601). If the trigger is carried in the first message of the PC5 connection like Direct Communication Request 611, the remote UE 113 could send the RRCSetupRequest message 641 after the completion of the PC5 establishment 610. Otherwise, if the trigger occurs after the PC5 establishment like for instance through the message 618, the remote UE 113 may send the RRCSetupRequest message 641 upon the reception of a feedback from the relay UE 112 to indicate when it becomes RRCCOXXECTED. Once in RRCCOXXECTED state, the relay UE 112 sends the SidelinkUEInformationNR message 642 to request to the gNB 101 for the dedicated configurations required to support the relay operation for the remote UE 113. Based on the information provided by the relay UE 112 through the SidelinkUEInformationNR, the gNB 101 configures the relay UE 112, (RLC channels for the SRB0 allowing to transmit the RRCSetup message...) and responds with a RRCSetup 643 to the remote UE 113 through the relayUEs 111 and 112. Then, the gNB 101 completes the configuration of the relay UE 112 and remote UE 113. Based on the configuration supplied by the gNB 101 (SRAP and RLC configuration for SRB1), both UEs 112 and 113 prepare a PC5 Relay RLC channel and relay UE 112 and gNB 101 prepare Uu Relay RLC channel for SRB1 which is used to send RRCSetupComplete, RRCReconfiguration and RRCReconfigurationComplete. Then, the remote UE 113 completes the RRCSetup by sending the RRCSetupComplete message 644 to the gNB though the relay UEs 111 and 112. The remote UE 113 is in RRC CONNECTED state. Then, gNB 101 continues the configuration of the remote UE’s SRB2 and DRB through RRCReconfiguration procedure (as described in the figure 5 for messages 535, 536 and the step 537). As explained above, the gNB 101 may also combine or aggregate the RRCReconfiguration of the remote UE and child or intermediate relay UE(s) into the parent RRCReconfiguration. Once combined or aggregated, the RRCReconfiguration for the root relay UE 111 includes the RRCReconfiguration of all the child and the remote UEs. In a variant, the RRCReconfiguration sent to the root relay UE 111 includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the intermediate Relay UE 112 which also includes a Multi-HopConfigurationCommand which encapsulates the RRCReconfiguration message for the remote UE 113. Each intermediate UE performs its own configuration based on the received RRCReconfiguration message and extract the RRCReconfiguration message embedded in the Multi-HopConfigurationCommand and sends it to its child relay UE or to the remote UE (by the last intermediate relay UE). This allows to decrease the latency of the overall establishment and configuration procedure and save some bandwidth. The above described mechanisms for triggering each of the relay UEs to send a message (e.g. RRCSetupRequest message) requesting the establishment of a connection (e.g. RRC connection) to the network enables connections to the network to be set up for multiple relays so that multi-hop communication can be established. Furthermore, if the relay UEs can be triggered early in the process of setting up multi-hop connections, such as when the triggering information is included in a message for establishing a PC5 connection between the UE (remote or relay UE) and a relay UE next in the multi-hop communication path (e.g. in a Direct Communication Request) such that the requests for establishing a connection to the network can be sent as soon as the PC5 connections are established, latency of the overall process for establishing multi-hop communication can be reduced or minimised. Referring now to figure 7 which is a schematic and simplified diagram illustrating an example of message flows for managing a UE-to-network establishment procedure in a wireless communication system, such as that shown in figure 1. More particularly, these figures illustrate examples of message flows for managing an End-to-End connection establishment between a remote UE and a gNB involving several Relay UEs, in accordance with one or more embodiments of the invention. In the example of the figure, the intermediate relay UE(s) act as UE-to-UE relay UEs (e.g. 112) to connect the remote UE (e.g. 113) with the (root) UE-to-Network relay UE (e.g. 111). The UE-to-Network relay UE (e.g. 111) connecting, in its turn, the remote UE to the gNB. For sake of clarity, this figure depicts only one intermediate relay UE (relay UE 112), however, the multi-hop network establishment procedure could be extended to several intermediate relay UEs. A remote UE, like remote UE 113, wants to establish a communication with the network, like the gNB 101. The remote UE 113 begins a discovery procedure 701 so as to discover the relay UE(s) in its surroundings. The discovery process can follow, for example, the discovery model A or model B such as described in the TS23.304. Briefly, the model A is initiated by the relay UE 112 which sends an announcement message including a list of UEs in its vicinity while the model B is initiated by the remote UE 113 which sends a discovery solicitation message and the relay UE 112 responds with a discovery response message similar to the announcement message of the model A. The discovery could be a new type of discovery dedicated to multi-hop UE-to-Network. The discovery procedure may be the discovery procedure described in GB2406657.3 filed on 10 May 2024 or in GB2406656.5 filed on 10 May 2024, both of which are incorporated herein by reference in its entirety. At the end of the discovery procedure 701, the remote UE 113 has a list of the potential relay UEs around it allowing a connection to the network through one intermediate relay before reaching the root UE-to-Network relay. The remote UE 113 may select one of these relays to establish a PC5 connection in view of reaching a gNB or in other words establishing a connection with the network. Then, the remote UE 113 and the relay UE 112 establish aPC5 connection 710 (ormodify an existing one). The details of the PC5 connection are ignored in this figure 7 and can be found above with respect to the description of figures 5 and 6. At the end of this step 710, the remote UE 113 and relay UE 112 may use the PC5 link to communicate with each other. Meanwhile, the relay UE 112 and the relay UE 111 establish a PC5 connection 720 (or modify an existing one). The details of the PC5 connection are ignored in this figure 7 and can be found above with respect to the description of figures 5 and 6. At the end of this step, the relay UE 112 and relay UE 111 may use the PC5 link to communicate with each other. Then, the relay UE 112 (acting as a UE-to-UE relay) provides two local IDs to each of the remote UE 113 and relay UE 111. The local IDs are delivered via RRCReconfigurationSidelink message. When the local IDs are delivered, an L2 ID of the relay UE 111 is also delivered to the remote UE 113 for making the association between the local ID and the L2 ID of the relay UE 111. In other words, relay UE 112 provides a local ID to both UEs 113 and 111. It also shares the L2 ID of the remote UE 113 with the relay UE 111 and L2 ID of the relay UE 111 with the remote UE 113. This allows the remote UE to make the correspondence between local ID that is used in SRAP configuration with the L2 ID which is used in PC5-S signalling (such as Direct Communication Request, Link Management Request, discovery, etc....). Then, in step 730, the remote UE 113 establishes End-to-End PC5 connection with the UE-to-Network relay 111 via the intermediate relay UE 112. This procedure is similar to the step 710 or 720 but all messages go through the intermediate relay UE 112. More especially, the Direct Communication Request or link modification request, which in this case is sent by the remote UE 113 to the relay UE 111 through the relay UE 112 to establish an End-to-End PC5 connection along the lines discussed above for 510 and 610, may include new parameters (e.g. additional information) besides the ones for the Direct Communication Request message 611 and the link modification request described above with reference to the figures 5 and 6. The Direct Communication Request or link modification request may include all or parts of the following: - RRCcontainer: This information indicates RRC information received from RRC layer. The information may include element(s) to help the root UE-to-Network relay 111 to establish a connection to its serving gNB for the remote UE 113. This container may include part or all the element of RemoteUEInformationSidelink defined in TS38.331. - SetupRequestCommand: This information may be used by the root UE-to-Network relay 111 to transfer the RRCSetupRequest (as defined in TS38.331) command as generated by the remote UE 111 to the gNB to initiate the RRC connection. By including this information, the remote UE 113 gives information helpful for the RRC connection of the remote UE 113 with the gNB 101. This also allows the time to establish the RRC connection to be reduced as well as saving bandwidth normally used to carry this information in subsequent messages (e.g. RRCSetupRequest 741 and RemoteUEInformationSidelink 751). Therefore, messages 741 and 751 could be skipped. The inclusion of the above IE(s) or information in the Direct Communication Request or Link Modification Request message as well as the connectionForMultiHop IE or information about the hop count sent to the relay UE 111 may trigger the root UE-to-Network relay 111 to enter in RRCCONNECTED state so as to forward the SetupRequestCommand to the gNB 101 on behalf of the remote UE 113 without waiting the reception of a message via SRB0 or SRB1, which usually (as defined by the release 17) triggers the relay UE to enter in RRC CO WECTED state if it is not in a connected state. In an example, the RRCcontainer and / or SetupRequestCommand may be included in the PC5 RRC messages exchanged between the remote UE 113 and the relay UE 111, such as for example RRCReconfigurationSidelink, to achieve the same purpose as previously described. Once the End-to-End PC5 connection established, the remote UE 113 sends the RRCSetupRequest message 741 to the gNB 101 through the intermediate relay UE 112 and the last hop to the network is ensured by the root UE-to-Network relay UE 111. If the root UE-to-Network relay 111 is not RRC CONNECTED, upon reception of the RRCSetupRequest message it may initiate the connection with the gNB 101 through the RRC Resume or RRC setup procedures as defined in the TS 38.331. Then, once RRC CONNECTED, the relay UE 111 forwards the RRCSetupRequest 741 from the remote UE 113 to the gNB 101 and also sends the SidelinkUEInformationNR message 752 to request to the gNB 101 for the dedicated configurations required to support the relay operation for the remote UE 113. In one variant, the relay UE 111 may also combine or aggregate the RRCSetupRequests of the remote UE 113 into its own RRCSetupRequest (or similarly in the RRCResumeRequest). In case of the inclusion of RRCRequest command in the Direct Communication Request, the relay UE 111 may include the RRCSetupRequest of the remote UE in its RRCSetupRequest or RRCResume. Based on this aggregated RRCSetupRequest sent to the network by the root relay UE 111, the network (e.g. gNB) sends a response to the relay UE 111 and the remote UE 113 to continue the establishment procedure or sends an aggregated RRCSetup including the configuration of both UEs. The relay UE 111 forwards the message after removing its own configuration. Based on the information provided by the relay UE 111 through the SidelinkUEInformationNR, the gNB 101 configures the relay UE 111, (RLC channels for the SRBO allowing to transmit the RRCSetup message...) and responds with a RRCSetup 742 to the remote UE 113 through the root UE-to-Network relay UE 111 and the intermediate relay UE 112. The information provided to the gNB 101 by the root UE-to-Network relay UE 111 through the SidelinkUEInformationNR are built based on the information carried in the RemoteUEInformationSidelink 751 (which information is typically information about paging, remote UE identity). The SidelinkUEInformationNR may also include all or part of the following information: intermediate relay UE(s) ID list: this information allows the gNB 101 to know the identity of the different intermediate relay UEs; - Hop count: this information is used to perform the QoS split for the different hops. This information could be inferred from the number of ID(s) from the intermediate relay UE(s) ID list which indicates the number of relay UE(s). These information elements or information are used by the gNB 101 to prepare the configuration of the QoS split that should be applied at the different intermediate relay UEs. The information may be gathered by relay UE 111 via the RemoteUEInformationSidelink 751 or through the discovery 701 or the different PC5 establishments 710, 720 and 730. In one aspect, the intermediate relay UE(s) ID list and the Hop count could be supplied by the remote UE 113 to the gNB 101 before the procedure of RRCReconfiguration (761 / 762) between the remote UE 113 and the gNB 101, for example, through the RRCSetupRequest 741 or the RRCSetupComplete 743. Based on this hop count and identity of the relay UEs, the gNB may prepare the QoS split that can be sent to and applied by the different UEs of the list and the remote UE. Then, the gNB 101 completes the configuration of the relay UE 111 and remote UE 113. Based on the configuration supplied by the gNB 101 (SRAP and RLC configuration for SRB1), both UEs 111 and 113 prepare a PC5 Relay RLC channel and relay UE 111 and gNB 101 prepare Uu Relay RLC channel for SRB1 which is used to send RRCSetupComplete, RRCReconfiguration and RRCReconfigurationComplete. Then, the remote UE 113 completes the RRCSetup by sending the RRCSetupComplete message 743 to the gNB 101 though the root UE-to-Network relay UE 111 and the intermediate relay UE 112. The remote UE 113 becomes RRC CONNECTED. Then, gNB 101 sends an RRCReconfiguration message 761 (including SL-SRAP-Config for the remote UE 113 and potentially SL-SRAP-ConfigU2U for the intermediate Relay(s)) to the remote UE 113 via the relay UEs 111 and 112, to setup the end-to-end SRB2 / DRBs of the remote UE 113. In a variant, as the relay 112 acts as both a remote UE and as a relay UE, this RRCReconfiguration message may include a multi-HopUEconfiguration IE including the configuration for the relay part as well as the configuration for the remote part. The remote UE 113 sends an RRCReconfigurationComplete 536 message to the gNB 101 via the root relay UE 111 as a response. In step 537, according to the configuration exchanged through the RRCReconfiguration messages, the gNB and the remote UE 113 prepare PC5 and Uu Relay RLC channel for the SRB2 and DRB. The steps and messages 781, 782 and 785 are used for the QoS split of the different PC5 hops. The remote UE 113 sends to the intermediate relay UE 112 all the QoS profiles for the end-to-end QoS flows via End-to-End QoS info message 781 (e.g. UEInformationRequestSidelink). The intermediate relay UE 112 performs QoS split (mainly for Packet Delay Budget i.e. the maximum acceptable duration for a packet to cross the network from a source to a destination). The relay UE 112 sends the split QoS value via Split QoS info message 782 (e.g. UEInformationResponseSidelink) to the remote UE 113. In case of several intermediate relay UEs, the first intermediate relay performs the QoS split for the first hop and propagates the End-to-End QoS info to its parent relay UE along with the split QoS value resulting from its QoS split i.e. it includes the information carried in the Split QoS info message. The second intermediate relay performs the QoS split for the hop corresponding to the link between its child relay node and itself. In its turn, it propagates the End-to-End QoS info to its parent relay UE along with the split QoS value resulting from its QoS split. The process stops when reaching the root UE-to-Network relay UE 111. In another aspect, the remote UE performs the QoS split for all the intermediate relay UEs and then sends the Split QoS info to the intermediate relay UEs. The QoS split when performed by the remote UE can be assisted or dictated by the gNB. The QoS split configuration is included in the RRCReconfiguration message 771. The QoS split may be performed before the remote UE 113 is RRCCONNECTED (after 730) or as illustrated in the example of the figure 7. If the QoS split is performed before the remote UE is RRCCOXXECTED. the result of the split may be transmitted to the gNB 101 (via SidelinkUEInformationNR 752 or RRCSetupRequest or RRCSetupComplete). The gNB 101 can modify the split and inform the UEs. In that case, the update is done similar to the initial configuration above when dictated by gNB. In step 791, the remote UE 113 (by itself or based on RRCReconfiguration from its serving gNB 101) derives the first hop configuration (e.g. PC5 Relay RLC Channel configuration) for SL-DRB, and provides the intermediate relay UE 112 with the configuration related to receiving on the first hop using per-hop RRCReconfigurationSidelink message. In step 792, the intermediate relay UE 112 (by itself or based on configuration from its serving gNB 101) derives the second hop configuration (e.g. PC5 Relay RLC Channel configuration) for each SL-DRB and provides the root UE-to-Network relay UE with the configuration related to receiving on the second hop (i.e., RX by the peer remote UE), using per-hop RRCReconfigurationSidelink message. While the above description uses an enhanced version of the current Direct Communication procedure, new signalling achieving the same results could be envisioned. For instance, a new Direct Communication for U2N multi-hop procedure with a Direct Communication for U2N multi-hop Request and a Direct Communication for U2N multi-hop Accept (or Reject). The above description uses the terms Direct Communication Request, Direct Communication Accept, Link Modification Request and Link Modification Accept, however, it will be appreciated that these terms can be replaced respectively by the terms Direct Link Establishment Request and Direct Link Establishment Accept, Direct Link Modification Request and Direct Link Modification Accept or any other labels can be used for these messages. It is not intended that the invention is limited to the specifically named messages as described above and could be any messages communicated between the remote UE (or first UE) and other relay UEs (e.g. intermediate or root relay UEs) and / or the network (e.g. base station or gNB) and / or between other relay UEs (e.g. intermediate or root relay UEs) and / or the network (e.g. base station or gNB), which messages include the information described above. While the present invention has been described with reference to embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. It will be appreciated by those skilled in the art that various changes and modification might be made without departing from the scope of the invention, as defined in the appended claims. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does 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 advantageously used. In the preceding embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over, as one or more instructions or code, a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may 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 may 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 may 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 may include a computer-readable medium. By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if 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 5 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 10 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 relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network, the method at a UE of the plurality of UEs including:sending a request to establish a connection between the UE and the network for establishing multi-hop communication between a first UE of the plurality of UEs and the network via at least two relay UEs of the plurality of UEs.

2. The method of claim 1, including:establishing a PC5 connection with a relay UE of the at least two relay UEs,wherein sending the request includes sending the request after the PC5 connection is established with the relay UE.

3. The method of claim 2, wherein establishing a PC5 connection includes:sending, to the relay UE, a request to establish a PC5 connection between the UE and the relay UE and configuration information for configuring the PC5 connection between the UE and the relay UE,receiving, from the relay UE, a response indicating the request has been accepted and configuration at the relay UE has been completed, the PC5 connection between the UE and the relay UE being established after configuration has been completed.

4. The method of any one of claims 1 to 3, including:sending, to a relay UE, a trigger to trigger the relay UE to send a request to establish a connection between the relay UE and the network for establishing multi-hop communication between the first UE and the network via at least two relay UEs, including the relay UE.

5. The method of claim 4, including:receiving, from the relay UE, information indicating the current connection state of the relay UE.

6. The method of claim 5, wherein sending a trigger includes, sending a trigger when the relay UE is determined to be in a non-connected state based on the received information indicating the current connection state of the relay UE.

7. The method of any one of claims 4 to 6, wherein sending a trigger includes sending, to the relay UE, a message including information for triggering the relay UE to request establishment of a connection to the network.

8. The method of claim 7, wherein the information includes at least one of:information for indicating the connection to be established is a multi-hop connection for use in multi-hop communication;information for indicating the number of hops from the first UE to the UE;information for identifying the network.

9. The method of claim 7 or claim 8, wherein the message is a RRC or a PC5 message.

10. The method of any one of the claims 7 to 9, wherein the message is one of:a message for requesting establishment of a PC5 connection between the UE and the relay UE;a message including configuration information for configuring the PC5 connection between the UE and the relay UE;RemoteUEInformationSidelink message;Link Modification Request message.

11. The method of any one of the preceding claims, including:in the case where the UE is the first UE, after sending the request for establishing a connection to the network, starting a timer set with a value of a time period for connection failure determination for multi-hop.

12. The method of any one of claims 1 to 10, including:in the case where the UE is a relay UE, updating a value of a time period for connection failure determination for multi-hop based on information indicating a number of hops from the first UE to the relay UE and on information indicating a maximum number of hops between the first UE and a root relay UE of the at least two relay UEs connected or to be connected to the network for establishing multi-hop communication;after sending, by the relay UE, the request for establishing a connection to the network, starting a timer set with the updated value of the time period for connection failure determination for multi-hop.

13. The method of claim 12, wherein the information indicating a number of hops from the first UE to the relay UE and the information indicating a maximum number of hops is provided to the relay during discovery or during establishing a PC5 connection to the relay UE.

14. The method of claim 12 or claim 13, including receiving a message including informationindicating the value of the time period for connection failure determination for multi-hop.

15. The method of claim 12 or claim 13, wherein the value of the time period for connection failure determination for multi-hop is pre-configured at the UE.

16. The method of any one of claims 11 to 15, wherein the value of the time period for connection failure determination for multi-hop is greater than a value of a time period for connection failure determination for one hop.

17. The method of any one of claims 11 to 16, including stopping the timer after receiving, from the network configuration information for configuring the UE for connection to the network to support multi-hop relay communication between the first UE and the network.

18. The method of any one of claims 11 to 16, including:after expiry of the time period which indicates to the UE a connection failure to a relay UE, initiating the establishment of a connection to another relay UE.

19. The method of claim 18, including:in the case where the UE is a relay UE, sending a notification indicating the connection failure, the notification including an identifier of a root relay UE of the at least two relay UEs, the root relay UE being connected or to be connected to the network for establishing multi-hop communication between the first UE and the network.

20. The method of claim 2 or any one of claims 3 to 11, 16 to 19 when dependent on claim 2, wherein establishing a PC5 connection in the case the UE is the first UE includes:sending, to the relay UE, a request to establish a PC5 connection between the first UE and the relay UE and configuration information for configuring the PC5 connection between the first UE and the relay UE,receiving, at the first UE from the relay UE, a response indicating the request has been accepted and configuration at the relay UE has been completed, the PC5 connection between the first UE and the relay UE being established after configuration has been completed.

21. The method of claim 20, wherein in the case where a PC5 connection is established between the first UE and the relay UE, sending a request to establish a connection between the UE and the network includes: sending, by the first UE to the relay UE, the request to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network via the relay UE.

22. The method of claim 2 or any one of claims 3 to 10, 12 to 19 when dependent on claim 2, wherein establishing a PC5 connection in the case the UE is another relay UE of the at least two relay UEs between the first UE and the relay UE includes:sending, by the other relay UE to the relay UE, a request to establish a PC5 connection between the other relay UE and the relay UE and configuration information for configuring the PC5 connection between the other relay UE and the relay UE,receiving, at the other relay UE from the relay UE, a response indicating the request has been accepted and configuration at the relay UE has been completed, the PC5 connection between the other relay UE and the relay UE being established after configuration has been completed.

23. The method of claim 22, wherein in the case where a PC5 connection is established between the other relay UE and the relay UE, sending a request to establish a connection between the UE and the network includes: sending, by the other relay UE to the relay UE, the request to establish a connection between the other relay UE and the network for establishing multi-hop communication between the first UE and the network via the other relay UE and the relay UE.

24. The method of claim 23, including:in the case where a PC5 connection is established between the first UE and the other relay UE, receiving, from the first UE, a request to establish a connection between the first UEand the network for establishing multi-hop communication between the first UE and the network via the other relay UE; andin the case wherein a PC5 connection is established between the other relay UE and the relay UE, forwarding, to the network via the relay UE, the request received, from the first UE, to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network via the other relay UE and the relay UE.

25. The method of claim 1, wherein in the case the UE is a root relay UE of the at least two relay UEs to be connected to the network, sending a request to establish a connection between the UE and the network includes: sending, by the root relay UE to the network, the request to establish a connection between the root relay UE and the network for establishing multi-hop communication between the first UE and the network via the root relay UE.

26. The method of claim 25, including:receiving, from another relay UE of the at least two relay UEs, a request to establish a PC5 connection between the other relay UE and the root relay UE and configuration information for configuring the PC5 connection between the other relay UE and the root relay UE,sending, by the root relay UE to the other relay UE, a response indicating the request has been accepted and configuration at the root relay UE has been completed, the PC5 connection between the other relay UE and the root relay UE being established after configuration has been completed.

27. The method of claim 25 or claim 26, wherein sending, by the root relay UE to the network, the request to establish a connection between the root relay UE and the network, includes sending, by the root relay UE to the network, the request to establish a connection between the root relay UE and the network, after receiving a trigger from the other relay UE.

28. The method of claim 26 or claim 27, including:in the case where a PC5 connection is established between the root relay UE and the other relay UE, receiving, via the other relay UE, a request, from the first UE, to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network; andin the case where a connection is established between the root relay UE and the network UE, forwarding, to the network, the request, from the first UE, to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network via the other relay UE and the root relay UE.

29. The method of any one of the preceding claims, including:in the case where the UE is a relay UE of the at least two relay UEs, sending, to the network, information associated with at least the relay UE of the at least two relay UEs for use by the network to configure the at least two relay UEs and first UE to support multi-hop relay communication between the first UE and the network.

30. The method of any one of the preceding claims, including:receiving, at the UE from the network, configuration information for configuring the UE for connection to the network to support multi-hop relay communication between the first UE and the network.

31. The method of claim 30 wherein, in the case where the UE is a root relay UE of the at least two relay UEs, the configuration information includes information for configuring another relay UE and a first UE for connection to the network to support multi-hop relay communication between the first UE and the network.

32. The method of claim 31, further comprising sending to the other relay UE the configuration information that includes information for configuring the another relay UE and a first UE for connection to the network to support multi-hop relay communication between the first UE and the network.

33. The method of claim 30 wherein, in the case where the UE is another relay UE of the at least two relay UEs, t the configuration information includes information for configuring a first UE for connection to the network to support multi-hop relay communication between the first UE and the network.

34. The method of claim 33, further comprising sending to the first UE the configuration information for configuring the first UE for connection to the network to support multi-hop relay communication between the first UE and the network.

35. The method of any of claims 30 to 33 wherein, in the case where the UE is another relay UE of the at least two relay UEs, the configuration information includes information for configuring the relay UE for communication with the network and configuration information for configuring the relay UE for communication with another relay UE or a first UE.

36. The method of any of claims 30 to 35, wherein the configuration information includes RLC channel information for configuring at least one of a first signalling radio bearer, a second signalling radio bearer and a data radio bearer.

37. The method of any of claims 30 to 36, including: after configuration is completed at the UE, sending a message to the network indicating configuration has been completed.

38. The method of claim 37, wherein in the case the UE is the first UE, sending a message to the network includes sending a message to the network indicating configuration of the signalling radio bearers and data radio bearers has been completed and indicating a connection between the UE and the network for multi-hop communication between the first UE and the network has been established.

39. A method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network, the method at a first UE of the plurality of UEs including: sending a request to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network via at least two relay UEs of the plurality of UEs.

40. The method of claim 39, including:establishing a PC5 connection with a first relay UE of the at least two relay UEs.

41. The method of claim 39 or claim 40, including:establishing an End-to-End PC5 connection between the first UE and a root relay UE of the at least two relay UEs via at least a first relay UE of the at least two relay UEs, the root relay UE being a relay UE of the at least two relay UEs connected or to be connected to the network,wherein sending the request includes sending the request after the End-to-End PC 5 connection is established with the root relay UE.

42. The method of claim 40 or claim 41, including:receiving identification information for identifying each of the at least two relay UEs, including identification information for at least the first relay UE, and identification information for a root relay UE of the at least two relay UEs, the root relay UE being a relay UE of the at least two relay UEs connected or to be connected to the network.

43. The method of claim 41, wherein establishing an End-to-End PC5 connection includes:sending, by the first UE to the root relay UE via at least the first relay UE, a message for establishing the End-to-End PC5 connection.

44. The method of claim 43, wherein the message includes information for use in establishing a connection between the first UE and the network.

45. The method of claim 44, wherein the message includes information to trigger the root relay UE to request establishment of a connection to the network.

46. The method of claim 45, wherein the information includes at least one of:information for indicating the connection to be established is a multi-hop connection for use in multi-hop communication;information for indicating the number of hops from the first UE to the root relay UE; information for identifying the network.

47. The method of any one of the claims 39 to 46, including:sending, to the network, information associated with the first UE for use by the network to configure the at least two relay UEs and first UE to support multi-hop relay communication between the first UE and the network.

48. The method of any one of claims 39 to 47, including:receiving, at the first UE from the network, configuration information for configuring the first UE for connection to the network to support multi-hop relay communication between the first UE and the network.

49. The method of claim 48, wherein the information includes RLC channel information for configuring at least one of a first signalling radio bearer, a second signalling radio bearer and a data radio bearer.

50. The method of claim 48 or claim 49, including: after configuration is completed at the UE, sending at least one message to the network indicating configuration has been completed.

51. A method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network, the method at a relay UE of the plurality of UEs including:sending, by the relay UE to the network, a request to establish a connection between the relay UE and the network for establishing multi-hop communication between a first UE of the plurality of UEs and the network via at least two relay UEs, including the relay UE which is a root relay UE to be connected to the network.

52. The method of claim 51, including:establishing a PC5 connection with another relay UE of the at least two relay UEs.

53. The method of claim 52, including:establishing an End-to-End PC5 connection between the first UE and the root relay UE of the at least two relay UEs via at least the other relay UE of the at least two relay UEs,wherein sending the request includes sending the request after the End-to-End PC5 connection is established with the first UE.

54. The method of claim 52 or claim 53, includingin the case where a PC5 connection is established between the root relay UE and the other relay UE, receiving, via the other relay UE, a request, from the first UE, to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network; andin the case where a connection is established between the root relay UE and the network UE, forwarding, to the network, the request, from the first UE, to establish a connection between the first UE and the network for establishing multi-hop communication between the first UE and the network via the other relay UE and the root relay UE.

55. The method of any one of claims 49 to 52, wherein sending, by the root relay UE to the network, the request to establish a connection between the root relay UE and the network, includes sending, by the root relay UE to the network, the request to establish a connection between the root relay UE and the network, after receiving a trigger at the root relay UE from another relay UE of the at least two relay UEs.

56. The method of claim 55, wherein receiving a trigger includes receiving a message including information for triggering the root relay UE to request establishment of a connection to the network.

57. The method of claim 56, wherein the information includes at least one of:information for indicating the connection to be established is a multi-hop connection for use in multi-hop communication;information for indicating the number of hops from the first UE to the UE; information for identifying the network.

58. The method of claim 56 or claim 57, wherein the message is one of:a message for requesting establishment of a PC5 connection between the root relay UE and the other relay UE;a message for requesting establishment of a connection between the first UE and the network via the at least two relay UEs, the at least two relay UEs including the root relay UE and at least the other relay UE;Link Modification Request message.

59. The method of any one of the claims 51 to 58, including, in the case where a PC5 connection is established between the root relay UE and another relay UE of the at least two relay UEs:receiving, from the other relay UE, information associated with the other relay UE and in the case where there are three or more relay UEs, information associated with all the relay UEs other than the root relay UE;after updating the information to include information associated with the root relay UE, sending the updated information to the network for use by the network to configure the threeor more relay UEs and first UE to support multi-hop relay communication between the first UE and the network.

60. The method of any one of claims 51 to 59, including:receiving, at the root relay UE from the network, configuration information for configuring the root relay UE for connection to the network to support multi-hop relay communication between the first UE and the network.

61. The method of claim 60, wherein the information includes RLC channel information for configuring at least one of a first signalling radio bearer, a second signalling radio bearer and a data radio bearer.

62. A method for managing relay communication in a wireless communication system supporting relaying, the wireless communication system comprising a plurality of User Equipment, UEs, and a network including a base station, the method at the base station including:establishing multi-hop communication between a first UE of the plurality of UEs and the network via at least two relay UEs.

63. The method of claim 62, including sending a message including information indicating a value of the time period for connection failure determination for multi-hop.

64. The method of claim 62 or claim 63, including sending to a relay UE a configuration message including configuration information for configuring another relay UE and / or a first UE for connection to the network to support multi-hop relay communication between the first UE and the network.

65. The method of claim 62, including sending to a relay UE a configuration message including configuration information for configuring the relay UE for communication with the network and for communication with another relay UE or a first UE.

66. A computer program comprising instructions which, when the program is executed by one or more processing units, cause the one or more processing units to carry out the method according to any one of claims 1 to 65.

67. A computer-readable medium carrying a computer program according to claim 66.

68. Apparatus for a User Equipment, UE, for a wireless communication system supporting5 relaying between a UE and a network, the apparatus comprising:one or more processing units and configured to perform the method as recited in any one of claims 1 to 61.

69. Apparatus for a base station, for a network of a wireless communication system 10 supporting relaying between a UE and the network, the apparatus comprising:one or more processing units configured to perform the method as recited in any one of claims 62 to 65.

Images