UE Routing Policy (ursp) Rules For Roaming User Equipments (UEs)

Abstract

The invention relates to improving roaming services. In an example, a method includes a remote user equipment (UE) receiving a discovery message from a relay UE, the discovery message indicating a capability of the relay UE for the first remote UE to arrive at a second remote UE. The remote UE may determine whether to select the relay UE to relay a message to the second remote UE based on the discovery message. The remote UE may select the relay UE to arrive at the second remote UE based on the determination.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications, and more particularly to UE routing policy (URSP) rules for roaming user equipment (UE). Background Art

[0002] Cellular communications may be defined in various standards to enable communications between user equipment and cellular networks. For example, the fifth generation mobile network (5G) is a wireless standard designed to improve data transmission speeds, reliability, availability, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Figure 1 is a signaling diagram of a user equipment (UE) to network (U2N) discovery procedure according to one or more embodiments.

[0004] Figure 2 is a signaling diagram of a U2N process according to one or more implementations.

[0005] Figure 3 is a signaling diagram for a connectivity-based scheme for UE-to-UE (U2U) relay discovery according to one or more embodiments.

[0006] Figure 4 is a signaling diagram for a connectivity-based scheme for U2U relay discovery according to one or more embodiments.

[0007] Figure 5 is an illustration of rebroadcasting for interest-based schemes according to one or more implementations.

[0008] Figure 6 is a signaling diagram for a connectivity-based scheme for U2U relay discovery according to one or more embodiments.

[0009] Figure 7 is a signaling diagram for a connectivity-based scheme for U2U relay discovery according to one or more embodiments.

[0010] Figure 8 is a signaling diagram for a connectivity-based scheme for U2U relay discovery according to one or more embodiments.

[0011] Fig. 9 is a signaling diagram for an interest-based scheme for U2U relay discovery according to one or more implementations.

[0012] Fig.10 is a signaling diagram for an interest-based scheme for U2U relay discovery according to one or more implementations.

[0013] Fig.11is an illustration of a table of discovery message types according to one or more embodiments.

[0014] Fig.12 is an illustration of a remote UE discovery message according to one or more embodiments.

[0015] Fig.13 is an illustration of a U2URelayconnectivity message for Layer 2 (L2) U2U Relay Discovery according to one or more embodiments.

[0016] Fig.14 is an illustration of a U2Uinterestrelay message and a U2Uinterestresponse message for L2 U2U relay discovery according to one or more embodiments.

[0017] Fig.15 is an illustration of a remote UE representation for L2 U2U relay discovery according to one or more embodiments.

[0018] Fig.16 is a process flow for selecting a relay according to one or more embodiments.

[0019] Fig.17 is a process flow for selecting a relay according to one or more embodiments.

[0020] Fig.18 is a process flow for selecting a relay according to one or more embodiments.

[0021] Fig.19 A receiving component of a UE according to one or more embodiments is illustrated.

[0022] Fig. 20 A UE according to one or more embodiments is illustrated.

[0023] Fig.21 A gNB according to one or more embodiments is illustrated. DETAILED DESCRIPTION

[0024] The following specific embodiments refer to the accompanying drawings. The same reference numerals may be used to identify the same or similar elements in different drawings. In the following description, specific details, such as specific structures, architectures, interfaces, technologies, etc., are set forth for the purpose of illustration rather than limitation, so as to provide a thorough understanding of various aspects of various embodiments. However, it is obvious to those skilled in the art who benefit from the present disclosure that various aspects of various embodiments may be practiced in other examples that deviate from these specific details. In some cases, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the descriptions of various embodiments due to unnecessary details. For the purposes of this document, the phrase "A or B" refers to (A), (B), or (A and B); and the phrase "based on A" refers to "based at least in part on A", for example, it can be "based only on A" or it can be "based in part on A".

[0025] Embodiments of the present disclosure are described in conjunction with 5G networks. However, the embodiments are not limited thereto and are similarly applicable to other types of communication networks including other types of cellular networks.

[0026] The following is a glossary of terms that may be used in this disclosure.

[0027] As used herein, the term "circuit" refers to, is part of, or includes a hardware component such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or group) or a memory (shared, dedicated, or group) configured to provide the functionality, an application specific integrated circuit (ASIC), a field programmable device (FPD) (e.g., a field programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high capacity PLD (HCPLD), a structured ASIC, or a programmable system on chip (SoC)), a digital signal processor (DSP), etc. In some embodiments, the circuit may execute one or more software or firmware programs to provide at least some of the functionality. The term "circuit" may also refer to a combination of one or more hardware elements and a program code for executing the functionality of the program code (or a combination of circuits used in an electrical or electronic system). In these embodiments, the combination of hardware elements and program code may be referred to as a specific type of circuit.

[0028] As used herein, the term "processor circuit" refers to, is part of, or includes a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transferring digital data. The term "processor circuit" may refer to an application processor, a baseband processor, a central processing unit (CPU), a graphics processing unit, a single-core processor, a dual-core processor, a triple-core processor, a quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions such as program code, software modules, and / or functional processes.

[0029] As used herein, the term "interface circuit" refers to, is a part of, or includes a circuit that enables information exchange between two or more components or devices. The term "interface circuit" may refer to one or more hardware interfaces, such as a bus, an I / O interface, a peripheral component interface, a network interface card, etc.

[0030] As used herein, the term "user equipment" or "UE" refers to a device that has radio communication capabilities and can describe a remote user of network resources in a communication network. In addition, the terms "user equipment" or "UE" may be considered synonymous and may be referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. In addition, the term "user equipment" or "UE" may include any type of wireless / wired device or any computing device that includes a wireless communication interface.

[0031] As used herein, the term "base station" refers to a device with radio communication capabilities, which is a network component of a communication network (or more concisely, a network) and can be configured as an access node in the communication network. The access of a UE to a communication network can be at least partially managed by a base station, whereby the UE connects to the base station to access the communication network. Depending on the radio access technology (RAT), a base station can be referred to as a gNodeB (gNB), an eNodeB (eNB), an access point, etc.

[0032] As used herein, the term "network" refers to a communication network comprising a collection of network nodes configured to provide communication functions to multiple user equipment via one or more base stations. For example, the network may be a public land mobile network (PLMN) implementing one or more communication technologies (including, for example, 5G communications).

[0033] As used herein, the term "computer system" refers to any type of interconnected electronic devices, computer devices, or components thereof. Additionally, the term "computer system" or "system" may refer to various components of a computer that are communicatively coupled to each other. Furthermore, the term "computer system" or "system" may refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or networked resources.

[0034] As used herein, the term "resource" refers to a physical or virtual device, a physical or virtual component within a computing environment, or a physical or virtual component within a specific device, such as a computer device, a mechanical device, a memory space, a processor / CPU time, a processor / CPU usage, a processor and accelerator load, a hardware time or usage, a power supply, an input / output operation, a port or a network socket, a channel / link allocation, throughput, memory usage, storage, a network, a database and an application, a unit of work, etc. "Hardware resources" may refer to computing, storage or network resources provided by physical hardware elements. "Virtualized resources" may refer to computing, storage or network resources provided by a virtualized infrastructure to an application, a device, a system, etc. The term "network resources" or "communication resources" may refer to resources that a computer device / system can access via a communication network. The term "system resources" may refer to any kind of shared entity that provides a service, and may include computing resources or network resources. System resources may be considered as a set of coherent functions, network data objects or services that can be accessed through a server, wherein such system resources reside on a single host or multiple hosts and can be clearly identified.

[0035] As used herein, the term "channel" refers to any tangible or intangible transmission medium for conveying data or data streams. The term "channel" may be synonymous or equivalent to "communication channel", "data communication channel", "transmission channel", "data transmission channel", "access channel", "data access channel", "link", "data link", "carrier", "radio frequency carrier" or any other similar term representing a path or medium through which data is transmitted. Additionally, as used herein, the term "link" refers to a connection made between two devices for sending and receiving information.

[0036] As used herein, the terms "instantiate," "instantiate," and the like refer to the creation of an instance. "Instance" also refers to a specific occurrence of an object, which may occur, for example, during the execution of program code.

[0037] The term "connected" may mean that two or more elements at a common communication protocol layer have an established signaling relationship with each other through a communication channel, link, interface, or reference point.

[0038] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure for providing wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as a networked computer, networking hardware, network equipment, network node, virtualized network function, etc.

[0039] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual contents of an information element, or a data element that contains the contents. An information element may include one or more additional information elements.

[0040] The term "3GPP access" refers to access (e.g., radio access technology) specified by the 3GPP standards. These accesses include, but are not limited to, GSM / GPRS, LTE, LTE-A, 5G NR, and / or 6G. In general, 3GPP access refers to various types of cellular access technologies.

[0041] The term "non-3GPP access" refers to any access (e.g., radio access technology) not specified by the 3GPP standards. These accesses include, but are not limited to, WiMAX, CDMA2000, Wi-Fi, WLAN, and / or fixed networks. Non-3GPP accesses can be divided into two categories: "trusted" and "untrusted". Trusted non-3GPP accesses can interact directly with the Evolved Packet Core (EPC) and / or 5G Core (5GC), while untrusted non-3GPP accesses communicate with the EPC / 5GC via network entities (such as Evolved Packet Data Gateways and / or 5G NR Gateways). In general, non-3GPP access refers to various types of non-cellular access technologies.

[0042] Relay discovery may be the process of identifying candidate relays to extend network coverage outside of a service area (eg, a cell). Figure 1 1 is a signaling diagram 100 (hereinafter referred to as "Model A") of a user equipment (UE) to network (U2N) discovery process according to one or more embodiments. A remote UE 102 may receive an advertisement 104 sent by a relay UE 106. The relay UE 106 may camp on a cell 108. The advertisement may indicate connectivity of the relay UE to the cell 108. The base station 110 may provide service to the cell 108. The remote UE 102 may be a UE that can use the relay UE 106 to access a wireless network via the base station 110. The relay UE 106 may be a UE that can permit the remote UE 102 to access the wireless network via the base station 110.

[0043] Figure 22 is a signaling diagram 200 of a U2N process according to one or more embodiments (hereinafter referred to as "Model B"). A remote UE 202 may send a query 204 to a relay UE 206 asking whether there is a U2N relay nearby for relay service. The relay UE 206 may unicast a response 208 regarding the availability of its relay service to the remote UE 202. In Model A or Model B, for the remote UE 102, 202, receiving a relay discovery message (e.g., announcement 104, response 208) is sufficient to determine whether the relay UE 106, 206 is a candidate. The relay UE 206 may camp on a cell 210. A base station 212 may provide service to the cell 210. For Figure 1 and Figure 2 , the announcement 104, the query 204 and the response 208 may be messages for discovery as described in 3GPP Technical Specification (TS) 24.554 v17.2.1 (2022-09-26).

[0044] Figure 3 300 is a signaling diagram for a connectivity-based scheme for UE-to-UE (U2U) relay discovery according to one or more embodiments. In U2U relay discovery, the discovery scheme is more complex than the U2N discovery scheme. This is because U2U relay discovery involves three nodes (source remote UE (S-remote UE) 302, relay UE 304, and target remote UE (T-remote UE) 306) and two PC5 hops, while U2N relay discovery involves only one PC5 hop. For U2U relay discovery, relay UE 304 can be a U2U relay UE and act as a bridge between S-remote UE 302 and T-remote UE 306. Therefore, relay UE 304 can be responsible for monitoring activities from S-remote UE 302 and T-remote UE 306. In addition, the relay UE does not have "useful" information to broadcast by default until the relay UE first discovers the remote UE.

[0045] The above-mentioned relay discovery model A and relay discovery model B become too simplistic by themselves to model the behaviors of S-remote UE 302, relay UE 304, and T-remote UE 306 in the U2U relay discovery scheme. As to what key information needs to be conveyed in the U2U relay discovery process, it is obvious that the first expected information is "U2U connectivity", which means that the S-remote UE 302 and the T-remote UE 306 can be connected via the relay UE 304. It is noted that the U2U connectivity information may include only one remote UE (S-remote UE 302 or T-remote UE 306), because when the message is received by the other remote UE in its PC5 interface, the receiving remote UE can recognize the complete connectivity (S-remote UE 302 to relay UE 304 to T-remote UE 306).

[0046] However, this information itself may not be sufficient to trigger relay selection, because the remote UE may not always be interested in communicating with another remote UE in the first place. In the U2U relay use case, it cannot be assumed that all remote UEs are always "interested" in each other to talk to each other. In many cases, the interest is unidirectional (e.g., from the S-remote UE 302 to the T-remote UE 306), and the peer remote UEs may not share the same interest at all. For example, when the T-remote UE 306 receives such a U2U "connectivity" discovery message, it may ignore the U2U "connectivity" discovery message because, from its own perspective, it has no particular interest in communicating with the S-remote UE 302. This leads to the definition of a second desired information (e.g., U2U interest) for U2U relay discovery, which indicates that there is a unidirectional interest in communicating with the S-remote UE 302 and the T-remote UE 306.

[0047] Based on the above analysis, there may be two scenarios for supporting relay discovery. In the first scenario, the remote UE has an interest in communicating with a peer UE, so it is sufficient to receive "U2U connectivity" information indicating its connectivity to the target remote UE from a candidate U2U relay UE. In the second scenario, there is a remote UE that is unaware of the interest of the peer UE. Therefore, both "U2U connectivity" and "U2U interest" may be delivered to the remote UE to trigger subsequent actions (e.g., relay selection).

[0048] The embodiments described herein involve two different discovery schemes for U2U relay discovery, namely, a connectivity-based scheme and an interest-based scheme. It should be noted that for each respective scheme, both U2U connectivity information and U2U interest information may be communicated in the discovery procedure. However, the names of those schemes only suggest which information, "U2U connectivity" or "U2U interest", plays the most important role in the respective discovery procedures.

[0049] For connectivity-based solutions, the relay UE is assumed to advertise its "own" 1-hop connectivity (e.g., the remote UEs it can reach). This approach is similar to the "route update" messaging in routing protocols. The approach can be further extended to multi-hop situations by the relay UE announcing information related to the number of hops used to reach the remote UE. "Multi-hop" as used herein refers to more than one hop. The remote UE can use information from the relay UE to determine whether the relay is a suitable candidate relay. The problem with this connectivity solution may be how the relay UE obtains connectivity information and how useful the information is. In addition, the connectivity information may include additional characteristics of the remote UE connectivity. For example, the PC5 link quality between the remote UE and the relay UE may be indicated, which may be based on side link (SL) unicast measurements (e.g., side link reference signal received power (SL-RSRP)) or SL broadcast measurements (e.g., side link discovery reference signal received power (SD-RSRP)). In addition, it may also indicate whether a PC5 link has been established between the remote UE and the relay UE.

[0050] For the interest-based scheme, the relay UE can rebroadcast the "end-to-end" link interest (E2E link interest) received from the remote UE. Once the target remote UE (T-remote UE) receives the "interest", the T-remote UE can determine whether to use the relay as a candidate relay for the "end-to-end" link. One problem with the interest-based scheme is that each relay is assumed to be a "relay", which can cause flooding and privacy issues related to the interest.

[0051] Figure 4 4 is a signaling diagram 400 for a connectivity-based scheme for U2U relay discovery according to one or more embodiments. For the connectivity-based scheme, the U2U relay UE may send an announcement 404 to a remote UE 406. The announcement may include an indication that the U2U relay UE 402 is connected to one or more other remote UEs. The announcement 404 may include connectivity information for the one or more other remote UEs. In some cases, the announcement 404 includes additional characteristics for connectivity, such as PC5 link quality or ranking of each of the one or more other remote UEs. The announcement 404 may be broadcast to any UE within the vicinity of the U2U relay UE 402. Alternatively, the announcement 404 may be targeted to a specific remote UE 406.

[0052] Figure 5is an illustration 500 of retransmission for an interest-based scheme according to one or more embodiments. An S-remote UE 502 may send a first message 504 indicating interest in connecting with another remote UE to a U2U relay UE 506. The U2U relay UE 506 may retransmit a second message 508 indicating interest in connecting with another remote UE to one or more other remote UEs. In some cases, when the U2U relay UE 506 cannot determine whether it can reach the T-remote UE in one hop, it may not further indicate in the second message 508 whether the S-remote UE 502 is interested in another hop. In other cases, the content of the first message 504 is the same as the content of the second message 508. In some embodiments, messages including content related to connectivity also include content related to interests. In other embodiments, these messages including content related to connectivity are separate from messages including content related to interests. These messages may be based on connectivity content and interest content based on Figure 4 and Figure 5 Designed according to the procedures described in .

[0053] Figure 6 600 is a signaling diagram for a connectivity-based scheme for U2U relay discovery according to one or more embodiments. As illustrated, a first remote UE 602 (e.g., an S-remote UE), a relay UE 604 (e.g., a U2U relay UE), and a second remote UE 606 (e.g., a T-remote UE) may participate in a connectivity-based scheme. At 608, the relay UE 604 and the second remote UE 606 may establish a link. In the scheme, the relay UE 604 may collect information about connectivity to the second remote UE 606 based on information exchanged on the link. At 610, the relay UE 604 may send a discovery message including a notification to the first remote UE 602. The notification may include connectivity information for connecting with the T-remote UE. The first remote UE 602 may select the relay UE 604 as a candidate for reaching the second remote UE 606 based on the content of the discovery message received at step 610.

[0054] Figure 7700 is a signaling diagram for a connectivity-based solution for U2U relay discovery according to one or more embodiments. As illustrated, a first remote UE 702 (e.g., S-remote UE), a relay UE 704 (e.g., U2U relay UE), and a second remote UE 706 (e.g., T-remote UE) may participate in a connectivity-based solution. At 708, the second remote UE 706 may send a discovery message including a notification message to the relay UE 704. The notification message may be considered to implicitly include connectivity information that any UE nearby that receives the notification message can connect to the T-remote UE. In this solution, the relay UE 704 may collect information about connectivity to the second remote UE 706 based on the content of the message. At 710, the relay UE 704 may send a message including the notification message to the first remote UE 702. The first remote UE 702 may select the relay UE 704 to reach the T-remote UE 706 based on the content of the message received at step 710.

[0055] Figure 8 800 is a signaling diagram for a connectivity-based scheme for U2U relay discovery according to one or more embodiments. As illustrated, a first remote UE 802 (e.g., an S-remote UE), a relay UE 804 (e.g., a U2U relay UE), and a second remote UE 806 (e.g., a T-remote UE) may participate in a connectivity-based scheme. At 808, the first remote UE 802 may send a discovery message including a notification to the relay UE 804. The notification may be considered to implicitly include connectivity information for connecting to the S-remote UE. It may also explicitly include any other 1-hop connectivity discovered by the S-remote UE. At 810, the second remote UE 806 may also transmit a discovery message including a notification to the relay UE 804. The notification may be considered to implicitly include connectivity information for connecting to the T-remote UE. It may also explicitly include any other 1-hop connectivity discovered by the T-remote UE. Alternatively, the discovery message may also be combined with an interest-based scheme to include an indication of looking for a relay to reach the second remote UE 806. In this scheme, the relay UE 804 may gather information about connectivity to the first remote UE 802 and the second remote UE 806 based on the content of the message. The relay UE 804 may further combine the two announcements to generate a single announcement. At 812, the relay UE 804 may send the combined announcement to the first remote UE 802. At 814, the relay UE 804 may send the combined announcement to the second remote UE 806. At 516, the first remote UE 802 may select a relay to reach the second remote UE 806.

[0056] Fig. 9900 is a signaling diagram for an interest-based scheme for U2U relay discovery according to one or more embodiments. As illustrated, a first remote UE 902 (e.g., an S-remote UE), a relay UE 904, and a second remote UE 906 (e.g., a T-remote UE) may participate in an interest-based scheme. At 908, the first remote UE 902 may broadcast a discovery message to the relay UE 904, the discovery message including an indication of end-to-end (E2E) interest compared to 1-hop connectivity information in a connectivity-based scheme. In this case, the relay UE 904 may not have information about how to reach the second remote UE 906. At 910, the relay UE 904 may broadcast the discovery message of the first remote UE and include its own relay information. If the second remote UE 906 is within the vicinity of the relay UE 904, the second remote UE 906 may receive the message from the relay UE 904. Here, upon receiving the message, discovery is completed, and the second remote UE 906 may select the relay UE 904 as a relay candidate to reach the first remote UE 902. Alternatively, the second remote UE 906 may also generate a U2U interest response message, and transmit the message back to the relay UE 904. The relay UE 904 may then forward the U2U interest response message along with its own relay UE information to the first remote UE 902. In this case, the first remote UE may consider that discovery is completed from the perspective of the first remote UE, and the first remote UE 902 may select the relay UE 904 as a relay candidate UE to reach the second remote UE.

[0057] Fig.10 1000 is a signaling diagram for an interest-based scheme for U2U relay discovery according to one or more embodiments. As illustrated, a first remote UE 1002 (e.g., an S-remote UE), a relay UE 1004, and a second remote UE 1006 (e.g., a T-remote UE) may participate in an interest-based scheme. At 1008, the first remote UE 1002 may broadcast a discovery message to the relay UE 1004, the discovery message including an indication of E2E interest. In this case, the relay UE 1004 may have information that it can use to reach the second remote UE 1006. At 1010, the relay UE 1004 may send a response message to the first remote UE 1002 to confirm its ability to satisfy the E2E interest of the first remote UE 1002, and

[0058] Here, upon receiving the message from the relay UE 1004, the discovery is completed, and the first remote UE 1002 may select the relay UE 1004 as a relay candidate to reach the second remote UE 1006.

[0059] Fig.11is an illustration of a discovery message type table 1100 according to one or more embodiments. Message types are added to the discovery message types as defined in 3GPP TS24.554. For a U2U connectivity based solution, the discovery message types include a relay UE connectivity notification message and a relay UE connectivity response message. The message types also include a remote UE query message and a remote UE notification message. For a U2U interest based solution, the discovery message types include a relay UE interest rebroadcast message, a relay UE interest response message, and a remote UE interest message.

[0060] Table 1100 includes a U2U interest message 1102 for transmitting a request for relay assistance to a remote UE. Table 1100 includes a U2U interest relay message 1104 for a relay UE to rebroadcast an announcement of its willingness to serve as a relay UE. The table includes a U2U interest response message 1106 for a relay UE to confirm that it can satisfy the interest. Table 1100 includes a U2U connectivity query message 1108 for a remote UE to query connectivity within its vicinity. The table includes a U2U relay connectivity message 1110, a relay UE's connectivity announcement. Figures 9 to 12 These messages are further described. It should be understood that the content of one or more of these messages may be combined into a single message. For example, in some cases, a UE may send to more than one other UE, and the UE may combine more than one message into a single message, wherein corresponding parts of the message will be received by different UEs.

[0061] Fig.12 is an example 1200 of a remote UE discovery message according to one or more embodiments. Fig.11 As described, two remote UE message design selection options are defined: U2Uconnectivityquery message 1108 and U2U interest message 1102. For the first option 1202, the U2Uconnectivityquery message may include a discovery message type 1204 (which may also be used to distinguish between direct discovery, U2N discovery, and U2U relay discovery, relay service code) 1206 and source user information 1208 (e.g., source remote UE information) that may be indicated by a PC5 discovery message type.

[0062] For the second option 1210, the U2Uinterest message may include a discovery message type, an RSC, source user information, and target user information 1212. For this message, the relay UE may use a different discovery message for each different target UE that the relay UE attempts to reach. For the first and second options, the two messages may be of the same discovery message type, with the difference being whether the message includes "target". In other words, the second option may be a target message.

[0063] The third option 1214 may include an optimized discovery message for an advanced design and may include multiple <S-remote UE, T-remote UE> from the same remote UE into one discovery message. The third option may include a message having a discovery type, an RSC, source user information, and multiple target source information instances 1216. In other words, the third option may include multiple target UEs. In another implementation, the third option may include multiple source UE information and multiple target UE information. Each source UE among the source UEs may be associated with a corresponding target UE, such that a message from the source UE may be intended for the corresponding target UE.

[0064] Fig.13 Is an illustration 1300 of a U2URelayconnectivity message for layer 2 (L2) U2U relay discovery according to one or more embodiments. After the U2U relay UE processes a remote UE model B discovery message for U2U relay, the U2U relay UE may establish a one-to-one relationship between the remote UE L2 identifier (ID) and the corresponding RSC. This entry may also contain the interests of the remote UE (e.g., a list of target user information). At least for a specific RSC, the U2U relay message may advertise the ability to act as a U2U relay; the connectivity of the U2U relay UE to reach the remote UE.

[0065] A first option 1302 for a U2URelayconnectivity message may include a discovery type 1304, relay user information 1306 (e.g., relay UE information), and RSC 1308. A second option 1310 for a U2URelayconnectivity message may include a discovery message type, relay user information, RSC, and a status indicator 1312. A third option 1314 for a U2URelayconnectivity message may include a discovery message type, relay user information, remote 11316 (e.g., first remote UE information), and a status indicator. For different relay services (e.g., represented by different RSCs (relay service codes)). The relay UE may use different discovery messages. Similarly, for each different target UE that the relay UE can reach, the relay UE can also place the target UE information into a different U2URelayconnectivity message. A fourth option 1318 for the U2URelayconnectivity message may include a discovery message type, relay user information, RSC, multiple remote instances 1320 (e.g., multiple remote UE information instances), and a status indicator. A fifth option 1322 may be an extension to account for multi-hop connectivity. A fifth option 1322 for the U2URelayconnectivity message may include a discovery message type, relay user information, RSC, source user information, remote instance, hop count 1324, and a status indicator.

[0066] Fig.14Illustration 1400 of U2U interest relay messages and U2U interest response messages for L2 U2U relay discovery according to one or more embodiments. The U2U relay discovery message may relay interests received from nearby remote UEs. The relay discovery message may indicate the willingness of the UE to act as a relay for the E2E link interest of <S-remote UE, T-remote UE>, but further indicate that at this time, the relay UE is not sure that it can still reach the T-remote UE. The first option 1402 for the U2U interest relay message may include a discovery message type 1404, relay user information 1406, RSC 1408, S-remote 1410 (e.g., S-remote UE information), T-remote 1412 (e.g., T-remote UE information), and a status indicator 1414. The PC5 discovery message type 1104 may indicate that this is a relay broadcast of an E2E interest. This does not mean that the relay can reach the target remote UE. To reduce the number of messages, multiple interests may be combined into one message. Thus, the second option 1416 for the U2U interest relay message may include a discovery message type, relay user information, RSC, number of interests 1418, multiple S-remote instances 1420, multiple T-remote instances 1422, and a status indicator.

[0067] The U2U interest relay message 1424 may include a discovery message type, relay user information, RSC, S-remote, T-remote, and a status indicator. The PC5 discovery type may indicate to the remote UE (e.g., S-remote UE) that this is a construct / response in which the relay UE can reach the target remote UE (e.g., T-remote UE).

[0068] Fig.151500 is an illustration of a remote UE representation for L2 U2U relay discovery according to one or more embodiments. Various information may be used in a relay discovery message of a U2U relay UE to help describe remote UE information 1506. A first option 1504 of the remote UE representation may include remote user information 1506. A second option 1508 of the remote UE representation may include remote user information and an L2 ID 1510 of the remote UE. A third option 1512 of the remote UE representation may include remote user information, an L2 ID of the remote UE, and a local identifier 1514, where the local identifier 1514 may be assigned to the remote UE (e.g., by the relay UE). If the relay UE already has a link to a T-remote UE, the local identifier 1514 is included. In some cases, the relay UE may have corresponding links with multiple remote UEs. In these cases, the relay UE may use the local identifier to distinguish the T-remote UE from other remote UEs of the multiple remote UEs. A fourth option 1516 of the remote UE representation may include remote user information, an L2 ID of the remote UE, and a local identifier, and an indication of whether a side link (SL) relay is connected 1518. A fifth option 1520 of the remote UE representation may include remote user information, an L2 ID of the remote UE, a local identifier, an indication of whether a side link (SL) relay is connected, and an indication of the quality of the SL relay 1522 (e.g., PC5 link quality, such as SL received signal reference power (SL-RSRP)). In some other embodiments, one or more of the above information elements may be omitted or rearranged in a different order.

[0069] Fig.16 1600 is a process flow for selecting a relay according to one or more embodiments. At 1602, the method may include a first remote user equipment (UE) receiving a discovery message from a relay UE. The first remote UE may be an S-remote UE that is searching for a connection to a T-remote UE. The discovery message may include a notification indicating the ability of the relay UE to serve as the first remote UE to reach the second remote UE. The relay UE may or may not be connected to the T-remote UE that is capable of connecting the S-remote UE. In some cases, the discovery message may be sent based on connectivity information received by the relay UE from the second remote UE. The connectivity information may be received based on a link between the relay UE and the second remote UE, the connectivity information may be received based on a notification of the second remote UE, or the connectivity information may be received based on other appropriate information received from the second remote UE via the relay UE.

[0070] At 1604, the method may include the first remote UE determining, based on the discovery message, whether to select a relay UE to relay the message to the second remote UE. The decision may be based on various factors, such as the number of hops, an identity of the T-remote UE, or other appropriate factors.

[0071] At 1606, the method may include the first remote UE selecting a relay UE to reach the second remote UE based on the determination.The first remote message may then relay messages to and from the second remote UE.

[0072] Fig.17 1700 is a process flow for selecting a relay according to one or more embodiments. At 1702, the method may include a relay UE receiving a first discovery message from a first remote UE. The first remote UE may be an S-remote UE. The first discovery message may include an indication of interest in an end-to-end (E2E) link with a second remote UE. The second remote UE may be a T-remote UE.

[0073] At 1704, the method may include the relay UE sending a second discovery message to the second remote UE or sending a third discovery message to the first remote UE based on the determination. If the relay UE does include information to connect to the second remote UE, the relay UE may send the second discovery message. The second discovery message includes an indication of interest in the E2E link from the first remote UE and relay information of the relay UE. If the relay UE does include information to connect to the second remote UE, the relay UE may send a third discovery message including an indication of the ability of the relay UE to serve as the first remote UE.

[0074] At 1706, the method may include the relay UE relaying the message from the first remote UE to the second remote UE based on the transmitting.

[0075] Fig.18 1800 is a process flow for selecting a relay according to one or more embodiments. At 1802, the method may include a first remote UE sending a first discovery message to a relay UE. The first remote UE may be a T-remote UE. The first discovery message may include connectivity information for the first remote UE.

[0076] At 1804, the method may include the first remote UE receiving a message from the second remote UE via the relay UE. The second remote UE is configured to select the relay UE to relay the message based on the second discovery message. The second discovery message may include connectivity information.

[0077] Fig.19 A receiving component 1900 of a UE according to one or more embodiments is illustrated. The receiving component 1900 may include an antenna panel 1904 including a plurality of antenna elements. The panel 1904 is shown with four antenna elements, but other embodiments may include other numbers of antenna elements.

[0078] The antenna panel 1904 may be coupled to an analog beamforming (BF) component including a plurality of phase shifters 1908(1)-1908(4). The phase shifters 1908(1)-1908(4) may be coupled to a radio frequency (RF) chain 1912. The RF chain 1912 may amplify received analog RF signals, down-convert the RF signals to baseband, and convert the analog baseband signals to digital baseband signals that may be provided to a baseband processor for further processing.

[0079] In various embodiments, control circuitry, which may reside in a baseband processor, may provide BF weights (e.g., W1-W4) to phase shifters 1908(1)-1908(4), which may represent phase shift values ​​to provide receive beams at antenna panel 1904. These BF weights may be determined based on channel-based beamforming.

[0080] Fig. 20 UE 2000 according to one or more embodiments is illustrated. UE 2000 may be any mobile or non-mobile computing device, such as, for example, a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a carbon dioxide sensor, a pressure sensor, a humidity sensor, a thermometer, a motion sensor, an accelerometer, a laser scanner, a fluid level sensor, an inventory sensor, a voltage / current meter, an actuator, etc.), a video surveillance / monitoring device (e.g., a camera, a video camera, etc.), a wearable device, or a loose IoT device. In some embodiments, the UE may be a reduced capacity UE or an NR-Light UE.

[0081] UE 2000 may include a processor 2004, an RF interface circuit 2008, a memory / storage device 2012, a user interface 2016, a sensor 2020, a driving circuit 2022, a power management integrated circuit (PMIC) 2024, and a battery 2028. The components of UE 2000 may be implemented as an integrated circuit (IC), a portion of an integrated circuit, a discrete electronic device or other module, logic device, hardware, software, firmware, or a combination thereof. Fig. 20 The block diagram of UE 2000 is intended to show a high-level view of some of the components of UE 2000. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other implementations.

[0082] Components of UE 2000 may be coupled to various other components via one or more interconnects 2032, which may represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, optical connection, etc., which allows various circuit components (on a common or different chip or chipset) to interact with each other.

[0083] The processor 2004 may include processor circuits, such as, for example, a baseband processor circuit (BB) 2004A, a central processor unit circuit (CPU) 2004B, and a graphics processor unit circuit (GPU) 2004C. The processor 2004 may include any type of circuit or processor circuit that executes or otherwise operates computer-executable instructions (such as program codes, software modules, or functional processes from the memory / storage device 2012) to cause the UE 2000 to perform operations as described herein.

[0084] In some embodiments, the baseband processor circuit 2004A can access the communication protocol stack 2036 in the memory / storage device 2012 to communicate through a 3GPP compatible network. Generally speaking, the baseband processor circuit 2004A can access the communication protocol stack to: perform user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer; and perform control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access layer (NAS) layer. In some embodiments, the PHY layer operations can be additionally / alternatively performed by components of the RF interface circuit 2008.

[0085] The baseband processor circuit 2004A may generate or process baseband signals or waveforms that carry information in a 3GPP-compatible network. In some embodiments, the waveforms used for NR may be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and discrete Fourier transform spread OFDM (DFT-S-OFDM) in the uplink.

[0086] The baseband processor circuit 2004A may also access the group information 2024 from the memory / storage 2012 to determine the search space groups in which the plurality of repetitions of the PDCCH may be sent.

[0087] The memory / storage 2012 may include any type of volatile or non-volatile memory that may be distributed throughout the UE 2000. In some embodiments, some of the memory / storage 2012 may be located on the processor 2004 itself (e.g., L1 cache and L2 cache), while other memory / storage 2012 is external to the processor 2004 but can be accessed via a memory interface. The memory / storage 2012 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0088] The RF interface circuit 2008 may include a transceiver circuit and a radio frequency front end module (RFEM), which allows the UE 2000 to communicate with other devices through a radio access network. The RF interface circuit 2008 may include various elements arranged in a transmit path or a receive path. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuits, control circuits, etc.

[0089] In the receive path, the RFEM may receive the radiated signal from the air interface via antenna 2024 and proceed to filter and amplify the signal (using a low noise amplifier). The signal may be provided to the transceiver's receiver, which down-converts the RF signal to a baseband signal that is provided to the baseband processor of processor 2004.

[0090] In the transmit path, the transmitter of the transceiver up-converts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier before the signal is radiated across the air interface via the antenna 2024.

[0091] In various embodiments, the RF interface circuit 2008 may be configured to send / receive signals in a manner compatible with NR access technology.

[0092] Antenna 2024 may include multiple antenna elements, each of which converts electrical signals into radio waves to travel through the air and converts received radio waves into electrical signals. These antenna elements may be arranged into one or more antenna panels. Antenna 2024 may have an antenna panel that is omnidirectional, directional, or a combination thereof to achieve beamforming and multiple-input / multiple-output communications. Antenna 2024 may include a microstrip antenna, a printed antenna manufactured on the surface of one or more printed circuit boards, a patch antenna, a phased array antenna, etc. Antenna 2024 may have one or more panels that are designed for a specific frequency band including a band in FR1 or FR2.

[0093] The user interface circuit 2016 includes various input / output (I / O) devices designed to implement user interaction with the UE 2000. The user interface 2016 includes input device circuits and output device circuits. The input device circuit includes any physical or virtual components for accepting input, and in particular includes one or more physical or virtual buttons (e.g., reset buttons), physical keyboards, keypads, mice, touch pads, touch screens, microphones, scanners, headphones, etc. The output device circuit includes any physical or virtual components for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other similar information). The output device circuit may include any number or combination of audio or visual displays, in particular including one or more simple visual outputs / indicators (e.g., binary state indicators (such as light emitting diodes "LEDs") and multi-character visual outputs) or more complex outputs (such as display devices or touch screens (e.g., liquid crystal displays (LCDs), LED displays, quantum dot displays, projectors, etc.)), where the output of characters, graphics, multimedia objects, etc. is generated or produced by the operation of the UE 2000.

[0094] Sensors 2020 may include devices, modules, or subsystems whose purpose is to detect events or changes in their environment, and to send information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others: an inertial measurement unit including an accelerometer; a gyroscope; or a magnetometer; a micro-electromechanical system or nano-electromechanical system including: a three-axis accelerometer; a three-axis gyroscope; or a magnetometer; a level sensor; a flow sensor; a temperature sensor (e.g., a thermistor); a pressure sensor; a barometric pressure sensor; a gravity meter; an altimeter; an image capture device (e.g., a camera or a lensless aperture); a light detection and ranging sensor; a proximity sensor (e.g., an infrared radiation detector, etc.); a depth sensor; an ambient light sensor; an ultrasonic transceiver; a microphone or other similar audio capture device; and the like.

[0095] The driver circuit 2022 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 2000. The driver circuit 2022 may include various drivers to allow other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 2000. For example, the driver circuit 2022 may include: a display driver for controlling and allowing access to a display device, a touch screen driver for controlling and allowing access to a touch screen interface, a sensor driver for obtaining sensor readings of the sensor circuit 2020 and controlling and allowing access to the sensor circuit 2020, a driver for obtaining an actuator position of an electromechanical component or controlling and allowing access to an electromechanical component, a camera driver for controlling and allowing access to an embedded image capture device, or an audio driver for controlling and allowing access to one or more audio devices.

[0096] The PMIC 2024 may manage power provided to various components of the UE 2000. Specifically, with respect to the processor 2004, the PMIC 2024 may control power selection, voltage scaling, battery charging, or DC-DC conversion.

[0097] In some embodiments, the PMIC 2024 may control or otherwise become part of various power saving mechanisms of the UE 2000. For example, if the platform UE is in the RRC_Connected state, in which the platform is still connected to the RAN node because it expects to receive traffic soon, then after a period of inactivity, the platform may enter a state known as discontinuous reception mode (DRX). During this state, the UE 2000 may be powered off for short intervals, thereby saving power. If there is no data traffic activity for an extended period of time, the UE 2000 may transition to the RRC_Idle state, in which the device is disconnected from the network and no operations such as channel quality feedback, handovers, etc. are performed. The UE 2000 enters a very low power state and performs paging, in which the device wakes up again periodically to listen to the network and then powers off again. The UE 2000 may not receive data in this state; in order to receive data, the platform must transition back to the RRC_Connected state. An additional power saving mode can prevent a device from using the network for a period of time exceeding the paging interval, ranging from a few seconds to a few hours. During this time, the device is completely unable to connect to the network and can be completely powered down. Any data transmitted during this time will be significantly delayed, assuming that the delay is acceptable.

[0098] The battery 2028 can power the UE 2000, but in some examples, the UE 2000 can be installed in a fixed location and can have a power source coupled to the power grid. The battery 2028 can be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, the battery 2028 can be a typical lead-acid automobile battery.

[0099] Fig.21 A gNB 2100 according to one or more embodiments is illustrated. The gNB 2100 may include a processor 2104, an RF interface circuit 2108, a core network (CN) interface circuit 2112, and a memory / storage device circuit 2116.

[0100] Components of gNB 2100 may be coupled to various other components via one or more interconnects 2128.

[0101] The processor 2104, RF interface circuit 2108, memory / storage circuit 2116 (including communication protocol stack 2110), antenna 2124, and interconnect 2128 may be similar to those described with respect to Fig.19 Like named elements are shown and described.

[0102] The CN interface circuitry 2112 may provide connectivity for a core network (e.g., a 5th Generation Core Network (5GC) using a 5th Generation Core Network (5GC) compatible network interface protocol such as a Carrier Ethernet protocol or some other suitable protocol). Network connectivity may be provided to / from the gNB 2100 via optical fiber or wireless backhaul. The CN interface circuitry 2112 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry 2112 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0103] It is well known that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0104] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods described in the following example section. For example, the baseband circuit described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. For another example, the circuits associated with the UE, base station, network element, etc. described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below in the example section.

[0105] Example

[0106] In the following sections, additional exemplary embodiments are provided.

[0107] Embodiment 1 includes a method, the method comprising a first remote user equipment (UE) receiving a discovery message from a relay UE, the discovery message indicating a capability of the relay UE to act as the first remote UE to reach a second remote UE. The first remote UE determines, based on the discovery message, to select the relay UE to relay a message to the second remote UE. The first remote UE selects the relay UE to reach the second remote UE based on the determination.

[0108] Embodiment 2 includes the method of embodiment 1, wherein the discovery message is sent when the relay UE determines connectivity to the second remote UE, wherein the connectivity determination is based on information received from the second remote UE.

[0109] Embodiment 3 includes the method of embodiment 1 or 2, wherein connectivity to the second remote UE is determined based on the relay UE having established a link with the second remote UE.

[0110] Embodiment 4 includes a method according to any one of Embodiments 1 to 3, wherein the discovery message is a first discovery message, wherein the first discovery message received by the first remote UE is based on the relay UE receiving a second discovery message from the second remote UE, wherein the second discovery message includes the connectivity information for the second remote UE, and wherein the relay UE is configured to include the connectivity information in the first message sent to the first remote UE

[0111] Embodiment 5 includes a method according to any one of Embodiments 1 to 4, wherein the discovery message is a first discovery message, and wherein the method further includes: sending a second discovery message to the relay UE, wherein the second discovery message includes an indication for searching for a relay for the second remote UE; receiving the first discovery message from the relay UE in response to the second discovery message, wherein the first discovery message is a combination of the second discovery message and a third discovery message from the second remote UE, wherein the third discovery message is from the second remote UE and includes the connectivity information.

[0112] Embodiment 6 includes the method according to any one of embodiments 1 to 5, wherein the second discovery message further includes a discovery type, a relay service code (RSC), and first remote UE information.

[0113] Embodiment 7 includes the method of any one of Embodiments 1 to 6, wherein the discovery message includes a discovery type, an indication of a capability to act as a user equipment to user equipment (U2U) relay UE based on a relay service code, and the RSC.

[0114] Embodiment 8 includes the method according to any one of embodiments 1 to 7, wherein the discovery message further includes second remote UE information, a status indicator, or a number of hops to reach the second remote UE.

[0115] Embodiment 9 includes a system comprising components for performing one or more elements of a method described in or related to embodiments 1-8.

[0116] Embodiment 10 includes a computer-readable medium having stored thereon a sequence of instructions that, when executed, cause a processor to perform operations including a method described in or related to Embodiments 1 to 8.

[0117] Embodiment 11 includes a relay UE, which includes: one or more processors; a communication interface; a radio frequency (RF) interface circuit; and a computer-readable medium, wherein the computer-readable medium includes instructions, which when executed by the one or more processors cause the relay UE to: receive a first discovery message from a first remote UE, the first discovery message including an indication of interest in an end-to-end (E2E) link with a second remote UE; and based on the determination, send a second discovery message to the second remote UE or send a third discovery message to the first remote UE, the second discovery message including the indication of interest in the E2E link from the first remote UE and relay information of the relay UE, the third discovery message including an indication of the ability of the UE to serve as a UE-to-UE relay UE for the first remote UE to reach the second remote UE.

[0118] Embodiment 12 includes the relay UE according to embodiment 11, wherein the third discovery message is sent to the first remote UE based on the relay UE determining that the relay UE is able to communicate with the second remote UE through an interface.

[0119] Embodiment 13 includes the relay UE according to embodiment 11 or 12, wherein the second remote UE is configured to determine whether to relay the message using the relay UE based on the second discovery message.

[0120] Embodiment 14 includes a relay UE according to any one of Embodiments 11 to 13, wherein the relay UE includes information reaching the second remote UE, and wherein the relay UE sends the third discovery message to the first remote UE, and wherein the first remote UE is configured to determine whether to use the relay UE to relay the message based on the third message.

[0121] Embodiment 15 includes a relay UE according to any one of embodiments 11 to 14, wherein the first discovery message includes a discovery message type, a relay service code (RSC), first remote UE information, or second remote UE information.

[0122] Embodiment 16 includes the relay UE according to any one of Embodiment 15, wherein the first discovery message further includes the second remote UE information and the third remote UE information.

[0123] Embodiment 17 includes a relay UE according to any one of embodiments 11 to 16, wherein the second discovery message includes a discovery message type, relay UE information, or a relay service code.

[0124] Embodiment 18 includes the relay UE according to embodiment 17, wherein the second discovery message further includes second remote UE information, and the second remote UE information includes a layer 2 identifier (L2 ID).

[0125] Embodiment 19 includes a relay UE according to any one of embodiments 11 to 18, wherein the second discovery message also includes a local identifier for the second remote UE based on that the relay UE has a link with the second remote UE, and wherein the relay UE intends to use the local identifier to distinguish a third remote UE linked to the relay UE.

[0126] Embodiment 20 includes the relay UE according to any one of embodiments 11 to 19, wherein the second discovery message further includes a PC5 link quality based on the relay UE and the second remote UE being connected in a sidelink (SL).

[0127] Embodiment 21 includes a system comprising components for performing one or more elements of a method described in or related to embodiments 11-20.

[0128] Embodiment 22 includes a computer-readable medium having stored thereon a sequence of instructions which, when executed, causes a processor to perform operations including a method described in or related to embodiments 11 to 20.

[0129] Embodiment 23 includes one or more computer-readable media, which include instructions stored thereon, which, when executed by one or more processors, cause a user equipment (UE) to: send a first discovery message to a relay user equipment (UE), wherein the first discovery message includes connectivity information for a first remote UE; and receive a message from a second remote UE via the relay UE, wherein the second remote UE is configured to select the relay UE to relay the message based on a second discovery message, wherein the second discovery message includes the connectivity information.

[0130] Embodiment 24 includes one or more computer-readable media according to embodiment 23, wherein the instructions, when executed by a processor, also cause the processor to perform operations, the operations comprising: receiving a second discovery message from the relay UE, the second discovery message including the connectivity information for the first remote UE and the connectivity information for the second remote UE.

[0131] Embodiment 25 includes a computer-readable medium having stored thereon a sequence of instructions which, when executed, causes a processor to perform operations of a method included in or related to embodiments 23 and 24.

[0132] Embodiment 26 includes a system comprising components for performing one or more elements of a method described in or related to embodiments 23 and 24.

[0133] Unless explicitly stated otherwise, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations are possible in view of the above teachings or may be obtained from the practice of various embodiments.

[0134] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to include all such variations and modifications.

Claims

1. A method performed by a first remote user equipment (UE), the method comprising: receiving a discovery message from a relay UE, the discovery message indicating a capability of the relay UE to act as the first remote UE to reach a second remote UE; determining, based on the discovery message, to select the relay UE to relay a message to the second remote UE; as well as The relay UE is selected based on the determination to reach the second remote UE.

2. The method of claim 1, the discovery message is sent when the relay UE determines connectivity to the second remote UE, wherein the connectivity determination is based on information received from the second remote UE.

3. The method of claim 2, wherein connectivity to the second remote UE is determined based on the relay UE having established a link with the second remote UE.

4. The method of claim 1 , wherein the discovery message is a first discovery message, wherein the first discovery message received by the first remote UE is based on the relay UE receiving a second discovery message from the second remote UE, wherein the second discovery message includes connectivity information for the second remote UE, and wherein the relay UE is configured to include the connectivity information in the first message sent to the first remote UE.

5. The method of claim 1, wherein the discovery message is a first discovery message, and wherein the method further comprises: Sending a second discovery message to the relay UE, wherein the second discovery message includes an indication for searching for a relay for the second remote UE; The first discovery message is received from the relay UE in response to the second discovery message, wherein the first discovery message is a combination of the second discovery message from the second remote UE and a third discovery message, wherein the third discovery message is from the second remote UE and includes connectivity information. The method of claim 4 , wherein the second discovery message further includes a discovery type, a relay service code (RSC), and first remote UE information.

7. The method of claim 1, wherein the discovery message comprises a discovery type, an indication of a capability of the UE to function as a user equipment to user equipment (U2U) relay based on a relay service code (RSC), and the RSC.

8. The method of claim 6, wherein the discovery message further includes second remote UE information, a state indicator, or a number of hops to reach the second remote UE.

9. A relay user equipment (UE), the relay UE comprising: one or more processors; Communication interface; Radio frequency (RF) interface circuit; as well as A computer-readable medium comprising instructions that, when executed by the one or more processors, cause the relay UE to: receiving a first discovery message from a first remote UE, the first discovery message comprising an indication of interest in an end-to-end (E2E) link with a second remote UE; and A second discovery message is sent to the second remote UE or a third discovery message is sent to the first remote UE, wherein the second discovery message includes the indication of the interest in the E2E link from the first remote UE and the relay information of the relay UE, and the third discovery message includes an indication of the capability of the UE to serve as a UE-to-UE (U2U) relay UE for the first remote UE to reach the second remote UE.

10. The relay UE of claim 9, wherein the third discovery message to the first remote UE is sent based on the relay UE determining that the relay UE is able to communicate with the second remote UE through an interface. 11 . The relay UE of claim 8 , wherein the second remote UE is configured to determine whether to relay the message using the relay UE based on the second discovery message.

12. The relay UE of claim 8, wherein the relay UE includes information reaching the second remote UE, and wherein the relay UE sends the third discovery message to the first remote UE, and wherein the first remote UE is configured to determine whether to use the relay UE to relay the message based on the third discovery message. 13 . The relay UE of claim 8 , wherein the first discovery message includes a discovery message type, a relay service code (RSC), first remote UE information, or second remote UE information. 14 . The relay UE according to claim 12 , wherein the first discovery message further includes the second remote UE information and third remote UE information. 15 . The relay UE according to claim 8 , wherein the second discovery message includes a discovery message type, relay UE information, or a relay service code. 16 . The relay UE of claim 14 , wherein the second discovery message further includes second remote UE information, and the second remote UE information includes a layer 2 identifier (L2 ID).

17. The relay UE according to claim 15, wherein the second discovery message also includes a local identifier for the second remote UE based on that the relay UE has a link with the second remote UE, and wherein the relay UE is configured to use the local identifier to distinguish the second remote UE from a third remote UE linked to the relay UE.

18. The relay UE of claim 14, wherein the second discovery message further comprises a PC5 link quality based on a side link (SL) connection between the relay UE and the second remote UE.

19. One or more computer-readable media comprising instructions stored thereon that, when executed by one or more processors, cause a user equipment (UE): sending a first discovery message to a relay user equipment (UE), the first discovery message comprising connectivity information for a first remote UE; and A message is received from a second remote UE via the relay UE, the second remote UE being configured to select the relay UE to relay the message based on a second discovery message, the second discovery message including the connectivity information.

20. The one or more computer-readable media of claim 19, wherein the instructions, when executed by a processor, further cause the processor to perform operations comprising: A second discovery message is received from the relay UE, the second discovery message including connectivity information for the first remote UE and connectivity information for the second remote UE.

Images