Method, apparatus for sidelink relay handover procedure

Abstract

Methods, systems, and devices are described for wireless communication. A first user equipment (UE) can relay wireless communications between a first base station and a second UE via at least a sidelink communication link with the second UE. The first UE can transmit, to the first base station, a measurement report for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operations. The first UE can receive an instruction to perform a handover procedure from the first base station to a second base station of the one or more candidate base stations based on the measurement report, where the second base station supports the sidelink relay operations. The first UE can then perform the handover procedure based on the instruction, the handover procedure including establishing a wireless connection with the second base station.

Description

Technical Field

[0001] The following discussion relates to wireless communications, including techniques used in side link relay handover procedures. Background Technology

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth-generation (4G) systems (e.g., Long Term Evolution (LTE) systems, improved LTE (LTE-A) systems, or LTE-A Pro systems) and fifth-generation (5G) systems (which may be referred to as New Radio (NR) systems). These systems may employ technologies such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each base station or network access node simultaneously supporting communication with multiple communication devices (which may also be referred to as User Equipment (UE)).

[0003] Some wireless communication systems support sidelink relay, where a relay UE can forward or relay wireless communications between a base station and a remote UE. Using sidelink relay allows remote UEs to reduce uplink transmission power, thereby reducing power consumption at the remote UE, and offers other advantages. However, using sidelink relay can introduce complexity in the context of performing cell handover procedures. Summary of the Invention

[0004] The described technology relates to improved methods, systems, devices, and apparatuses for supporting techniques used in sidelink relay handover procedures. In general, the described technology can be implemented by a relay user equipment (UE) and / or a remote UE to identify whether a target base station supports sidelink relay operations (e.g., whether the base station includes a base station with sidelink relay capability or not), which can contribute to informed decision-making for the handover process. Specifically, the relay UE and the remote UE can perform a handover procedure from a first base station to a second base station based on determining that the second base station supports sidelink relay operations. In some aspects, the UE (e.g., relay UE, remote UE) can determine whether a base station supports sidelink relay operations based on a System Information Block (SIB) message received from the respective base station. In some cases, the SIB can explicitly (e.g., based on explicit bit fields within the SIB) and / or implicitly (e.g., based on identifying the absence of a sidelink relay configuration) indicate whether the base station supports sidelink relay operations. In some cases, both relay UEs and remote UEs can control or influence which candidate base stations they will perform the handover process with based on measurement reports. For example, when sending measurement reports for candidate base stations, the UE may omit measurements for base stations that do not support sidelink relay operations, may indicate which base stations do not support sidelink relay operations, may indicate a preference for base stations that support sidelink relay operations, or any combination thereof.

[0005] A method for wireless communication at a first UE is described. The method may include: relaying wireless communication between a first base station and a second UE at least via a sidelink communication link with the second UE; sending a measurement report to the first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation; receiving instructions for performing a handover procedure from the first base station to a second base station among the one or more candidate base stations based on the measurement report, wherein the second base station supports sidelink relay operation; and performing the handover procedure based on the instructions, the handover procedure including establishing a wireless connection with the second base station.

[0006] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: relay wireless communication between a first base station and a second UE at least via a sidelink communication link with the second UE; send a measurement report to the first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation; receive instructions for performing a handover procedure from the first base station to a second base station among the one or more candidate base stations based on the measurement report, wherein the second base station supports sidelink relay operation; and perform the handover procedure based on the instructions, the handover procedure including establishing a wireless connection with the second base station.

[0007] Another apparatus for wireless communication at a first UE is described. The apparatus may include: a unit for relaying wireless communication between a first base station and a second UE, at least via a sidelink communication link with the second UE; a unit for sending a measurement report to the first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation; a unit for receiving instructions for performing a handover procedure from the first base station to the second base station among the one or more candidate base stations based on the measurement report, wherein the second base station supports sidelink relay operation; and a unit for performing the handover procedure based on the instructions, the handover procedure including establishing a wireless connection with the second base station.

[0008] A non-transitory computer-readable medium is described, storing code for wireless communication at a first UE. The code may include processor-executable instructions to: relay wireless communication between a first base station and a second UE, at least via a sidelink communication link with the second UE; send a measurement report to the first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation; receive instructions for performing a handover procedure from the first base station to the second base station among the one or more candidate base stations based on the measurement report, wherein the second base station supports sidelink relay operation; and perform the handover procedure based on the instructions, the handover procedure including establishing a wireless connection with the second base station.

[0009] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: receiving an SIB message from at least one of one or more candidate base stations; and determining, based on the SIB message, that at least one candidate base station supports side-link relay operation, wherein a first UE transmits a measurement report based on the determination that at least one candidate base station supports side-link relay operation.

[0010] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for receiving one or more bit field values ​​via an SIB message indicating that at least one candidate base station supports sidelink relay operation, wherein the determination may be based on one or more bit field values.

[0011] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining that a third base station does not support sidelink relay operations, wherein sending a measurement report, performing a handover procedure, or both may be based on determining that the third base station does not support sidelink relay operations.

[0012] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for receiving SIB messages from a third base station, wherein determining that the third base station does not support sidelink relay operations may be based on the SIB messages.

[0013] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining that a third base station does not support sidelink relay operation may be based on identifying one or more bit fields in an SIB message that indicate that the third base station does not support sidelink relay operation, identifying that data in an SIB message indicating that the third base station supports sidelink relay operation does not exist, or both.

[0014] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the measurement report omits measurements for the third base station based on the fact that the third base station does not support sidelink relay operation, and the handover process with the second base station may be based on the omission of measurements for the third base station in the measurement report.

[0015] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: receiving a radio resource control (RRC) message from a first base station, the RRC message instructing a first UE to omit measurements associated with a base station that does not support sidelink relay operations, wherein the first UE omits measurements for a third base station based on the RRC message.

[0016] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, transmitting a measurement report may include operations, features, units, or instructions for transmitting measurements for a third base station via the measurement report, wherein the measurement report includes an indication that the third base station does not support sidelink relay operations, and wherein a handover procedure with a second base station may be based on the indication that the third base station does not support sidelink relay operations.

[0017] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: receiving from a first base station an indication that a third base station does not support sidelink relay operations, wherein the determination may be based on the indication that the third base station does not support sidelink relay operations.

[0018] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining a sidelink relay configuration associated with a first base station; and performing a discovery procedure based on the determined sidelink relay configuration, wherein performing a handover procedure may be based on performing the discovery procedure.

[0019] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for receiving SIB messages from a first base station, wherein determining the sidelink relay configuration associated with the first base station may be based on the SIB messages.

[0020] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, one or more candidate base stations support sidelink relay operation by supporting a sidelink relay discovery process, a sidelink relay transmission, or both.

[0021] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: communicating with a second base station in a first frequency range; determining that a third base station supports sidelink relay operation in a second frequency range that may be different from the first frequency range; determining a sidelink relay configuration associated with the third base station based on the fact that the third base station supports sidelink relay operation in the second frequency range; and performing a discovery process associated with the third base station based on the sidelink relay configuration.

[0022] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: receiving side link relay configuration; communicating with a second base station in a first frequency range; determining that no base station is configured to communicate in a second frequency range different from the first frequency range; and performing a discovery process in the second frequency range and according to the side link relay configuration.

[0023] A method for wireless communication at a second UE is described. The method may include: communicating with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE; receiving instructions for performing a handover procedure from the first base station to the second base station based on the second base station supporting sidelink relay operation; and performing the handover procedure based on the instructions to establish wireless communication with the second base station.

[0024] An apparatus for wireless communication at a second UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: communicate with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE; receive instructions for performing a handover process from the first base station to the second base station based on the second base station supporting sidelink relay operation; and perform the handover process based on the instructions to establish wireless communication with the second base station.

[0025] Another apparatus for wireless communication at a second UE is described. The apparatus may include: a unit for communicating with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE; a unit for receiving instructions for performing a handover process from the first base station to the second base station based on the second base station supporting sidelink relay operation; and a unit for performing the handover process based on the instructions to establish wireless communication with the second base station.

[0026] A non-transitory computer-readable medium is described, storing code for wireless communication at a second UE. The code may include processor-executable instructions to: communicate with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE; receive instructions for performing a handover procedure from the first base station to the second base station based on the second base station supporting sidelink relay operation; and perform the handover procedure based on the instructions to establish wireless communication with the second base station.

[0027] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: transmitting a measurement report for one or more candidate base stations to a first base station via a first UE, the measurement report indicating that one or more candidate base stations support sidelink relay operation, wherein the handover process may be based on transmitting the measurement report.

[0028] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: receiving an SIB message from at least one of one or more candidate base stations; and determining, based on the SIB message, that at least one base station supports side-link relay operation, wherein a second UE sends a measurement report based on the determination that at least one candidate base station supports side-link relay operation.

[0029] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for receiving one or more bit field values ​​via an SIB message indicating that at least one candidate base station supports sidelink relay operation, wherein the determination may be based on one or more bit field values.

[0030] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining that a third base station does not support sidelink relay operations, wherein sending a measurement report, performing a handover procedure, or both may be based on determining that the third base station does not support sidelink relay operations.

[0031] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for receiving SIB messages from a third base station, wherein determining that the third base station does not support sidelink relay operations may be based on the SIB messages.

[0032] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining that a third base station does not support sidelink relay operation may be based on identifying one or more bit fields in an SIB message that indicate that the third base station does not support sidelink relay operation, identifying that data in an SIB message indicating that the third base station supports sidelink relay operation does not exist, or both.

[0033] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the measurement report omits measurements for the third base station based on the fact that the third base station does not support sidelink relay operation, and the handover process with the second base station may be based on the omission of measurements for the third base station in the measurement report.

[0034] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: receiving an RRC message from a first base station via a first UE, the RRC message instructing a second UE to omit measurements associated with a base station that does not support sidelink relay operations, wherein the second UE omits measurements for a third base station based on the RRC message.

[0035] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: receiving a policy control function message that instructs a second UE to omit measurements associated with a base station that does not support sidelink relay operations, wherein the second UE omits measurements for a third base station based on the policy control function message.

[0036] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, transmitting a measurement report may include operations, features, units, or instructions for performing the following: transmitting measurements for a third base station via a measurement report, wherein the measurement report includes an indication that the third base station does not support sidelink relay operations, and wherein a handover procedure with a second base station may be based on the indication that the third base station does not support sidelink relay operations.

[0037] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: receiving, via a first UE, an indication from a first base station that a third base station does not support sidelink relay operation, wherein the determination may be based on the indication that the third base station does not support sidelink relay operation.

[0038] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: determining that a third base station may not be associated with a UE that can be configured to relay wireless communication between the third base station and one or more additional UEs; and sending a measurement report, wherein the measurement report omits measurements for the third base station based on the determination that the third base station may not be associated with a UE that can be configured to relay wireless communication between the third base station and one or more additional UEs.

[0039] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: sending an indication of a priority associated with a base station supporting sidelink relay operation via a measurement report, wherein the handover procedure may be performed based on that priority.

[0040] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing the following: determining a sidelink relay configuration associated with a first base station; and performing a discovery procedure based on the determined sidelink relay configuration, wherein performing a handover procedure may be based on performing the discovery procedure.

[0041] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for receiving SIB messages from a first base station, wherein determining the sidelink relay configuration associated with the first base station may be based on the SIB messages.

[0042] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: sending a handover request to a third base station for a second handover procedure from a first base station to a third base station, wherein the third base station does not support sidelink relay operations; and receiving a control message from the third base station rejecting the handover request, wherein performing the handover procedure from the first base station to the second base station may be based on receiving the control message.

[0043] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: executing a relay UE reselection process from a first UE to a third UE; and communicating with a first base station via a third UE based on executing the relay UE reselection process, wherein the third UE may be configured to relay wireless communication between a second UE and a first base station at least via a sidelink communication link between the first UE and the third UE.

[0044] In some examples of the methods, apparatuses and non-transitory computer-readable media described herein, the second base station supports sidelink relay operation by supporting a sidelink relay discovery process, a sidelink relay transmission, or both.

[0045] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: communicating with a second base station in a first frequency range; determining that a third base station supports sidelink relay operation in a second frequency range that may be different from the first frequency range; determining a sidelink relay configuration associated with the third base station based on the fact that the third base station supports sidelink relay operation in the second frequency range; and performing a discovery process associated with the third base station based on the sidelink relay configuration.

[0046] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, units, or instructions for performing: receiving side link relay configuration; communicating with a second base station in a first frequency range; determining that no base station is configured to communicate in a second frequency range different from the first frequency range; and performing a discovery process in the second frequency range and according to the side link relay configuration. Attached Figure Description

[0047] Figure 1 An example of a wireless communication system is shown that supports techniques for side link relay handover processes according to various aspects of this disclosure.

[0048] Figure 2 An example of a trunk configuration supporting technologies for sidelink trunk handover procedures, based on various aspects of this disclosure, is shown.

[0049] Figure 3 An example of a wireless communication system is shown that supports techniques for side link relay handover processes according to various aspects of this disclosure.

[0050] Figure 4 An example of a process flow illustrating the technologies supporting sidelink trunk handover procedures according to various aspects of this disclosure is shown.

[0051] Figure 5 An example of a process flow illustrating the technologies supporting sidelink trunk handover procedures according to various aspects of this disclosure is shown.

[0052] Figure 6 and Figure 7 A block diagram of an apparatus supporting techniques for side link relay handover procedures, according to various aspects of this disclosure, is shown.

[0053] Figure 8 A block diagram of a communication manager supporting technologies for sidelink relay handover procedures, according to various aspects of this disclosure, is shown.

[0054] Figure 9A diagram of a system including devices supporting technologies for side link trunk handover processes is shown, according to various aspects of this disclosure.

[0055] Figures 10 to 12 A flowchart illustrating a method for supporting techniques for side link relay handover procedures according to various aspects of this disclosure is shown. Detailed Implementation

[0056] Some wireless systems support sidelink relay, where a relay user equipment (UE) can forward or relay wireless communications between a base station and a remote UE. Using sidelink relay allows remote UEs to reduce uplink transmission power, thereby reducing power consumption at the remote UE, and offers other advantages. However, in the context of performing a cell handover process from one base station to another, using sidelink relay can introduce complexity.

[0057] The complexity of performing cell handover using sidelink relay may be further exacerbated by the fact that not all base stations in a wireless communication system can support sidelink relay operation. For example, some base stations can support sidelink relay operation (e.g., SL-RelayCapableBS), while others may not (e.g., non-SL-RelayCapableBS). For the purposes of this disclosure, a base station may be considered to support sidelink relay operation if it is associated with a sidelink relay configuration within a single carrier, supports sidelink relay transmission, supports a sidelink relay discovery process (e.g., it can provide a sidelink relay discovery configuration), or any combination thereof. Conversely, for the purposes of this disclosure, a base station that does not support a sidelink relay configuration may not be associated with a sidelink relay configuration, may not support a sidelink relay discovery process and / or sidelink relay transmission, or any combination thereof.

[0058] In some wireless communication systems, a relay UE may only connect to base stations that support sidelink relay operation (e.g., SL-RelayCapableBS), thus limiting the number of base stations with which the relay UE can perform handover procedures. Furthermore, a remote UE may prefer to perform handover procedures to base stations that support sidelink relay operation (e.g., SL-RelayCapableBS). However, some wireless communication systems do not provide signaling or technologies that enable relay UEs and / or remote UEs to identify which base stations support sidelink relay operation and which do not.

[0059] Therefore, the techniques described herein relate to signaling and other configurations that enable relay UEs and / or remote UEs to identify whether a target base station supports sidelink relay operations (e.g., whether the base station includes an SL-RelayCapable BS or a non-SL-RelayCapable BS), which can aid in informed decision-making for the handover process. Specifically, relay UEs and remote UEs can perform a handover process from a first base station to a second base station based on the determination that the second base station supports sidelink relay operations.

[0060] In some respects, a UE (e.g., a relay UE, a remote UE) can determine whether a base station supports sidelink relay operation based on a System Information Block (SIB) message received from the respective base station. In some cases, the SIB can explicitly (e.g., based on explicit bit fields within the SIB) and / or implicitly (e.g., based on identifying the absence of a sidelink relay configuration) indicate whether a base station supports sidelink relay operation. In some cases, both the relay UE and the remote UE can control or influence which candidate base stations they will perform the handover procedure with based on measurement reports. For example, when sending measurement reports for candidate base stations, the UE can omit measurements for base stations that do not support sidelink relay operation, can indicate which base stations do not support sidelink relay operation, can indicate a preference for base stations that support sidelink relay operation, or any combination thereof.

[0061] Various aspects of this disclosure are first described in the context of a wireless communication system. Additional aspects of this disclosure are described in the context of example relay configurations and example process flows. Various aspects of this disclosure are further illustrated by apparatus diagrams, system diagrams, and flowcharts relating to techniques used in side-link relay handover procedures, and are described with reference to these diagrams.

[0062] Figure 1 Examples of wireless communication systems 100 supporting techniques for sidelink relay handover processes according to various aspects of this disclosure are shown. Wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, wireless communication system 100 may be a Long Term Evolution (LTE) network, an improved LTE (LTE-A) network, an LTE-APro network, or a New Radio (NR) network. In some examples, wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, or communication with low-cost and low-complexity devices, or any combination thereof.

[0063] Base stations 105 can be distributed throughout a geographical area to form a wireless communication system 100, and can be devices of different forms or with different capabilities. Base stations 105 and UE 115 can communicate wirelessly via one or more communication links 125. Each base station 105 can provide a coverage area 110, and UE 115 and base station 105 can establish one or more communication links 125 on the coverage area 110. Coverage area 110 can be an example of a geographical area where base station 105 and UE 115 can support signal transmission according to one or more radio access technologies.

[0064] UE 115 can be distributed throughout the entire coverage area 110 of the wireless communication system 100, and each UE 115 can be stationary, mobile, or both at different times. UE 115 can be devices of different forms or with different capabilities. Figure 1 Some example UE 115s are shown in the document. The UE 115 described herein may be able to communicate with various types of devices, such as other UE 115s, base station 105, or network devices (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network devices), such as... Figure 1 As shown.

[0065] Base station 105 can communicate with core network 130, communicate with each other, or perform both of these operations. For example, base station 105 can interface with core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). Base station 105 can communicate with each other directly (e.g., directly between base stations 105) on backhaul links 120 (e.g., via X2, Xn, or other interfaces), or indirectly (e.g., via core network 130), or perform both of these operations. In some examples, backhaul link 120 can be or includes one or more radio links.

[0066] One or more of the base stations 105 described herein may include, or may be referred to by those skilled in the art as, base station transceiver, radio base station, access point, radio transceiver, node B, evolved node B (eNB), next-generation node B or gigabit node B (any of which may be referred to as gNB), home node B, home evolved node B, or other suitable terms.

[0067] UE 115 may include or be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or some other suitable term, wherein "device" may also be referred to as a unit, station, terminal, or client, and other examples. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or machine-type communication (MTC) device, and other examples, which may be implemented in various items such as appliances, vehicles, meters, and other examples.

[0068] The UE 115 described in this document may be able to communicate with various types of devices, such as other UEs 115 that can sometimes act as repeaters, as well as base station 105 and network devices (including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations and other examples), such as Figure 1 As shown.

[0069] UE 115 and base station 105 can communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" can refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communication link 125. For example, a carrier for communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling coordinating operation for the carrier, user data, or other signaling. Wireless communication system 100 can support communication with UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used in conjunction with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers.

[0070] The signal waveform transmitted on a carrier can consist of multiple subcarriers (e.g., using multicarrier modulation (MCM) techniques such as Orthogonal Frequency Division Multiplexing (OFDM) or Discrete Fourier Transform Spread Spectrum OFDM (DFT-S-OFDM). In a system employing MCM, a resource element can include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried through each resource element can depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Therefore, the more resource elements UE 115 receives and the higher the order of the modulation scheme, the higher the data rate can be for UE 115. Wireless communication resources can refer to a combination of radio frequency spectrum resources, temporal resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers can further increase the data rate or data integrity used for communication with UE 115.

[0071] One or more digital schemes (numerologies) can be supported for a carrier, where the digital scheme may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier can be divided into one or more BWPs with the same or different digital schemes. In some examples, UE 115 can be configured with multiple BWPs. In some examples, a single BWP for a carrier can be active at a given time, and communication for UE 115 can be restricted to one or more active BWPs.

[0072] It can be expressed in a basic unit of time (which can be, for example, T). s =1 / (Δf) max ·N f The sampling period is ) seconds, where Δf max This can represent the maximum supported subcarrier spacing, and N f The time interval for base station 105 or UE 115 can be represented as a multiple of the maximum supported Discrete Fourier Transform (DFT) size. The time interval for communication resources can be organized based on radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame can be identified by a System Frame Number (SFN) (e.g., ranging from 0 to 1023).

[0073] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of symbol periods (e.g., this depends on the length of the cyclic prefix added before each symbol period). In some wireless communication systems 100, time slots may be further divided into multiple micro-time slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N) f (Number) sampling periods. The duration of a symbol period can depend on the subcarrier spacing or the operating frequency band.

[0074] A subframe, time slot, micro-time slot, or symbol can be the smallest scheduling unit of the wireless communication system 100 (e.g., in the time domain) and can be referred to as a transmission time interval (TTI). In some examples, the duration of the TTI (e.g., the number of symbol periods in the TTI) can be variable. Alternatively, the smallest scheduling unit of the wireless communication system 100 can be dynamically selected (e.g., in a burst form of a shortened TTI (sTTI)).

[0075] Physical channels can be multiplexed on a carrier using various techniques. For example, one or more of Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels on a downlink carrier. A control region (e.g., a control resource set (CORESET)) for physical control channels can be defined by the number of symbol periods and can extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) can be configured for a group of UEs 115. For example, one or more of the UEs 115 can monitor or search for control regions for control information based on one or more search space sets, and each search space set can include one or more control channel candidates arranged in a cascaded manner at one or more aggregation levels. The aggregation level for control channel candidates can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space set may include a common search space set configured to send control information to multiple UEs 115 and a UE-specific search space set used to send control information to a specific UE 115.

[0076] Each base station 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used (e.g., on a carrier) to communicate with base station 105 and may be associated with an identifier used to distinguish adjacent cells (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID), or other identifier). In some examples, a cell may also refer to a geographic coverage area 110 or a portion of geographic coverage area 110 (e.g., a sector) on which a logical communication entity operates. Depending on various factors such as the capabilities of base station 105, the range of such cells can range from small areas (e.g., structures, subsets of structures) to large areas. For example, a cell may be or include buildings, subsets of buildings, or external space between or overlapping geographic coverage areas 110, and other examples.

[0077] Macro cells typically cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access by UE 115 with a service subscription to a network provider supporting the macro cell. In contrast, small cells can be associated with a lower-power base station 105 and can operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells can provide unrestricted access to UE 115 with a service subscription to a network provider, or restricted access to UE 115 associated with the small cell (e.g., UE 115 in a Closed Subscriber Group (CSG), or UE 115 associated with a user in a residence or office). Base station 105 can support one or more cells and can also support communication on one or more cells using one or more component carriers.

[0078] In some examples, a carrier can support multiple cells and can be configured with different cells based on different protocol types that can provide access for different types of devices (e.g., MTC, Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB)).

[0079] In some examples, base station 105 may be mobile, and therefore provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. Wireless communication system 100 may include, for example, a heterogeneous network, in which different types of base stations 105 use the same or different radio access technologies to provide coverage for various geographic coverage areas 110.

[0080] Wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UE 115 can be designed to support ultra-reliable, low-latency, or mission-critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private or group communication and may be supported by one or more mission-critical services (such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData)). Support for mission-critical functions may include service prioritization, and mission-critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency are used interchangeably herein.

[0081] In some examples, UE 115 may also be able to communicate directly with other UE 115s on a device-to-device (D2D) communication link 135 (e.g., using peer-to-peer (P2P) or D2D protocols). One or more UEs 115s utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115s in such a group may be outside the geographic coverage area 110 of base station 105 or otherwise unable to receive transmissions from base station 105. In some examples, groups of UEs 115s communicating via D2D communication may utilize a one-to-many (1:M) system, wherein each UE 115 transmits to each other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving base station 105.

[0082] In some systems, the D2D communication link 135 may be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these. Vehicles may signal information relating to traffic conditions, signal control, weather, safety, emergencies, or any other information relating to the V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure (such as roadside units), or communicate with the network via one or more network nodes (e.g., base station 105) using vehicle-to-network (V2N) communication, or both.

[0083] Core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 can be an evolved packet core (EPC) or a 5G core (5GC), and can include at least one control plane entity (e.g., a mobility management entity (MME), access and mobility management function unit (AMF)) managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), packet data network (PDN) gateway (P-GW), or user plane function unit (UPF)) routing packets to or interconnecting with external networks. The control plane entity can manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management for UE 115 served by base station 105 associated with core network 130. User IP packets can be transmitted through the user plane entity, which can provide IP address allocation and other functions. The user plane entity can connect to IP service 150 for one or more network operators. IP services 150 may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0084] Some network devices (e.g., base station 105) may include sub-components such as access network entity 140, which may be an example of an access node controller (ANC). Each access network entity 140 may communicate with UE 115 through one or more other access network transport entities 145 (which may be referred to as a radio headend, smart radio headend, or transmit / receive point (TRP)). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across individual network devices (e.g., radio headends and ANCs) or incorporated into a single network device (e.g., base station 105).

[0085] Wireless communication system 100 can operate using one or more frequency bands (typically in the range of 300 MHz to 300 GHz). The region from 300 MHz to 3 GHz is often referred to as the Ultra High Frequency (UHF) region or decimeter band because the wavelength range extends from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features, but the waves can be sufficiently permeable to penetrate structures for use in macrocells to provide service to UE 115 located indoors. Compared to the transmission of smaller frequencies and longer waves in the lower 300 MHz portion of the spectrum in the High Frequency (HF) or Very High Frequency (VHF) regions, UHF wave transmission can be associated with smaller antennas and shorter distances (e.g., less than 100 km).

[0086] Wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communication system 100 may employ Licensed Assisted Access (LAA), LTE Unlicensed (LTE-U) radio access technology, or NR technology in unlicensed frequency bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band). When operating in unlicensed radio frequency spectrum bands, devices (such as base station 105 and UE 115) may employ carrier sensing for collision detection and avoidance. In some examples, operation in unlicensed frequency bands may be based on carrier aggregation configurations that combine component carriers operating in licensed frequency bands (e.g., LAA). Operation in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer (P2P) transmissions, or digital-to-digital (D2D) transmissions, and other examples.

[0087] Base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. The antennas of base station 105 or UE 115 may be located within one or more antenna arrays or antenna panels (which may support MIMO operation or transmit or receive beamforming). For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, the antennas or antenna arrays associated with base station 105 may be located in different geographical locations. Base station 105 may have an antenna array having a number of rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, antenna panels may support radio frequency beamforming for signals transmitted via antenna ports.

[0088] Base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such a technique can be called spatial multiplexing. For example, a transmitting device can transmit multiple signals via different antennas or different combinations of antennas. Similarly, a receiving device can receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals can be referred to as a separate spatial stream and can carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers can be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) (where multiple spatial layers are transmitted to the same receiving device) and multi-user MIMO (MU-MIMO) (where multiple spatial layers are transmitted to multiple devices).

[0089] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., base station 105, UE 115) to form or guide an antenna beam (e.g., transmit beam, receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array such that some signals propagating relative to a specific orientation of the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements can include applying amplitude offset, phase offset, or both to the signals carried via the antenna elements associated with the transmitting or receiving device. The adjustments associated with each antenna element can be defined by a set of beamforming weights associated with a specific orientation (e.g., relative to the antenna array of the transmitting or receiving device, or relative to some other orientation).

[0090] As part of beamforming operations, base station 105 or UE 115 may use beam scanning techniques. For example, base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Base station 105 may transmit some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) multiple times in different directions. For example, base station 105 may transmit signals according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by a transmitting device (such as base station 105) or by a receiving device (such as UE 115)) to identify the beam direction for subsequent transmissions or receptions by base station 105.

[0091] Base station 105 may transmit signals (e.g., data signals associated with a specific receiving device, such as UE 115) in a single beam direction (e.g., a direction associated with a particular receiving device, such as UE 115). In some examples, the beam direction associated with transmission along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 that has the highest signal quality or otherwise acceptable signal quality.

[0092] In some examples, multiple beam directions can be used to perform transmissions by a device (e.g., base station 105 or UE 115), and the device can use a combination of digital precoding or radio frequency beamforming to generate combined beams for (e.g., from base station 105 to UE 115) transmissions. UE 115 can report feedback indicating precoding weights for one or more beam directions, and this feedback can correspond to a configured number of beams spanning the system bandwidth or one or more subbands. Base station 105 can transmit reference signals that can be precoded or unprecoded (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)). UE 115 can provide feedback on beam selection, which can be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., multi-panel type codebook, linear combination type codebook, port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may employ similar techniques to transmit signals multiple times in different directions (e.g., to identify beam directions for subsequent transmissions or receptions by UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0093] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105, the receiving device (e.g., UE 115) can attempt multiple receiving configurations (e.g., directional listening). For example, the receiving device can attempt multiple receiving directions by receiving via different antenna subarrays, by processing the received signals according to different antenna subarrays, by receiving according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array (e.g., different sets of directional listening weights), or by processing the received signals according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array (any of these operations can be referred to as "listening" according to different receiving configurations or receiving directions). In some examples, the receiving device can use a single receiving configuration to receive along a single beam direction (e.g., when receiving data signals). A single receiver configuration can be aligned to a beam direction determined based on listening in different receiver configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), highest signal-to-interference-plus-noise ratio (SINR), or otherwise acceptable signal quality based on listening in multiple beam directions).

[0094] The wireless communication system 100 can be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or Packet Data Convergence Protocol (PDCP) layer can be IP-based. The Radio Link Control (RLC) layer can perform packet segmentation and reassembly for transmission over logical channels. The Media Access Control (MAC) layer can perform priority handling and multiplexing of logical channels to transport channels. The MAC layer can also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer can provide the establishment, configuration, and maintenance of RRC connections (which support radio bearers for user plane data) between the UE 115 and the base station 105 or core network 130. At the physical layer, transport channels can be mapped to physical channels.

[0095] UE 115 and base station 105 can support data retransmission to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique used to increase the likelihood of correct data reception on communication link 125. HARQ can include a combination of error detection (e.g., using Cyclic Redundancy Check (CRC)), forward error correction (FEC), and retransmission (e.g., Automatic Repeat Request (ARQ)). HARQ can improve throughput at the MAC layer under poor radio conditions (e.g., low signal and noise conditions). In some examples, the device can support same-slot HARQ feedback, where the device can provide HARQ feedback for data received in a previous symbol within a specific time slot. In other cases, the device can provide HARQ feedback in subsequent time slots or according to some other time interval.

[0096] In some aspects, the UE 115 and base station 105 of the wireless communication system 100 may support signaling and other technologies that enable the relay UE 115 and / or the remote UE 115 to identify whether the target base station 105 supports sidelink relay operations (e.g., whether base station 105 includes SL-RelayCapableBS or non-SL-RelayCapableBS), which can contribute to informed decision-making for the handover process. Specifically, the relay UE 115 and the remote UE 115 may perform a handover process from the first base station 105 to the second base station 105 based on the determination that the second base station 105 supports sidelink relay operations.

[0097] In some aspects, a UE 115 of the wireless communication system 100 (e.g., a relay UE 115, a remote UE 115) can determine whether a base station 105 supports sidelink relay operation based on an SIB message received from the corresponding base station 105. In some cases, the SIB can explicitly (e.g., based on explicit bit fields within the SIB) and / or implicitly (e.g., based on identifying the absence of a sidelink relay configuration) indicate whether the base station 105 supports sidelink relay operation. Alternatively, the UE 115 can determine whether the base station 105 supports sidelink relay operation based on Policy Control Function (PCF) signaling received from the core network.

[0098] In some cases, both the relay UE 115 and the remote UE 115 can control or influence which candidate base stations 105 they will perform the handover process with based on measurement reports. For example, when sending measurement reports for candidate base stations, UE 115 can omit measurements for base stations 105 that do not support sidelink relay operations, can indicate which base stations 105 do not support sidelink relay operations, can indicate a preference for base stations 105 that support sidelink relay operations, or any combination thereof. In some aspects, UE 115 can be configured (e.g., via RRC signaling) to customize measurement reports based on whether base station 105 supports sidelink relay operations.

[0099] In the context of wireless communication systems, the techniques described herein enable an improved handover process for both remote UE 115 and relay UE 115. Specifically, the techniques described herein enable UE 115 (e.g., relay UE 115, remote UE 115) to determine whether base station 105 supports sidelink relay operation, which allows for more informed decisions regarding the handover process. By enabling UE 115 to determine whether base station 105 supports sidelink relay operation, the techniques described herein allow UE 115 to perform a handover process with a base station that supports sidelink repeater operation, thereby providing wider use of sidelink relay and reducing power consumption at the remote UE 115.

[0100] Figure 2 An example of a relay configuration 200 supporting techniques for lateral link relay handover procedures according to various aspects of this disclosure is shown. The relay configuration 200 may be implemented by or by various aspects of the wireless communication system 100.

[0101] In some aspects, relay configuration 200 illustrates relay schemes 205-a and 205-b for Layer 2 (L2) relay communication between a remote UE and a relay UE, wherein the relay UE is configured to relay communication between the remote UE and a base station. Specifically, relay scheme 205-a illustrates a control plane protocol stack for L2 relay, and relay scheme 205-b illustrates a user plane protocol stack for L2 relay. Relay scheme 205 illustrates various signaling operations performed across the entire protocol stack of various devices used to perform corresponding handovers.

[0102] In each of the relay schemes 205, a remote UE can be communicatively coupled to a relay UE via a PC5 link (e.g., a sidelink communication link). The relay UE can be communicatively coupled to a base station via a Uu link (e.g., an uplink / downlink communication link) and can be configured to relay wireless communication between the remote UE and the base station. The base station can be communicatively coupled to the user plane function (UPF) of the wireless communication system via an N3 interface, and the UPF can be coupled to the data network via an N6 interface.

[0103] In the context of the control plane protocol stack for L2 relay, relay scheme 205-a illustrates both the PC5 C-plane and the NR Uu C-plane at the remote UE. The PC5 C-plane can be configured to establish a unicast link with the relay UE prior to relay communication. In some aspects, the remote UE can support NR Uu access layer (AS) and non-access layer (NAS) connections above the PC5 radio link control (RLC) layer. In some aspects, the base station (e.g., NG-RAN) shown in relay scheme 205-a can be configured to control the PC5 link of the remote UE via the NR RRC layer. Additionally, the adaptive layer at the relay UE can be configured to support the multiplexing of services for multiple remote UEs on the Uu link between the relay UE and the base station.

[0104] Referring to the user plane protocol stack for L2 relay shown in Relay Scheme 205-b, relaying can be performed below the PDCP layer. Specifically, the relay UE can use adaptive layer functions to forward PC5 and Uu bearers. In some aspects, the dedicated radio bearer (DRB) of the remote UE can be controlled by the base station (e.g., NG-RAN). Furthermore, in L2 relay, all services can terminate at 5GC, and direct communication may not exist between remote UEs or between remote UEs and relay UEs.

[0105] Figure 3 Examples of wireless communication systems 300 supporting techniques for side link relay handover processes according to various aspects of this disclosure are shown. In some aspects, aspects of wireless communication system 300 may be implemented by or by aspects of wireless communication system 100, relay configuration 200, or both.

[0106] The wireless communication system 300 may include a first base station 105-a, a second base station 105-b, a third base station 105-c, a relay UE 115-a, and remote UEs 115-b and 115-c, as well as a core network 305, which may be as described in reference. Figure 1 and Figure 2Examples of UE 115, base station 105 and other wireless devices described.

[0107] In some aspects, the first base station 105-a, the second base station 105-b, and the third base station 105-c can communicate with the core network 305 using communication links 310-a, 310-b, and 310-c, respectively. Communication links 310-a, 310-b, and 310-c can be examples of the N3 interface between the base station 105 and the core network 305 of the wireless communication system 300.

[0108] Relay UE 115-a can communicate with first base station 105-a (e.g., source base station 105-a) using communication link 310-d. Communication link 310-d may include examples of an NR or LTE link between relay UE 115-a and first base station 105-a. In some cases, communication link 310-d may include examples of an access link (e.g., a Uu link), which may include a bidirectional link enabling both uplink and downlink communication. For example, relay UE 115-a can use communication link 310-d to send uplink signals, such as uplink control signals or uplink data signals, to first base station 105-a, and first base station 105-a can use communication link 310-d to send downlink signals, such as downlink control signals or downlink data signals, to relay UE 115-a.

[0109] In some aspects, relay UE 115-a may be communicatively coupled to remote UE 115-b via communication link 310-e. Communication link 310-e may include examples of a sidelink communication link or a PC5 link between relay UE 115-a and remote UE 115-b. In some aspects, relay UE 115-a may be configured to forward or relay wireless communications between first base station 105-a and remote UE 115-b. For example, remote UE 115-b may be configured to send data to relay UE 115-a via communication link 310-e, and relay UE 115-a may be configured to forward (e.g., relay) data received from remote UE 115-b to first base station 105-a via communication link 310-d. Conversely, the first base station 105-a can be configured to transmit data (e.g., downlink signals) to the relay UE 115-a via communication link 310-d, and the relay UE 115-a can be configured to forward (e.g., relay) data received from the first base station 105-a to the remote UE 115-b via communication link 310-e. As previously mentioned herein, using sidelink relay (e.g., using relay UE 115-a) allows the remote UE 115-b to reduce the transmission power of uplink transmissions, thereby reducing power consumption at the remote UE 115-b.

[0110] As previously mentioned herein, the use of sidelink relay can introduce complexity in the context of performing a cell handover process from one base station 105 to another. This complexity can be further exacerbated by the fact that not all base stations 105 in the wireless communication system can support sidelink relay operation. For example, first base station 105-a and second base station 105-b may support sidelink relay operation (e.g., SL-RelayCapableBS), while third base station 105-c may not support sidelink relay operation (e.g., non-SL-RelayCapableBS). For the purposes of this disclosure, a base station 105 can be considered to support sidelink relay operation if it supports sidelink relay discovery procedures and sidelink relay communication (e.g., sidelink relay operation) within a single carrier. Conversely, for the purposes of this disclosure, a base station 105 that does not support sidelink relay configuration may not support sidelink relay discovery procedures and sidelink relay communication within a single carrier. In cases where UE 115 supports sidelink relay but candidate base station 105 does not, it may be particularly important to identify base stations that do not support sidelink relay operation (e.g., non-SL-RelayCapableBS).

[0111] In some wireless communication systems, a relay UE 115 (e.g., relay UE 115-a) may only connect to base stations 105 that support sidelink relay operation (e.g., SL-RelayCapableBS), thus limiting the number of base stations 105 with which the relay UE 115 can perform handover procedures. For example, in the context of L2 sidelink relay, relay UE 115-a may only be able to connect to base stations 105 that support sidelink relay operation (including the transmission of discovery messages). In contrast, in the context of L3 sidelink relay, relay UE 115-a may be configured to communicate with base stations 105 that do not support sidelink relay operation. In such a case, when relay UE 115-a connects to a non-SL-RelayCapableBS whose serving carrier is not shared with a sidelink carrier, relay UE 115-a may be configured to send discovery messages according to a signaled or configured (e.g., pre-configured) sidelink relay configuration.

[0112] Furthermore, a remote UE 115 (e.g., remote UE 115-b) may prefer to perform a handover procedure to a base station 105 (e.g., an SL-RelayCapableBS) that supports sidelink relay operation. However, some wireless communication systems do not provide signaling or techniques that enable relay UE 115 and / or remote UE 115 to identify which base stations 105 support sidelink relay operation and which do not. Additionally, in cases where a remote UE 115 (e.g., remote UE 115-b) supporting L2 and / or L3 relay is directly coupled (e.g., via a Uu link) to a base station 105 that does not support sidelink relay (e.g., a non-SL-RelayCapableBS), when the remote UE 115 connects to a non-SL-RelayCapableBS whose serving carrier is not shared with a sidelink carrier, the remote UE 115 can be configured to send discovery messages according to a signaled or configured (e.g., pre-configured) sidelink relay configuration.

[0113] Therefore, the UE 115 and base station 105 of the wireless communication system 300 can support signaling and other technologies that enable the relay UE 115-a and / or the remote UE 115-b to identify whether the base station 105 supports sidelink relay operations (e.g., whether the base station 105 includes SL-RelayCapableBS or non-SL-RelayCapableBS), which can contribute to informed decision-making for the handover process. In particular, the relay UE 115-a and the remote UE 115-b can perform the handover process from the source base station 105 (e.g., the first base station 105-a) to the target base station 105 based on the determination that the target base station 105 (e.g., the second base station 105-b) supports sidelink relay operations.

[0114] In some aspects, relay UE 115-a and / or remote UE 115-b can determine whether the respective base station 105 supports sidelink relay operation based on SIB messages received from base station 105 of wireless communication system 300. In some cases, the SIB can explicitly (e.g., based on explicit bit fields within the SIB) and / or implicitly (e.g., based on identifying the absence of a sidelink relay configuration) indicate whether base station 105 supports sidelink relay operation. Alternatively or additionally, relay UE 115-a and / or remote UE 115-b can determine whether base station 105 supports sidelink relay operation based on PCF signaling received from core network 305.

[0115] In some cases, both relay UE 115-a and remote UE 115-b can control or influence which candidate base stations 105 they will perform the handover process with based on measurement reports. For example, when sending measurement reports for candidate base stations, UE 115-a and / or 115-b may omit measurements for base stations 105 that do not support sidelink relay operations, may indicate which base stations 105 do not support sidelink relay operations, may indicate a preference for base stations 105 that support sidelink relay operations, or any combination thereof. For example, if the second base station 105-b supports sidelink relay operation (e.g., SL-RelayCapableBS) but the third base station 105-c does not support sidelink relay operation (e.g., non-SL-RelayCapableBS), UE 115-a and / or 115-b can be configured to send a measurement report to the first base station 105-a, wherein the measurement report omits measurements for the third base station 105-c, indicates that the third base station 105-c does not support sidelink relay operation, indicates a preference for the second base station 105-b, or any combination thereof. In some aspects, UE 115 can be configured to customize the measurement report based on RRC signaling (e.g., omitting measurements for non-SL-RelayCapableBS, marking non-SL-RelayCapableBS).

[0116] As previously mentioned, relay UE 115-a may be required to couple to base station 105 (e.g., SL-RelayCapableBS) that supports sidelink relay operation for L2 relay communication, but may couple to base station 105 (e.g., non-SL-RelayCapableBS) that does not support sidelink relay operation for L3 relay communication. Furthermore, remote UE 115-a may couple to both SL-RelayCapableBS and non-SL-RelayCapableBS for both L2 and L3 relay communication. However, it may be preferred that both relay UE 115-a and remote UE 115-b are coupled to base station 105 that supports sidelink relay to facilitate wider use of sidelink relay.

[0117] Therefore, the techniques described herein enable UE 115 (e.g., relay UE 115-a, remote UE 115-b) to determine that they are communicatively coupled to base station 105 that does not support sidelink relay operation, and to perform a handover procedure to base station 105 that supports sidelink relay operation. In some cases, the handover procedure and the determination of whether a candidate base station 105 supports sidelink relay can be aided by the network via measurement reports, as will be discussed herein. Figure 4 and Figure 5Further detailed description.

[0118] In an additional or alternative aspect, relay UE 115-a and / or remote UE 115-b may trigger (e.g., initiate) a discovery process to connect to an SL-RelayCapableBS if the respective UE 115 is connected to a non-SL-RelayCapableBS. For example, in some cases, the first base station 105-a may not support sidelink relay operation in a first frequency range. In this example, remote UE 115-b may be communicatively coupled to the first base station 105-a via communication link 310-f and may communicate with the first base station 105-a in the first frequency range. In this example, in order to connect to a base station 105 that does support sidelink relay operation, remote UE 115-b may be configured (e.g., via an upper layer) to search for base stations 105 that support sidelink relay operation in a second frequency range different from the first frequency range (e.g., first base station 105-a, second base station 105-b, third base station 105-c). In this regard, the remote UE 115-b can search between frequencies for base stations 105 that support sidelink discovery procedures and sidelink relay configurations within a given frequency range.

[0119] Continuing with the same example, in some cases, the remote UE 115-b can identify the frequency range that base station 105 supports both the sidelink discovery process and the sidelink relay configuration. In such cases, the remote UE 115-b can camp on the corresponding cell with the strongest signal (e.g., strongest reference signal received power (RSRP), strongest reference signal received quality (RSRQ)) at the identified frequency and can trigger the sidelink discovery process based on the sidelink relay configuration associated with that cell. In contrast, in other cases, the remote UE 115-b may not identify the frequency range that supports both the sidelink discovery process and the sidelink relay configuration. In such cases, the remote UE 115-b can select a frequency range without cellular coverage and can trigger the discovery process for SL-RelayCapableBS based on a pre-configured sidelink relay configuration. In this regard, the remote UE 115-b can be configured to trigger the discovery process for L2 and L3 relays by searching between frequencies that support both the sidelink discovery process and the sidelink relay configuration. In addition, relay UE 115-a can be configured to perform similar techniques in order to trigger the discovery process for L3 relay.

[0120] This article refers to Figure 4 and Figure 5The techniques that UE 115 and base station 105 can use to identify whether base station 105 supports side link relay operation and to perform the handover process based on the ability of base station 105 to support side link relay operation are discussed in further detail.

[0121] Figure 4 Examples of process flow 400 supporting techniques for lateral link relay handover procedures according to various aspects of this disclosure are shown. In some examples, process flow 400 may be implemented by aspects of wireless communication system 100, relay configuration 200, wireless communication system 300, or any combination thereof, or by aspects of wireless communication system 100, relay configuration 200, wireless communication system 300, or any combination thereof. For example, process flow 400 may show relay UE 115-d determining whether candidate base station 105 supports lateral link relay operation, and performing a handover procedure with candidate base station 105 based on this determination, as shown in reference to Figure 1-3 Described.

[0122] In some cases, process flow 400 may include remote UE 115-c, relay UE 115-d, first base station 105-d, second base station 105-e, and third base station 105-f, which may be examples of corresponding devices as described herein. For example, in some cases, Figure 4 The remote UE 115-c and relay UE 115-d shown can be respectively as follows: Figure 3 Examples of remote UE115-b and relay UE115-a are shown. Similarly, Figure 4 The first base station 105-d, the second base station 105-e, and the third base station 105-f shown in the figure can be respectively as follows: Figure 3 Examples of the first base station 105-a, the second base station 105-b, and the third base station 105-c are shown.

[0123] In some examples, the operations shown in process flow 400 can be performed by hardware (e.g., including circuitry, processing blocks, logic components, and other components), code executed by a processor (e.g., software or firmware), or any combination thereof. Alternative examples are possible, some of which may be performed in a different order than described or not at all. In some cases, steps may include additional features not mentioned below, or additional steps may be added.

[0124] At position 405, relay UE 115-d can receive SIB messages from first base station 105-d. In some aspects, the SIB message may indicate whether first base station 105-d supports sidelink relay operation (e.g., determining whether first base station 105-d is an SL-RelayCapable BS or a non-SL-RelayCapable BS). For example, in some cases, the SIB message may include one or more bit fields explicitly indicating whether first base station 105-d supports sidelink relay operation. In this respect, the SIB message may include one or more bit fields indicating whether first base station 105-d supports sidelink discovery procedures and sidelink relay within a single carrier.

[0125] In an additional or alternative manner, the SIB message may implicitly indicate whether the first base station 105-d supports sidelink relay operation. For example, if the relay UE 115-d determines that the SIB message provides a sidelink relay configuration for sidelink relay operation, then UE 115-d can determine that the first base station 105-d supports sidelink relay operation. Conversely, if the relay UE 115-d decodes (e.g., demodulates) the SIB message and does not recognize the sidelink relay configuration, then the relay UE 115-d can determine that the first base station 105-d does not support sidelink relay operation.

[0126] As previously mentioned herein, for L2 relay, relay UE 115-d may be communicatively coupled to base station 105 that supports sidelink relay operation (e.g., only connected to SL-RelayCapableBS). In this regard, in the context of L2 relay, SIB messages sent by the first base station 105-d may indicate that the first base station 105-d supports sidelink relay operation. Furthermore, in the context of a handover procedure for L2 relay, both the source base station 105 and the target base station 105 used for the handover procedure at relay UE 115-d may include base station 105 that supports sidelink relay operation.

[0127] At 410, relay UE 115-d can receive RRC messages from the first base station 105-d. Relay UE 115-d can receive RRC messages at 410 based on receiving SIB messages at 405. In some aspects, the RRC message can indicate a measurement report configuration for sending measurement reports to the first base station 105-d. In this respect, the RRC message can indicate whether relay UE 115-d wants to measure and / or report measurements of SL-RelayCapableBS, non-SL-RelayCapableBS, or both. Alternatively or additionally, the RRC message can indicate whether the measurement report should indicate (e.g., mark) which base stations 105 support sidelink relay operation, whether relay UE 115-d should indicate a preference for base stations 105 that support sidelink relay operation, or any combination thereof.

[0128] For example, in some cases, an RRC message may instruct relay UE 115-d to omit measurements associated with candidate base station 105 in a measurement report indicating measurements for candidate base station 105. In other words, an RRC message may instruct relay UE 115-d to omit measurements for non-SL-RelayCapableBSs from the measurement report. Alternatively, an RRC message may instruct relay UE 115-d to avoid performing measurements on signals associated with non-SL-RelayCapableBSs.

[0129] As another example, an RRC message could instruct that a measurement report sent by relay UE 115-d should include an indication of whether the base station 105 associated with the reported measurement is associated with an SL-RelayCapable BS, a non-SL-RelayCapable BS, or both. In this respect, the RRC message could instruct relay UE 115-d to mark the measurement as associated with a base station 105 that supports or does not support sidelink relay operation.

[0130] At 415, relay UE 115-d can determine the sidelink relay configuration associated with the first base station 105-d. In some aspects, the sidelink relay configuration can provide a set of rules or other configurations for performing a discovery process at relay UE 115-d, for relayed communication between the first base station 105-d and the remote UE 115-c, etc. Relay UE 115-d can determine the sidelink relay configuration based on receiving an SIB message at 405, receiving an RRC message at 410, or both.

[0131] At 420, relay UE 115-d can be configured to communicate with the first base station 105-d. Additionally, in some aspects, relay UE 115-d can be configured to relay (e.g., forward) wireless communications between the first base station 105-d and the remote UE 115-c. For example, relay UE 115-d can be configured to relay wireless communications between the first base station 105-d and the remote UE 115-c at least via a sidelink communication link between the remote UE 115-c and relay UE 115-d, a Uu link between relay UE 115-d and the first base station 105-d, or both. In this respect, the remote UE 115-c can communicate with the first base station 105-d at least via a sidelink communication link between the remote UE 115-c and relay UE 115-d (e.g., exchange uplink and / or downlink signals).

[0132] At 425, relay UE 115-d can perform a discovery procedure. As previously mentioned herein, for L2 relay, relay UE 115-d can be configured to connect only to base station 105 that supports sidelink relay operation. In this regard, relay UE 115-d can be configured to perform a discovery procedure at 425 to identify another base station 105 that supports sidelink relay operation. In some aspects, relay UE 115-d can perform the discovery procedure at 425 based on receiving an SIB message at 405, receiving an RRC message at 410, determining a sidelink relay configuration associated with the first base station 105-d at 415, or any combination thereof. For example, relay UE 115-d can perform the discovery procedure based on (e.g., according to) the determined sidelink relay configuration.

[0133] At position 430, relay UE 115-d can receive SIB messages from at least one candidate base station 105. For example, as Figure 4 As shown, relay UE 115-d can receive SIB messages from the second base station 105-e, the third base station 105-d, or both.

[0134] As previously mentioned, SIB messages received from candidate base stations can explicitly or implicitly indicate whether the corresponding base station (e.g., second base station 105-e, third base station 105-f) supports sidelink relay operation. For example, in some cases, an SIB message received from second base station 105-e may include one or more bit field values ​​that explicitly indicate whether second base station 105-e supports sidelink relay operation. As another example, an SIB message received from third base station 105-f may or may not include data indicating the sidelink relay configuration associated with third base station 105-f, which can be used as an implicit indication of whether third base station 105-f supports sidelink relay operation.

[0135] At 435, the first base station 105-d may perform an Xn interface procedure (e.g., exchange Xn signaling) with the candidate base station 105 to determine whether the corresponding candidate base station 105 supports sidelink relay operation. For example, the first base station 105-d may exchange Xn signaling with the second base station 105-e to determine whether the second base station 105-e supports sidelink relay operation.

[0136] At 440, the first base station 105-d can send a downlink transmission indicating whether the corresponding candidate base station 105 supports sidelink relay operation. The first base station 105-d can send the indication at 440 based on the execution of the Xn procedure at 435. For example, by exchanging Xn signaling at 435, the first base station 105-d can determine that the second base station 105-e does indeed support sidelink relay operation, and the third base station 105-f does not support sidelink relay operation. In this example, the first base station 105-d can send an indication to the relay UE 115-d that the second base station 105-e does indeed support sidelink relay operation and the third base station 105-f does not support sidelink relay operation.

[0137] At 445, relay UE 115-d can determine whether candidate base station 105 supports sidelink relay operation (e.g., whether candidate base station 105 is an SL-RelayCapable BS or a non-SL-RelayCapable BS). For example, relay UE 115-d can determine that second base station 105-e supports sidelink relay operation, and third base station 105-f does not support sidelink relay operation. In some aspects, relay UE 115-d can determine whether candidate base station 105 supports sidelink relay operation based on performing a discovery procedure at 425, receiving an SIB message from candidate base station 105 at 430, receiving an explicit indication from first base station 105-d at 440, or both.

[0138] For example, if the SIB message received at 430 includes one or more bit field values ​​indicating whether the respective base stations 105-e and 105-f support sidelink relay operation, the relay UE 115-d can determine whether the respective base stations 105-e and 105-f support sidelink relay operation based on one or more bit field values. As another example, when receiving an SIB from the third base station 105-f, the relay UE 115-d can be configured to determine that the third base station 105-f does not support sidelink relay operation based on the absence of data indicating that the third base station 105-f supports sidelink relay operation within the received SIB message (e.g., based on implicit determination in the SIB message).

[0139] At 450, relay UE 115-d can send one or more measurement reports to the first base station 105-d. The measurement reports can indicate measurements performed on signals received from one or more candidate base stations 105 (e.g., RSRP, RSRQ, SNR, SINR, Channel Quality Indicator (CQI)). In this regard, the measurement reports can indicate measurements performed by relay UE 115-d on signals (e.g., reference signals) received from the second base station 105-e, the third base station 105-f, or both. Alternatively, the measurement reports can indicate whether the respective candidate base station 105 supports sidelink relay operation.

[0140] In some aspects, relay UE 115-d can send a measurement report at 450 based on receiving an SIB message at 405, receiving an RRC message at 410, determining the sidelink relay configuration associated with the first base station 105-d at 415, performing a discovery process at 425, receiving an SIB message from candidate base station 105 at 430, receiving an indication at 440, determining at 445 whether candidate base station 105 supports sidelink relay operation, or any combination thereof.

[0141] For example, relay UE 115-d can be configured to send a measurement report at 450 based on the measurement report received at 410 via an RRC message. For instance, in some cases, the RRC message can instruct that the measurement report sent by relay UE 115-d should omit measurements associated with base station 105 that does not support sidelink relay operation. In this example, relay UE 115-f can omit measurements for the third base station 105-f from the measurement report based on the determination that the third base station 105-f does not support sidelink relay operation.

[0142] As another example, the RRC message could instruct that a measurement report sent by relay UE 115-d should include an indication of whether the base station 105 associated with the reported measurement is associated with an SL-RelayCapableBS, a non-SL-RelayCapableBS, or both. In this example, the measurement report could include measurements for both the second base station 105-e and the third base station 105-f, and could indicate that the second base station 105-e supports sidelink relay operation, the third base station 105-f does not support sidelink relay operation, or both.

[0143] At 455, relay UE 115-d can receive instructions from first base station 105-d to perform a handover procedure. First base station 105-d can send instructions for the handover procedure based on performing the Xn procedure at 435, receiving a measurement report at 450, or both.

[0144] In some aspects, the instruction can direct relay UE 115-d to perform a handover procedure from first base station 105-d to candidate base station 105 that supports sidelink relay operation. For example, if a measurement report indicates that second base station 105-e supports sidelink relay operation, the instruction received at 455 can direct relay UE 115-d to perform a handover procedure from first base station 105-d to second base station 105-e.

[0145] At 460, relay UE 115-d can perform a handover procedure from the first base station 105-d to the second base station 105-f. Relay UE 115-d can perform the handover procedure based on (e.g., according to) instructions received at 455. Alternatively, relay UE 115-d can perform the handover procedure based on receiving an SIB message from the first base station 105-d at 405, receiving an RRC message at 410, determining the sidelink relay configuration associated with the first base station 105-d at 415, performing a discovery procedure at 425, determining whether the candidate base station 105 supports sidelink relay operation at 445, sending a measurement report at 450, receiving instructions at 455, or any combination thereof.

[0146] At point 465, relay UE 115-d can communicate with the second base station 105-e. In some aspects, relay UE 115-d can communicate with the second base station 105-e based on a handover procedure performed at point 460. In this respect, relay UE 115-d can exchange uplink and downlink transmissions with the second base station 105-e via the Uu link between relay UE 115-d and the second base station 105-f.

[0147] In some respects, relay UE 115-d can be configured to relay communication between the second base station 105-d and the remote UE 115-c. For example, in cases where the wireless communication system supports group mobility for both relay and remote UE 115, the remote UE 115-c can perform a handover procedure together with the relay UE 115-d, in which case the relay UE 115-d can relay communication between the respective devices, as previously mentioned herein. As another example, in cases where the wireless communication system does not support group mobility, after the relay UE 115-d performs a handover procedure at 460, the remote UE 115-c can perform its own handover or reselection procedure to re-establish a wireless connection with the relay UE 115-d. In this example, once the wireless connection is re-established between UE 115-c and 115-d, the relay UE 115-d can be configured to relay communication between the corresponding remote UE 115-c and the second base station 105-d.

[0148] In some cases, as previously mentioned herein, relay UE 115-d can be configured to search for frequencies and trigger (e.g., initiate) a discovery process to connect to an SL-RelayCapableBS when it is connected to a non-SL-RelayCapableBS. For example, in the context of L3 relay, relay UE 115-d can communicatively couple to a third base station 105-f. In this example, relay UE 115-d can communicate with the third base station 105-f in a first frequency range, where the third base station 105-f does not support sidelink relay operation in the first frequency range. To connect to a base station 105 that supports sidelink relay operation, relay UE 115-d can be configured (e.g., via an upper layer) to search for base stations 105 that support sidelink relay operation in a frequency range different from the first frequency range (e.g., first base station 105-d, second base station 105-e, and third base station 105-f). In this regard, the remote UE 115-b can search between frequencies for base stations 105 that support sidelink discovery procedures and sidelink relay configurations within a given frequency range.

[0149] Continuing with the same example, in some cases, relay UE 115-d can determine that the fourth base station 105 (not shown) supports sidelink relay operation in a second frequency range different from the first frequency range. Relay UE 115-d can determine the sidelink relay configuration associated with the fourth base station 105 and can perform a discovery procedure associated with the fourth base station 105 based on (e.g., according to) the sidelink relay configuration. The frequency range in which base station 105 supports both the sidelink discovery procedure and the sidelink relay configuration can be identified. In such a case, relay UE 115-d can camp on the corresponding cell of the fourth base station 105 with the strongest signal (e.g., strongest RSRP, strongest RSRQ) in the second frequency range and can trigger the sidelink discovery procedure according to the sidelink relay configuration associated with the fourth base station 105.

[0150] In contrast, under other circumstances, relay UE 115-d may not recognize the frequency range supporting both the sidelink discovery procedure and the sidelink relay configuration. In such cases, relay UE 115-d can select a frequency range without cellular coverage and can trigger the discovery procedure for base station 105 supporting sidelink relay operation based on a pre-configured sidelink relay configuration (e.g., based on the sidelink relay configuration received via RRC message at 410). In this regard, relay UE 115-d can be configured to trigger the discovery procedure for L3 relay by searching between frequencies supporting both the sidelink discovery procedure and the sidelink relay configuration.

[0151] The techniques described herein enable an improved handover process for both remote UE 115 and relay UE 115 within the context of a wireless communication system. Specifically, the techniques described herein enable relay UE 115-d to determine whether base station 105 supports sidelink relay operation, allowing for more informed decisions regarding the handover process. By enabling relay UE 115-d to determine whether base station 105 supports sidelink relay operation, the techniques described herein allow relay UE 115-d to perform a handover process with base station 105 that supports sidelink relay operation, thereby providing broader use of sidelink relay and reducing power consumption at remote UE 115 (e.g., remote UE 115-c).

[0152] Figure 5Examples of process flow 500 supporting techniques for lateral link relay handover procedures according to various aspects of this disclosure are shown. In some examples, process flow 500 may be implemented by aspects of wireless communication system 100, relay configuration 200, wireless communication system 300, process flow 400, or any combination thereof, or by aspects of wireless communication system 100, relay configuration 200, wireless communication system 300, process flow 400, or any combination thereof. For example, process flow 400 may show a remote UE 115-e determining whether candidate base station 105 supports lateral link relay operation and performing a handover procedure with candidate base station 105 based on this determination, as shown in reference to Figure 1-3 Described.

[0153] In some cases, process flow 500 may include remote UE 115-e, relay UE 115-f, first base station 105-g, second base station 105-h, and third base station 105-i, which may be examples of corresponding devices as described herein. For example, in some cases, Figure 5 The remote UE 115-e and relay UE 115-f shown can be respectively as follows: Figure 3 Examples of remote UE115-b and relay UE115-a are shown. Similarly, Figure 5 The first base station 105-g, the second base station 105-h, and the third base station 105-i shown in the figure can be respectively as follows: Figure 3 Examples of the first base station 105-a, the second base station 105-b, and the third base station 105-c are shown.

[0154] In some examples, the operations shown in process flow 500 can be performed by hardware (e.g., including circuits, processing blocks, logic components, and other components), code executed by a processor (e.g., software or firmware), or any combination thereof. Alternative examples are possible, some of which may be performed in a different order than described or not at all. In some cases, steps may include additional features not mentioned below, or additional steps may be added.

[0155] At position 505, remote UE 115-e can receive SIB messages from first base station 105-g. In some aspects, the SIB message may indicate whether first base station 105-b supports sidelink relay operation (e.g., determining whether first base station 105-g is an SL-RelayCapable BS or a non-SL-RelayCapable BS). For example, in some cases, the SIB message may include one or more bit fields explicitly indicating whether first base station 105-g supports sidelink relay operation. In this respect, the SIB message may include one or more bit fields indicating whether first base station 105-g supports sidelink discovery procedures and sidelink relay within a single carrier.

[0156] In an additional or alternative manner, the SIB message may implicitly indicate whether the first base station 105-g supports sidelink relay operation. For example, if the remote UE 115-e determines that the SIB message provides a sidelink relay configuration for sidelink relay operation, then the remote UE 115-e can determine that the first base station 105-g supports sidelink relay operation. Conversely, if the remote UE 115-e decodes (e.g., demodulates) the SIB message and does not recognize the sidelink relay configuration, then the remote UE 115-e can determine that the first base station 105-g does not support sidelink relay operation.

[0157] In some aspects, the SIB message sent by the first base station 105-g can instruct the first base station 105-g to support sidelink relay operation. Furthermore, as... Figure 5 As shown, the remote UE 115-e can be communicatively coupled to the first base station 105-g with or without the relay UE 115-f. In this regard, the remote UE 115-e can receive SIB messages directly from the first base station 105-g (e.g., via a Uu link between the first base station 105-g and the remote UE 115-e), via the relay UE 115-f (e.g., at least via a sidelink communication link between the remote UE 115-e and the relay UE 115-f), or both.

[0158] At 510, remote UE 115-e can receive RRC messages from the first base station 105-g. Remote UE 115-e can receive RRC messages at 510 based on receiving SIB messages at 505. Furthermore, remote UE 115-e can receive RRC messages directly from the first base station 105-g (e.g., via the Uu link between the first base station 105-g and remote UE 115-e), via relay UE 115-f (e.g., at least via the sidelink communication link between remote UE 115-e and relay UE 115-f), or both.

[0159] In some aspects, the RRC message may indicate the measurement report configuration for sending measurement reports to the first base station 105-g. In this regard, the RRC message may indicate whether the remote UE 115-e wants to measure and / or report measurements of SL-RelayCapableBS, non-SL-RelayCapableBS, or both. Alternatively or additionally, the RRC message may indicate whether the measurement report should indicate (e.g., mark) which base stations 105 support sidelink relay operation, whether the remote UE 115-e should indicate a preference for base stations 105 that support sidelink relay operation, or any combination thereof.

[0160] For example, in some cases, an RRC message may instruct the remote UE 115-e to omit measurements associated with candidate base station 105 in a measurement report indicating measurements for candidate base station 105. In other words, the RRC message may instruct the remote UE 115-e to omit measurements for non-SL-RelayCapableBSs from the measurement report. Alternatively, the RRC message may instruct the remote UE 115-e to avoid performing measurements on signals associated with non-SL-RelayCapableBSs.

[0161] As another example, an RRC message may instruct the remote UE 115-e to include an indication of whether the base station 105 associated with the reported measurement is associated with an SL-RelayCapable BS, a non-SL-RelayCapable BS, or both. In this regard, the RRC message may instruct the remote UE 115-e to mark the measurement as associated with a base station 105 that supports or does not support sidelink relay operation. Furthermore, as another example, an RRC message may instruct the remote UE 115-e to include measurements for a base station 105 associated with relay UE 115, a base station 105 not associated with relay UE 115, or both. For example, in the case where the remote UE 115-e prioritizes sidelink relay, the RRC message may instruct the remote UE 115-e to omit measurements associated with a base station 105 not associated with relay UE 115 (e.g., omitting measurements for a base station 105 that does not have relay UE 115).

[0162] In an additional or alternative aspect, the remote UE 115-e may receive a measurement report configuration for sending measurement reports via a PCF message received from the first base station 105-g, the core network associated with the first base station 105-g, or both. For example, the remote UE 115-e may receive a PCF message from the core network instructing the remote UE 115-e to omit measurements associated with base station 105, which does not support sidelink relay operation. In this regard, the remote UE 115-e may receive the measurement report configuration via an RRC message at 510, via a PCF message received through the core network, or both.

[0163] At 515, remote UE 115-e can determine the sidelink relay configuration associated with the first base station 105-g. In some aspects, the sidelink relay configuration can provide a set of rules or other configurations for performing a discovery process at remote UE 115-e, for relaying communication between the first base station 105-g and remote UE 115-e via relay UE 115-f, etc. Remote UE 115-e can determine the sidelink relay configuration based on receiving an SIB message at 505, receiving an RRC message at 510, receiving a PCF message, or any combination thereof.

[0164] At point 520, the remote UE 115-e can be configured to communicate with the first base station 105-g. In some aspects, the remote UE 115-e can be configured to communicate with the first base station 105-g via a relay UE 115-f, which is configured to relay (e.g., forward) wireless communications between the first base station 105-g and the remote UE 115-e. For example, the relay UE 115-f can be configured to relay wireless communications between the first base station 105-g and the remote UE 115-e at least via a sidelink communication link between the remote UE 115-e and the relay UE 115-f, a Uu link between the relay UE 115-f and the first base station 105-g, or both. In this respect, the remote UE 115-e can communicate with the first base station 105-g at least via the sidelink communication link between the remote UE 115-e and the relay UE 115-f (e.g., exchanging uplink and / or downlink signals).

[0165] At 525, the remote UE 115-e can perform a discovery procedure. The relay UE 115-e can be configured to perform the discovery procedure at 525 to identify another base station 105 that supports sidelink relay operation. In some aspects, the remote UE 115-e can perform the discovery procedure at 525 based on receiving an SIB message at 505, receiving an RRC message at 510, determining a sidelink relay configuration associated with the first base station 105-g at 515, or any combination thereof. For example, the remote UE 115-e can perform the discovery procedure based on (e.g., according to) the determined sidelink relay configuration.

[0166] At position 530, remote UE 115-e can send a handover request to base station 105, which does not support sidelink relay operation. For example, as Figure 5 As shown, remote UE 115-e can send a handover request to third base station 105-i, where third base station 105-i does not support sidelink relay operations. Remote UE 115-e can send the handover request directly to third base station 105-i, send the handover request via relay UE 115-f to third base station 105-i, or both. The handover request may include a request for remote UE 115-e to perform a handover process from first base station 105-g and / or relay UE 115-f to third base station 105-e.

[0167] At 535, the third base station 105-i can send a control message to the remote UE 115-i. In some aspects, the control message can reject the handover request received at 530. Specifically, the third base station 105-i can reject the handover request based on the fact that the third base station 105-i does not support sidelink relay operation. In this regard, the third base station 105-i can be configured to determine that the remote UE 115-e is a remote UE 115 and / or that the remote UE 115-e may prefer to hand over to a base station 105 that supports sidelink relay operation (with or without relay UE 115), and can reject the handover request based on the fact that the third base station 105-i does not support sidelink relay operation.

[0168] At point 540, the remote UE 115-e can receive SIB messages from at least one candidate base station 105. For example, as Figure 5 As shown, the remote UE 115-e can receive SIB messages from the second base station 105-h, the third base station 105-i, or both. Furthermore, the remote UE 115-e can be configured to receive SIB messages via a Uu link with the respective base stations 105-h and 105-i, via a relay UE 115-f (e.g., at least via a sidelink communication link between the remote UE 115-e and the relay UE 115-f), or both.

[0169] As previously mentioned, SIB messages received from candidate base stations can explicitly or implicitly indicate whether the corresponding base station (e.g., second base station 105-h, third base station 105-i) supports sidelink relay operation. For example, in some cases, an SIB message received from the second base station 105-h may include one or more bit field values ​​that explicitly indicate whether the second base station 105-h supports sidelink relay operation. As another example, an SIB message received from the third base station 105-i may or may not include data indicating the sidelink relay configuration associated with the third base station 105-i, which can be used as an implicit indication of whether the third base station 105-i supports sidelink relay operation.

[0170] At point 545, the first base station 105-g may perform an Xn interface procedure (e.g., exchange Xn signaling) with the candidate base station 105 to determine whether the corresponding candidate base station 105 supports sidelink relay operation. For example, the first base station 105-g may exchange Xn signaling with the second base station 105-h to determine whether the second base station 105-h supports sidelink relay operation.

[0171] At 550, the first base station 105-g can send a downlink transmission indicating whether the corresponding candidate base station 105 supports sidelink relay operation. The first base station 105-g can send the indication at 550 based on the execution of the Xn procedure at 545. For example, by exchanging Xn signaling at 545, the first base station 105-g can determine that the second base station 105-h supports sidelink relay operation and the third base station 105-i does not. In this example, the first base station 105-g can send an indication to the remote UE 115-e regarding the second base station 105-h supporting sidelink relay operation and the third base station 105-i not supporting sidelink relay operation. At 550, the remote UE 115-e may receive the instruction via a Uu link with the first base station 105-g, via a relay UE 115-f (e.g., at least via a side link communication link between the remote UE 115-e and the relay UE 115-f), or both.

[0172] At 555, the remote UE 115-e can determine whether candidate base station 105 supports side-link relay operation (e.g., whether candidate base station 105 is an SL-RelayCapable BS or a non-SL-RelayCapable BS). For example, the remote UE 115-e can determine that the second base station 105-h supports side-link relay operation, and the third base station 105-i does not support side-link relay operation. In some aspects, the remote UE 115-e can determine whether candidate base station 105 supports side-link relay operation based on performing a discovery procedure at 525, receiving an SIB message from candidate base station 105 at 540, receiving an explicit indication from first base station 105-g at 550, or both.

[0173] For example, if the SIB message received at 540 includes one or more bit field values ​​indicating whether the corresponding base stations 105-h and 105-i support sidelink relay operation, the remote UE 115-e can determine whether the corresponding base stations 105-h and 105-i support sidelink relay operation based on one or more bit field values. As another example, when receiving an SIB from the third base station 105-i, the remote UE 115-e can be configured to determine that the third base station 105-i does not support sidelink relay operation based on the absence of data indicating that the third base station 105-i supports sidelink relay operation within the received SIB message (e.g., based on implicit determination of the SIB message).

[0174] At 560, the remote UE 115-e can determine whether a corresponding candidate base station 105 is associated with a relay UE 115, which is configured to relay wireless communication between the corresponding candidate base station 105 and the remote UE 115. In this respect, the remote UE 115-e can determine whether the candidate base station 105 is communicatively coupled to the relay UE 115, which can facilitate (e.g., relay, forward) wireless communication between the remote UE 115-e and the corresponding candidate base station 105. In some aspects, the remote UE 115-e may determine whether the candidate base station 105 is associated with the relay UE 115 based on receiving an SIB message at 505, receiving an RRC message at 510, determining the sidelink relay configuration associated with the first base station 105-g at 515, receiving an SIB message from the candidate base station 105 at 540, receiving an indication at 550, determining whether the candidate base station 105 supports sidelink relay operation at 555, or any combination thereof.

[0175] At point 565, remote UE 115-e can send one or more measurement reports to first base station 105-g. The measurement reports can be sent to first base station 105-g via a Uu link with first base station 105-g, via relay UE 115-f (e.g., at least via a sidelink communication link between remote UE 115-e and relay UE 115-f), or both. The measurement reports can indicate measurements (e.g., RSRP, RSRQ, SNR, SINR, CQI) performed on signals received from one or more candidate base stations 105. In this respect, the measurement reports can indicate measurements performed by remote UE 115-e on signals (e.g., reference signals) received from second base station 105-h, third base station 105-i, or both. In another or alternative aspect, the measurement reports can indicate whether the corresponding candidate base station 105 supports sidelink relay operation, indicate the priority of the handover process for performing and supporting sidelink relay operation by base station 105, or any combination thereof.

[0176] In some aspects, the remote UE 115-e can send a measurement report at 565 based on receiving an SIB message at 505, receiving an RRC message at 510, receiving a PCF message from the core network, determining the sidelink relay configuration associated with the first base station 105-g at 515, performing a discovery procedure at 525, receiving an SIB message from the candidate base station 105 at 540, receiving an indication at 550, determining at 555 whether the candidate base station 105 supports sidelink relay operation, determining at 560 whether the candidate base station 105 is associated with the relay UE 115, or any combination thereof.

[0177] For example, remote UE 115-e can be configured to send a measurement report at 565 based on the measurement report received at 510 via an RRC message. For instance, in some cases, the RRC message and / or PCF message can instruct the measurement report sent by remote UE 115-e to omit measurements associated with base station 105 that does not support sidelink relay operation. In this example, remote UE 115-e can omit measurements for third base station 105-i from the measurement report based on the determination that third base station 105-i does not support sidelink relay operation.

[0178] As another example, an RRC message could instruct that a measurement report sent by remote UE 115-e should include an indication of whether the base station 105 associated with the reported measurement is associated with an SL-RelayCapableBS, a non-SL-RelayCapableBS, or both. In this example, the measurement report could include measurements for both the second base station 105-h and the third base station 105-i, and could indicate that the second base station 105-h supports sidelink relay operation, the third base station 105-i does not support sidelink relay operation, or both. Furthermore, as another example, an RRC message could instruct remote UE 115-e to omit measurements for candidate base stations 105 that do not include relay UE 115. In this example, remote UE 115-e could determine that the second base station 105-h includes relay UE 115, but the third base station 105-e does not include relay UE 115. Therefore, in this example, the measurement report sent at 565 could omit measurements for the third base station 105-i.

[0179] At 570, the remote UE 115-e can receive instructions from the first base station 105-g to perform a handover procedure. The first base station 105-g can send instructions for the handover procedure based on performing the Xn procedure at 545, receiving a measurement report at 565, or both.

[0180] In some aspects, the instruction can direct the remote UE 115-e to perform a handover procedure from the first base station 105-g and / or relay UE 115-f to a candidate base station 105 that supports sidelink relay operation. For example, if a measurement report indicates that the second base station 105-h supports sidelink relay operation, the instruction received at 570 can direct the remote UE 115-e to perform a handover procedure from the first base station 105-g and / or relay UE 115-f to the second base station 105-h.

[0181] At 575, remote UE 115-e can perform a handover procedure from the first base station 105-g to the second base station 105-h. UE 115-d can perform the handover procedure based on (e.g., according to) instructions received at 555. Alternatively, relay UE 115-d can perform the handover procedure based on receiving an SIB message from the first base station 105-g at 505, receiving an RRC message at 510, determining the sidelink relay configuration associated with the first base station 105-g at 515, performing a discovery procedure at 525, receiving a control message at 535, determining whether candidate base station 105 supports sidelink relay operation at 555, determining whether candidate base station 105 is associated with relay UE 115 at 560, sending a measurement report at 565, receiving instructions at 570, or any combination thereof.

[0182] At point 580, remote UE 115-e can communicate with the second base station 105-h. In some aspects, remote UE 115-d can communicate with the second base station 105-h based on a handover procedure performed at point 575. In this respect, remote UE 115-e can exchange uplink and downlink transmissions with the second base station 105-h via the Uu link between remote UE 115-e and the second base station 105-h. Alternatively or additionally, remote UE 115-e can communicate with the second base station 105-h via a relay UE 115 configured to relay (e.g., forward) wireless communications between remote UE 115-e and the second base station 105-h.

[0183] In an additional or alternative aspect, the remote UE 115-e can be configured to initiate a handover procedure to establish wireless communication with a different relay UE 115 (which may be communicatively coupled to the first base station 105-g or a different base station 105). In this respect, the remote UE 115-e can be configured to trigger a relay reselection and / or relay handover procedure to establish wireless communication with a different relay UE 115.

[0184] Furthermore, as previously mentioned herein, the remote UE 115-e can be configured to search for frequencies and trigger (e.g., initiate) a discovery process to connect to an SL-RelayCapableBS when the remote UE 115-e is connected to a non-SL-RelayCapableBS. For example, in the context of L2 or L3 relay, the remote UE 115-e can communicatively couple to a third base station 105-i. In this example, the remote UE 115-e can communicate with the third base station 105-i within a first frequency range, where the third base station 105-i does not support sidelink relay operation within the first frequency range. To connect to a base station 105 that supports sidelink relay operation, the remote UE 115-e can be configured (e.g., via an upper layer) to search for base stations 105 that support sidelink relay operation in a frequency range different from the first frequency range (e.g., the first base station 105-g, the second base station 105-h, and the third base station 105-i). In this regard, the remote UE 115-e can search between frequencies for base stations 105 that support sidelink discovery procedures and sidelink relay configurations within a given frequency range.

[0185] Continuing with the same example, in some cases, the remote UE 115-e can determine that a fourth base station 105 (not shown) supports sidelink relay operation in a second frequency range different from the first frequency range. The remote UE 115-e can determine the sidelink relay configuration associated with the fourth base station 105 and can perform a discovery procedure associated with the fourth base station 105 based on (e.g., according to) the sidelink relay configuration. The frequency range in which base station 105 supports both the sidelink discovery procedure and the sidelink relay configuration can be identified. In such a case, the remote UE 115-e can camp on the corresponding cell of the fourth base station 105 that has the strongest signal (e.g., strongest RSRP, strongest RSRQ) in the second frequency range and can trigger the sidelink discovery procedure according to the sidelink relay configuration associated with the fourth base station 105.

[0186] In contrast, under other circumstances, the remote UE 115-e may not recognize the frequency range supporting both the sidelink discovery procedure and the sidelink relay configuration. In such cases, the remote UE 115-e can select a frequency range without cellular coverage and can trigger the discovery procedure for the base station 105 supporting sidelink relay operation based on a pre-configured sidelink relay configuration (e.g., based on the sidelink relay configuration received via an RRC message at 510). In this regard, the remote UE 115-e can be configured to trigger the discovery procedure for L2 and / or L3 relay by searching between frequencies supporting both the sidelink discovery procedure and the sidelink relay configuration.

[0187] The techniques described herein enable an improved handover process for both remote UE 115 and relay UE 115 within the context of a wireless communication system. Specifically, the techniques described herein enable remote UE 115-e to determine whether base station 105 supports sidelink relay operation, allowing for more informed decisions regarding the handover process. By enabling remote UE 115-e to determine whether base station 105 supports sidelink relay operation, the techniques described herein allow remote UE 115-e to perform a handover process with base station 105 that supports sidelink relay operation, thereby providing broader use of sidelink relay and reducing power consumption at remote UE 115 (e.g., remote UE 115-e).

[0188] Figure 6A block diagram 600 of a device 605 supporting techniques for sidelink relay handover procedures according to various aspects of this disclosure is shown. Device 605 may be an example of various aspects of UE 115 as described herein. Device 605 may include a receiver 610, a transmitter 615, and a communications manager 620. Device 605 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0189] Receiver 610 may provide a unit for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to technologies used for side link relay handover procedures). The information may be transmitted to other components of device 605. Receiver 610 may utilize a single antenna or a collection of multiple antennas.

[0190] Transmitter 615 may provide a unit for transmitting signals generated by other components of device 605. For example, transmitter 615 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques used for side-link relay handover procedures). In some examples, transmitter 615 may be co-located with receiver 610 in a transceiver module. Transmitter 615 may utilize a single antenna or a collection of multiple antennas.

[0191] The communication manager 620, receiver 610, transmitter 615, or various combinations thereof, or various components thereof, may be examples of units for performing various aspects of the techniques described herein for side link relay handover procedures. For example, the communication manager 620, receiver 610, transmitter 615, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0192] In some examples, the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be implemented in hardware (e.g., in communication management circuitry). The hardware may include a processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured to or otherwise support units for performing the functions described herein. In some examples, the processor and memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in memory by the processor).

[0193] Alternatively or concurrently, in some examples, the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be implemented using code executed by a processor (e.g., as communication management software or firmware). If implemented using processor-executed code, the functionality of the communication manager 620, receiver 610, transmitter 615, or various combinations or components thereof may be performed by any combination of a general-purpose processor, DSP, central processing unit (CPU), ASIC, FPGA, or these or other programmable logic devices (e.g., units configured or otherwise supported for performing the functions described in this disclosure).

[0194] In some examples, the communication manager 620 may be configured to use or otherwise cooperate with the receiver 610, transmitter 615, or both to perform various operations (e.g., receiving, monitoring, transmitting). For example, the communication manager 620 may receive information from the receiver 610, send information to the transmitter 615, or integrate with the receiver 610, transmitter 615, or both to receive information, send information, or perform various other operations as described herein.

[0195] According to the examples disclosed herein, the communication manager 620 may support wireless communication at the first UE. For example, the communication manager 620 may be configured or otherwise supported to support elements for relaying wireless communication between the first base station and the second UE, at least via a sidelink communication link with the second UE. The communication manager 620 may be configured or otherwise supported to support elements for sending measurement reports to the first base station for one or more candidate base stations, the measurement reports indicating that the one or more candidate base stations support sidelink relay operation. The communication manager 620 may be configured or otherwise supported to support elements for receiving instructions for performing a handover procedure from the first base station to a second base station among one or more candidate base stations based on the measurement reports, wherein the second base station supports sidelink relay operation. The communication manager 620 may be configured or otherwise supported to support elements for performing a handover procedure based on instructions, the handover procedure including establishing a wireless connection with the second base station.

[0196] Alternatively or additionally, according to the examples disclosed herein, the communication manager 620 may support wireless communication at the second UE. For example, the communication manager 620 may be configured or otherwise supported to support elements for communicating with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE. The communication manager 620 may be configured or otherwise supported to support elements for receiving instructions for performing a handover process from the first base station to the second base station based on the second base station supporting sidelink relay operation. The communication manager 620 may be configured or otherwise supported to support elements for performing a handover process based on instructions to establish wireless communication with the second base station.

[0197] By including or configuring a communication manager 620 according to the examples described herein, device 605 (e.g., a processor that controls or otherwise couples to receiver 610, transmitter 615, communication manager 620, or combinations thereof) can support techniques for improved handover procedures for both remote UE 115 and relay UE 115 in the context of a wireless communication system. In particular, the techniques described herein enable UE 115 (e.g., relay UE 115, remote UE 115) to determine whether base station 105 supports sidelink relay operation, which allows for more informed decisions regarding the handover procedure. By enabling UE 115 to determine whether base station 105 supports sidelink relay operation, the techniques described herein enable UE 115 to perform handover procedures with base stations that support sidelink relay operation, thereby providing broader use of sidelink relay and reducing power consumption at remote UE 115.

[0198] Figure 7 A block diagram 700 of a device 705 supporting techniques for lateral link relay handover procedures according to various aspects of this disclosure is shown. Device 705 may be an example of aspects of device 605 or UE 115 as described herein. Device 705 may include a receiver 710, a transmitter 715, and a communications manager 720. Device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0199] Receiver 710 may provide a unit for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to technologies used for side link relay handover procedures). The information may be transmitted to other components of device 705. Receiver 710 may utilize a single antenna or a collection of multiple antennas.

[0200] Transmitter 715 may provide a unit for transmitting signals generated by other components of device 705. For example, transmitter 715 may transmit information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques used for side-link relay handover procedures). In some examples, transmitter 715 may be co-located with receiver 710 in a transceiver module. Transmitter 715 may utilize a single antenna or a collection of multiple antennas.

[0201] Device 705 or its various components may be examples of units used to perform various aspects of the techniques described herein for sidelink relay handover procedures. For example, communication manager 720 may include sidelink relay manager 725, measurement report sending manager 730, handover command receiving manager 735, handover process manager 740, base station communication manager 745, or any combination thereof. Communication manager 720 may be examples of various aspects of communication manager 620 as described herein. In some examples, communication manager 720 or its various components may be configured to use receiver 710, transmitter 715, or both, or otherwise cooperate with receiver 710, transmitter 715, or both to perform various operations (e.g., receiving, monitoring, transmitting). For example, communication manager 720 may receive information from receiver 710, send information to transmitter 715, or be integrated with receiver 710, transmitter 715, or both to receive information, send information, or perform various other operations as described herein.

[0202] According to the examples disclosed herein, the communication manager 720 may support wireless communication at the first UE. The sidelink relay manager 725 may be configured or otherwise supported to relay wireless communication between the first base station and the second UE, at least via a sidelink communication link with the second UE. The measurement report sending manager 730 may be configured or otherwise supported to send measurement reports to the first base station for one or more candidate base stations, the measurement reports indicating that the one or more candidate base stations support sidelink relay operation. The handover command receiving manager 735 may be configured or otherwise supported to receive instructions for performing a handover procedure from the first base station to a second base station among one or more candidate base stations based on the measurement reports, wherein the second base station supports sidelink relay operation. The handover procedure manager 740 may be configured or otherwise supported to perform a handover procedure based on instructions, the handover procedure including establishing a wireless connection with the second base station.

[0203] Alternatively or additionally, according to the examples disclosed herein, the communication manager 720 may support wireless communication at the second UE. The base station communication manager 745 may be configured or otherwise supported for communication between the first UE and the first base station via the first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE. The handover command receiving manager 735 may be configured or otherwise supported for receiving instructions for performing a handover process from the first base station to the second base station based on the second base station supporting sidelink relay operation. The handover process manager 740 may be configured or otherwise supported for performing a handover process based on instructions to establish wireless communication with the second base station.

[0204] Figure 8 A block diagram 800 is shown of a communication manager 820 supporting techniques for sidelink trunk handover procedures according to various aspects of this disclosure. The communication manager 820 may be an example of aspects of the communication manager 620, communication manager 720, or both as described herein. The communication manager 820 or its various components may be examples of units for performing various aspects of the techniques for sidelink trunk handover procedures as described herein. For example, the communication manager 820 may include a sidelink trunk manager 825, a measurement report sending manager 830, a handover command receiving manager 835, a handover process manager 840, a base station communication manager 845, an SIB message receiving manager 850, a discovery process manager 855, a handover request sending manager 860, a control message receiving manager 865, a reselection process manager 870, an RRC message receiving manager 875, a PCF message receiving manager 880, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0205] According to the examples disclosed herein, the communication manager 820 may support wireless communication at the first UE. The sidelink relay manager 825 may be configured or otherwise supported to support elements for relaying wireless communication between the first base station and the second UE, at least via a sidelink communication link with the second UE. The measurement report sending manager 830 may be configured or otherwise supported to send measurement reports to the first base station for one or more candidate base stations, the measurement reports indicating that the one or more candidate base stations support sidelink relay operation. The handover command receiving manager 835 may be configured or otherwise supported to receive instructions for performing a handover procedure from the first base station to the second base station among one or more candidate base stations based on the measurement reports, wherein the second base station supports sidelink relay operation. The handover procedure manager 840 may be configured or otherwise supported to perform a handover procedure based on instructions, the handover procedure including establishing a wireless connection with the second base station.

[0206] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported to include elements for receiving system information block messages from at least one candidate base station among one or more candidate base stations. In some examples, the sidelink relay manager 825 may be configured or otherwise supported to include elements for determining, based on system information block messages, that at least one base station supports sidelink relay operation, wherein the first UE sends a measurement report based on the determination that at least one candidate base station supports sidelink relay operation.

[0207] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported to receive, via system information block messages, one or more bit field values ​​indicating that at least one candidate base station supports sidelink relay operation, wherein the determination is based on one or more bit field values.

[0208] In some examples, the sidelink relay manager 825 can be configured or otherwise supported as a unit for determining that a third base station does not support sidelink relay operations, wherein sending a measurement report, performing a handover procedure, or both are based on the determination that the third base station does not support sidelink relay operations.

[0209] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported for receiving system information block messages from a third base station, wherein the determination that the third base station does not support side link relay operation is based on the system information block messages.

[0210] In some examples, determining that a third base station does not support sidelink relay operation is based on identifying one or more bit fields in the system information block message that indicate that the third base station does not support sidelink relay operation, identifying that there is no data in the system information block message that indicates that the third base station supports sidelink relay operation, or both.

[0211] In some examples, measurement reports omit measurements for the third base station because it does not support sidelink relay operations. In some examples, handover procedures with the second base station are performed based on measurement reports that omit measurements for the third base station.

[0212] In some examples, the RRC message receiving manager 875 may be configured or otherwise supported to receive radio resource control messages from a first base station, the radio resource control messages instructing the first UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the first UE omits measurements for a third base station based on the radio resource control messages.

[0213] In some examples, to support the transmission of measurement reports, the measurement report transmission manager 830 can be configured or otherwise support units for transmitting measurements for a third base station via measurement reports, wherein the measurement reports include an indication that the third base station does not support side link relay operations, and the handover process with the second base station is based on the indication that the third base station does not support side link relay operations.

[0214] In some examples, the sidelink relay manager 825 may be configured or otherwise supported to receive an indication from the first base station that the third base station does not support sidelink relay operation, wherein the determination is based on the indication that the third base station does not support sidelink relay operation.

[0215] In some examples, the sidelink relay manager 825 may be configured or otherwise supported as a unit for determining the sidelink relay configuration associated with the first base station. In some examples, the discovery process manager 855 may be configured or otherwise supported as a unit for performing a discovery process based on the determined sidelink relay configuration, wherein the handover process is performed based on the discovery process.

[0216] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported for receiving system information block messages from a first base station, wherein determining the side link relay configuration associated with the first base station is based on the system information block messages.

[0217] In some examples, one or more candidate base stations support sidelink relay operations by supporting the sidelink relay discovery process, sidelink relay transmission, or both.

[0218] In some examples, the base station communication manager 845 may be configured or otherwise supported to enable communication with a second base station within a first frequency range. In some examples, the sidelink relay manager 825 may be configured or otherwise supported to enable determination of whether a third base station supports sidelink relay operation in a second frequency range different from the first frequency range. In some examples, the sidelink relay manager 825 may be configured or otherwise supported to enable determination of the sidelink relay configuration associated with the third base station based on its support for sidelink relay operation in the second frequency range. In some examples, the discovery process manager 855 may be configured or otherwise supported to enable execution of a discovery process associated with the third base station based on the sidelink relay configuration.

[0219] In some examples, the sidelink relay manager 825 may be configured or otherwise supported as a unit for receiving sidelink relay configurations. In some examples, the base station communication manager 845 may be configured or otherwise supported as a unit for communicating with a second base station within a first frequency range. In some examples, the base station communication manager 845 may be configured or otherwise supported as a unit for determining that no base station is configured to communicate in a second frequency range different from the first frequency range. In some examples, the discovery process manager 855 may be configured or otherwise supported as a unit for performing a discovery process within a second frequency range and according to the sidelink relay configuration.

[0220] Alternatively or additionally, according to the examples disclosed herein, the communication manager 820 may support wireless communication at the second UE. The base station communication manager 845 may be configured or otherwise supported for communication between the first UE and the first base station via the first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE. In some examples, the handover command receiving manager 835 may be configured or otherwise supported for receiving instructions for performing a handover procedure from the first base station to the second base station based on the second base station supporting sidelink relay operation. In some examples, the handover procedure manager 840 may be configured or otherwise supported for performing a handover procedure based on instructions to establish wireless communication with the second base station.

[0221] In some examples, the measurement report sending manager 830 may be configured or otherwise supported to send a measurement report for one or more candidate base stations to a first base station via a first UE, the measurement report indicating that one or more candidate base stations support sidelink relay operation, wherein the handover process is performed based on sending the measurement report.

[0222] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported to include elements for receiving system information block messages from at least one candidate base station among one or more candidate base stations. In some examples, the sidelink relay manager 825 may be configured or otherwise supported to include elements for determining, based on system information block messages, that at least one base station supports sidelink relay operation, wherein the second UE sends a measurement report based on the determination that at least one candidate base station supports sidelink relay operation.

[0223] In some examples, the SIB message receiving manager 850 may be configured or otherwise support units for indicating one or more bit field values ​​via system information block message receiving to support sidelink relay operation at least one candidate base station, wherein the determination is based on one or more bit field values.

[0224] In some examples, the sidelink relay manager 825 can be configured or otherwise supported as a unit for determining that a third base station does not support sidelink relay operations, wherein sending a measurement report, performing a handover procedure, or both are based on the determination that the third base station does not support sidelink relay operations.

[0225] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported for receiving system information block messages from a third base station, wherein the determination that the third base station does not support side link relay operation is based on the system information block messages.

[0226] In some examples, determining that a third base station does not support sidelink relay operation is based on identifying one or more bit fields in the system information block message that indicate that the third base station does not support sidelink relay operation, identifying that there is no data in the system information block message that indicates that the third base station supports sidelink relay operation, or both.

[0227] In some examples, measurement reports omit measurements for the third base station because it does not support sidelink relay operations. In some examples, handover procedures with the second base station are performed based on measurement reports that omit measurements for the third base station.

[0228] In some examples, the RRC message receiving manager 875 may be configured or otherwise supported for receiving radio resource control messages from a first base station via a first UE, the radio resource control messages instructing a second UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the second UE omits measurements for a third base station based on the radio resource control messages.

[0229] In some examples, the PCF message receiving manager 880 may be configured or otherwise supported for receiving policy control function messages that instruct a second UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the second UE omits measurements for a third base station based on the policy control function messages.

[0230] In some examples, to support the transmission of measurement reports, the measurement report transmission manager 830 can be configured or otherwise support units for transmitting measurements for a third base station via measurement reports, wherein the measurement report includes an indication that the third base station does not support side link relay operations, and the handover process with the second base station is based on the indication that the third base station does not support side link relay operations.

[0231] In some examples, the sidelink relay manager 825 may be configured or otherwise supported to receive, via a first UE, an indication from a first base station that a third base station does not support sidelink relay operation, wherein the determination is based on the indication that the third base station does not support sidelink relay operation.

[0232] In some examples, the base station communication manager 845 may be configured or otherwise supported to determine that a third base station is not associated with a UE configured to relay wireless communication between the third base station and one or more additional UEs. In some examples, the measurement report sending manager 830 may be configured or otherwise supported to send measurement reports, wherein the measurement reports omit measurements for the third base station based on the determination that the third base station is not associated with a UE configured to relay wireless communication between the third base station and one or more additional UEs.

[0233] In some examples, the measurement report sending manager 830 may be configured or otherwise supported as a unit for sending indications of priorities associated with base stations supporting sidelink relay operations via measurement reports, wherein the handover process is performed based on priorities.

[0234] In some examples, the sidelink relay manager 825 may be configured or otherwise supported as a unit for determining the sidelink relay configuration associated with the first base station. In some examples, the discovery process manager 855 may be configured or otherwise supported as a unit for performing a discovery process based on the determined sidelink relay configuration, wherein the handover process is performed based on the discovery process.

[0235] In some examples, the SIB message receiving manager 850 may be configured or otherwise supported for receiving system information block messages from a first base station, wherein determining the side link relay configuration associated with the first base station is based on the system information block messages.

[0236] In some examples, the handover request sending manager 860 may be configured or otherwise supported to include a unit for sending a handover request to a third base station for a second handover procedure from the first base station to the third base station, wherein the third base station does not support sidelink relay operations. In some examples, the control message receiving manager 865 may be configured or otherwise supported to include a unit for receiving a control message from the third base station for receiving a handover rejection request, wherein the handover procedure from the first base station to the second base station is performed based on receiving the control message.

[0237] In some examples, the reselection process manager 870 may be configured or otherwise supported to enable units for performing a relay UE reselection process from the first UE to the third UE. In some examples, the base station communication manager 845 may be configured or otherwise supported to enable units for communicating with the first base station via the third UE based on the execution of the relay UE reselection process, wherein the third UE is configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link between the first UE and the third UE.

[0238] In some examples, the second base station supports sidelink relay operations by supporting the sidelink relay discovery process, sidelink relay transmission, or both.

[0239] In some examples, the base station communication manager 845 may be configured or otherwise supported to enable communication with a second base station within a first frequency range. In some examples, the sidelink relay manager 825 may be configured or otherwise supported to enable determination of whether a third base station supports sidelink relay operation in a second frequency range different from the first frequency range. In some examples, the sidelink relay manager 825 may be configured or otherwise supported to enable determination of the sidelink relay configuration associated with the third base station based on its support for sidelink relay operation in the second frequency range. In some examples, the discovery process manager 855 may be configured or otherwise supported to enable execution of a discovery process associated with the third base station based on the sidelink relay configuration.

[0240] In some examples, the sidelink relay manager 825 may be configured or otherwise supported as a unit for receiving sidelink relay configurations. In some examples, the base station communication manager 845 may be configured or otherwise supported as a unit for communicating with a second base station within a first frequency range. In some examples, the base station communication manager 845 may be configured or otherwise supported as a unit for determining that no base station is configured to communicate in a second frequency range different from the first frequency range. In some examples, the discovery process manager 855 may be configured or otherwise supported as a unit for performing a discovery process within a second frequency range and according to the sidelink relay configuration.

[0241] Figure 9 A diagram of a system 900 including a device 905 supporting a sidelink relay handover process, according to various aspects of this disclosure, is shown. Device 905 may be an example of device 605, device 705, or UE 115 as described herein, or a component including device 605, device 705, or UE 115. Device 905 may wirelessly communicate with one or more base stations 105, UE 115, or any combination thereof. Device 905 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, such as a communication manager 920, an input / output (I / O) controller 910, a transceiver 915, an antenna 925, a memory 930, a code 935, and a processor 940. These components may communicate electronically or be coupled in other ways (e.g., operational ground, communication ground, functional ground, electronic ground, electrical ground) via one or more buses (e.g., bus 945).

[0242] I / O controller 910 can manage input and output signals for device 905. I / O controller 910 can also manage peripheral devices not integrated into device 905. In some cases, I / O controller 910 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 910 can utilize, for example... The operating system may be a known operating system. Alternatively, the I / O controller 910 may represent or interact with a modem, keyboard, mouse, touchscreen, or similar device. In some cases, the I / O controller 910 may be implemented as part of a processor (such as processor 940). In some cases, a user may interact with device 905 via the I / O controller 910 or via hardware components controlled by the I / O controller 910.

[0243] In some cases, device 905 may include a single antenna 925. However, in other cases, device 905 may have more than one antenna 925, which may be capable of transmitting or receiving multiple wireless transmissions simultaneously. Transceiver 915 may communicate bidirectionally via one or more antennas 925, wired or wireless links as described herein. For example, transceiver 915 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 915 may also include a modem for modulating packets, providing modulated packets to one or more antennas 925 for transmission, and demodulating packets received from one or more antennas 925. Transceiver 915, or transceiver 915 and one or more antennas 925, may be examples of transmitter 615, transmitter 715, receiver 610, receiver 710, or any combination thereof or components thereof as described herein.

[0244] Memory 930 may include random access memory (RAM) and read-only memory (ROM). Memory 930 may store computer-readable, computer-executable code 935, which includes instructions that, when executed by processor 940, cause device 905 to perform the various functions described herein. Code 935 may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some cases, code 935 may not be directly executable by processor 940, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, in addition, memory 930 may also include a basic I / O system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0245] Processor 940 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 940 may be configured to use a memory controller to operate a memory array. In other cases, the memory controller may be integrated into processor 940. Processor 940 may be configured to execute computer-readable instructions stored in memory (e.g., memory 930) to cause device 905 to perform various functions (e.g., functions or tasks supporting techniques for side link relay switching processes). For example, device 905 or components of device 905 may include processor 940 and memory 930 coupled to processor 940, processor 940 and memory 930 being configured to perform the various functions described herein.

[0246] According to the examples disclosed herein, the communication manager 920 may support wireless communication at the first UE. For example, the communication manager 920 may be configured or otherwise supported to support elements for relaying wireless communication between the first base station and the second UE, at least via a sidelink communication link with the second UE. The communication manager 920 may be configured or otherwise supported to support elements for sending measurement reports to the first base station for one or more candidate base stations, the measurement reports indicating that the one or more candidate base stations support sidelink relay operation. The communication manager 920 may be configured or otherwise supported to support elements for receiving instructions for performing a handover procedure from the first base station to a second base station among one or more candidate base stations based on the measurement reports, wherein the second base station supports sidelink relay operation. The communication manager 920 may be configured or otherwise supported to support elements for performing a handover procedure based on instructions, the handover procedure including establishing a wireless connection with the second base station.

[0247] Alternatively or additionally, according to the examples disclosed herein, the communication manager 920 may support wireless communication at the second UE. For example, the communication manager 920 may be configured or otherwise supported to support elements for communicating with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE. The communication manager 920 may be configured or otherwise supported to support elements for receiving instructions for performing a handover process from the first base station to the second base station based on the second base station supporting sidelink relay operation. The communication manager 920 may be configured or otherwise supported to support elements for performing a handover process based on instructions to establish wireless communication with the second base station.

[0248] By including or configuring a communication manager 920 according to the examples described herein, device 905 can support techniques for improved handover procedures for both remote UE 115 and relay UE 115 in the context of a wireless communication system. Specifically, the techniques described herein enable UE 115 (e.g., relay UE 115, remote UE 115) to determine whether base station 105 supports sidelink relay operation, which allows for more informed decisions regarding the handover procedure. By enabling UE 115 to determine whether base station 105 supports sidelink relay operation, the techniques described herein enable UE 115 to perform handover procedures with base stations that support sidelink relay operation, thereby providing wider use of sidelink relay and reducing power consumption at the remote UE 115.

[0249] In some examples, the communication manager 920 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or in cooperation with transceiver 915, one or more antennas 925, or any combination thereof. Although the communication manager 920 is shown as a separate component, in some examples, one or more functions described with reference to the communication manager 920 may be supported or performed by processor 940, memory 930, code 935, or any combination thereof. For example, code 935 may include instructions executable by processor 940 to cause device 905 to perform various aspects of the techniques described herein for sidelink relay handover procedures, or processor 940 and memory 930 may be otherwise configured to perform or support such operations.

[0250] Figure 10 A flowchart illustrating a method 1000 for supporting techniques for a side-link relay handover process according to various aspects of this disclosure is shown. Operation of method 1000 can be implemented by a UE or its components as described herein. For example, operation of method 1000 can be implemented by, as referred to... Figures 1 to 9 The UE 115 described is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Alternatively, the UE can use dedicated hardware to perform aspects of the described function.

[0251] At point 1005, the method may include: relaying wireless communication between the first base station and the second UE at least via a sidelink communication link with the second UE. Operation 1005 can be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1005 may be derived from references... Figure 8 The side link relay manager 825 is described and executed.

[0252] At point 1010, the method may include: sending a measurement report to a first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation. The operation at 1010 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1010 may be provided by reference to... Figure 8 The measurement report sending manager 830 is described and executed.

[0253] At point 1015, the method may include: receiving instructions for performing a handover procedure from a first base station to a second base station among one or more candidate base stations based on a measurement report, wherein the second base station supports sidelink relay operation. The operation at 1015 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1015 may be provided by reference to... Figure 8 The switching command described is executed by the receiver manager 835.

[0254] At point 1020, the method may include: performing a handover procedure based on instructions, the handover procedure including establishing a wireless connection with a second base station. The operation at point 1020 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at point 1020 may be derived from references... Figure 8 The switching process described is executed by the manager 840.

[0255] Figure 11 A flowchart illustrating a method 1100 for supporting techniques for a side-link relay handover process according to various aspects of this disclosure is shown. Operation of method 1100 can be implemented by a UE or its components as described herein. For example, operation of method 1100 can be performed by, as described in reference... Figures 1 to 9 The UE 115 described is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Alternatively, the UE can use dedicated hardware to perform aspects of the described function.

[0256] At 1105, the method may include: relaying wireless communication between the first base station and the second UE at least via a sidelink communication link with the second UE. The operation of 1105 can be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1105 may be derived from references... Figure 8 The side link relay manager 825 is described and executed.

[0257] At 1110, the method may include: receiving a system information block message from at least one of one or more candidate base stations. The operation at 1110 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1110 may be derived from, as referenced... Figure 8The SIB message receiving manager 850 is described and executed.

[0258] At 1115, the method may include: determining, based on system information block messages, that at least one candidate base station supports sidelink relay operation. The operation at 1115 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1115 may be derived from, as referenced... Figure 8 The side link relay manager 825 is described and executed.

[0259] At 1120, the method may include: sending a measurement report to a first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation, wherein the first UE sends the measurement report based on determining that at least one candidate base station supports sidelink relay operation. The operation at 1120 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1120 may be provided by reference to... Figure 8 The measurement report sending manager 830 is described and executed.

[0260] At 1125, the method may include: receiving instructions for performing a handover procedure from a first base station to a second base station among one or more candidate base stations based on a measurement report, wherein the second base station supports sidelink relay operation. The operation at 1125 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1125 may be provided by reference to... Figure 8 The switching command described is executed by the receiver manager 835.

[0261] At 1130, the method may include: performing a handover procedure based on instructions, the handover procedure including establishing a wireless connection with a second base station. The operation at 1130 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1130 may be derived from references... Figure 8 The switching process described is executed by the manager 840.

[0262] Figure 12 A flowchart illustrating a method 1200 for supporting techniques for a side-link relay handover process according to various aspects of this disclosure is shown. Operation of method 1200 can be implemented by a UE or its components as described herein. For example, operation of method 1200 can be implemented by, as referred to... Figures 1 to 9 The UE 115 described is used to perform this function. In some examples, the UE can execute a set of instructions to control the functional elements of the UE to perform the described function. Alternatively, the UE can use dedicated hardware to perform aspects of the described function.

[0263] At 1205, the method may include: communicating with a first base station via a first UE, wherein the first UE is configured to relay wireless communication between a second UE and the first base station at least via a sidelink communication link with the first UE. The operation of 1205 can be performed according to examples as disclosed herein. In some examples, aspects of the operation of 1205 may be derived from references... Figure 8 The base station communication manager 845 is described and executed.

[0264] At 1210, the method may include: receiving instructions for performing a handover process from a first base station to a second base station based on a second base station-supported crosslink relay operation. The operation at 1210 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1210 may be provided by reference to... Figure 8 The switching command described is executed by the receiver manager 835.

[0265] At 1215, the method may include: performing a handover process based on instructions to establish wireless communication with a second base station. The operation at 1215 can be performed according to examples as disclosed herein. In some examples, aspects of the operation at 1215 may be derived from references... Figure 8 The switching process described is executed by the manager 840.

[0266] The following provides a summary of various aspects of this disclosure:

[0267] Aspect 1: A method for wireless communication at a first UE, comprising: relaying wireless communication between a first base station and a second UE at least via a sidelink communication link with a second UE; sending a measurement report to the first base station for one or more candidate base stations, the measurement report indicating that the one or more candidate base stations support sidelink relay operation; receiving an instruction for performing a handover procedure from the first base station to a second base station among the one or more candidate base stations, at least in part based on the measurement report, wherein the second base station supports sidelink relay operation; and performing the handover procedure at least in part based on the instruction, the handover procedure including establishing a wireless connection with the second base station.

[0268] Aspect 2: The method according to aspect 1 further includes: receiving an SIB message from at least one of the one or more candidate base stations; and determining, at least in part, that the at least one candidate base station supports side-link relay operation based on the SIB message, wherein the first UE sends the measurement report at least in part based on the determination that the at least one candidate base station supports side-link relay operation.

[0269] Aspect 3: The method according to aspect 2 further includes: receiving one or more bit field values ​​via the SIB message indicating that the at least one candidate base station supports sidelink relay operation, wherein the determination is at least partially based on the one or more bit field values.

[0270] Aspect 4: The method according to any one of Aspects 1 to 3 further includes: determining that the third base station does not support sidelink relay operation, wherein sending the measurement report, performing the handover procedure, or both are based at least in part on determining that the third base station does not support sidelink relay operation.

[0271] Aspect 5: The method according to aspect 4 further includes: receiving an SIB message from the third base station, wherein determining that the third base station does not support sidelink relay operation is at least in part based on the SIB message.

[0272] Aspect 6: According to the method of aspect 5, wherein determining that the third base station does not support sidelink relay operation is based at least in part on identifying one or more bit fields in the SIB message indicating that the third base station does not support sidelink relay operation, identifying that there is no data in the SIB message indicating that the third base station supports sidelink relay operation, or both.

[0273] Aspect 7: The method according to any one of Aspects 4 to 6, wherein the measurement report omits measurements for the third base station at least in part based on the fact that the third base station does not support sidelink relay operation, and the handover process performed by the second base station is at least in part based on the fact that measurements for the third base station are omitted from the measurement report.

[0274] Aspect 8: The method according to aspect 7 further includes: receiving an RRC message from the first base station, the RRC message instructing the first UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the first UE omits the measurements for the third base station at least in part based on the RRC message.

[0275] Aspect 9: The method according to any one of Aspects 4 to 8, wherein sending the measurement report comprises: sending a measurement for the third base station via the measurement report, wherein the measurement report includes an indication that the third base station does not support sidelink relay operation, wherein the handover procedure with the second base station is based at least in part on the indication that the third base station does not support sidelink relay operation.

[0276] Aspect 10: The method according to any one of Aspects 4 to 9 further includes: receiving from the first base station an indication that the third base station does not support sidelink relay operation, wherein the determination is based at least in part on the indication that the third base station does not support sidelink relay operation.

[0277] Aspect 11: The method according to any one of Aspects 1 to 10 further includes: determining a sidelink relay configuration associated with the first base station; and performing a discovery process at least in part based on the determined sidelink relay configuration, wherein performing the handover process is at least in part based on performing the discovery process.

[0278] Aspect 12: The method according to aspect 11 further includes: receiving an SIB message from the first base station, wherein determining the sidelink relay configuration associated with the first base station is at least partially based on the SIB message.

[0279] Aspect 13: The method according to any one of Aspects 1 to 12, wherein the one or more candidate base stations support sidelink relay operation by supporting a sidelink relay discovery process, a sidelink relay transmission, or both.

[0280] Aspect 14: The method according to any one of Aspects 1 to 13 further includes: communicating with the second base station in a first frequency range; determining that the third base station supports sidelink relay operation in a second frequency range different from the first frequency range; determining a sidelink relay configuration associated with the third base station based at least in part on the fact that the third base station supports sidelink relay operation in the second frequency range; and performing a discovery process associated with the third base station based on the sidelink relay configuration.

[0281] Aspect 15: The method according to any one of aspects 1 to 14 further includes: receiving a side-link relay configuration; communicating with the second base station in a first frequency range; determining that there is no base station configured to communicate in a second frequency range different from the first frequency range; and performing a discovery process in the second frequency range and according to the side-link relay configuration.

[0282] Aspect 16: A method for wireless communication at a second UE, comprising: communicating with a first base station via a first UE, the first UE being configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE; receiving instructions for performing a handover procedure from the first base station to the second base station based at least in part on the second base station supporting sidelink relay operation; and performing the handover procedure based at least in part on the instructions to establish wireless communication with the second base station.

[0283] Aspect 17: The method according to aspect 16 further includes: sending a measurement report for one or more candidate base stations to the first base station via the first UE, the measurement report indicating that the one or more candidate base stations support sidelink relay operation, wherein the handover process is performed at least in part based on sending the measurement report.

[0284] Aspect 18: The method according to aspect 17 further includes: receiving an SIB message from at least one of the one or more candidate base stations; and determining, at least in part, that the at least one base station supports side-link relay operation based on the SIB message, wherein the second UE transmits the measurement report based at least in part on the determination that the at least one candidate base station supports side-link relay operation.

[0285] Aspect 19: The method according to aspect 18 further includes: receiving, via the SIB message, one or more bit field values ​​indicating that the at least one candidate base station supports sidelink relay operation, wherein the determination is based at least in part on the one or more bit field values.

[0286] Aspect 20: The method according to any one of Aspects 17 to 19 further includes: determining that the third base station does not support sidelink relay operation, wherein sending the measurement report, performing the handover procedure, or both are based at least in part on determining that the third base station does not support sidelink relay operation.

[0287] Aspect 21: The method according to aspect 20 further includes: receiving an SIB message from the third base station, wherein determining that the third base station does not support sidelink relay operation is at least in part based on the SIB message.

[0288] Aspect 22: The method according to aspect 21 further includes: determining that the third base station does not support sidelink relay operation based at least in part on identifying one or more bit fields in the SIB message indicating that the third base station does not support sidelink relay operation, identifying that there is no data in the SIB message indicating that the third base station supports sidelink relay operation, or both.

[0289] Aspect 23: The method according to any one of Aspects 20 to 22, wherein the measurement report omits measurements for the third base station at least in part based on the fact that the third base station does not support sidelink relay operation, and the handover process performed by the second base station is at least in part based on the omission of measurements for the third base station in the measurement report.

[0290] Aspect 24: The method according to aspect 23 further includes: receiving an RRC message from the first base station via the first UE, the RRC message instructing the second UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the second UE omits the measurements for the third base station at least in part based on the RRC message.

[0291] Aspect 25: The method according to any one of Aspects 23 to 24 further includes: receiving a policy control function message, the policy control function message instructing the second UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the second UE omits the measurements for the third base station at least in part based on the policy control function message.

[0292] Aspect 26: The method according to any one of Aspects 20 to 25, wherein sending the measurement report comprises: sending a measurement for the third base station via the measurement report, wherein the measurement report includes an indication that the third base station does not support sidelink relay operation, wherein the handover procedure with the second base station is based at least in part on the indication that the third base station does not support sidelink relay operation.

[0293] Aspect 27: The method according to any one of Aspects 20 to 26 further includes: receiving from the first base station via the first UE an indication that the third base station does not support sidelink relay operation, wherein the determination is based at least in part on the indication that the third base station does not support sidelink relay operation.

[0294] Aspect 28: The method according to any one of Aspects 17 to 27 further includes: determining that a third base station is not associated with a UE configured to relay wireless communication between the third base station and one or more additional UEs; and sending the measurement report, wherein the measurement report omits measurements for the third base station based at least in part on the determination that the third base station is not associated with a UE configured to relay wireless communication between the third base station and the one or more additional UEs.

[0295] Aspect 29: The method according to any one of Aspects 17 to 28 further includes: sending an indication of a priority associated with a base station supporting side-link relay operation via the measurement report, wherein the handover process is performed at least in part based on the priority.

[0296] Aspect 30: The method according to any one of Aspects 16 to 29 further includes: determining a sidelink relay configuration associated with the first base station; and performing a discovery process at least in part based on the determined sidelink relay configuration, wherein performing the handover process is at least in part based on performing the discovery process.

[0297] Aspect 31: The method according to aspect 30 further includes: receiving an SIB message from the first base station, wherein determining the sidelink relay configuration associated with the first base station is at least partially based on the SIB message.

[0298] Aspect 32: The method according to any one of Aspects 16 to 31 further includes: sending a handover request to a third base station for a second handover process from the first base station to the third base station, wherein the third base station does not support sidelink relay operation; and receiving a control message from the third base station rejecting the handover request, wherein the handover process from the first base station to the second base station is performed at least in part based on receiving the control message.

[0299] Aspect 33: The method according to any one of aspects 16 to 32 further includes: performing a relay UE reselection process from the first UE to the third UE; and communicating with the first base station via the third UE at least in part based on performing the relay UE reselection process, wherein the third UE is configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link between the first UE and the third UE.

[0300] Aspect 34: The method according to any one of aspects 16 to 33, wherein the second base station supports sidelink relay operation by supporting a sidelink relay discovery process, a sidelink relay transmission, or both.

[0301] Aspect 35: The method according to any one of Aspects 16 to 34 further includes: communicating with the second base station in a first frequency range; determining that the third base station supports sidelink relay operation in a second frequency range different from the first frequency range; determining a sidelink relay configuration associated with the third base station based at least in part on the fact that the third base station supports sidelink relay operation in the second frequency range; and performing a discovery process associated with the third base station based on the sidelink relay configuration.

[0302] Aspect 36: The method according to any one of aspects 16 to 35 further includes: receiving a side-link relay configuration; communicating with the second base station in a first frequency range; determining that there is no base station configured to communicate in a second frequency range different from the first frequency range; and performing a discovery process in the second frequency range and according to the side-link relay configuration.

[0303] Aspect 37: An apparatus for wireless communication at a first UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of Aspects 1 to 15.

[0304] Aspect 38: An apparatus for wireless communication at a first UE, comprising at least one unit for performing the method of any one of aspects 1 to 15.

[0305] Aspect 39: A non-transitory computer-readable medium storing code for wireless communication at a first UE, the code comprising instructions executable by a processor to perform the methods of any one of Aspects 1 to 15.

[0306] Aspect 40: An apparatus for wireless communication at a second UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of Aspects 16 to 36.

[0307] Aspect 41: An apparatus for wireless communication at a second UE, comprising at least one unit for performing the method of any one of aspects 16 to 36.

[0308] Aspect 42: A non-transitory computer-readable medium storing code for wireless communication at a second UE, the code comprising instructions executable by a processor to perform the methods of any one of Aspects 16 to 36.

[0309] It should be noted that the methods described in this paper describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are possible. Furthermore, aspects from two or more methods can be combined.

[0310] While aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used extensively in the description, the techniques described herein apply beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described can be applied to a variety of other wireless communication systems, such as Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0311] The information and signals described herein can be represented using any of a variety of different techniques and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0312] The various illustrative blocks and components described herein can be implemented or performed using a general-purpose processor, DSP, ASIC, CPU, FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware component, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but alternatively, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration).

[0313] The functions described herein can be implemented using hardware, software executed by a processor, firmware, or any combination thereof. If implemented using software executed by a processor, the functions can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination of these. Features implementing the functions can also be physically located in various locations, including being distributed such that different parts of the functions are implemented in different physical locations.

[0314] Computer-readable media includes both non-transitory computer storage media and communication media, with communication media encompassing any medium that facilitates the transfer of a computer program from one place to another. Non-transitory storage media can be any available medium accessible by a general-purpose computer or a special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compressed optical disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code units in the form of instructions or data structures, and accessible by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Furthermore, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of computer-readable media. As used herein, disks and optical discs include CDs, laser discs, optical discs, digital multifunction discs (DVDs), floppy disks, and Blu-ray discs, wherein disks typically copy data magnetically, while optical discs use lasers to copy data optically. The combination described above is also included within the scope of computer-readable media.

[0315] As used herein (including in the claims), the word "or" in a list of items (e.g., a list of items ending with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, such that a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be construed as a reference to a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0316] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, various components of the same type can be distinguished by a dash and a second reference numeral following the reference numeral, used to differentiate between similar components. If only the first reference numeral is used in the specification, the description applies to any one of the similar components having the same first reference numeral, without regard to the second reference numeral or other subsequent reference numerals.

[0317] This document describes exemplary configurations in conjunction with the accompanying drawings, and does not represent all examples that can be implemented or that are within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," and not "preferred" or "advantageous over other examples." The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be implemented without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0318] The description herein is provided to enable those skilled in the art to implement or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of the disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a first user equipment (UE), comprising: Wireless communication is relayed between the first base station and the second UE at least via a side-link communication link with the second UE; Send a measurement report for one or more candidate base stations to the first base station, the measurement report indicating that the one or more candidate base stations support sidelink relay operation; Receive instructions for performing a handover process from the first base station to a second base station among the one or more candidate base stations, based at least in part on the measurement report, wherein the second base station supports sidelink relay operation; The handover process is performed at least in part based on the instructions, the handover process including establishing a wireless connection with the second base station; and It is determined that the third base station does not support sidelink relay operation, wherein sending the measurement report, performing the handover procedure, or both are at least partially based on the determination that the third base station does not support sidelink relay operation. The measurement report omits measurements for the third base station, at least in part, because the third base station does not support sidelink relay operation. The handover process with the second base station is performed at least in part based on the measurement report, which omits measurements for the third base station.

2. The method according to claim 1, further comprising: Receive system information block messages from at least one of the one or more candidate base stations; as well as The first UE determines that the at least one base station supports sidelink relay operation based at least in part on the system information block message, wherein the first UE sends the measurement report based at least in part on the determination that the at least one candidate base station supports sidelink relay operation.

3. The method according to claim 2, further comprising: The system information block message receives one or more bit field values ​​indicating that the at least one candidate base station supports sidelink relay operation, wherein the determination is at least in part based on the one or more bit field values.

4. The method according to claim 1, further comprising: The system information block message is received from the third base station, wherein the determination that the third base station does not support sidelink relay operation is based at least in part on the system information block message.

5. The method according to claim 4, wherein, The determination that the third base station does not support sidelink relay operation is based at least in part on identifying one or more bit fields in the system information block message that indicate that the third base station does not support sidelink relay operation, identifying that there is no data in the system information block message indicating that the third base station supports sidelink relay operation, or both.

6. The method according to claim 1, further comprising: The first UE receives a radio resource control message from the first base station, the radio resource control message instructing the first UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the first UE omits the measurements for the third base station at least in part based on the radio resource control message.

7. The method according to claim 1, wherein, Sending the measurement report includes: Measurements for the third base station are transmitted via the measurement report, wherein the measurement report includes an indication that the third base station does not support sidelink relay operation, and the handover procedure with the second base station is performed at least in part based on the indication that the third base station does not support sidelink relay operation.

8. The method according to claim 1, further comprising: The first base station receives an indication that the third base station does not support sidelink relay operation, wherein the determination is at least in part based on the indication that the third base station does not support sidelink relay operation.

9. The method according to claim 1, further comprising: Determine the sidelink relay configuration associated with the first base station; as well as The discovery process is performed at least in part based on the determined sidelink relay configuration, wherein the handover process is performed at least in part based on the performance of the discovery process.

10. The method of claim 9, further comprising: A system information block message is received from the first base station, wherein the determination of the sidelink relay configuration associated with the first base station is at least in part based on the system information block message.

11. The method according to claim 1, wherein, The one or more candidate base stations support sidelink relay operation by supporting sidelink relay discovery process, sidelink relay transmission, or both.

12. A method for wireless communication at a second user equipment (UE), comprising: The first UE communicates with the first base station via the first UE, and the first UE is configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE. Receive instructions for performing a handover process from the first base station to the second base station, at least in part based on the second base station-supported side link relay operation; The handover process is performed at least in part based on the instructions to establish wireless communication with the second base station; as well as Send a handover request to a third base station for a second handover process from the first base station to the third base station, wherein the third base station does not support sidelink relay operation; and The third base station receives a control message rejecting the handover request, wherein the handover process from the first base station to the second base station is at least partially based on receiving the control message.

13. The method of claim 12, further comprising: The first UE sends a measurement report for one or more candidate base stations to the first base station, the measurement report indicating that the one or more candidate base stations support sidelink relay operation, wherein the handover process is performed at least in part based on sending the measurement report.

14. The method of claim 13, further comprising: Receive system information block messages from at least one of the one or more candidate base stations; as well as The at least one base station is determined to support sidelink relay operation based at least in part on the system information block message, wherein the second UE sends the measurement report based at least in part on the determination that the at least one candidate base station supports sidelink relay operation.

15. The method of claim 14, further comprising: The system information block message receives one or more bit field values ​​indicating that the at least one candidate base station supports sidelink relay operation, wherein the determination is at least in part based on the one or more bit field values.

16. The method of claim 13, further comprising: It is determined that the third base station does not support sidelink relay operation, wherein sending the measurement report, performing the handover procedure, or both are based at least in part on the determination that the third base station does not support sidelink relay operation.

17. The method of claim 16, further comprising: The system information block message is received from the third base station, wherein the determination that the third base station does not support sidelink relay operation is based at least in part on the system information block message.

18. The method according to claim 16, wherein, The measurement report omits measurements for the third base station at least in part because the third base station does not support sidelink relay operation, and the method further includes: The handover process with the second base station is performed at least in part based on the measurement report, which omits measurements for the third base station.

19. The method of claim 18, further comprising: The first UE receives a radio resource control message from the first base station, the radio resource control message instructing the second UE to omit measurements associated with a base station that does not support sidelink relay operation, wherein the second UE omits the measurements for the third base station at least in part based on the radio resource control message.

20. The method of claim 18, further comprising: The second UE receives a policy control function message instructing it to omit measurements associated with a base station that does not support sidelink relay operation, wherein the second UE omits the measurements for the third base station at least in part based on the policy control function message.

21. The method according to claim 16, wherein, Sending the measurement report includes: Measurements for the third base station are sent via the measurement report, wherein the measurement report includes an indication that the third base station does not support sidelink relay operation, and the handover procedure with the second base station is performed at least in part based on the indication that the third base station does not support sidelink relay operation.

22. The method of claim 13, further comprising: It is determined that the third base station is not associated with a UE configured to relay wireless communication between the third base station and one or more additional UEs; as well as The measurement report is sent, wherein the measurement report omits measurements for the third base station based at least in part on the determination that the third base station is not associated with a UE configured to relay wireless communication between the third base station and the one or more additional UEs.

23. The method of claim 13, further comprising: The measurement report is used to send an indication of the priority associated with the base station supporting sidelink relay operation, wherein the handover process is performed at least in part based on the priority.

24. The method of claim 12, further comprising: Determine the sidelink relay configuration associated with the first base station; as well as The discovery process is performed at least in part based on the determined sidelink relay configuration, wherein the handover process is performed at least in part based on the performance of the discovery process.

25. The method of claim 24, further comprising: A system information block message is received from the first base station, wherein the determination of the sidelink relay configuration associated with the first base station is at least in part based on the system information block message.

26. An apparatus for wireless communication at a first user equipment (UE), comprising: processor; Memory coupled to the processor; as well as Instructions, which are stored in the memory and executable by the processor, cause the device to perform the following operations: Wireless communication is relayed between the first base station and the second UE at least via a side-link communication link with the second UE; Send a measurement report for one or more candidate base stations to the first base station, the measurement report indicating that the one or more candidate base stations support sidelink relay configuration; Receive instructions for performing a handover process from the first base station to a second base station among the one or more candidate base stations, based at least in part on the measurement report, wherein the second base station supports sidelink relay operation; The handover process is performed at least in part based on the instructions, the handover process including establishing a wireless connection with the second base station; and It is determined that the third base station does not support sidelink relay operation, wherein sending the measurement report, performing the handover procedure, or both are at least partially based on the determination that the third base station does not support sidelink relay operation. The measurement report omits measurements for the third base station, at least in part, because the third base station does not support sidelink relay operation. The handover process with the second base station is performed at least in part based on the measurement report, which omits measurements for the third base station.

27. An apparatus for wireless communication at a second user equipment (UE), comprising: processor; Memory coupled to the processor; as well as Instructions, which are stored in the memory and executable by the processor, cause the device to perform the following operations: The first UE communicates with the first base station via the first UE, and the first UE is configured to relay wireless communication between the second UE and the first base station at least via a sidelink communication link with the first UE. Receive instructions for performing a handover process from the first base station to the second base station, at least in part based on the second base station-supported side link relay operation; The handover process is performed at least in part based on the instructions to establish wireless communication with the second base station; as well as Send a handover request to a third base station for a second handover process from the first base station to the third base station, wherein the third base station does not support sidelink relay operation; and The third base station receives a control message rejecting the handover request, wherein the handover process from the first base station to the second base station is at least partially based on receiving the control message.

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