Method, apparatus and system for coordinated multi-relay link wireless communication and UE cooperation

Abstract

One embodiment of coordinated multi-relay link wireless communication and user equipment (UE) cooperation includes: coordinating the configuration of a secondary relay link between the UE and a wireless communication network with a primary relay link between the UE and the wireless communication network; transmitting signaling to enable the secondary relay link to be configured according to the coordination. After the primary relay link and the secondary relay link are configured, communication with the UE is coordinated through the primary relay link and the secondary relay link. Other embodiments may include a first relay link and a second relay link of the UE, and these relay links of the UE may be between the UE and a wireless communication network, or in the case of a UE-to-UE relay link, between the UE and another UE.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 932,211, filed on November 7, 2019, entitled "METHODS, APPARATUS, AND SYSTEMS FOR COORDINATED MULTIPLE RELAY LINK WIRELESS COMMUNICATION WITH UE COOPERATION", and U.S. Application No. 17 / 087,733, filed on November 3, 2020, entitled "METHODS, APPARATUS, AND SYSTEMS FOR COORDINATED MULTIPLE RELAY LINK WIRELESS COMMUNICATION WITH UE COOPERATION", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application generally relates to communications in a wireless communication network, and more particularly to communications including multiple coordinated relay links and user equipment (UE) cooperation. Background Art

[0004] In Long Term Evolution (LTE), device - to - device (D2D) technology for UEs to communicate directly with each other has been studied and specified. The research focus of LTE D2D has mainly been on the communication between D2D devices. For the New Radio (NR) vehicle - to - anything (V2X) scenario, D2D - related research has focused on the "Uu link" transmission between the gNodeB (gNB) and the UE, as well as the sidelink (SL) transmission between UEs.

[0005] UE cooperation is a communication technology that focuses on the cooperation process among UEs in a group of UEs. UE cooperation can be used to enhance the throughput, coverage, and capacity of the system, and can improve communication latency and increase reliability. UE cooperation can be beneficial for scenarios such as V2X, as well as other scenarios such as enhanced mobile broadband (eMBB) and ultra-reliable low latency communication (URLLC).

[0006] UE cooperation can be achieved by a group of UEs helping each other using Uu link transmission and / or sidelink transmission. UE cooperation includes the interaction among UEs in the group for sending and receiving.

[0007] Relay is another technology related to the above scenarios and is widely used to improve the coverage of the radio access network. Relay nodes are mainly deployed by operators at fixed sites. "UE relay" provides a more flexible alternative. There are different types of UE relays, including Layer 2 (L2) relay and Layer 3 (L3) relay. Some current mobile relay technologies are only used to meet emergency needs such as basic public safety, where the data rate is low and the latency requirement is not very high.

[0008] There is a desire to adopt other relay-based technologies that are more generally suitable for various scenarios or applications and potentially improve the performance of communication systems. Summary of the Invention

[0009] Supporting multiple relay links and the coordination or cooperation between these links may be feasible for purposes such as improving the system performance of emerging and important applications in terms of latency or throughput. Technologies related to coordinating among relay UEs or more generally among multiple relay links to improve relay link and system performance are rare, especially for usage scenarios or scenarios such as in-coverage scenarios and out-of-coverage scenarios.

[0010] One aspect of the present disclosure relates to a method, the method including: coordinating the configuration of a second relay link of a UE with a first relay link of the UE in a wireless communication network; transmitting signaling to enable the second relay link to be configured according to the coordination.

[0011] An apparatus according to another aspect of the present disclosure includes: a communication interface; a processor coupled to the communication interface; and a non-transitory computer-readable storage medium coupled to the processor and storing a program for execution by the processor. The program includes instructions for performing a method comprising: coordinating a configuration of a second relay link of a UE with a first relay link of the UE in a wireless communication network; and transmitting signaling to enable configuring the second relay link according to the coordination.

[0012] Such a computer-readable storage medium may be provided in the apparatus as described above, or a computer program product may include a non-transitory computer-readable storage medium storing the program. In one embodiment, the program includes instructions for performing a method comprising: coordinating a configuration of a second relay link of a UE with a first relay link of the UE in a wireless communication network; and transmitting signaling to enable configuring the second relay link according to the coordination.

[0013] Another method disclosed herein includes: configuring a first relay link and a second relay link for a UE in a wireless communication network; and coordinating communication with the UE via the first relay link and the second relay link.

[0014] Yet another method includes: a component participating in a first relay link of a remote UE in a wireless communication network receiving signaling indicating measurements performed by a first UE on a direct wireless communication link between the first UE and a second UE; and determining, based on the received signaling, whether a second relay link of the remote UE should be established via the direct wireless communication link.

[0015] A method is also disclosed, the method including: configuring a first relay link to transmit data and control information and / or feedback information with a UE in a wireless communication network; configuring a second relay link to transmit data with the UE. This method may also include: reconfiguring the second relay link to transmit data and control information and / or feedback information with the UE, and reconfiguring the first relay link to transmit data with the UE, according to a relay link role switching condition.

[0016] The present disclosure also partly relates to a method, the method including: coordinating a configuration of a secondary relay link between a UE and a wireless communication network with a primary relay link between the UE and the wireless communication network; and transmitting signaling to enable configuring the secondary relay link according to the coordination.

[0017] Another aspect of the present disclosure relates to a method, the method including: configuring a primary relay link and a secondary relay link between a UE and a wireless communication network; and coordinating communication with the UE via the primary relay link and the secondary relay link.

[0018] A method may include: components participating in a primary relay link between a remote UE and a wireless communication network receive signaling indicating measurements performed by a first UE on a direct wireless communication link between the first UE and a second UE; and based on the received signaling, determine whether a secondary relay link between the remote UE and the wireless communication network should be established via the direct wireless communication link.

[0019] Another aspect of the present disclosure relates to a method, the method including: configuring a primary relay link to carry data, control information, and / or feedback information between a UE and a wireless communication network; configuring a secondary relay link to carry data between the UE and the wireless communication network; and based on a relay link role switching condition, reconfiguring the secondary relay link to carry data, control information, and / or feedback information between the UE and the wireless communication network, and reconfiguring the primary relay link to carry data between the UE and the wireless communication network.

[0020] An apparatus according to another aspect of the present disclosure includes: a communication interface; a processor coupled to the communication interface; and a non-transitory computer-readable storage medium coupled to the processor and storing a program for execution by the processor, the program including instructions for performing the methods disclosed herein.

[0021] According to another aspect, a computer program product includes a non-transitory computer-readable storage medium storing a program, the program including instructions for performing the methods disclosed herein.

[0022] Other aspects and features of embodiments of the present disclosure will become apparent to those of ordinary skill in the art in conjunction with the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more fully understand the current embodiments and their advantages, reference is now made, by way of example, to the following description in conjunction with the accompanying drawings, in which:

[0024] Figure 1 An exemplary communication system implementing aspects of the present disclosure in some embodiments is shown;

[0025] Figure 2 is a block diagram of another exemplary communication system showing multiple relay links;

[0026] Figure 3 is a block diagram of another exemplary communication system showing another multi-relay link scenario;

[0027] Figure 4 and Figure 5 is a block diagram of a further exemplary communication system showing additional multi-relay link scenarios;

[0028] Figure 6 and Figure 7A is a block diagram of a further exemplary communication system showing an additional multi-relay link scenario including a "help" remote UE;

[0029] Figure 7B is a block diagram of another exemplary communication system showing a multi-hop UE-to-UE relay link;

[0030] Figure 8 is a flowchart of a method according to an embodiment;

[0031] Figure 9 is a flowchart of a method according to another embodiment;

[0032] Figure 10 is similar to Figure 2 but is a block diagram of another exemplary communication system with an added multi-relay link scenario for helping a remote UE;

[0033] Figure 11 shows examples of cyclic redundancy check (CRC) scrambling of downlink control information (DCI), scrambling of coded bits of DCI, and generation of demodulation reference signals (DMRS) for a physical downlink control channel (PDCCH);

[0034] Figure 12 shows examples of CRC scrambling of a physical downlink shared channel (PDSCH), scrambling of coded bits of the PDSCH, and generation of PDSCH DMRS;

[0035] Figure 13 is a signal flow diagram of an example of sidelink scheduling and transmission procedures according to an embodiment;

[0036] Figure 14 is a block diagram of an exemplary data splitting option for relay link coordination;

[0037] Figure 15 is a signal flow diagram of an example for configuring a relay link and a discovery process;

[0038] Figure 16 is a signal flow diagram of an example for configuring another relay link and relay link transmission;

[0039] Figure 17A andFigure 17B is a block diagram of an exemplary apparatus that can implement the methods and teachings of the present disclosure;

[0040] Figure 18 is a block diagram of an example of a communication network according to one embodiment;

[0041] Figure 19 is a block diagram of an example of a network serving two UEs. DETAILED DESCRIPTION

[0042] As described above, supporting multiple relay links and coordination or cooperation between these links may be feasible for purposes such as improving system performance in terms of latency or throughput for emerging and important applications. Examples of new use cases include those for industrial manufacturing or for providing enhanced public safety video surveillance and feedback for public authorities such as firefighters or police. These use cases or other use cases may require higher data throughput, e.g., at the level of dozens of megabits per second (Mbps), and low latency, e.g., on the order of milliseconds (ms), which cannot be met by current UE relay link designs. In relay link cooperation as disclosed herein, multiple relay links coordinate or cooperate, and thus can provide a feasible solution and meet the requirements of higher throughput and lower latency.

[0043] The present disclosure addresses several problems, including multi-relay link configuration for in-coverage and out-of-coverage remote UEs, relay link establishment procedures, adaptation between single-relay link and multi-relay link cooperation, and various aspects of relay link cooperation such as scheduling, scrambling, transmission, data splitting, data aggregation, and general relay link cooperation data streams.

[0044] Multi - relay link coordination according to some embodiments disclosed herein includes the configuration of one relay link, also referred to herein as the primary relay link or major relay link (MRL) or the first relay link, and at least one other relay link, also referred to herein as the secondary relay link (SRL) or the second relay link. In some embodiments, the relay links have different roles, and the naming of MRL and SRL is used herein for ease of reference to relay links with different roles. For example, in some embodiments, the MRL carries more information, such as control and feedback, than the SRL, while both the MRL and SRL carry data. The roles of the MRL and SRL can be switched or updated between any of the multiple relay links under any of various conditions. Features disclosed herein in the context of the MRL or SRL can apply to the first relay link and the second relay link, which may (or may not) be referred to as the primary or major relay link and the secondary relay link. The same applies to components of such relay links, such as including primary, major, or secondary relay UEs.

[0045] There are different ways to establish multiple relay links and configure their cooperation. For example, the first relay link or MRL through one or more relay UEs (also referred to herein as the main relay UE (MRU)) can be established first and then used to add one or more second relay links or SRLs through signaling from the MRU to enable one or more UEs (which may include remote UEs and / or other relay UEs) to send discovery signals and feedback measurements. In another embodiment, one or more UEs send discovery signals and cause other UEs to perform measurements and report the measurements. One or more of the remote UE, MRU, and gNB can negotiate with other remote UEs and / or other relay UEs to establish the SRL. In some embodiments, the configuration of the SRL includes the gNB, but there may also be other embodiments for configuration.

[0046] Different options for switching between single - relay - link transmission and multi - relay - link cooperation are described, including semi - static configuration and dynamic signaling. This type of switching can be useful, for example, in providing flexibility to accommodate different requirements between robustness and performance.

[0047] These and other features are described in further detail herein.

[0048] First, refer to Figure 1, which shows an exemplary communication system 100 that implements aspects of the present disclosure in some embodiments. Generally, system 100 enables multiple wireless or wired elements to transmit data and / or other content. System 100 is designed to provide content (e.g., any one or more of voice, data, video, text, collectively referred to herein as "data") via broadcast, unicast, multicast, user equipment to user equipment, etc. System 100 can operate efficiently by sharing communication resources such as bandwidth.

[0049] In this example, communication system 100 includes electronic devices (EDs) 110a to 110c, radio access networks (RANs) 120a and 120b, a core network 130, a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160. Although Figure 1 a certain number of these components or elements are shown, any reasonable number of these components or elements may be included in system 100.

[0050] EDs 110a to 110c are used to operate and / or communicate in system 100. For example, EDs 110a to 110c are used to transmit and / or receive via wireless communication channels. Each of EDs 110a to 110c represents any suitable end-user device for wireless operation and may include the following devices (or may be referred to as): UE, wireless transmit / receive unit (WTRU), mobile station, mobile subscriber unit, cellular phone, station (STA), machine type communication (MTC) device, personal digital assistant (PDA), smartphone, laptop computer, computer, touchpad, wireless sensor, or consumer electronic device.

[0051] In Figure 1In [the figure], RANs 120a and 120b respectively include base stations 170a and 170b. Each of base stations 170a and 170b is used for wireless connection with one or more of EDs 110a to 110c to enable access to any other base stations 170a and 170b, core network 130, PSTN 140, Internet 150, and / or other networks 160. For example, base stations 170a and 170b may include or may be one or more of several known devices, such as a base transceiver station (BTS), Node-B, evolved NodeB (eNodeB), home eNodeB, next generation NodeB (gNB), transmission point (TP), transmission reception point (TRP), site controller, access point (AP), or wireless router. Any of EDs 110a to 110c may alternatively or jointly be used for connection to, access to, or communication with any other base stations 170a and 170b, Internet 150, core network 130, PSTN 140, other networks 160, or any combination of the above. Optionally, the system may include a RAN, such as RAN 120b, where the corresponding base station 170b accesses the core network 130 via the Internet 150, as shown in the figure.

[0052] EDs 110a - 110c and base stations 170a - 170b are examples of communication devices that may be used to implement some or all of the functions or embodiments described herein. In Figure 1In the illustrated embodiment, base station 170a forms part of RAN 120a, which may include other base stations, a base station controller (BSC), a radio network controller (RNC), relay nodes, elements, and / or devices. Either base station 170a or 170b may be a single element, as shown, or may be multiple elements distributed within the corresponding RAN, and so on. In addition, base station 170b forms part of RAN 120b, which may include other base stations, elements, and / or devices. Each of base stations 170a and 170b may be used to transmit and / or receive wireless signals within a particular geographical area (sometimes referred to as a coverage area). A cell may be further divided into cell sectors, and base stations 170a and 170b, for example, may employ multiple transceivers to serve multiple sectors. In some embodiments, base stations 170a - 170b may be implemented as pico nodes or femto nodes, where the radio access technology supports pico nodes or femto nodes. In some embodiments, MIMO technology may be employed, with multiple transceivers in each coverage area. The number of RANs 120a and 120b shown is merely exemplary. Any number of RANs may be considered when designing system 100.

[0053] Base stations 170a and 170b communicate with one or more of EDs 110a - 110c via one or more air interfaces 190 using wireless communication links such as RF, microwave, IR, etc. The air interface 190 may use any suitable radio access technology. For example, system 100 may implement one or more channel access methods in air interface 190, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single - carrier FDMA (SC - FDMA).

[0054] Base stations 170a and 170b may implement Universal Mobile Telecommunication System (UMTS) Universal Terrestrial Radio Access (UTRA) to establish an air interface 190 using Wideband CDMA (WCDMA). In this case, base stations 170a and 170b may implement protocols such as HSPA, HSPA+, where HSPA+ optionally includes HSDPA and / or HSUPA. Alternatively, base stations 170a and 170b may establish an air interface 190 with Evolved UMTS Terrestrial Radio Access (E-UTRA) using LTE, LTE-A, and / or LTE-B. It may be considered that system 100 may use multi-channel access capabilities, including the scenarios described above. Other wireless technologies for implementing the air interface include IEEE 802.11, 802.15, 802.16, CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, IS-2000, IS-95, IS-856, GSM, EDGE, and GERAN. Of course, other multiple access schemes and wireless protocols may also be used.

[0055] RANs 120a and 120b communicate with the core network 130 to provide various services to the EDs 110a to 110c, such as voice, data, and other services. It is understood that RANs 120a and 120b and / or the core network 130 may communicate directly or indirectly with one or more other RANs (not shown), which may or may not be directly served by the core network 130 and may or may not employ the same radio access technology as RAN 120a, RAN 120b, or both. The core network 130 may also serve as a gateway access between (i) RANs 120a and 120b, or EDs 110a to 110c, or both and (ii) other networks such as the PSTN 140, the Internet 150, and other networks 160. In addition, some or all of the EDs 110a to 110c may include functionality to communicate with different wireless networks over different wireless links using different wireless technologies and / or protocols. The PSTN 140 may include a circuit-switched telephone network for providing plain old telephone service (POTS). The Internet 150 may include a computer network, a subnet (intranet), or both and incorporate protocols such as IP, TCP, UDP. The EDs 110a to 110c may be multimode devices capable of operating according to multiple radio access technologies and include multiple transceivers required to support these technologies.

[0056] It is contemplated that Figure 1 The illustrated communication system 100 may support NR cells, also referred to as hypercells. Each NR cell includes one or more base stations. The base stations of an NR cell may use the same NR cell ID. The NR cell ID is a logical assignment for all physical base stations in the NR cell and may be carried in a broadcast synchronization signal. The NR cells may be dynamically configured. The boundaries of the NR cells may be flexible, and the system may dynamically add base stations to or remove base stations from the NR cells.

[0057] In one embodiment, an NR cell may have one or more base stations within the NR cell that transmit UE-specific data channels for serving the UE. The one or more base stations associated with the UE-specific data channels are also UE-specific and are transparent to the UE. Multiple parallel data channels may be supported within a single NR cell, e.g., each data channel serving a different UE.

[0058] Direct communication between UEs (such as Figure 1 the EDs 110a to 110c) is also possible and in Figure 1It is represented by a dashed line in the figure. In some embodiments, as will be described in further detail hereinafter, UEs communicate with each other via sidelinks to implement multiple relay links for UE cooperation and coordination.

[0059] A relay link technology that can be used to improve wireless communication network coverage, for example, at the cell edge or indoors, includes relaying data of a remote UE by a relay UE. In an uplink operation where the data originates from a remote UE and the destination is a network device, the remote UE can be referred to as a source UE (SUE). Another uplink technology is to share the data of the SUE to a cooperative UE (CUE) via a sidelink between the SUE and the CUE, and then perform joint transmission on the uplink via the Uu link and the sidelink to improve system throughput. For different scenarios, each of these technologies can assist the SUE. For example, if the SUE is in a coverage blind area and does not have a large amount of data to send, the relay UE can assist the SUE. In another case, if the SUE has a large amount of data to send and the SUE can find a nearby CUE, the SUE can share some data with the CUE via the sidelink, and both the CUE and the SUE can perform joint uplink transmission. Therefore, it may be beneficial to support these two types of uplink UE cooperation and support adaptation between these two types. The CUE can be configured in different uplink cooperation modes, including a relay mode and a joint transmission mode. In addition, these two technologies can also be used together to achieve certain goals.

[0060] This disclosure mainly focuses on multi-relay link applications, where the relay UE assists the remote UE in some way. Although mainly referred to as "relay UE" herein, the relay UE can also be referred to as CUE here and elsewhere. A relay link refers to a link that includes at least one intermediate component (including at least one relay UE). The relay link enables communication between a communication network and a remote UE, and the remote UE can be within the network coverage or not.

[0061] Figure 2 is a block diagram of another exemplary communication system showing multiple relay links. The exemplary system 200 includes a network device 202 and UEs, which include relay UEs 204, 208 and a remote UE 206. The communication between the UEs 204, 208 and the network device 202 is via Figure 2 an interface shown as "Uu" 210 in the figure, while the direct sidelink communication between each of the relay UEs 204, 208 and the remote UE 206 is via sidelinks 212, 214. Examples of these components and implementation options for communication between these components are provided elsewhere in this document. The network device 202 can be a network device, such as Figure 1the base stations 170a, 170b therein. The UE can be, for example, Figure 1 the EDs 110a to 110c therein.

[0062] Figure 2 represents a scenario where relay UE coordination or cooperation may be useful. In this scenario, the remote UE 206 is "out of coverage" (outside the geographical area for direct communication with network devices), and the relay UEs 204, 208 are within the coverage of the network device. There are two relay links, each relay link including a Uu segment between the network device 202 and the relay UEs 204, 208, and a sidelink segment between each relay UE 204, 208 and the remote UE 206.

[0063] Figure 3 is a block diagram of another exemplary communication system showing another multi-relay link scenario. In Example 300, the difference from Example 200 is that Figure 3 the remote UE 206 therein is within coverage. However, in Example 300, there are still two relay links, each relay link including a Uu segment between the network device 202 and the relay UEs 204, 208, and a sidelink segment between each relay UE 204, 208 and the remote UE 206.

[0064] Regardless of whether the remote UE 206 is out of coverage as shown in Figure 2 or within coverage as shown in Figure 3 For downlink (DL) transmission, it can include the network device 202 (exemplarily a gNB) sending data to multiple relay UEs 204, 208 on the Uu link 210, and the relay UEs cooperatively relaying the data from the gNB to the remote UE 206 on the sidelink 212, 214. For uplink (UL) transmission, the remote UE 206 sends data to multiple relay UEs 204, 208 on the sidelink 212, 214. Then, each relay UE 204, 208 cooperatively relays the data from the remote UE 206 to the gNB 202 on the Uu link 210.

[0065] The relay link does not necessarily include Figure 2 and Figure 3 the same network device 202 as shown. Figure 4 and Figure 5 are block diagrams of further exemplary communication systems showing additional multi-relay link scenarios, where each relay UE 204, 208 communicates with different network devices 202, 402 (for example, different TRPs) via Uu links 210, 410. In other aspects, Figure 4 and Figure 5 are respectively similar toFigure 2 and Figure 3 In Examples 400 and 500, there are two relay links, and each relay link includes a Uu segment 210, 410 between the network devices 202, 402 and the relay UEs 204, 208, and a sidelink segment between each relay UE 204, 208 and the remote UE 206. Downlink transmission may include the network devices 202, 402 (exemplarily different TRPs) sending data to multiple relay UEs 204, 208 on the Uu links 210, 410, and the relay UEs cooperatively relaying the data to the remote UE 206 on the sidelinks 212, 214. Uplink transmission may include the remote UE 206 sending data to multiple relay UEs 204, 208 on the sidelinks 212, 214, and the relay UEs cooperatively relaying the data to the TRPs 202, 402 on the Uu links 210, 410.

[0066] Figure 6 and Figure 7A is a block diagram of a further exemplary communication system showing additional multi-relay link scenarios, which scenarios include yet another UE for assisting a remote UE in multi-relay link communication. These assisting UEs may be based on another remote UE or another relay UE; thus, they may be referred to as "helper" remote UEs, helper relay UEs, secondary relay UEs, or some other variant.

[0067] Example 600 includes multiple out-of-coverage remote UEs 206, 602 and in-coverage relay UEs 208. In this example, two relay links are provided for the remote UE 206: a relay link via the sidelink 214, and a relay link via the sidelinks 612, 616 (which are via a "helper" remote UE 602). For downlink transmission, in one embodiment, the network device 202 (exemplarily a gNB) sends data to the in-coverage relay UE 208 on the Uu link 210, the relay UE broadcasts or otherwise relays the data from the gNB to the out-of-coverage remote UEs 206, 602 on the sidelinks 214, 616, and the out-of-coverage helper remote UE 602 relays the data to the out-of-coverage destination remote UE 206 on the sidelink 612. In one embodiment of uplink transmission, the out-of-coverage remote UE 206 sends data to the out-of-coverage helper remote UE 602 on the sidelink 612, the out-of-coverage remote UE 206 and the out-of-coverage helper remote UE 602 cooperatively send data to the in-coverage relay UE 208, and the in-coverage relay UE relays the data to the gNB 202.

[0068] Figure 7AA similar example 700 is shown, but includes two in-coverage relay UEs 204, 208, multiple out-of-coverage assisting remote UEs 704, 708, and another remote UE 206. In this example, two relay links are provided for remote UE 206: a relay link through sidelinks 212, 712 (which passes through assisting remote UE 704), and a relay link through sidelinks 214, 714 (which passes through assisting remote UE 708). Similarly, as in other examples, multiple relay links are formed, where one end is a base station, gNB, TRP, or other network device 202, and the other end is remote UE 206, which can be considered as the destination UE in the downlink transmission context or the source UE in the uplink transmission context.

[0069] For the downlink transmission in example 700, in one embodiment, gNB 202 sends data on Uu link 210 to each of the in-coverage relay UEs 204, 208, and the relay UEs relay the data from the gNB to the next assisting remote UEs 704, 708 on each relay link through sidelinks 212, 214. In another embodiment, there are multiple relay UEs in the relay link, and each relay UE relays the data to the next relay UE through the sidelink. The last relay UE or assisting remote UEs 704, 708 relay the data to the out-of-coverage destination remote UE 206 on sidelinks 712, 714. For the uplink transmission, in one embodiment, the out-of-coverage source remote UE 206 sends data to the nearby assisting remote UEs 704, 708 on sidelinks 712, 714 of each relay link. The assisting remote UEs 704, 708 relay the data to the next assisting remote UE or the relay UEs 204, 208 in the shown example on each relay link through sidelinks 212, 214. The last in-coverage relay UEs 204, 208 relay the data to gNB 202 on Uu link 210 on each relay link.

[0070] Figure 7B is a block diagram of another exemplary communication system showing multi-hop UE-to-UE relay links. Example 750 is similar to Figure 7A example 700 in, but does not include the gNB and the Uu link, but includes a source UE 752, which has sidelinks 754, 756 with two relay UEs 204, 208. In this example, two multi-hop UE-to-UE relay links are provided for remote UE 206: a relay link through sidelinks 754, 212, 712 (which passes through relay UE 204 and assisting remote UE 704), and a relay link through sidelinks 756, 214, 714 (which passes through relay UE 208 and assisting remote UE 708).

[0071] In Example 750, multiple relay links are formed between two UEs 752, 206. If UE 752 has data to send to the remote UE 206, then UE 752 can be regarded as the source UE and the remote UE 206 can be regarded as the destination UE. For this transmission direction, in one embodiment, the source UE 752 sends data to each of the relay UEs 204, 208 on the sidelinks 754, 756, and the relay UEs relay the data from the source UE 752 to the next assisting remote UEs 704, 708 on each relay link via the sidelinks 212, 214. In another embodiment, there are multiple relay UEs in the relay link, and each relay UE relays the data to the next relay UE via the sidelink. The last relay UE or the assisting remote UEs 704, 708 relay the data to the destination UE 206 on the sidelinks 712, 714. For the transmission in the opposite direction, in one embodiment, the remote UE 206 sends data to the nearby assisting remote UEs 704, 708 on the sidelinks 712, 714 of each relay link. The assisting remote UEs 704, 708 relay the data to the next assisting remote UE or the relay UEs 204, 208 in the illustrated example on each relay link via the sidelinks 212, 214. The last relay UEs 204, 208 relay the data to the UE 752 on the sidelinks 754, 756 of each relay link.

[0072] Figures 2 to 7B Merely as an example. There may be other embodiments including one or more relay UEs and remote UEs within or outside the coverage area. The present disclosure and the coordination or cooperation between multiple relay links are not limited to these examples, nor to the specific examples used to describe the embodiments in detail below.

[0073] In some embodiments, the base station, gNB, or other network devices configure multiple UE relay links for the remote UE. Consider Figure 2Example 200 in. gNB 202 may configure the first UE relay link in the UE relay link as an MRL and configure another second UE relay link as an SRL. The configuration may include the index of each relay link, such as relay link #1 of the first relay link or MRL, relay link #2 of the SRL or the second relay link, and the index of any other relay link or SRL of the same remote UE 206. Additionally or alternatively, the configuration may include one or more indices of the relay UE participating in each relay link, the assisting remote UE, and any UE among the remote UEs, such as a UE radio network temporary identifier (RNTI). The relay link may include multiple UE relays. Additionally or alternatively, the relay link may include multiple assisting remote UEs.

[0074] As described above, relay links such as MRL and any SRL may have different roles. For example, the MRL may carry more information (such as control and feedback), while both the MRL and each SRL may carry data. In some embodiments, the roles of the MRL and SRL, or more generally, the roles of different relay links, may be switched or updated between any of the multiple relay links.

[0075] For example, as part of the configuration, or by actually sending data on the relay link after the relay link configuration, the relay link may be activated or enabled. For example, when scheduled or initiated by the gNB, when scheduled or initiated by the remote UE of the MRL, when scheduled or initiated by the MRU, or when scheduled or initiated by the assisting remote UE in the MRL, data may be sent on the relay link. In some embodiments, the relay link may be disabled through the configuration or signaling of one or more of the gNB, MRU, the assisting remote UE in the MRL, and the remote UE.

[0076] Each embodiment does not necessarily require the use of scheduling, but in some embodiments, a scheduler is used to determine the scheduling policy between relay links. For example, for diversity or reliability, the best relay link or multiple relay links may be scheduled or otherwise selected to send the same data. For a higher aggregated data rate, multiple relay links may be scheduled or otherwise selected to send different data. Link scheduling or selection may be based on any of various factors or conditions, such as any one or more of the following: the quality of service (QoS) provided by the link, the QoS required by the data application, the UE buffer status report (BSR) of the remote UE uplink transmission, and the channel state information (CSI) of the link.

[0077] Potential benefits of configuring multiple relay links include improved multi-relay link UE diversity, since the same data can be sent over multiple relay links instead of just one link, providing a multi-relay link gain. There are also potential benefits in increasing the aggregated throughput and coverage, since data can be split over multiple relay links and sent to remote UEs in the downlink or gNB or other network devices in the uplink, and aggregated or combined at the downlink or uplink destination.

[0078] To illustrate an example of relay link cooperation establishment and configuration, consider Figure 7A the exemplary communication system 700 in Figure 8 and the flow chart in Figure 8 illustrating a method according to an embodiment. The exemplary method 800 includes: at 802, configuring and enabling a first relay link as an MRL. For example, gNB 202 may configure and enable the MRL, and this may include the gNB configuring one of the relay UEs (e.g., relay UE 208) as an MRU. In a multi-relay link scenario, configuring and enabling one or more SRLs may be coordinated with the MRL.

[0079] In the case where the MRL has been configured at 802, gNB 202 or MRU 208 may configure the SRL for relay link cooperation. In one embodiment, at 804, gNB 202 or MRU 208 sends signaling to help the remote UE 708 signal the remote UE 206 to send side link discovery signaling on side link 712 in the example shown via the MRL through Figure 7A the side links 214, 714 in Figure 8 The signaling that causes the remote UE 206 to send discovery signaling is also referred to herein as a discovery request or discovery request signaling, and may more generally be considered a request to search for other relay links, as

[0080] At 808, a component that receives discovery signaling (e.g., the assisting remote UE 704 in the exemplary system 700) performs one or more measurements based on the received discovery signaling and, as shown at 810, may exchange information with the remote UE 206 over the sidelink 712. For example, the receiving component may send information indicating any one or more of the following: capabilities such as the component's relay capabilities; the availability of the relay link that the component supports for the remote UE 206; and whether the component is currently within or outside of coverage. In some embodiments, such information may be pre-exchanged and stored in the gNB or MRU to determine the SRL.

[0081] In one embodiment, as shown at 820, the receiving component (in this example, the assisting remote UE 704) passes or reports its measurements and possibly other information to the gNB 202, and at 822, the gNB configures or enables an additional relay link as the SRL via the relay UE 204 (which may be referred to as a secondary relay UE (SRU)). The gNB 202 may configure the SRL based on any of a number of factors, such as any one or more of the following: the channel quality of the Uu link to the first relay UE (e.g., relay UE 204) in the candidate SRL; the channel quality of the sidelink(s) (e.g., sidelink 212 and / or sidelink 712) on the candidate SRL; the overall channel quality of multiple relay link segments or a complete link including the Uu link and at least one sidelink; the load of one or more UEs (including relay UEs and / or assisting UEs on the relay link); the capabilities of one or more UEs (including relay UEs and / or assisting UEs on the relay link); and the availability of one or more UEs (including relay UEs and / or assisting UEs on the relay link).

[0082] As shown at 830, another option includes the receiving component passing or reporting the measurements and possibly other information to the MRU, and at 832, the MRU configures or enables the SRL. The MRU may apply any of a variety of criteria to select between multiple SRLs or determine whether an SRL should be established, including the examples provided above for the gNB.

[0083] According to another embodiment, at 840, the receiving component reports to the remote UE 206, and at 842, the remote UE configures or enables the SRL. In the example 700, the remote UE 206 selects and configures the assisting remote UE 704 and the relay UE 204 for the SRL. Similarly, additionally or alternatively, the exemplary criteria provided above for the gNB or other components may be applied by the remote UE 206 to determine whether an SRL should be established and / or to select between candidate SRLs.

[0084] Method 800 represents a possible embodiment. Other embodiments may include additional, fewer, or different operations performed in a similar or different order. For example, some embodiments may not include a discovery process that includes discovery request signaling, discovery signaling, measurement, and reporting. The remote UE may already have one or more other configured sidelinks. For example, in such cases, identifying the sidelink, assisting the remote UE, and / or the SRU may not necessarily include a discovery process.

[0085] Measurement reports and / or information exchange may be constrained by any of a variety of conditions. For example, if the power measurement based on the discovery signaling is below a threshold, there may be no measurement report or information exchange, thus avoiding further signaling and processing related to the SRL in cases where the sidelink is not sufficient to support the SRL. Additionally or alternatively, other conditions, such as relay capabilities, availability, or coverage status (in-coverage or out-of-coverage), may be applied to the measurement report or information exchange.

[0086] Figure 8 It also includes operations that may be performed on multiple different components in some embodiments. A particular component may perform some of the illustrated operations, but not necessarily all of them.

[0087] In addition, although the above Figure 8 description refers to Figure 7A , and only one SRL is established as an example, additionally or alternatively, method 800 may be applied to different scenarios. For example, in the Figure 2 exemplary system 200 in Figure 3 or the

[0088] exemplary system 300 in Figure 7B , the relay UEs 204, 208 may receive discovery signaling from the remote UE 206. The discovery signaling may be received by the candidate SRU and / or the assisting remote UE. Different types of relay links may exist in the same system. Some relay links may include an assisting remote UE, while others may not. Additionally or alternatively, different relay links may have different hop counts through one or more relay UEs and / or one or more assisting remote UEs.

[0089] Figure 9 is a flowchart showing a method according to another embodiment. In the Figure 8 exemplary method 800, the discovery signaling is sent by the remote UE for which multiple relay links are being established. Figure 9 The exemplary method 900 in Figure 2will be described with respect to the exemplary system 200 in

[0090] At 902, a first relay link is configured and enabled as an MRL, e.g., by gNB 202. gNB 202 may configure one of the relay UEs (e.g., relay UE 208) as an MRU. At 904, gNB 202 and / or MRU 208 may signal another relay UE 204 to send sidelink discovery signaling, or more generally, send a request to one or more relay UEs to search for other relay links, as Figure 9 shown. At 906, relay UE 204 sends discovery signaling at least on sidelink 212 and may broadcast the discovery signaling or send the discovery signaling at least over all known sidelinks.

[0091] For Figure 2 the purposes of the SRLs of the exemplary system 200 and the remote UE 206 in

[0092] it is of interest that the remote UE 206 receives the discovery signaling. Assuming that the discovery signaling sent by relay UE 204 at 906 is detected, at 908, remote UE 206 performs one or more measurements based on the received discovery signaling. Relay UE 204 is a candidate SRU in this example and may, at 910, exchange other information with remote UE 206 on sidelink 212. Examples of such information include information indicating any one or more of the following: capabilities such as the relay capabilities of relay UE 204, the availability of the relay link that relay UE 204 supports for remote UE 206, and whether relay UE 204 is currently within or outside the coverage area. In some embodiments, such information may be stored in the gNB or MRU to determine the SRL.

[0093] As shown at 930, measurements and possibly other information can be transferred or reported to the MRU 208 via the sidelink 214. At 932, the MRU configures the SRL. The MRU can apply any of a variety of criteria to select between multiple SRLs and / or determine whether an SRL should be established, including the examples provided above for the gNB.

[0094] At 942, Figure 9 it is shown that the remote UE 206 itself can configure the SRL by selecting and configuring the relay UE 204 as the SRU of the SRL. At 942, additionally or alternatively, the exemplary criteria provided above for the gNB or other components can be applied by the remote UE 206. Although not explicitly shown in Figure 9 , the remote UE 206 can also suggest the configuration of the SRL to the MRU 208 and / or the gNB.

[0095] Similar to Figure 8 the method 800 in, the method 900 represents one embodiment, and other embodiments can include additional, fewer, or different operations performed in a similar or different order. At least Figure 8 the above variations can also apply to Figure 9 . For example, other embodiments may or may not include a discovery process, the measurement reporting and / or information exchange can be subject to one or more conditions or criteria, certain components can perform some but not necessarily all of the shown operations, additionally or alternatively, the method 900 can be applied to scenarios different from the specific examples discussed with reference to Figure 2 , and different types of relay links can exist in the same system. Other variations can be or become apparent.

[0096] Figure 8 and Figure 9 the embodiments shown in are not mutually exclusive and are not exhaustive. Taking Figure 10 as an example. Figure 10 is a block diagram of another exemplary communication system 1000, showing a multi-relay link scenario similar to Figure 2 , but adding a helper remote UE 1004 with sidelinks 1012, 1014. Assume that the MRL of the remote UE 206 has been configured by the relay UE 208, which is the MRU in this example. The gNB 202 and / or the MRU 208 can configure the SRL via the relay UE 204, which is the SRU in this example.

[0097] In one embodiment, a discovery request can be sent from the gNB 202, the MRU 208, or even the remote UE 206 to the candidate SRU 204. Additionally or alternatively, a discovery request can be sent from the gNB 202 or the MRU 208 to the remote UE 206. Thus, the candidate SRU 204 and / or the remote UE 206 can send discovery signaling. The discovery signaling from the candidate SRU 204 can be received by the assisting remote UE 1004 and / or the remote UE 206, and similarly, the discovery signaling from the remote UE 206 can be received by the assisting remote UE 1004 and / or the candidate SRU 204. The component receiving the discovery signaling can exchange measurements and possibly other information with the component from which it receives the discovery signaling, and / or even possibly exchange measurements and possibly other information with one or more other components. For example, a UE such as the relay UE 204 or the assisting remote UE 1004 can communicate with the MRU 208 via a further sidelink (not shown to avoid overcrowding in the figure) in Figure 10 and exchange measurements and / or other information with the MRU. Figure 10 in the figure and exchange measurements and / or other information with the MRU.

[0098] For example, one or more of the gNB 202, the MRU 208, and the remote UE 206 can collect measurements and / or other information to determine whether an SRL should be configured or to select between multiple SRLs. Any of these components can make an SRL establishment and / or selection decision, and any of these components can potentially send configuration signaling to the candidate SRU 204 and the assisting remote UE 1004 (if that UE is to participate in the SRL) to configure the SRL.

[0099] Additionally or alternatively, Figure 8 and Figure 9 the examples provided in Figure 8 can be extended to other embodiments, such as Figure 7B the UE-to-UE relay link embodiment shown by way of example in Figure 7B . Figure 8 and Figure 9 the features described in Figure 9 in connection with the gNB or network device can be applied to the UE in the examples described above in connection with Figure 7B e.g., the source UE 752. The relay link through the relay UE 208 and the assisting remote UE 708 can be regarded as the first relay link of the remote UE 206. In this case, the relay UE 208 can be regarded as the MRU. The source UE 752 and / or the MRU 208 can configure a second relay link, and in this example, the relay UE 204 can be regarded as the SRU.

[0100] In one embodiment, a discovery request can be sent from the source UE 752 or the MRU 208, or even from the assisting remote UE 708 or the remote UE 206 to the candidate SRU 204. Additionally or alternatively, the discovery request can be sent from the source UE 752, the MRU 208, or the assisting remote UE 708 to the remote UE 206. Thus, the candidate SRU 204 and / or the remote UE 206 can send discovery signaling. In some embodiments, additionally or alternatively, an assisting remote UE such as the assisting remote UE 708 can receive the discovery request and send discovery signaling.

[0101] In Figure 7B , using the indicated sidelink, the assisting remote UE 704 can receive discovery signaling from the candidate SRU 204, and similarly, the assisting remote UE 704 can receive discovery signaling from the remote UE 206. The component that receives the discovery signaling can exchange measurements and possibly other information with the component from which it receives the discovery signaling, and / or even possibly exchange measurements and possibly other information with one or more other components. For example, a UE such as the relay UE 204 or the assisting remote UE 704 can communicate with the MRU 208 via Figure 7B a further sidelink (not shown to avoid overcrowding in the figure) in

[0102] and exchange measurements and / or other information with the MRU. For example, one or more of the source UE 752, the MRU 208, the assisting remote UE 708, and the remote UE 206 can collect measurements and / or other information to determine whether an SRL should be configured or to select among multiple SRLs. Any of these components can make an SRL establishment and / or selection decision, and any of these components can potentially send configuration signaling to the candidate SRU 204 and the assisting remote UE 704 (if that UE is to participate in the SRL) to configure the SRL.

[0103] Figures 8 to 10 and the examples with reference to Figure 7B are intended to illustrate some of the multiple options for coordination or cooperation between multiple relay links. Other options are possible. Generally, any of the various components can participate in the discovery process or other processes to identify candidate SRLs or SRUs; any of the various components can participate in determining whether an SRL should be configured or in selecting one or more SRLs and SRUs from multiple candidate SRLs or SRUs; and any of the various components can participate in configuring the SRL. Thus, it should be understood that there are many different options for establishing multiple relay links for relay cooperation or for features such as switching between multi-relay link cooperation and single-relay link transmission.

[0104] Multiple relay links can provide greater flexibility to accommodate different requirements. For example, some embodiments may include switching between a single link and multiple links with relay cooperation.

[0105] One possible option includes semi-static switching via control signaling (e.g., radio resource control (RRC) signaling) to indicate whether the current configuration is for multiple links (relay cooperation) or a single relay link.

[0106] Another option includes dynamic switching, such as using downlink control information (DCI). In one embodiment, each relay UE uses a separate DCI, and each relay UE decodes its own physical downlink control channel (PDCCH). If the relay UE does not detect and decode its PDCCH, the relay UE may not be able to receive data and relay the data to the remote UE or gNB.

[0107] According to another DCI embodiment, a single DCI is used for all relay UEs. For explicit indication, the DCI can carry an indication of which relay UE should handle the relay transmission. For example, a 1-bit field can indicate whether the MRL or SRL should be used to relay data. Implicit indication can use some other type of indication to implicitly indicate whether the current configuration is for single-relay UE transmission or relay UE cooperation. For example, if the DCI indicates dual codeword (CW) transmission, the first CW transmission can be carried by the MRL, and the second CW transmission can be carried by the SRL. Another example is that if the DCI indicates single CW transmission, the CW is only carried by the MRL and the SRL is not used.

[0108] For example, these are illustrative examples of options for switching between single-relay transmission and multi-relay link cooperation to provide flexibility to accommodate different requirements.

[0109] Some aspects of the present disclosure relate to scheduling, transmission, data splitting, data aggregation, and data flow.

[0110] Figure 11 Examples of cyclic redundancy check (CRC) scrambling of downlink control information (DCI), coding bit scrambling of DCI, and generation of demodulation reference signals (DMRS) for the physical downlink control channel (PDCCH) are shown. Figure 11 The examples in are for the Uu link.

[0111] There are several options for Uu link scheduling, including at least that the transmission on the Uu link is scheduled by a network device (e.g., gNB), or the cooperating relay UEs receive a single DCI (PDCCH).

[0112] For transmissions on the Uu link scheduled by the gNB, each relay UE can receive its own DCI (PDCCH). Identifiers of the UE at the far-end of the relay link, such as the far-end UE RNTI, can be used for CRC scrambling, coded-bit scrambling, and DMRS generation. Another embodiment includes using a relay cooperation RNTI or other identifier for CRC scrambling, coded-bit scrambling, and DMRS generation. In yet another embodiment, the identifier of the relay UE on the relay link, such as the relay UE RNTI, is used for CRC scrambling, coded-bit scrambling, and DMRS generation. An identifier configured by a higher layer can be used in combination with one of the above identifiers, as Figure 11 shown.

[0113] Embodiments where all relay UEs receive a single DCI (PDCCH) include using an identifier of the far-end UE, such as an RNTI or a relay cooperation RNTI or other identifier, for CRC scrambling, coded-bit scrambling, and DMRS generation. As Figure 11 shown, an identifier configured by a higher layer can be used in combination with any of these identifiers.

[0114] Figure 12 Examples of CRC scrambling of the physical downlink shared channel (PDSCH) for Uu link data transmission, coded-bit scrambling of the PDSCH, and PDSCH DMRS generation are shown. In one embodiment, one or more PDSCHs (including one PDSCH for each relay link) are transmitted on the Uu link. Identifiers such as the RNTI of the far-end UE for the relay link, relay cooperation identifiers such as the RNTI, or other identifiers of the relay UE for the relay link can be combined Figure 12 with the identifier configured by a higher layer in the example shown for CRC scrambling, coded-bit scrambling, and DMRS generation.

[0115] The identifiers referred to above with reference to Figure 11 and Figure 12 are merely examples. Other embodiments may use combinations of these exemplary identifiers and / or use one or more other identifiers.

[0116] As Figure 11 and Figure 12 shown, CRC scrambling by masking, encoding by an encoder, applying coded-bit scrambling to the encoded output of the encoder, and generating DMRS by a DMRS generator are also illustrative and non-limiting examples.

[0117] Figure 13 is a signal flow diagram of an example of a sidelink scheduling and transmission procedure according to an embodiment. Figure 13 The upper part of Figure 13The lower part shows sidelink scheduling and transmission for the downlink.

[0118] In some embodiments, the uplink transmission on the sidelink is scheduled by a network device (e.g., gNB). In the first option (Option 1), each relay UE sends sidelink control information (SCI) to the remote UE. The SCI contains sidelink scheduling information from the gNB (e.g., Mode 1 in V2X). The second option (Option 2) includes the relay UE sending SCI, which includes the scheduling information as in Option 1, and thus Figure 13 the label in the upper right corner is "Option 1 / 2", but in Option 2, the scheduling information comes from the relay UE (e.g., Mode 2d in V2X). The remote UE sends uplink data to the relay UE on the sidelink according to the scheduling in Option 1 and Option 2. If more than one relay link is configured for the remote UE, such as an MRL and one or more SRLs, then for Option 1 / 2, the remote UE can detect SCI from the relay UE of each relay link (e.g., from the MRU and SRU) to obtain the scheduling information. If the remote UE detects only one SCI, then the remote UE can only send uplink data to the specific relay UE in the physical shared sidelink channel (PSSCH) on the sidelink according to the scheduling information indicated in the SCI. If the remote UE detects two SCIs, including one SCI from the relay UE of each of the two relay links respectively, then the remote UE can split or duplicate the data according to the scheduling in the corresponding SCI and send the data to each relay UE in separate PSSCHs on the sidelink.

[0119] According to Figure 13In the third uplink option (Option 3), uplink transmission on the sidelink uses one or more preconfigured communication resources, and the remote UE uses the preconfigured resources to send data to the relay UE on the sidelink. For Option 3, the remote UE can configure more than one set of resources (e.g., time-frequency resources) and corresponding parameters (e.g., DMRS, modulation and coding scheme (MCS)) on the sidelink, including one set for the remote UE to send data to each relay UE of each relay link. For example, one set of resources for the remote UE to send data to the MRU of the MRL and one set of resources for the remote UE to send data to the SRU of the SRL. These sets of resources can be orthogonal in one or more of the time domain, frequency domain, and code domain, or they can overlap or partially overlap, while the configured DMRS can still be orthogonal. The remote UE can send data to the corresponding relay UE of each relay link on one or both of the sets of resources. The relay UE of each relay link can blindly detect data transmission on each set of resources on the sidelink and determine whether there is data sent from the remote UE to this relay UE. If the relay UE detects data transmission, it can attempt to decode the data transmission.

[0120] Figure 13 Options 1 / 2 and Option 3 for the downlink in [document] are similar to Options 1 / 2 and Option 3 for the uplink, except that each relay UE sends the SCI and data to the remote UE in the downlink direction.

[0121] If more than one relay link is configured for the remote UE, such as the MRL and one or more SRLs, then for Option 1 / 2, the remote UE can detect the SCI from the relay UE of each relay link (e.g., from the MRU and SRU) to obtain scheduling information. If the remote UE detects only one SCI, the remote UE can only receive downlink data from this specific relay UE in the PSSCH on the sidelink according to the scheduling information indicated in the SCI. If the remote UE detects two SCIs, including one SCI from the relay UE of each of the two relay links respectively, the remote UE can receive data from each relay UE in a separate PSSCH on the sidelink according to the scheduling information in the corresponding SCI and aggregate the received data according to the data splitting between the relay links.

[0122] For option 3, the remote UE can configure more than one set of resources (e.g., time-frequency resources) and corresponding parameters (e.g., DMRS, MCS) on the sidelink, including a set for each relay UE of each relay link to send data to the remote UE. For example, a set of resources for the MRU of the MRL to send data to the remote UE and a set of resources for the SRU of the SRL to send data to the remote UE. These sets of resources can be orthogonal in one or more of the time domain, frequency domain, and code domain, or can overlap or partially overlap, while the configured DMRS can still be orthogonal. The remote UE can blindly detect data transmissions on each set of resources on the sidelink and determine whether there is data sent from the corresponding relay UE to the remote UE. If the remote UE detects a data transmission, it can attempt to decode the data transmission.

[0123] Additionally or alternatively, other features can be provided for sidelink transmissions. For example, any one of CRC scrambling, coded bit scrambling, and DMRS generation similar to that shown in Figure 11 and Figure 12 or at least the examples described above can be applied to the PSSCH by using a remote UE identifier such as an RNTI, a relay cooperation identifier such as an RNTI, a higher layer configured identifier, or one or more other identifiers.

[0124] Considering the above scheduling and transmission examples, an example of the downlink transmission procedure in the exemplary system 200 according to an embodiment Figure 2 includes the gNB 202 scheduling downlink data transmissions on the Uu link 210 and the sidelinks 212, 214, or scheduling sidelink transmissions using one or more pre-configured communication resources. For each of the two relay links, the gNB 202 sends a separate PDCCH and PDSCH to the relay UEs 204, 208 via the Uu link 210. The PDCCH of each relay UE 204, 208 is scrambled by the RNTI of that relay UE, and a field in the DCI can be used to indicate the destination identifier of the remote UE 206. The PDSCH of each relay UE 204, 208 is also scrambled by the RNTI of that relay UE. Then, each relay UE 204, 208 relays the data to the remote UE 206 on the sidelinks 212, 214 between the relay UE 204, 208 and the remote UE in a separate PSSCH scrambled by the remote UE ID.

[0125] As an example of the uplink transmission procedure of the exemplary system 200, the remote UE passes its scheduling request (SR) or BSR to the gNB 202, for example, via one of the relay links and the relay UEs 204, 208. The gNB 202 schedules the uplink data transmission on the Uu link and the sidelink. In some embodiments, the sidelink transmission uses one or more preconfigured communication resources. The remote UE sends data to each relay UE 204, 208 on the sidelinks 212, 214 in a separate PSSCH. The PSSCH may be scrambled by the remote UE ID (e.g., RNTI). Then, each relay UE 204, 208 relays the data to the gNB 202 in a physical uplink shared channel (PUSCH) on the Uu link 210. In some embodiments, each PUSCH is scrambled by the relay UE ID (e.g., RNTI). If the same data is sent via different relay links, different redundancy versions (RVs) of the data packet may be sent. The association between the relay link and the RV may be configured semi-statically or indicated dynamically, for example, configured semi-statically in the RRC signaling or indicated dynamically in the DCI.

[0126] These are just illustrative examples of uplink and downlink transmissions. Other embodiments are possible. For example, as Figure 7B illustrated by way of example in, the transmission between the remote UE and another UE via the UE-to-UE relay link may be substantially similar to the uplink and downlink transmissions between the network device and the remote UE.

[0127] Figure 14 is a block diagram showing exemplary data splitting options for relay link coordination. Sending data using multiple relay links includes data splitting by transmitting different data via multiple relay links, or data replication by transmitting the same data via multiple relay links. Data replication can be regarded as a special case of data splitting, in which the same data is replicated to be transmitted via two paths. Figure 14 Illustrates some general options.

[0128] At the transmitter, specifically, in some embodiments, at the remote UE or the network device (e.g., gNB), or in the UE-to-UE relay link embodiment, at one of the two UEs, the data may be split or replicated at any of several different layers. According to the first option ( Figure 14Option 1) in which data splitting or duplication is performed at the packet data convergence protocol (PDCP) layer. For example, Option 1 may be used for L2 relay. The second option (Option 2) includes data splitting or duplication at the media access control (MAC) layer, for example, data splitting or duplication at the transport block (TB) level. For example, Figure 14 Also shown is data splitting or replication at the physical (PHY) layer, for example, data splitting or replication at the codeword or code block group (CBG) level.

[0129] At the receiver, the data may be aggregated based on where data splitting or replication was implemented at the transmitter, which in some embodiments may be a remote UE or network device (e.g., a gNB), or in a UE-to-UE relay link embodiment, may be one of the two UEs.

[0130] Figure 14 is an example, and other embodiments may be implemented in similar or different manners, and in similar or different architectures.

[0131] Figure 15 is a signal flow diagram illustrating an example of configuring a relay link (which is an MRL in the illustrated example) and a discovery process. Figure 16 is a signal flow diagram illustrating an example of configuring another relay link (which is a SRL in the illustrated example) and relay link transmissions, wherein the relay link transmissions include downlink transmissions and uplink transmissions on the MRL and / or the SRL. Figure 15 and Figure 16 This is intended to illustrate various scenarios. For example, helping a remote UE may or may not participate in a relay link. In the case of a UE-to-UE relay link, the gNB or TRP may not participate in the relay link, such as Figure 7B In these links, Figure 15 and Figure 16 The features shown for gNB or TRP can be applied to UE, such as Figure 7B UE 752 in. It should also be noted that MRL, MRU, SRL and SRU are Figure 15 and Figure 16 Shown and referenced in Figure 15 and Figure 16 This description is only for convenience in distinguishing different relay links and components of these links from each other.More generally, a primary or main relay link or component and a similar secondary relay link or component may be considered as examples of different (eg, first and second) relay links or components.

[0132] The examples in these figures are also not intended to be restrictive or exhaustive, and the examples include some possible options. For example, when configuring the MRL in Figure 15 , if the helping remote UE in the MRL is within the coverage area, the configuration signaling can be sent from network devices such as gNB or TRP to the helping remote UE, as shown by the second solid line in the upper left corner in Figure 15 , or the configuration signaling can be sent to the MRU and relayed by the MRU to the MRL helping remote UE, as shown by the dashed line below the solid line. Different solid lines can also represent options rather than features that can be implemented in each embodiment. For example, one or more discovery requests can be sent by the gNB or TRP in Figure 15 , but not all or even any of the discovery requests shown in Figure 15 must be sent by the gNB or TRP. As described above, discovery is an optional process and may not be performed at all.

[0133] Figure 15 and Figure 16 The signaling in covers multiple options (including at least those described above) applicable to any scenario among various scenarios, and shows various possibilities that can be implemented in the embodiments. Although the signaling coverage in Figure 15 and Figure 16 is already wide, other embodiments can also include additional features. For example, before the data received through the Uu link is relayed to the remote UE or the helping remote UE, the relay UE can perform operations such as data processing and / or decoding on the data. Similarly, before the data received through the sidelink is relayed to the gNB or TRP through the Uu link, the relay UE can perform operations such as data processing and / or decoding on the data.

[0134] Generally, although Figure 15 and Figure 16 include many embodiments, other embodiments can include additional, fewer, and / or different features.

[0135] At least various features have been described in detail above. More generally, the method according to the embodiment includes coordinating the configuration of the secondary relay link between the UE and the wireless communication network with the primary relay link between the UE and the wireless communication network. The method according to the embodiment further includes transmitting signaling to enable the configuration of the secondary relay link according to the coordination. The primary relay link and the secondary relay link are referred to as MRL and SRL respectively herein. "Primary relay link" is synonymous with "MRL" and can be interchanged, and similarly, "secondary relay link" is synonymous with "SRL" and can be interchanged.

[0136] This document also supports other terms and features, including a first relay link and a second relay link and their components, and relay links that are not necessarily between a UE and a wireless communication network. For example, according to another embodiment, a method includes: coordinating the configuration of a second relay link of a UE with a first relay link of the UE in a wireless communication network; transmitting signaling to enable the second relay link to be configured according to the coordination. The first relay link and the second relay link can be or include a relay link between a UE and a network device in a wireless communication network, or a relay link between a UE and another UE.

[0137] For example, as can be seen Figure 15 from Figure 16 and, relay link coordination can include the participation of any of various components, which include one or more gNBs or other network devices, one or more UEs, or both a network device and one or more UEs. The coordination and communication can take any of various forms, depending on the particular components being considered and their role in the relay link configuration or use. For example, the components participating in the first relay link or MRL may have a more active role in coordinating the configuration of the SRL than the components that may participate in the second relay link, SRL, candidate second relay link, or candidate SRL.

[0138] Taking the MRU as an example, the MRU is the relay UE of the first relay link. When the MRL or the first relay link has been configured, the MRU can send a discovery request to one or more other components. In this example, from the perspective of the MRU, transmitting signaling includes sending signaling in the form of a discovery request. In this example, from the perspective of the receiving component (such as a candidate second relay UE or SRU), coordinating with the MRL includes receiving a discovery request from the MRU, and transmitting signaling can include the candidate SRU sending discovery signaling. This is just one example of how the features disclosed in this document can be implemented or realized by different components in different ways.

[0139] For illustrative purposes only, Figure 7A is referred to in the following description. It is convenient to select Figure 7A as an example because it includes network device 202, relay UEs 204, 208, remote UE 206, and assisting remote UEs 704, 708. Other embodiments may include fewer, additional, or different components. For example, in the case of a UE-to-UE relay link, the features described by way of example in connection with network device 202 can be applied to another UE, such as Figure 7B UE 752 in

[0140] Consider an exemplary scenario of configuring an MRL between a network device 202 and a remote UE 206 through a relay UE 208 (which is an MRU in this example) and a helping remote UE 708. An initial decision can be made on whether to establish or attempt an SRL. In this example, the coordinated configuration of the SRL and the MRL can include making such an initial decision by determining whether the SRL establishment conditions associated with the MRL are met. Then, the operation of transmitting signaling as described above can include transmitting signaling related to determining that the SRL establishment conditions are met. The determination of whether the SRL establishment conditions associated with the MRL are met can be performed by a component participating in the MRL, such as a gNB or other network device 202, or in the case of a UE-to-UE relay link, a UE such as UE 752( Figure 7B ) etc., the MRU 208, the helping remote UE 708, or the remote UE of the primary relay link. The SRL establishment conditions can include any one or more of the following: the configuration of the MRL, such as the initiation or completion of the MRL configuration, determining that communication diversity will be provided for communication with the remote UE 206, determining that a greater aggregated bandwidth will be provided for communication with the remote UE, and determining that a lower communication latency will be provided for communication with the remote UE. In some scenarios, a single relay link may be sufficient and it may be determined that an SRL is not needed.

[0141] Some embodiments include signaling in the form of a discovery request as described above, so the operation of transmitting signaling as described above can include transmitting the signaling from a component participating in the MRL to one or more other components, for example, to cause the other components to send discovery signaling. The discovery signaling enables the identification of candidate relay links configured as SRLs. In the context of the above example with reference Figure 7A , the MRL components that can send one or more discovery requests include the network device 202, the MRU 208, the helping remote UE 708, and the remote UE 206, and a UE such as UE 752( Figure 7B ) etc. can send one or more discovery requests in the case of a UE-to-UE relay link. Any one or more of these components can send one or more discovery request signals to one or more other components.

[0142] The other components to which the discovery requests are sent can include one or more of the following: the remote UE 206, another component (such as the MRU 208 and / or the helping remote UE 708 participating in the MRL), and candidate components through which the SRL can be configured (such as candidate SRUs 204 and / or candidate helping remote UEs 704). These components and the relay links that can be configured through these components are called candidates because the SRL has not been configured in this example.

[0143] In some embodiments, a component may send discovery signaling without necessarily first receiving a discovery request, e.g., when the MRL configuration has been completed and the MRL has been established. Thus, the transmission signaling as described above may include sending discovery signaling that enables identification of candidate relay links configured as SRLs without necessarily first receiving other signaling. For example, any one or more of MRU 208, assisting remote UE 708, and remote UE 206 may detect that the MRL has been configured and then broadcast or otherwise send discovery signaling without first receiving a discovery request.

[0144] The discovery signaling as disclosed herein may be or include a reference signaling, such as CSI-RS or DMRS, as described above.

[0145] The discovery request and discovery signaling are illustrative of signaling that in some embodiments may be received and may participate in the coordination described above. Thus, such coordination may include receiving signaling associated with the MRL, and such signaling may be received by any one or more of MRU 208, candidate SRU (e.g., 204), remote UE 206, and one or more assisting remote UEs (e.g., 708) in the MRL or candidate SRL. From the perspective of a component that waits for signaling and then performs an action when the signaling is received, the above-described transmission signaling for enabling configuration of the SRL is in response to receiving signaling associated with the MRL, such as a discovery request or discovery signaling. In the discovery request and discovery signaling example, the signaling associated with the MRL is or includes the signaling that causes the transmission of the discovery signaling, and as described above, the discovery signaling enables identification of candidate relay links configured as SRLs, and the above-described transmission signaling for enabling configuration of the SRL includes sending discovery signaling.

[0146] From the perspective of a receiving component that receives discovery signaling, in some embodiments, the discovery signaling is in the form of signaling associated with the MRL and that causes the receiving component to initiate an action. For example, the method may include performing measurements according to the discovery signaling. In embodiments involving performing measurements, the above-described transmission signaling for enabling configuration of the SRL may involve sending signaling associated with the measurements. Such signaling associated with the measurements may be or include one or more of the following: signaling indicating the measurements, signaling indicating whether the measurements meet the conditions for configuring a relay link as an SRL, the relay link including the link between the component from which the discovery signaling is received. Thus, the component performing the measurements may report or feedback the measurements themselves, and additionally or alternatively, may report or feedback a decision regarding whether the measurements meet conditions such as minimum signal strength to support the SRL. Alternatively, the decision may be made by the component to which the measurements are reported. Additional information associated with the candidate relay link for which the measurements are performed may also be transmitted. The transmission of the measurements and / or additional information is respectively referenced Figure 8 andFigure 9 810 - 840 and 910 - 930 in

[0147] Referring again to Figure 7A , components that can receive discovery signaling include any one or more of the following: MRU 208, one or more assisting remote UEs (such as 708), remote UE 206, candidate SRU 204, and one or more candidate assisting remote UEs (such as 704). Any component among these that receives discovery signaling can perform one or more measurements and may make decisions based on the measurements. The measurements, decisions based on the measurements, or both, can be reported or fed back to any other component, including network device 202 or, in the case of a UE - to - UE relay link, UE 752 ( Figure 7B ), etc. In some embodiments, the decision based on the measurement is made by a component that receives the measurement from one or more other components. For example, the final decision regarding a candidate SRL, candidate SRU, or other candidate SRL components through which the SRL will be configured can be made by network device 202, or other components such as MRU 208 or remote UE 206, or in the case of a UE - to - UE relay link, by UE 752 ( Figure 7B ), etc.

[0148] In some embodiments, the transmission of signaling to coordinate the configuration of the SRL includes being sent by one or more components that are not part of the MRL (such as Figure 7A candidate SRU 204 and / or assisting remote UE 704 of the candidate SRL in

[0149] ). Generally, the signaling associated with the MRL initiates actions through one or more other components, and this signaling can be sent by one or more components participating in the MRL. Additionally or alternatively, this signaling can be sent by one or more components not participating in the MRL. Figure 7A ). Considering now some features related to the actual configuration of the SRL, the coordination as described above can include receiving signaling indicating a candidate relay link to be configured as an SRL. For example, the signaling can be or include: the remote UE 206 sending signaling to the MRU 208 regarding which candidate SRU to contact, for example, in a scenario where the remote UE 206 knows candidate SRU 204 through information exchange with the assisting remote UE 704; a measurement report, which can indicate the link for which measurements are to be performed; signaling indicating that the measurements meet the conditions for establishing an SRL; sending a reply signaling to the network device 202 to specify the candidate SRL to be configured as an SRL, for example, by identifying the candidate SRL or components of the candidate SRL (such as

[0150] In the context of SRL configuration, the above-described transport signaling to enable configuring the operation of the SRL can include sending configuration signaling from components participating in the MRL to configure the SRL. Although the actual configuration of the SRL can be handled by the gNB or other network devices (such as 202) or, in the case of a UE-to-UE relay link, by a UE such as UE 752( Figure 7B ), other components can also be involved as disclosed herein. For example, one or more of the MRU 208, candidate SRU 204, assisting remote UE 708, assisting remote UE 704, and remote UE 206 can at least relay the configuration signaling to one or more other components to be configured to establish the SRL. The configuration signaling can be generated by the network device 202 or, in the case of a UE-to-UE relay link, by a UE such as UE 752( Figure 7B ), and relayed by one or more of these other components. In some embodiments, the configuration signaling does not necessarily come only from the network device 202 or, in the case of a UE-to-UE relay link, from a UE such as UE 752( Figure 7B ). For example, the MRU 208 can generate and send the configuration signaling.

[0151] For example, as Figure 7B shown, for the MRL and SRL configured for a UE between a UE and a wireless communication network, or between a UE and another UE, the method can include coordinating communication with the UE via the MRL and SRL. In Figure 7A , the network device 202 and the remote UE 206 can communicate with each other via both the MRL (via the MRU 208 and the assisting remote UE 708) and the SRL (via the SRU 204 and the assisting remote UE 704). Additionally or alternatively, UEs can communicate with each other via the relay link, as Figure 7B shown by way of example.

[0152] For example, coordinating communication via the MRL and SRL can include determining data splitting for communication with a remote UE via the MRL and SRL. In some embodiments, one or more of the following actions can be performed: sending signaling indicating data splitting to one or more components participating in the MRL; sending signaling indicating data splitting to one or more components participating in the SRL; splitting data (e.g., received data) for transmission via the MRL and SRL according to the data splitting; aggregating received data for transmission via the MRL and SRL according to the data splitting.

[0153] For example, the network device 202 or, in the case of a UE-to-UE relay link, a UE such as UE 752( Figure 7B)UEs such as can determine how data should be split between the MRL and the SRL, and send signaling indicating the data split to at least the remote UE 206 so that the remote UE can aggregate the received data according to the data split. In other embodiments, the MRU 208 can determine the data split and signal the data split to one or more other components, such as, for example, the network device 202, in the case of a UE-to-UE relay link, the UE 752( Figure 7B )UEs such as, and the remote UE 206. Additionally or alternatively, the data split can be determined by the remote UE 206 and signaled to the network device 202 or, in the case of a UE-to-UE relay link, the UE 752( Figure 7B )UEs such as.

[0154] The actual splitting and aggregation of the data can also be handled by any of the various components. For Figure 7A the example in, for downlink transmissions, the data split is handled by the network device 202 and the data aggregation is handled by the remote UE 206; for uplink transmissions, the data split is handled by the remote UE and the data aggregation is handled by the network device. Other embodiments are possible. Consider Figure 6 the example in which the data split for downlink transmissions and the data aggregation for uplink transmissions can be handled by the relay UE 208. As another example, consider Figure 7B , in which the data split for transmissions to the remote UE 206 and the data aggregation for data transmissions in the opposite direction can be handled by the UE 752.

[0155] The signaling indicating the data split can be or include an SCI. For example, in this case, the splitting and aggregation are performed according to the received SCI. In other embodiments, preconfigured communication resources are used. At this time, the data split can include, for example, splitting the data (e.g., the received data) for transmission through the preconfigured communication resources associated with the primary relay link and the SRL, and the data received for aggregation can include the data received through the preconfigured communication resources associated with the primary relay link and the SRL. At least the examples of the SCI and the preconfigured resources are discussed in detail above with reference to Figure 13 .

[0156] Some embodiments support switching between multi-link communication and single-link communication. For example, coordinating communication via the MRL and SRL may include determining whether to maintain communication with the remote UE 206 via both the MRL and SRL. For example, multi-link communication may no longer be needed to support a higher data rate for communicating with the remote UE 206. Then, in response to determining not to maintain communication via both the MRL and SRL, communication with the UE via only the MRL may be enabled. This is an example of a multi-link to single-link switch. To switch from single-link communication to multi-link communication, coordinating communication via the MRL and SRL may include determining whether to maintain communication with the remote UE 206 via only the MRL, and in response to determining not to maintain communication with the UE via only the primary relay link, enabling communication with the remote UE via both the MRL and SRL. This may include reconfiguring the same SRL previously used or configuring another SRL. Thus, when switching to multi-link communication, the SRL may or may not be the same as the previously used SRL.

[0157] MRL / SRL role switching is also possible. For example, an MRU can be reconfigured as an SRU, and an SRU can be reconfigured as an MRU. This reconfiguration can be performed by a network device in some embodiments, or by a UE 752 ( Figure 7B ) or other UEs in the case of a UE-to-UE relay link.

[0158] Any one or more of the various components can participate in the operations disclosed herein. For example, Figure 7A the MRU 208 in can handle any one or more of the following actions: determining data splitting, determining whether to maintain communication with the remote UE 206 via the MRL and SRL, in response to determining not to maintain communication with the remote UE 206 via the MRL and SRL, enabling communication with the remote UE via only the MRL, determining whether to maintain communication with the remote UE via only the MRL, in response to determining not to maintain communication with the remote UE via only the MRL, enabling communication with the remote UE via the MRL and SRL or another SRL, performing one or more of the following actions: sending signaling indicating data splitting to one or more components participating in the MRL; sending signaling indicating data splitting to one or more components participating in the SRL; splitting data (e.g., received data) for transmission via the MRL and SRL according to the data splitting; aggregating received data for transmission via the MRL and SRL according to the data splitting. Additionally or alternatively, these and / or other operations can be performed by other components, such as by the network device 202, an SRU (e.g., 204), a helping remote UE (e.g., 704, 708), and the remote UE 206, one or more of them.

[0159] Taking SRU 204 as an example, coordinating communication through the MRL and SRL may include the SRU performing one or more of the following actions: receiving signaling indicating data splitting, the data splitting being determined for communication with the remote UE 206 through the MRL and SRL; splitting data (e.g., received data) for transmission through the SRL according to the data splitting; disabling communication with the remote UE through the SRL in response to signaling received from the MRU 208, and enabling communication with the remote UE through the SRL in response to signaling received from the MRU.

[0160] From the perspective of the remote UE 206, coordinating communication may include the remote UE performing one or more of the following actions: receiving signaling indicating data splitting, the data splitting being determined for communication with the UE through the MRL and SRL; splitting data for transmission through the MRL and SRL according to the data splitting; aggregating data received through the MRL and SRL according to the data splitting; disabling communication through the SRL in response to signaling received from the MRU 208, and enabling communication with the remote UE through the SRL or another SRL in response to signaling received from the MRU.

[0161] In some embodiments, other features disclosed herein may also be provided. For example, in some embodiments, the MRL includes at least one relay UE 208 within the coverage area of the wireless communication network, and the remote UE 206 is outside the coverage area of the wireless communication network. The MRL may include a helper remote UE, such as 708, that is outside the coverage area of the wireless communication network and communicates with the relay UE 208 and the remote UE 206. Similarly, the SRL may include at least one secondary relay UE 204 within the coverage area of the wireless communication network, where the remote UE 206 is outside the coverage area, and in some embodiments, includes a secondary helper remote UE 704 that is outside the coverage area and communicates with the secondary relay UE and the remote UE.

[0162] The exemplary methods described above are intended to be illustrative and non - limiting. Another method includes components involved in the MRL of the UE (e.g., the relay link between the remote UE and the wireless communication network) receiving signaling indicating measurements performed by a first UE on a direct wireless communication link (e.g., a sidelink between the first UE and the second UE). Referring again to Figure 7A , any one or more of the network device 202, the MRU 208, the helper remote UE 708, and the remote UE 206 may receive the measurement signaling, as well as other information that may be related to the direct wireless communication link (e.g., the sidelink). Additionally or alternatively, in the case of a UE - to - UE relay link, a UE such as UE 752 ( Figure 7B ) may receive the measurement signaling and other information that may be related to the direct wireless communication link.

[0163] Determine whether the SRL between the remote UE and the radio communication network should be established via a direct radio communication link according to the received signaling. In response to determining that the SRL should be established via a direct radio communication link, send configuration signaling for configuring the SRL.

[0164] Although the remote UE 206 is part of the MRL, the remote UE can also participate in the sidelink that is part of the candidate SRL. Consider the scenario where the remote UE 206 performs measurements on the sidelink 712. In this scenario, the remote UE 206 is the first UE that performs the measurements as described above. In another scenario, the assisting remote UE 704 helps the remote UE 206 perform measurements on the sidelink 712. In this case, the assisting remote UE 704 is the first UE that performs the measurements as described above, and the remote UE 206 is the second UE that participates in the sidelink for which the measurements are performed as described above. Therefore, the remote UE 206 can be the first UE or the second UE as described above.

[0165] The method can include: components that participate in the primary relay link and receive measurement signaling send further signaling to enable the first UE to perform measurements. For example, the further signaling can be or include discovery signaling.

[0166] Some embodiments include sending further signaling by components that participate in the primary relay link and receive measurement signaling to cause the second UE to send signaling to the first UE, thereby enabling the first UE to perform measurements. In combination Figure 10 , for example, the remote UE 206 can send a discovery request to the assisting remote UE 1004 to cause the assisting remote UE 1004 to send discovery signaling to the relay UE 204, which in turn performs measurements on the sidelink 1012 and sends the measurement signaling back to the remote UE 206.

[0167] Another method consistent with the present disclosure relates to the type or role of relay link switching, such as the MRL / SRL role. For example, such a method can include configuring the MRL to carry data and control information and / or feedback information between the UE and the radio communication network; configuring the SRL to carry data between the UE and the radio communication network; according to the relay link role switching condition, reconfiguring the SRL as a new MRL to carry data and control information and / or feedback information between the UE and the radio communication network, and reconfiguring the MRL as a new SRL to carry data between the UE and the radio communication network. In some embodiments, the data and control information and / or feedback information can be carried between the UE and the radio communication network, or in other ways for transmission with the UE, such as in the case of a UE-to-UE relay link.

[0168] Additionally or alternatively, further features disclosed herein can be implemented in combination with these methods.

[0169] The above embodiments are mainly described in the context of exemplary methods. Other embodiments are also possible.

[0170] For example, referring to Figure 17A and Figure 17B , exemplary devices that can implement the methods and teachings according to the present disclosure are shown.

[0171] Figure 17A An exemplary ED 1710 is shown, Figure 17B and an exemplary base station 1770 is shown. These components can be used in system 100 ( Figure 1 ) or any other suitable system.

[0172] As Figure 17A shown, the ED 1710 includes at least one processing unit 1700. The processing unit 1700 implements various processing operations of the ED 1710. For example, the processing unit 1700 can perform signal encoding, data processing, power control, input processing, output processing, or any other function that enables the ED 1710 to operate in a communication system. The processing unit 1700 can also be used to implement some or all of the functions or embodiments described in detail herein. Each processing unit 1700 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 1700 can include a microprocessor, a microcontroller, a digital signal processor, a field programmable gate array, or an application specific integrated circuit.

[0173] The ED 1710 also includes at least one transceiver 1702. The transceiver 1702 is used to modulate data or other content for transmission via at least one antenna or a network interface controller (NIC) 1704. The transceiver 1702 is also used to demodulate data or other content received by at least one antenna 1704. Each transceiver 1702 includes any suitable structure for generating signals for wireless transmission and / or for processing signals received wirelessly or by wire. Each antenna 1704 includes any suitable structure for transmitting and / or receiving wireless signals. One or more transceivers 1702 can be used for the ED 1710, and one or more antennas 1704 can be used for the ED 1710. Although the transceiver 1702 is shown as a single functional unit, the transceiver 1702 can be implemented using at least one transmitter and at least one separate receiver.

[0174] ED 1710 also includes one or more input / output devices 1706 or interfaces. The input / output devices 1706 facilitate interaction with users or other devices in the network (network communication). Each input / output device 1706 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communication.

[0175] In addition, ED 1710 includes at least one memory 1708. The memory 1708 stores instructions and data used, generated, or collected by ED 1710. For example, the memory 1708 may store software instructions or modules executed by the processing unit 1700 for implementing some or all of the functions or embodiments described above. Each memory 1708 includes any suitable volatile and / or non-volatile storage and retrieval device. Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, etc.

[0176] As Figure 17B shown, the base station 1770 includes at least one processing unit 1750, at least one transmitter 1752, at least one receiver 1754, one or more antennas 1756, at least one memory 1758, and one or more input / output devices or interfaces 1766. A transceiver (not shown) may be used instead of the transmitter 1752 and the receiver 1754. The scheduler 1753 may be coupled to the processing unit 1750. The scheduler 1753 may be included within the base station 1770 or may operate separately from the base station 1770. The processing unit 1750 implements various processing operations of the base station 1770, such as signal encoding, data processing, power control, input processing, output processing, or any other function. The processing unit 1750 may also be used to implement some or all of the functions and / or embodiments detailed herein. Each processing unit 1750 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 1750 may include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

[0177] Each transmitter 1752 includes any suitable structure for generating signals for wireless transmission with one or more EDs or other devices. Each receiver 1754 includes any suitable structure for processing signals received wirelessly or wired from one or more EDs or other devices. Although shown as separate components, at least one transmitter 1752 and at least one receiver 1754 can be combined into a transceiver. Each antenna 1756 includes any appropriate structure for transmitting, receiving, or both transmitting and receiving wireless signals. Although a common antenna 1756 is shown here coupled to the transmitter 1752 and the receiver 1754, one or more antennas 1756 can be coupled to the transmitter 1752, while one or more separate antennas 1756 can be coupled to the receiver 1754. Each memory 1758 includes any suitable volatile and / or non-volatile memory and retrieval devices, such as those described above in connection with the ED 1710. The memory 1758 stores instructions and data used, generated, or collected by the base station 1770. For example, the memory 1758 can store software instructions or modules executed by the processing unit 1750 for implementing some or all of the functions or embodiments described herein.

[0178] Each input / output device 1766 facilitates interaction with users or other devices in the network (network communication). Each input / output device 1766 includes any suitable structure for providing information to or receiving information from a user, including a network communication interface.

[0179] It should be understood that one or more steps of the example methods provided herein can be performed by corresponding units or modules. For example, signals can be transmitted by a transmitting unit or module. Signals can be received by a receiving unit or module. Signals can be processed by a processing unit or module. Other steps can be performed by these or other modules. The corresponding units or modules can be implemented using hardware, software-executing components, or a combination thereof. For example, one or more units or modules can be or include one or more integrated circuits, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). It should be understood that if the modules are implemented using software, these modules can be retrieved in whole or in part by a processor as needed, retrieved individually or collectively for processing, retrieved in one or more instances as needed, and the modules themselves can include instructions for further deployment and instantiation.

[0180] Generally, hardware, firmware, components that execute software, or some combination thereof can be used to implement the features disclosed herein. Electronic devices that may be suitable for implementing any or all of these components include microprocessors, microcontrollers, programmable logic devices (PLDs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), and other types of "intelligent" integrated circuits, etc.

[0181] Any storage device among various types of memory devices can be implemented. For example, memory 1708 and / or memory 1758 may include one or more physical storage devices. Solid-state storage devices such as flash devices can be implemented. Additionally or alternatively, storage devices with removable or even detachable storage media can be implemented.

[0182] Figure 17A and Figure 17B respectively show examples of a UE and a network device in which embodiments can be implemented. More generally, a device may include a processor and a non-transitory computer-readable storage medium, such as Figure 17A or Figure 17B the processing units 1700, 1750 and memories 1708, 1758 in. The device can be a UE, including a relay UE, a source UE, a destination UE, a helping remote UE, or a remote UE. Another example of the device is a network device, which can be a gNB, a TRP, a base station, or any other type of network device in this document. In one embodiment, the storage medium stores a program for the processor to execute, and the program includes instructions for performing the methods disclosed herein. For example, when executed by the processor, the instructions can cause the processor to perform any of various operations.

[0183] Another embodiment relates to a computer program product, which includes a non-transitory computer-readable storage medium storing a program. The program includes instructions for performing the methods disclosed herein.

[0184] In some embodiments, the program includes instructions for causing the processor to perform the following actions: coordinating the configuration of a secondary relay link between a UE and a wireless communication network with a primary relay link between the UE and the wireless communication network; and transmitting signaling to enable the configuration of the secondary relay link according to the coordination. In another embodiment, the program includes instructions for causing the processor to perform a method including the following steps: coordinating the configuration of a second relay link of a UE with a first relay link of the UE in a wireless communication network; and transmitting signaling to enable the configuration of the second relay link according to the coordination. As in other embodiments, the first relay link and the second relay link can be or include a relay link between a UE and a network device in a wireless communication network, or a relay link between a UE and another UE.

[0185] In any combination of various combinations, some embodiments include any one or more of the following features:

[0186] Coordination includes determining whether the SRL or the second relay link establishment condition associated with the primary relay link or the first relay link is satisfied;

[0187] Transmission includes transmitting signaling in response to determining that the SRL or the second relay link establishment condition is satisfied;

[0188] Determining whether the SRL or the second relay link establishment condition associated with the primary relay link or the first relay link is satisfied includes being determined by components participating in the primary relay link or the first relay link;

[0189] Transmission includes transmitting signaling from a component participating in the primary relay link or the first relay link to another component to cause the other component to send discovery signaling, and the discovery signaling enables identification of candidate relay links configured as the SRL or the second relay link;

[0190] The other components are one or more of the following: UE, another component participating in the primary relay link or the first relay link, and candidate components through which the SRL or the second relay link can be configured;

[0191] Transmission includes sending discovery signaling, and the discovery signaling enables identification of candidate relay links configured as the SRL or the second relay link;

[0192] Coordination includes receiving signaling associated with the primary relay link or the first relay link;

[0193] Transmission includes transmitting signaling in response to receiving signaling associated with the primary relay link or the first relay link to enable configuration of the SRL or the second relay link;

[0194] The signaling associated with the primary relay link or the first relay link is or includes signaling for transmitting discovery signaling, and the discovery signaling enables identification of candidate relay links configured as the SRL or the second relay link;

[0195] Transmission includes sending discovery signaling;

[0196] The signaling associated with the primary relay link or the first relay link is or includes discovery signaling, and the discovery signaling enables identification of candidate relay links configured as the SRL or the second relay link;

[0197] The program further includes instructions for performing measurements according to the discovery signaling;

[0198] Transmission includes sending signaling associated with the measurements;

[0199] The discovery signaling is or includes a reference signaling, such as CSI-RS or DMRS;

[0200] The signaling associated with the measurement is or includes one or more of the following: signaling indicating the measurement, signaling indicating whether the measurement meets the conditions for configuring a relay link as an SRL or a second relay link, the relay link including a link between the component from which the discovery signaling is received;

[0201] The procedure further includes instructions for transmitting additional information associated with a candidate relay link for which the measurement is performed;

[0202] The signaling associated with the primary relay link or the first relay link is or includes signaling sent by a component not participating in the primary relay link or the first relay link;

[0203] Coordination includes receiving signaling indicating a candidate relay link for configuring as an SRL or a second relay link;

[0204] Transmission includes sending configuration signaling for configuring an SRL or a second relay link from a component participating in the primary relay link or the first relay link;

[0205] Additionally or alternatively, the procedure may include instructions for coordinating communication with a UE via the primary relay link or the first relay link and the SRL or the second relay link;

[0206] Coordinating communication includes determining data splitting for communication with a UE via the primary relay link or the first relay link and the SRL or the second relay link;

[0207] Coordinating communication includes performing one or more of the following actions: sending signaling indicating data splitting to one or more components participating in the primary relay link or the first relay link; sending signaling indicating data splitting to one or more components participating in the SRL or the second relay link; splitting data (e.g., received data) according to the data splitting for transmission via the primary relay link or the first relay link and the SRL or the second relay link; aggregating received data according to the data splitting for transmission via the primary relay link or the first relay link and the SRL or the second relay link;

[0208] The signaling indicating data splitting is or includes an SCI;

[0209] Splitting and aggregation are performed according to the received SCI;

[0210] Splitting includes splitting data (e.g., received data) for transmission via preconfigured communication resources associated with the primary relay link or the first relay link and the SRL or the second relay link;

[0211] The data received for aggregation includes data received via preconfigured communication resources associated with the primary relay link or the first relay link and the SRL or the second relay link;

[0212] Coordinated communication includes determining whether to maintain communication with the UE via the primary relay link or the first relay link and the SRL or the second relay link, and in response to determining not to maintain communication with the UE via the primary relay link or the first relay link and the SRL or the second relay link, enabling communication with the UE only via the primary relay link or the first relay link;

[0213] Coordinated communication includes determining whether to maintain communication with the UE only via the primary relay link or the first relay link, and in response to determining not to maintain communication with the UE only via the primary relay link or the first relay link, enabling communication with the UE via the primary relay link or the first relay link and another relay link such as the secondary relay link or the second relay link or another secondary relay link;

[0214] The procedure includes instructions for a relay UE of the primary relay link or the first relay link to perform any one or more of the following actions: determining data splitting, determining whether to maintain communication with the UE via the primary relay link or the first relay link and the secondary relay link or the second relay link, in response to determining not to maintain communication with the UE via the primary relay link or the first relay link and the secondary relay link or the second relay link, enabling communication with the UE only via the primary relay link or the first relay link, determining whether to maintain communication with the UE only via the primary relay link or the first relay link, in response to determining not to maintain communication with the UE only via the primary relay link or the first relay link, enabling communication with the UE via the primary relay link or the first relay link and another relay link such as the secondary relay link or the second relay link or another secondary relay link;

[0215] The primary relay link or the first relay link includes at least one relay UE within the coverage area of the wireless communication network;

[0216] The UE is outside the coverage area of the wireless communication network;

[0217] The primary relay link or the first relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE;

[0218] The SRL or the second relay link includes at least one relay UE within the coverage area of the wireless communication network, such as a secondary relay UE;

[0219] The SRL further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE of the secondary relay link or the second relay link and the UE, such as a secondary helping remote UE;

[0220] Coordinated communication includes one or more of the following actions performed by a relay UE of the SRL: receiving signaling indicating data splitting determined for communication with the UE via a primary relay link or a first relay link and the SRL or a second relay link; splitting data (e.g., received data) for transmission via the SRL or the second relay link according to the data splitting; disabling communication with the UE via the SRL or the second relay link in response to signaling received from a relay UE of the primary relay link or the first relay link, and enabling communication with the UE via the SRL or the second relay link in response to signaling received from a relay UE of the primary relay link or the first relay link;

[0221] Coordinated communication includes one or more of the following actions performed by a UE: receiving signaling indicating data splitting determined for communication with the UE via a primary relay link or a first relay link and the SRL or a second relay link; splitting data for transmission via the primary relay link or the first relay link and the SRL or the second relay link according to the data splitting; aggregating data received via the primary relay link or the first relay link and the SRL or the second relay link according to the data splitting; disabling communication via the SRL or the second relay link in response to signaling received from a relay UE of the primary relay link or the first relay link, enabling communication via the SRL or the second relay link or another relay link such as another secondary relay link with the UE in response to signaling received from a relay UE of the primary relay link or the first relay link.

[0222] In another embodiment, the program includes instructions for performing the following actions: causing a processor in a component participating in the MRL between a remote UE and a wireless communication network to receive signaling indicating measurements performed by a first UE on a direct wireless communication link (e.g., a sidelink between the first UE and the second UE); determining, based on the received signaling, whether an SRL between the remote UE and the wireless communication network should be established via the direct wireless communication link. Similar features can be applied to a UE-to-UE link, where the instructions are for performing the following actions: causing a processor in a component participating in a first relay link of a remote UE in a wireless communication network to receive signaling indicating measurements performed by a first UE on a direct wireless communication link (e.g., a sidelink between the first UE and the second UE); determining, based on the received signaling, whether a second relay link of the remote UE should be established via the direct wireless communication link.

[0223] By any combination of various combinations, some embodiments include any one or more of the following features:

[0224] The components participating in the primary relay link or the first relay link are or include one of the following components: a network device in a communication network, a relay UE of the primary relay link or the first relay link, an assisting remote UE of the primary relay link or the first relay link, and a remote UE;

[0225] The program includes instructions for causing a processor to perform the following actions: in response to determining that the SRL or the second relay link should be established via a direct wireless communication link, sending configuration signaling for configuring the SRL or the second relay link;

[0226] The remote UE is the first UE or the second UE;

[0227] The program includes instructions for causing a processor to perform the following actions: sending signaling to enable the first UE to perform measurements;

[0228] The program includes instructions for causing a processor to perform the following actions: sending signaling to cause the second UE to send signaling to the first UE, so that the first UE can perform measurements.

[0229] In another embodiment, the program includes instructions for causing a processor to perform the following actions: configuring the MRL to carry data, control information, and / or feedback information between the UE and the wireless communication network; configuring the SRL to carry data between the UE and the wireless communication network; according to the relay link role switching condition, reconfiguring the SRL as a new MRL to carry data, control information, and / or feedback information between the UE and the wireless communication network, and reconfiguring the MRL as a new SRL to carry data between the UE and the wireless communication network.

[0230] In another reconfiguration embodiment, the program includes instructions for causing a processor to perform the following actions: configuring the first relay link MRL to transmit data, control information, and / or feedback information with a UE in the wireless communication network; configuring the second relay link to transmit data with the UE; according to the relay link role switching condition, reconfiguring the second relay link to transmit data, control information, and / or feedback information with the UE, and reconfiguring the first relay link to transmit data with the UE.

[0231] For example, through the method embodiments disclosed herein, other features that can be implemented in the device embodiments and / or computer program product embodiments may be or become apparent.

[0232] Figure 18FIG. is a block diagram of an example of a communication network 1800 according to one embodiment. The communication network 1800 includes a core network 1802 and an access network 1806. The access network 1806 serves a plurality of UEs 1804a, 1804b, 1804c, 1804d, 1804e, 1804f, 1804g, 1804h, and 1804i. In some embodiments, the access network 1806 is an evolved universal terrestrial access (E-UTRA) network. Another example of the access network 1806 is a cloud access network (C-RAN). The access network 1806 includes a plurality of BSs 1808a, 1808b, and 1808c. Each of the BSs 1808a-c provides a corresponding wireless coverage area 1810a, 1810b, and 1810c, also referred to as a cell. Each of the BSs 1808a-c can be implemented using a wireless transceiver, one or more antennas, and associated processing circuitry (such as antenna radio frequency (RF) circuitry), one or more analog-to-digital converters, one or more digital-to-analog converters, and the like.

[0233] Although not shown, each of the BSs 1808a-c is directly or indirectly connected to the core network 1802 through one or more central processing hubs (such as servers). The BSs 1808a-c can act as gateways between the wired and wireless portions of the access network 1806.

[0234] Depending on the implementation, each of the BSs 1808a-c can also be referred to as a base station transceiver station, a wireless BS, a network node, a transmitting node, a transmission point, a Node B, an eNode B, a remote radio head (RRH), etc.

[0235] In operation, the plurality of UEs 1804a-i access the communication network 1800 using the access network 1806 through wireless communication with one or more of the BSs 1808a-c.

[0236] UEs 1804a-d are very close to each other. Although each of the UEs 1804a-d can communicate wirelessly with the BS 1808a, they can also communicate directly with each other, as shown at 1816. The communication represented at 1816 is direct communication between UEs, such as the sidelink communication disclosed herein, which does not pass through access network components such as BSs. As Figure 18As shown, the communication 1816 between UEs is directly carried out between UEs 1804a - d and is not routed through BS 1808a or any other part of the access network 1806. The communication 1816 can also be referred to as sidelink communication. In the embodiments disclosed herein, the communication between UEs uses sidelink channels and sidelink air interfaces. On the other hand, the communication between an access network component (such as BS 1808a) and a UE (such as communication 1814) is called access communication. Access communication occurs on an access channel, which can be an uplink channel or a downlink channel, and access communication uses a radio access communication interface, such as a cellular radio access air interface. The access and sidelink air interfaces can use different transmission formats, such as different waveforms, different multiple access schemes, or different radio access technologies. Some examples of radio access technologies that can be used for the access air interface or the sidelink air interface are: Long Term Evolution (LTE), LTE License Assisted Access (LTE-LAA), and WiFi.

[0237] By using the sidelink communication 1816, UEs 1804a - d can assist in the wireless communication between UEs 1804a - d and BS 1808a. For example, if UE 1804c fails to correctly decode a data packet received from BS 1808a, but UE 1804d can receive and correctly decode the data packet from BS 1808a, then UE 1804d can directly send the decoded data packet to UE 1804c by using the sidelink communication 1816. Another example is that if UE 1804c moves out of the wireless coverage area 1810c such that UE 1804c can no longer communicate wirelessly with BS 1808a, then UE 1804b can forward the messages between UE 1804c and BS 1808a. Another example is that both UE1804a and UE 1804c can receive a signal sent from BS 1808a, and the signal carries a data packet for UE 1804c. Then, UE 1804a can send the signal received by UE 1804a to UE 1804c through the sidelink communication 1816. Then, UE1804c can use the information received from UE 1804a to assist in decoding the data packet from BS 1808a. In these examples, the capacity or coverage can be enhanced by the assistance of one or more of UEs 1804a, 1804b, and 1804d.

[0238] In some embodiments, UEs 1804a - d form a UE group 1820. However, it should be noted that the relay links disclosed herein do not depend on the UE group.

[0239] The access network 1806 may assign a group identifier (ID) to the UE group 1820. The UE group ID may allow the access network 1806 to address the UE group 1820 as a whole and distinguish the UE group 1820 from other UE groups. The UE group ID may also be used to broadcast information within the UE group, i.e., to address all other UEs within the UE group 1820. The UE group 1820 may form a logical or virtual device grid, where the members of the UE group 1820 communicate with each other using UE communication over the sidelink air interface, but the UE group 1820 acts as a single distributed virtual transceiver relative to the access network 1806. For example, the UE group ID may be a group radio network temporary identifier (G-RNTI).

[0240] When a particular UE (e.g., UE 1804c) in the UE group 1820 is or will be assisting the wireless communication between this UE and the BS 1808a, the other UEs 1804a, 1804b, and 1804d in the group 1820 may be considered candidates for relay UEs or assisting UEs. In a group-based embodiment, the subset of UEs that actually assist UE 1804c forms a cooperative active set or cooperative group. The cooperative active set can be dynamically selected to assist UE 1804c.

[0241] In the UE group 1820, UEs 1804a, 1804b, and 1804d form a cooperative candidate set. If UEs 1804a and 1804b actually assist UE 1804c, then UEs 1804a and 1804b form a cooperative active set. As UEs 1804a - d move around, some UEs may leave the UE group 1820. Additionally or alternatively, UE movement may cause other UEs to join the UE group 1820. Therefore, the cooperative candidate set may change over time. For example, the cooperative candidate set may change semi-statically. For example, if the network determines that the UE group 1820 is no longer needed or no longer has the opportunity to assist the wireless communication between the BS 1808a and the members of the UE group 1820, then the UE group 1820 may also be terminated by the network 1806.

[0242] There may be more than one UE group. For example, Figure 18 UEs 1804e and 1804f in form another UE group 1822.

[0243] Figure 19 is a block diagram of an example of a network 1952 serving two UEs 1954a and 1954b according to one embodiment. The network 1952 may be Figure 18 the access network 1806 in, and the two UEs 1954a and 1954b may beFigure 18 Two of the four UEs 1804a-d, or UEs 1954a and 1954b can be Figure 18 UEs 1804e and 1804f in. However, more generally, this need not be the case, and thus different reference numerals are used in Figure 19 the drawings.

[0244] Network 1952 includes BS 1956 and management module 1958. Management module 1958 instructs BS 1956 to perform actions. Management module 1958 is shown physically separate from BS 1956 and coupled to BS 1956 via communication link 1960. For example, management module 1958 can be part of a server in network 1952. Alternatively, management module 1958 can be part of BS 1956.

[0245] Management module 1958 includes processor 1962, memory 1964, and communication module 1966. Communication module 1966 is implemented by processor 1962 when the processor 1962 accesses and executes a series of instructions stored in memory 1964, and these instructions define the actions of communication module 1966. When the instructions are executed, communication module 1966 causes BS 1956 to perform the actions described herein such that network 1952 can establish, coordinate, instruct, or control relays and may perform these operations on a group of UEs. Alternatively, communication module 1966 can be implemented using dedicated circuitry, such as an application specific integrated circuit (ASIC) or a programmed field programmable gate array (FPGA).

[0246] UE 1954a includes communication subsystem 1970a, two antennas 1972a and 1974a, processor 1976a, and memory 1978a. UE 1954a also includes communication module 1980a. Communication module 1980a is implemented by processor 1976a when the processor 1976a accesses and executes a series of instructions stored in memory 1978a, and these instructions define the actions of communication module 1980a. When the instructions are executed, communication module 1980a causes UE 1954a to perform the actions described herein with respect to one or more of a relay UE, a helping UE, and a remote UE. Features related to establishing and participating in a group of UEs can also be supported. Alternatively, module 1980a can be implemented by dedicated circuitry (such as an ASIC or FPGA).

[0247] The communication subsystem 1970a includes processing circuitry, a transmitting circuit, and a receiving circuit for transmitting messages from the UE 1954a and receiving messages at the UE 1954a. Although one communication subsystem 1970a is shown, the communication subsystem 1970a can be multiple communication subsystems. The antenna 1972a transmits wireless communication signals to the BS 1956 and receives wireless communication signals from the BS 1956. The antenna 1974a transmits sidelink communication signals to other UEs (including the UE 1954b) and receives sidelink communication signals from other UEs. In some implementations, there may not be two separate antennas 1972a and 1974a. A single antenna can be used. Alternatively, there can be multiple antennas, but they are not divided into antennas only for sidelink communication and antennas only for communication with the BS 1956.

[0248] SL communication can be via Wi-Fi, in which case the antenna 1974a can be a Wi-Fi antenna. Alternatively, the sidelink communication can be via Bluetooth TM ), in which case the antenna 1974a can be a Bluetooth TM ) antenna. Additionally or alternatively, the sidelink communication can be via licensed spectrum or unlicensed spectrum.

[0249] The UE 1954b includes the same components described above with respect to the UE 1954a. That is, the UE 1954b includes a communication subsystem 1970b, antennas 1972b and 1974b, a processor 1976b, a memory 1978b, and a communication module 1980b.

[0250] Figure 18 and Figure 19 illustrates a system in which embodiments can be implemented. In some embodiments, the UE includes a processor (e.g., Figure 19 1976a, 1976b therein) and a non-transitory computer-readable storage medium for storing programs for execution by the processor (e.g., Figure 19 1978a, 1978b therein). Additionally or alternatively, the non-transitory computer-readable storage medium can be provided separately as a computer program product. Examples are provided elsewhere in this document.

[0251] The present disclosure presents embodiments of multi-relay link configurations that can help improve the relay performance of remote UEs and relay link coordination or cooperation, including multiple scenarios for in-coverage and out-of-coverage situations.

[0252] Various methods for establishing multiple relay links and configuring cooperation between them are disclosed. For example, the MRL can be established first and then used to add one or more SRLs by sending signaling to one or more of the MRL remote UE, another relay UE, and one or more other components. For example, signaling can be sent to such components to cause one or more operations such as the transmission of discovery signaling and measurement feedback to be performed. Additionally or alternatively, one or more of the MRL remote UE, relay UE, and assisting UE can be used to send discovery signaling and cause one or more other remote UEs or relay UEs to perform one or more measurements. One or more of the MRL remote UE and relay UE can negotiate with one or more other remote UEs or relay UEs to establish the SRL, or the SRL configuration can be handled by a network device (such as a gNB or TRP).

[0253] Options for switching between single-relay transmission and multi-relay link cooperation are also described and can include semi-static configuration or dynamic signaling, etc. Such switching can provide flexibility to adapt to different requirements between robustness and performance.

[0254] This disclosure includes various embodiments, including the following examples.

[0255] According to Example 1, a method includes: coordinating the configuration of a secondary relay link between a UE and a wireless communication network with a primary relay link between the UE and the wireless communication network; transmitting signaling to enable the configuration of the secondary relay link according to the coordination.

[0256] Example 2 relates to the method according to Example 1, wherein the coordination includes determining whether a secondary relay link establishment condition associated with the primary relay link is satisfied, and the transmission includes transmitting the signaling related to determining that the secondary relay link establishment condition is satisfied.

[0257] Example 3 relates to the method according to Example 2, wherein the determination includes being determined by a component participating in the primary relay link.

[0258] Example 4 relates to the method according to Example 1 or 2, wherein the transmission includes sending the signaling from a component participating in the primary relay link to another component to cause the other component to send discovery signaling, and the discovery signaling enables the identification of candidate relay links for configuring as the secondary relay link.

[0259] Example 5 relates to the method according to Example 4, wherein the other component includes one or more of the following: the UE, another component participating in the primary relay link, and a candidate component through which the secondary relay link can be configured.

[0260] Example 6 relates to the method according to Example 1 or 2, wherein the transmission includes sending discovery signaling that enables identification of candidate relay links for configuring as the secondary relay link.

[0261] Example 7 relates to the method according to Example 1 or 2, wherein the coordination includes receiving signaling associated with the primary relay link, and the transmission includes transmitting signaling in response to receiving the signaling associated with the primary relay link to enable configuration of the secondary relay link.

[0262] Example 8 relates to the method according to Example 7, wherein the signaling associated with the primary relay link includes signaling for transmitting discovery signaling that enables identification of candidate relay links for configuring as the secondary relay link, and the transmission includes sending the discovery signaling.

[0263] Example 9 relates to the method according to Example 7, wherein the signaling associated with the primary relay link includes discovery signaling that enables identification of candidate relay links for configuring as the secondary relay link, the method further includes performing measurements according to the discovery signaling, and the transmission includes sending signaling associated with the measurements.

[0264] Example 10 relates to the method according to any one of Examples 4 to 6, 8, and 9, wherein the discovery signaling includes reference signaling.

[0265] Example 11 relates to the method according to Example 9, wherein the signaling associated with the measurements includes one or more of the following: signaling indicating the measurements, signaling indicating whether the measurements satisfy conditions for configuring a relay link as the secondary relay link, the relay link including a link between components from which the discovery signaling is received.

[0266] Example 12 relates to the method according to Example 9 or 11, wherein the method further includes: transmitting additional information associated with the candidate relay link for which the measurements are performed.

[0267] Example 13 relates to the method according to any one of Examples 7 to 12, wherein the signaling associated with the primary relay link includes signaling sent by components not participating in the primary relay link.

[0268] Example 14 relates to the method according to Example 1, wherein the coordination includes receiving signaling indicating candidate relay links for configuring as the secondary relay link.

[0269] Example 15 relates to the method according to any one of Examples 1 to 14, wherein the transmission includes sending configuration signaling for configuring the secondary relay link from a component participating in the primary relay link.

[0270] Example 16 relates to the method according to any one of Examples 1 to 15, further comprising: coordinating communication with the UE via the primary relay link and the secondary relay link.

[0271] Example 17 relates to the method according to Example 16, wherein coordinating communication includes determining data splitting for communication with the UE via the primary relay link and the secondary relay link.

[0272] Example 18 relates to the method according to Example 17, wherein coordinating communication further comprises performing one or more of the following actions: sending signaling indicating the data splitting to one or more components participating in the primary relay link; sending signaling indicating the data splitting to one or more components participating in the secondary relay link; splitting the received data according to the data splitting for transmission via the primary relay link and the secondary relay link; aggregating the received data according to the data splitting for transmission via the primary relay link and the secondary relay link.

[0273] Example 19 relates to the method according to Example 18, wherein the signaling indicating the data splitting includes SCI, and the splitting and the aggregation are performed according to the received SCI.

[0274] Example 20 relates to the method according to Example 18, wherein the splitting includes splitting the received data for transmission via pre-configured communication resources associated with the primary relay link and the secondary relay link, and the data received for the aggregation includes data received via pre-configured communication resources associated with the primary relay link and the secondary relay link.

[0275] Example 21 relates to the method according to Example 16, wherein coordinating communication includes determining whether to maintain communication with the UE via the primary relay link and the secondary relay link, and in response to determining not to maintain communication with the UE via the primary relay link and the secondary relay link, enabling communication with the UE only via the primary relay link.

[0276] Example 22 relates to the method according to Example 21, wherein coordinating communication includes determining whether to maintain communication with the UE only via the primary relay link, and in response to determining not to maintain communication with the UE only via the primary relay link, enabling communication with the UE via the primary relay link and the secondary relay link or another secondary relay link.

[0277] Example 23 relates to the method according to any one of Examples 17 to 22, including one or more of the following actions performed by a relay UE of the primary relay link: determining data splitting, determining whether to maintain communication with the UE via the primary relay link and the secondary relay link, in response to determining not to maintain communication with the UE via the primary relay link and the secondary relay link, enabling communication with the UE only via the primary relay link, determining whether to maintain communication with the UE only via the primary relay link, and in response to determining not to maintain communication with the UE only via the primary relay link, enabling communication with the UE via the primary relay link and the secondary relay link or another secondary relay link.

[0278] Example 24 relates to the method according to any one of Examples 1 to 23, wherein the primary relay link includes at least one relay UE within a coverage area of the wireless communication network, and the UE is outside the coverage area of the wireless communication network.

[0279] Example 25 relates to the method according to Example 24, wherein the primary relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE.

[0280] Example 26 relates to the method according to Example 24 or 25, wherein the secondary relay link includes at least one secondary relay UE within a coverage area of the wireless communication network, and the UE is outside the coverage area of the wireless communication network.

[0281] Example 27 relates to the method according to Example 26, wherein the secondary relay link further includes a secondary helping remote UE outside the coverage area of the wireless communication network and communicating with the secondary relay UE and the UE.

[0282] Example 28 relates to a method, including: configuring a primary relay link and a secondary relay link between a UE and a wireless communication network; coordinating communication with the UE via the primary relay link and the secondary relay link.

[0283] Example 29 relates to the method according to Example 28, wherein coordinating communication includes determining data splitting for communication with the UE via the primary relay link and the secondary relay link.

[0284] Example 30 relates to the method according to Example 29, wherein the coordinated communication further includes performing one or more of the following actions: sending a signaling indicating the data splitting to one or more components participating in the primary relay link; sending a signaling indicating the data splitting to one or more components participating in the secondary relay link; splitting the received data according to the data splitting for transmission through the primary relay link and the secondary relay link; aggregating the received data according to the data splitting for transmission through the primary relay link and the secondary relay link.

[0285] Example 31 relates to the method according to Example 30, wherein the signaling indicating the data splitting includes SCI, and the splitting and the aggregation are performed according to the received SCI.

[0286] Example 32 relates to the method according to Example 30, wherein the splitting includes splitting the received data for transmission through preconfigured communication resources associated with the primary relay link and the secondary relay link, and the received data for the aggregation includes the data received through the preconfigured communication resources associated with the primary relay link and the secondary relay link.

[0287] Example 33 relates to the method according to Example 28, wherein the coordinated communication includes determining whether to maintain the communication with the UE through the primary relay link and the secondary relay link, and in response to determining not to maintain the communication with the UE through the primary relay link and the secondary relay link, enabling the communication with the UE only through the primary relay link.

[0288] Example 34 relates to the method according to Example 33, wherein the coordinated communication includes determining whether to maintain the communication with the UE only through the primary relay link, and in response to determining not to maintain the communication with the UE only through the primary relay link, enabling the communication with the UE through the primary relay link and the secondary relay link or another secondary relay link.

[0289] Example 35 relates to the method according to any one of Examples 29 to 34, including performing one or more of the following actions by the relay UE of the primary relay link: determining the data splitting, determining whether to maintain the communication with the UE through the primary relay link and the secondary relay link, in response to determining not to maintain the communication with the UE through the primary relay link and the secondary relay link, enabling the communication with the UE only through the primary relay link, determining whether to maintain the communication with the UE only through the primary relay link, in response to determining not to maintain the communication with the UE only through the primary relay link, enabling the communication with the UE through the primary relay link and the secondary relay link or another secondary relay link.

[0290] Example 36 relates to the method according to any one of Examples 28 to 35, wherein the primary relay link includes at least one relay UE within the coverage area of the wireless communication network, and the UE is outside the coverage area of the wireless communication network.

[0291] Example 37 relates to the method according to Example 36, wherein the primary relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE.

[0292] Example 38 relates to the method according to Example 36 or 37, wherein the secondary relay link includes at least one secondary relay UE within the coverage area of the wireless communication network, and the UE is outside the coverage area of the wireless communication network.

[0293] Example 39 relates to the method according to Example 38, wherein the secondary relay link further includes a secondary helping remote UE outside the coverage area of the wireless communication network and communicating with the secondary relay UE and the UE.

[0294] Example 40 relates to the method according to Example 28, wherein the coordinated communication includes one or more of the following actions performed by a relay UE of the secondary relay link: receiving signaling indicating data splitting determined for communication with the UE via the primary relay link and the secondary relay link; splitting the received data according to the data splitting for transmission via the secondary relay link; disabling communication with the UE via the secondary relay link in response to signaling received from the relay UE of the primary relay link, and enabling communication with the UE via the secondary relay link in response to signaling received from the relay UE of the primary relay link.

[0295] Example 41 relates to the method according to Example 28, wherein the coordinated communication includes one or more of the following actions performed by the UE: receiving signaling indicating data splitting determined for communication with the UE via the primary relay link and the secondary relay link; splitting the data according to the data splitting for transmission via the primary relay link and the secondary relay link; aggregating the data received via the primary relay link and the secondary relay link according to the data splitting; disabling communication via the secondary relay link in response to signaling received from the relay UE of the primary relay link, and enabling communication with the UE via the secondary relay link or another secondary relay link in response to signaling received from the relay UE of the primary relay link.

[0296] Example 42 relates to a method, including: components participating in a primary relay link between a remote UE and a wireless communication network receive signaling indicating measurements performed by a first UE on a direct wireless communication link between the first UE and the second UE; and based on the received signaling, determine whether a secondary relay link between the remote UE and the wireless communication network should be established via the direct wireless communication link.

[0297] Example 43 relates to the method according to Example 42, wherein the components participating in the primary relay link include one of the following: a network device in the communication network, a relay UE of the primary relay link, a helping remote UE of the primary relay link, and the remote UE.

[0298] Example 44 relates to the method according to Example 42 or 43, wherein the remote UE is the first UE or the second UE.

[0299] Example 45 relates to the method according to any one of Examples 42 to 44, further including: in response to determining that the secondary relay link between the remote UE and the wireless communication network should be established via the direct wireless communication link, send configuration signaling for configuring the secondary relay link.

[0300] Example 46 relates to the method according to any one of Examples 42 to 45, further including: send signaling by the components participating in the primary relay link to enable the first UE to perform the measurement.

[0301] Example 47 relates to the method according to any one of Examples 42 to 46, further including: the components participating in the primary relay link send signaling to cause the second UE to send signaling to the first UE, so that the first UE can perform the measurement.

[0302] Example 48 relates to a method, including: configure a primary relay link to carry data, control information, and / or feedback information between a UE and a wireless communication network; configure a secondary relay link to carry data between the UE and the wireless communication network; according to relay link role switching conditions, reconfigure the secondary relay link to carry data, control information, and / or feedback information between the UE and the wireless communication network, and reconfigure the primary relay link to carry data between the UE and the wireless communication network.

[0303] Example 49 relates to a device, including: a communication interface; a processor coupled to the communication interface; a non-transitory computer-readable storage medium coupled to the processor and storing a program for execution by the processor, the program including instructions for performing the method according to any one of Examples 1 to 48.

[0304] Example 50 relates to a computer program product comprising a non-transitory computer-readable storage medium storing a program, the program comprising instructions for performing the method according to any one of Examples 1 to 48.

[0305] What has been described is only the application of the principles of the embodiments of the present disclosure for illustration. Those skilled in the art can implement other devices and methods.

[0306] For example, although combinations of features are shown in the illustrated embodiments, not all features need to be combined to achieve the advantages of the various embodiments of the present disclosure. In other words, a system or method designed according to the embodiments of the present disclosure does not necessarily include all the features shown in any one of the drawings or all the parts schematically shown in the drawings. In addition, selected features of one exemplary embodiment may be combined with selected features of other exemplary embodiments.

[0307] Although the present disclosure has been described with reference to the illustrative embodiments, this description is not intended to be construed in a limiting sense. After referring to this specification, various modifications and combinations of the illustrative embodiments and other embodiments of the present disclosure will be apparent to those skilled in the art. Accordingly, the appended claims include any such modifications or embodiments.

[0308] Although aspects of the present invention have been described with reference to specific features and embodiments of the present invention, various modifications and combinations can be made without departing from the scope of the present invention. Accordingly, the specification and drawings should be regarded only as illustrative of some embodiments of the present invention as defined by the appended claims, and should be considered to cover any and all modifications, variations, combinations or equivalents falling within the scope of the present invention. Accordingly, although the embodiments and potential advantages have been described in detail, various changes, substitutions and alterations can be made without departing from the present invention as defined by the appended claims. In addition, the scope of the present application is not limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, modules, methods and steps described in the specification. Those of ordinary skill in the art will readily appreciate from the disclosure of the present invention that processes, machines, manufactures, compositions of matter, modules, methods or steps (currently existing or later developed) that perform or achieve substantially the same functions or results as the corresponding embodiments described herein can be used according to the present invention. Accordingly, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, modules, methods or steps.

[0309] In addition, although mainly described in the context of methods and devices, other implementations are also contemplated, for example, as instructions stored on a non-transitory computer-readable medium. These media can store programming or instructions to perform any of the various methods consistent with the present disclosure.

[0310] In addition, any module, component, or device that executes instructions as illustrated in this document may include or otherwise access one or more non-transitory computer-readable or processor-readable storage media for storing information, such as computer-readable or processor-readable instructions, data structures, program modules, and / or other data. A non-exhaustive list of examples of non-transitory computer-readable or processor-readable storage media includes magnetic tape cartridges, tapes, disk memories, or other magnetic storage devices, compact disc read-only memory (CD-ROM), digital video disc or digital versatile disc (DVD), Blu-ray Disc TM ), and other optical discs, or other optical storage, volatile and non-volatile removable and non-removable media implemented in any method or technology, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other storage technologies. Any of these non-transitory computer-readable or processor-readable storage media may be part of the device or may be accessible to or connected to the device. Any application or module described in this document may be implemented using computer-readable and executable instructions, or the processor may be stored or otherwise maintained by such non-transitory computer-readable or processor-readable storage media.

Claims

1. A communication method, characterized in that, Comprising: Coordinating a second relay link of a user equipment (UE) in a wireless communication network with a first relay link of the UE; Transmitting signaling to enable configuration of the second relay link according to the coordination, wherein the first relay link includes a relay UE within a coverage area of the wireless communication network, the UE is outside the coverage area of the wireless communication network, and the first relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE.

2. The method according to claim 1, wherein: the coordination includes determining whether a second relay link establishment condition associated with the first relay link is satisfied, the transmission includes transmitting the signaling related to determining that the second relay link establishment condition is satisfied.

3. The method according to claim 1, characterized in that The transmission includes transmitting the signaling from a component participating in the first relay link to another component to cause the another component to send discovery signaling, and the discovery signaling enables identification of a candidate relay link configured as the second relay link.

4. The method according to claim 1, characterized in that, The transmission includes sending discovery signaling, and the discovery signaling enables identification of a candidate relay link configured as the second relay link.

5. The method according to claim 1, wherein: the coordination includes receiving signaling associated with the first relay link, the transmission includes, in response to receiving the signaling associated with the first relay link, transmitting the signaling to enable configuration of the second relay link.

6. The method according to claim 1, wherein The coordination includes receiving signaling indicating a candidate relay link configured as the second relay link.

7. The method according to claim 1, wherein The transmission includes sending configuration signaling for configuring the second relay link from a component participating in the first relay link.

8. The method according to claim 1, wherein Further comprising: Determining data splitting for communication with the UE via the first relay link and the second relay link.

9. The method according to claim 1, characterized in that, The second relay link includes a relay UE within the coverage area of the wireless communication network.

10. The method according to claim 9, characterized in that, The second relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE of the second relay link and the UE.

11. The method according to any one of claims 1 to 10, characterized in that, The first relay link and the second relay link include a relay link between the UE and a network device in the wireless communication network, or a relay link between the UE and another UE.

12. A communication method, characterized in that, Comprising: Configuring a first relay link and a second relay link for a user equipment (UE) in a wireless communication network; Coordinating communication with the UE via the first relay link and the second relay link, wherein the first relay link includes a relay UE within a coverage area of the wireless communication network, the UE is outside the coverage area of the wireless communication network, and the first relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE.

13. The method according to claim 12, characterized in that, The coordinating communication includes determining data splitting for communication with the UE via the first relay link and the second relay link.

14. The method according to claim 12, wherein, The coordinated communication includes determining whether to maintain communication with the UE via the first relay link and the second relay link, and in response to determining not to maintain communication with the UE via the first relay link and the second relay link, enabling communication with the UE only via the first relay link.

15. The method according to claim 12, wherein The second relay link includes a relay UE within the coverage area of the wireless communication network.

16. The method according to claim 15, characterized in that, The second relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE of the second relay link.

17. A communication method, characterized in that, Comprising: Components participating in a first relay link of a remote user equipment (UE) in a wireless communication network receive signaling indicating measurements performed by a first UE on a direct wireless communication link between the first UE and a second UE. Based on the received signaling, determine whether a second relay link of the remote UE should be established via the direct wireless communication link. Wherein, the first relay link includes a relay UE within the coverage area of the wireless communication network, the remote UE is outside the coverage area of the wireless communication network, and the first relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the remote UE.

18. The method according to claim 17, wherein The components participating in the first relay link include one of the following: a network device in the communication network, a relay UE of the first relay link, a helping remote UE of the first relay link, and the remote UE.

19. The method according to claim 17, wherein The remote UE is the first UE or the second UE.

20. The method according to any one of claims 17 to 19, characterized in that, Further comprising: In response to determining that the second relay link should be established via the direct wireless communication link, send configuration signaling for configuring the second relay link.

21. The method according to any one of claims 17 to 19, characterized in that, Further comprising: The components participating in the first relay link send signaling to enable the first UE to perform the measurement.

22. The method according to any one of claims 17 to 19, characterized in that, Further comprising: The components participating in the first relay link send signaling to cause the second UE to send signaling to the first UE, so that the first UE can perform the measurement.

23. A communication method, characterized in that, Comprising: Configure a first relay link to transmit data, control information, and / or feedback information with a user equipment (UE) in a wireless communication network. Configure a second relay link to transmit data with the UE. According to relay link role switching conditions, reconfigure the second relay link to transmit data, control information, and / or feedback information with the UE, and reconfigure the first relay link to transmit data with the UE. Wherein, the first relay link includes a relay UE within the coverage area of the wireless communication network, the UE is outside the coverage area of the wireless communication network, and the first relay link further includes a helping remote UE outside the coverage area of the wireless communication network and communicating with the relay UE and the UE.

24. A communication device, characterized in that, Comprising: A communication interface; A processor, coupled to the communication interface; A non-transitory computer-readable storage medium, coupled to the processor, and storing a program for execution by the processor, the program including instructions for performing the method according to any one of claims 1 to 23.

25. A computer program product, characterized in that, A non-transitory computer-readable storage medium including a stored program, the program including instructions for performing the method according to any one of claims 1 to 23.

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