NR side-link fast intra-cell relay handover

Abstract

A configuration sets the UE to establish a connection with one or more candidate repeaters in preparation for handover to a target repeater from the one or more candidate repeaters. The device receives a candidate repeater configuration from a source repeater, which includes at least information about the candidate repeaters. The device measures a reference signal for the source repeater and each of the candidate repeaters based on the candidate repeater configuration. The device establishes a connection with a subset of the candidate repeaters. The device sends a measurement report of the reference signal of the subset of candidate repeaters to the source repeater. The device receives a repeater handover command from the source repeater for handover to a target repeater from the subset of candidate repeaters.

Description

Technical Field

[0001] In summary, this disclosure relates to communication systems, and more specifically, to configurations for sidelink intra-cell relay handover. Background Technology

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol enabling different wireless devices to communicate at the city, country, region, and even global levels. An example telecommunications standard is 5G New Radio (NR). 5G NR is part of the continuous evolution of mobile broadband released by the 3rd Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., in conjunction with the Internet of Things (IoT),) and others. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Some aspects of 5G NR can be based on the 4G Long Term Evolution (LTE) standard. There is a need for further improvements to 5G NR technology. These improvements can also be applied to other multiple access technologies and telecommunications standards that adopt them. Summary of the Invention

[0004] The following provides a brief overview of one or more aspects to offer a basic understanding of such aspects. This overview is not a comprehensive summary of all anticipated aspects, nor is it intended to identify key or extremely important elements of all aspects, nor to depict the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed descriptions that follow.

[0005] In one aspect of this disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus may be a device at a UE. The device may be a processor and / or modem at the UE or the UE itself. The apparatus receives candidate relay configurations from a source repeater, the candidate relay configurations including at least information about the candidate repeaters. The apparatus measures reference signals for the source repeater and each of the candidate repeaters based on the candidate relay configurations. The apparatus establishes connections with a subset of the candidate repeaters. The apparatus sends a measurement report of the reference signals of the subset of candidate repeaters to the source repeater. The apparatus receives a relay handover command from the source repeater for switching to a target repeater from the subset of candidate repeaters.

[0006] In one aspect of this disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus may be a device at a UE or a base station. The device may be a processor and / or modem at the UE or base station, or the UE or base station itself. The apparatus sends a candidate relay configuration to the UE, the candidate relay configuration including at least information about candidate repeaters. The apparatus receives measurement reports of a subset of the candidate repeaters from the UE. The apparatus sends a relay handover command to the UE for switching to a target repeater from the subset of candidate repeaters.

[0007] In one aspect of this disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus may be a device at a base station. The device may be a processor and / or modem at the base station or the base station itself. The apparatus configures a candidate relay configuration, including at least information about candidate repeaters. The apparatus sends the candidate relay configuration to a source repeater. The apparatus receives a measurement report of reference signals from a subset of the candidate repeaters from the source repeater. The apparatus selects a target repeater from the subset of candidate repeaters based on the measurement report. The apparatus sends a relay handover command to the source repeater for the UE to hand over to the target repeater.

[0008] To achieve the foregoing and related objectives, one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and drawings set forth certain illustrative features of one or more aspects in detail. However, these features indicate only some of the various ways in which the principles of each aspect may be employed, and this description is intended to include all such aspects and their equivalents. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating an example of a wireless communication system and access network.

[0010] Figure 2A This is a schematic diagram illustrating an example of the first frame of various aspects according to this disclosure.

[0011] Figure 2BThis is a schematic diagram illustrating an example of a DL channel within a subframe according to various aspects of this disclosure.

[0012] Figure 2C This is a schematic diagram illustrating an example of a second frame according to various aspects of this disclosure.

[0013] Figure 2D This is a schematic diagram illustrating an example of a UL channel within a subframe according to various aspects of this disclosure.

[0014] Figure 3 This is a schematic diagram illustrating an example of a base station and user equipment (UE) in an access network.

[0015] Figure 4 This illustrates an example of relay handover in a wireless communication system.

[0016] Figure 5 This illustrates an example of a radio link failure in a relay device.

[0017] Figure 6 This is a call flow diagram of signaling between the UE, relay equipment, and base station.

[0018] Figure 7 This is a flowchart of a wireless communication method.

[0019] Figure 8 This is a schematic diagram illustrating an example of a hardware implementation for an example device.

[0020] Figure 9 This is a flowchart of a wireless communication method.

[0021] Figure 10 This is a schematic diagram illustrating an example of a hardware implementation for an example device.

[0022] Figure 11 This is a flowchart of a wireless communication method.

[0023] Figure 12 This is a schematic diagram illustrating an example of a hardware implementation for an example device. Detailed Implementation

[0024] The specific embodiments described below with reference to the accompanying drawings are intended as descriptions of various configurations and are not intended to represent only the configurations in which the concepts described herein can be practiced. Specific details are included in the specific embodiments for the purpose of providing a full understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0025] Several aspects of a telecommunications system will now be described with reference to various apparatuses and methods. These apparatuses and methods will be described in detail below, and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively, “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the system as a whole.

[0026] For example, an element, or any part of an element, or any combination of elements, can be implemented as a "processing system" including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described herein. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise, software should be broadly interpreted as meaning instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc.

[0027] Accordingly, in one or more example embodiments, the described functionality may be implemented in hardware, software, or any combination thereof. If implemented in software, the functionality may be stored or encoded as one or more instructions or code on a computer-readable medium. A computer-readable medium includes a computer storage medium. The storage medium may be any available medium accessible by a computer. By way of example, and not limitation, such a computer-readable medium may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of computer-readable media of the types described above, or any other medium that may be used to store computer-executable code accessible by a computer in the form of instructions or data structures.

[0028] Figure 1This is a schematic diagram illustrating an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes base station 102, UE 104, evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). Base station 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells include base stations. Small cells include femtocells, picocells, and microcells.

[0029] Base station 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via a first backhaul link 132 (e.g., S1 interface). Base station 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) can interface with core network 190 via a second backhaul link 184. Among other functions, base station 102 can also perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, RAN information management (RIM), paging, location, and delivery of warning messages. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC 160 or core network 190) on a third backhaul link 134 (e.g., an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 can be wired or wireless.

[0030] Base station 102 can communicate wirelessly with UE 104. Each base station 102 in the base station 102 can provide communication coverage for its respective geographic coverage area 110. Overlapping geographic coverage areas 110 may exist. For example, a small cell 102' may have a coverage area 110' that overlaps with the coverage areas 110 of one or more macro base stations 102. A network that includes both small cells and macro cells can be referred to as a heterogeneous network. The heterogeneous network may also include a Home Evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a Closed Subscriber Group (CSG). The communication link 120 between base station 102 and UE 104 may include uplink (UL) (also referred to as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also referred to as forward link) transmission from base station 102 to UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link may be via one or more carriers. Base station 102 / UE 104 may use spectrum allocated in carrier aggregation for up to a total of Yx MHz (x component carriers) for transmission in each direction, with a bandwidth of up to Y MHz per carrier (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.). Carriers may be adjacent to each other or may not be adjacent to each other. Carrier allocation may be asymmetrical with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL than to UL). Component carriers may include primary component carriers and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell), and the secondary component carrier may be referred to as the secondary cell (SCell).

[0031] Some UEs 104 can communicate with each other using device-to-device (D2D) communication link 158. D2D communication link 158 can use DL / UL WWAN spectrum. D2D communication link 158 can use one or more sideline channels, such as the Physical Sideline Broadcast Channel (PSBCH), Physical Sideline Discovery Channel (PSDCH), Physical Sideline Shared Channel (PSSCH), and Physical Sideline Control Channel (PSCCH). D2D communication can be achieved through a variety of wireless D2D communication systems, such as, for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0032] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154, for example, in an unlicensed spectrum such as 5 GHz. When communicating in unlicensed spectrum, the STA 152 / AP 150 may perform a free channel assessment (CCA) to determine whether the channel is available before communication.

[0033] Small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell 102' can employ NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) as used by Wi-Fi AP 150. Small cell 102' employing NR in unlicensed spectrum can improve coverage for the access network and / or increase the capacity of the access network.

[0034] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc., based on frequency / wavelength. In 5G NR, the two initial operating bands have been designated as frequency range names FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often (interchangeably) referred to as the "below 6GHz" band in various documents and articles. Similar naming issues sometimes arise regarding FR2, which is often (interchangeably) referred to as the "millimeter wave" band in documents and articles, although this differs from the extremely high frequency (EHF) band (30GHz-300GHz), which is designated as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0035] In light of the above, unless otherwise specifically stated, it should be understood that the terms "below 6 GHz," if used herein, can broadly refer to frequencies that are less than 6 GHz, within FR1, or may include mid-band frequencies. Furthermore, unless otherwise specifically stated, it should be understood that the terms "millimeter wave," if used herein, can broadly refer to frequencies that may include mid-band frequencies, within FR2, or within the EHF band.

[0036] Base station 102 (whether a small cell 102' or a large cell (e.g., a macro base station)) may include and / or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations (such as gNB 180) may operate in conventional sub-6 GHz spectrum, millimeter wave frequencies, and / or near-millimeter wave frequencies to communicate with UE 104. When gNB 180 operates in millimeter wave or near-millimeter wave frequencies, gNB 180 may be referred to as a millimeter wave base station. Millimeter wave base station 180 may utilize beamforming 182 with UE 104 to compensate for path loss and short range. Base station 180 and UE 104 may each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming.

[0037] Base station 180 may transmit beamformed signals to UE 104 in one or more transmit directions 182'. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182'. UE 104 may also transmit beamformed signals to base station 180 in one or more transmit directions. Base station 180 may receive beamformed signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to determine the optimal receive and transmit directions for each of base station 180 / UE 104. The transmit and receive directions for base station 180 may be the same or different. The transmit and receive directions for UE 104 may be the same or different.

[0038] EPC 160 may include Mobility Management Entity (MME) 162, other MMEs 164, Serving Gateway 166, Multimedia Broadcast Multicast Service (MBMS) Gateway 168, Broadcast Multicast Service Center (BM-SC) 170, and Packet Data Network (PDN) Gateway 172. MME 162 may communicate with Home Subscriber Server (HSS) 174. MME 162 is the control node that processes signaling between UE 104 and EPC 160. Typically, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which is itself connected to PDN Gateway 172. PDN Gateway 172 provides IP address allocation and other functions to the UE. PDN Gateway 172 and BM-SC 170 are connected to IP Service 176. IP Service 176 may include the Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming service, and / or other IP services. The BM-SC 170 provides functions for setting up and delivering MBMS user services. The BM-SC 170 can act as an entry point for MBMS transmissions to content providers, approving and initiating MBMS bearer services within a Public Land Mobile Network (PLMN), and scheduling MBMS transmissions. The MBMS gateway 168 can distribute MBMS services to base stations 102 belonging to areas of a Multicast-Broadcast Single Frequency Network (MBSFN) that broadcasts specific services, and can be responsible for session management (start / stop) and collecting billing information related to eMBMS.

[0039] Core network 190 may include Access and Mobility Management Functions (AMF) 192, other AMFs 193, Session Management Functions (SMF) 194, and User Plane Functions (UPF) 195. AMF 192 can communicate with Unified Data Management (UDM) 196. AMF 192 is the control node that processes signaling between UE 104 and core network 190. Typically, AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted via UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 connects to IP service 197. IP service 197 may include the Internet, intranet, IP Multimedia Subsystem (IMS), packet-switched (PS) streaming service, and / or other IP services.

[0040] Base stations may include and / or be referred to as gNB, Node B, eNB, access point, base transceiver, radio base station, radio transceiver, transceiver function, Basic Services Set (BSS), Extended Services Set (ESS), Transmitter Receiver Point (TRP), or some other suitable term. Base station 102 provides UE 104 with access to EPC 160 or core network 190. Examples of UE 104 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radio units, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electricity meters, air pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, or any other similarly functional devices. Some UEs in UE 104 may be referred to as IoT devices (e.g., parking meters, air pumps, ovens, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, mobile station, user station, mobile unit, user unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, radio terminal, remote terminal, handheld device, user agent, mobile client, client, or any other suitable term.

[0041] Refer again Figure 1 In some aspects, UE 104 can be configured to establish connections with one or more candidate repeaters in preparation for a handover to a target repeater. For example, UE 104 may include a connectivity component 198 configured to establish connections with a subset of candidate repeaters. UE 104 may receive candidate repeater configurations from a source repeater, the candidate repeater configurations including at least information about the candidate repeaters. UE 104 may measure reference signals for the source repeater and each of the candidate repeaters based on the candidate repeater configurations. UE 104 may establish connections with a subset of candidate repeaters. UE 104 may send a measurement report of the reference signals of the subset of candidate repeaters to the source repeater. UE 104 may receive a repeater handover command from the source repeater for handover to a target repeater from the subset of candidate repeaters.

[0042] Refer again Figure 1In some aspects, a source repeater (e.g., UE 104 or base station 102 / 180) can be configured to configure the UE with candidate repeater configurations for handover to a target repeater based on the candidate repeater configurations. For example, the source repeater may include a candidate repeater component 199 configured to send candidate repeater configurations to the UE. The source repeater may send candidate repeater configurations to UE 104, the candidate repeater configurations including at least information about the candidate repeaters. The source repeater may receive measurement reports of a subset of the candidate repeaters from UE 104. The source repeater may send a repeater handover command to UE 104 for handover to a target repeater from the subset of candidate repeaters.

[0043] Refer again Figure 1 In some aspects, base station 180 can be configured to configure the UE with candidate relay configurations for handover to a target relay based on the candidate relay configurations. For example, base station 180 may include a candidate relay component 199 configured to send the candidate relay configurations to a source relay. Base station 180 can be configured with candidate relay configurations that include at least information about the candidate relays. Base station 180 can send the candidate relay configurations to the source relay. Base station 180 can receive measurement reports of reference signals from a subset of the candidate relays from the source relay. Base station 180 can select a target relay from the subset of candidate relays based on the measurement reports. Base station 180 can send a relay handover command to the source relay for the UE to hand over to the target relay.

[0044] Although the following description may focus on 5G NR, the concepts described herein can be applied to other similar fields, such as LTE, LTE-A, CDMA, GSM and other wireless technologies.

[0045] Figure 2A This is a schematic diagram 200 showing an example of the first subframe within a 5G NR frame structure. Figure 2B This is a schematic diagram 230 showing an example of a DL channel within a 5G NR subframe. Figure 2C This is a schematic diagram 250 showing an example of a second subframe within a 5G NR frame structure. Figure 2D This is a schematic diagram 280 illustrating an example of a UL channel within a 5G NR subframe. The 5G NR frame structure can be Frequency Division Duplex (FDD) (where, for a specific set of subcarriers (carrier system bandwidth), subframes within that set are dedicated to either DL or UL), or Time Division Duplex (TDD) (where, for a specific set of subcarriers (carrier system bandwidth), subframes within that set are dedicated to both DL and UL). In the process of... Figure 2A , Figure 2CIn the provided example, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (mostly DL), where D is DL, U is UL, and F is flexible for use between DL / UL, and subframe 3 is configured with slot format 1 (all UL). Although subframes 3 and 4 are shown as having slot format 1 and slot format 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot format 0 and slot format 1 are all DL and all UL, respectively. Other slot formats 2-61 include a mixture of DL, UL, and flexible symbols. The UE is configured with a slot format via the received Slot Format Indicator (SFI) (dynamically via DL Control Information (DCI) or semi-statically / statically via Radio Resource Control (RRC) signaling). Note that the following description also applies to 5G NR frame structures that are TDD.

[0046] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10 ms) can be divided into 10 equal-sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include micro-time slots, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. Symbols on the DL can be Cyclic Prefix (CP) OFDM (CP-OFDM) symbols. Symbols on the UL can be CP-OFDM symbols (for high-throughput scenarios) or Discrete Fourier Transform (DFT) Extended OFDM (DFT-s-OFDM) symbols (also known as Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols) (for power-constrained scenarios; limited to single-stream transmission). The number of time slots within a subframe can be based on the time slot configuration and the numbering scheme. For slot configuration 0, different digital schemes μ0 to μ4 consider 1, 2, 4, 8, and 16 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to μ2 consider 2, 4, and 8 slots per subframe, respectively. Accordingly, for slot configuration 0 and digital scheme μ, there are 14 symbols / slot and 2... μ Each time slot / subframe. Subcarrier spacing and symbol length / duration are functions of the digital scheme. Subcarrier spacing can be equal to 2. μ *15kHz, where μ is the digital scheme from 0 to 4. Accordingly, digital scheme μ = 0 has a subcarrier spacing of 15kHz, and digital scheme μ = 4 has a subcarrier spacing of 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2DExamples are provided for slot configuration 0 (14 symbols per slot) and digital scheme μ=2 (4 slots per subframe). The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, one or more distinct bandwidth portions (BWPs) of frequency division multiplexing can exist (see [link to relevant documentation]). Figure 2B Each BWP can have a specific digital scheme.

[0047] A resource grid can be used to represent the frame structure. Each time slot includes a resource block (RB) (also called a physical RB (PRB)), which extends for 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried through each RE depends on the modulation scheme.

[0048] As in Figure 2A As shown, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (indicated as R for a particular configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0049] Figure 2BExamples of various DL channels within a subframe of a frame are shown. The Physical Downlink Control Channel (PDCCH) carries DCI within one or more Control Channel Elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE comprising six RE Groups (REGs), each REG comprising 12 consecutive REs in the OFDM symbol of the RB. A PDCCH within a BWP can be referred to as a Control Resource Set (CORESET). The UE is configured to monitor PDCCH candidates in the PDCCH search space (e.g., a common search space, a UE-specific search space) during PDCCH monitoring timing on the CORESET, where PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs can span the channel bandwidth at larger and / or lower frequencies. The Primary Synchronization Signal (PSS) can be within symbol 2 of a specific subframe of the frame. The PSS is used by the UE 104 to determine subframe / symbol timing and physical layer identification. The Secondary Synchronization Signal (SSS) can be within symbol 4 of a specific subframe of the frame. The SSS is used by the UE to determine the Physical Layer Cell Identifier Group Number and radio frame timing. Based on the Physical Layer Identifier and the Physical Layer Cell Identifier Group Number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS mentioned above. The Physical Broadcast Channel (PBCH) (which carries the Master Information Block (MIB)) can be logically grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block (also called an SS block (SSB)). The MIB provides the number of RBs and the System Frame Number (SFN) in the system bandwidth. The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted via the PBCH (such as System Information Block (SIB)), and paging messages.

[0050] As in Figure 2C As shown, some of the REs in the diagram carry DM-RS for channel estimation at the base station (indicated as R for one specific configuration, but other DM-RS configurations are possible). The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and DM-RS for the Physical Uplink Shared Channel (PUSCH). The PUSCH DM-RS can be transmitted in the preceding one or two symbols of the PUSCH. The PUCCH DM-RS can be transmitted in different configurations depending on whether a short or long PUCCH is transmitted and depending on the specific PUCCH format used. The UE can transmit a Sounding Reference Signal (SRS). The SRS can be transmitted in the last symbol of a subframe. The SRS can have a comb structure, and the UE can transmit the SRS on one of the combs. The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0051] Figure 2D Examples of various UL channels within a subframe of a frame are shown. The PUCCH can be positioned as indicated in a configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and hybrid automatic repeat request (HARQ) ACK / NACK feedback. The PUSCH carries data, and may additionally be used to carry buffer status reports (BSR), power headroom reports (PHR), and / or UCI.

[0052] Figure 3 This is a block diagram illustrating communication between base station 310 and UE 350 in the access network. In the DL, IP packets from EPC 160 can be provided to controller / processor 375. Controller / processor 375 implements Layer 3 and Layer 2 functions. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Service Data Adaptation Protocol (SDAP) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer. The controller / processor 375 provides the following associated RRC layer functions: broadcasting system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-Radio Access Technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with: header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with: transmission of upper-layer packet data units (PDUs), error correction via ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with: mapping between logical channels and transport channels, multiplexing of MAC SDUs to transport blocks (TBs), and MAC... SDU performs demultiplexing of TB, scheduling information reporting, error correction via HARQ, priority processing, and logical channel prioritization.

[0053] Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functions associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection of the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to OFDM subcarriers, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domains, and then combined using inverse fast Fourier transform (IFFT) to produce a physical channel carrying a stream of time-domain OFDM symbols. The OFDM streams are spatially precoded to produce multiple spatial streams. The channel estimate from channel estimator 374 can be used to determine coding and modulation schemes and for spatial processing. The channel estimate can be derived based on reference signals transmitted by UE 350 and / or channel condition feedback. Each spatial stream can then be provided to different antennas 320 via a separate transmitter 318TX. Each transmitter 318TX can use its respective spatial stream to modulate an RF carrier for transmission.

[0054] At UE 350, each receiver 354RX receives signals via its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for UE 350. If multiple spatial streams are destined for UE 350, they can be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal consists of a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the most probable signal constellation points transmitted by base station 310. These soft decisions can be based on channel estimates calculated by channel estimator 358. The soft decision is then decoded and deinterleaved to recover the data and control signals originally transmitted by base station 310 on the physical channel. The data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functions.

[0055] The controller / processor 359 may be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between the transport and logical channels to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0056] Similar to the functions described in conjunction with DL transmissions performed by base station 310, controller / processor 359 provides RRC layer functions associated with: system information (e.g., MIB, SIB) acquisition, RRC connection and measurement reporting; PDCP layer functions associated with: header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with: transmission of upper-layer PDUs, error correction via ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with: mapping between logical channels and transport channels, multiplexing of MAC SDUs to TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority processing, and logical channel prioritization.

[0057] The channel estimate derived by the channel estimator 358 from the reference signal or feedback transmitted by the base station 310 can be used by the TX processor 368 to select appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial stream generated by the TX processor 368 can be provided to different antennas 352 via individual transmitters 354TX. Each transmitter 354TX can use its own spatial stream to modulate an RF carrier for transmission.

[0058] UL transmission is handled at base station 310 in a manner similar to that described for the receiver functions incorporated at UE 350. Each receiver 318RX receives signals via its respective antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides the information to the RX processor 370.

[0059] The controller / processor 375 may be associated with a memory 376 that stores program code and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between the transport channel and the logical channel to recover IP packets from the UE 350. IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0060] At least one of the TX processor 368, RX processor 356, and controller / processor 359 can be configured to perform and Figure 1 All aspects related to 198 or 199.

[0061] At least one of the TX processor 316, RX processor 370, and controller / processor 375 can be configured to perform operations related to... Figure 1 All aspects related to 198 or 199.

[0062] In wireless communication systems, a UE may lose coverage due to the loss of connection to a base station or a Uu link. In some cases, one or more repeaters with a Uu connection to the base station may be within range of the UE that has lost coverage. The repeater and the UE may be in an RRC connection state, allowing the UE to select one of the repeaters and establish a PC5 connection with the selected source repeater. The UE may then be able to communicate with the base station through the source repeater. For example, see reference... Figure 4 In example 400, remote UE 402 may lose its Uu link 408 with base station 404. Repeater 1 406 and repeater 2 406 can be within range of UE 402, allowing UE 402 to establish a PC5 connection 410 with either repeater 1 406 or repeater 2 406.

[0063] In some cases, the PC5 connection to the source repeater (e.g., repeater 1 406) may weaken, and the remote UE 402 may switch to another repeater (e.g., repeater 2 406). In such a situation, repeater 1 406 may encounter a radio link failure on its Uu link 408 with base station 404, causing the PC5 link 410 between repeater 1 406 and UE 402 to become unreliable. The PC5 link 410 between repeater 1 406 and UE 402 may be degraded or weakened because repeater 1 406 is outside the range of UE 402.

[0064] Figure 5Example 500 illustrates a radio link failure in a relay device. Example 500 includes UE 1 502, UE 2 502, source repeater 506, and base station 504. Figure 5 As shown in Example 500, UE 1 502 and UE 2 502 may be in a connected state with source repeater 506 (e.g., 508). In some cases, source repeater 506 may experience a failure on its Uu link with the base station (e.g., 504) when connected to UE 1 502 and UE 2 502. Source repeater 506 may experience a failure on its Uu link for various reasons, such as, but not limited to, Uu radio link failure, Uu handover failure, or Uu reconfiguration failure. At 510, source repeater 506 may detect a radio link failure and may trigger a re-establishment upon detection of a radio link failure. Source repeater 506 may enter an idle mode after detecting a radio link failure (e.g., 512). At 514, base station 504 may release the UE context of source repeater 506 and the associated connected UEs (e.g., UE 1 502 and UE 2 502) upon the expiration of the repeater inactivity timer.

[0065] Source repeater 506 can handle PC5 links with UE1 502 and UE2 502 by releasing or suspending PC5 links. For example, source repeater 506 can send a sidelink command (e.g., 516) to release or suspend PC5 links with any active UE (e.g., UE1 502 and UE2 502), causing the active UE (e.g., UE1 502 and UE2 502) to enter an idle state (e.g., 518). Additionally, source repeater 506 can stop advertising support for relaying in discovery messages. After a successful Uu link establishment, source repeater 506 can restore the suspended PC5 links with the UEs (e.g., UE1 502 and UE2 502) and can resume advertising support for relay services in accordance with relay advertising standards.

[0066] When a source repeater experiences a radio link failure, the connected UE can initiate a relay handover mechanism. For example, after the source repeater releases its PC5 link with the UE, the UE can determine that the radio link with the source repeater has failed. The UE can then search for a new source repeater. In some cases, the UE can receive an RRC reconfiguration to hand over to the new repeater. The RRC reconfiguration can be sent from the source repeater to the UE. In response, the source repeater can suspend its active PC5 link with the UE, and can resume the active PC5 link after the repeater successfully restores its Uu link with the base station. The PC5 link between the source repeater and the UE may fail or may not be a reliable connection, allowing the UE to initiate a relay handover mechanism. However, relay handover mechanisms can introduce long handover delays.

[0067] The aspects described herein provide configurations for an improved trunk handover mechanism. This improved handover mechanism allows a UE to be configured to establish a connection with one or more candidate trunks in preparation for handover from one or more candidate trunks to a target trunk. At least one advantage of this disclosure is that it allows the UE to establish a connection with a candidate trunk before receiving a command for handover from one or more candidate trunks to the target trunk, which reduces handover latency and allows the UE to handover to another trunk more quickly, thus improving performance.

[0068] In some aspects, the source repeater can indicate the configuration of candidate repeaters to the UE. The configuration of the candidate repeaters may include information associated with the candidate repeaters, such as, but not limited to, repeater identifiers or resource pools used for discovery. In some aspects, a base station with a Uu connection to the source repeater can determine which repeaters can act as candidate repeaters. The base station can then send the candidate repeater information to the source repeater, causing the source repeater to send the candidate repeater information to the UE. In some aspects, the source repeater can be configured to evaluate repeaters and determine a list of candidate repeaters. The source repeater can determine the list of candidate repeaters independently and without input from the base station.

[0069] The UE can be configured to measure reference signals from a source repeater and a list of candidate repeaters. The UE can be triggered to perform such measurements under certain conditions (e.g., if the signal measurement result of the source repeater is below a threshold). The threshold can be pre-configured or configured by the source repeater or base station. The UE can measure the DMRS of the discovery channel from the source repeater and candidate repeaters. The UE can be configured to rank candidate repeaters based on signal measurements. When certain conditions are met, the UE can establish a PC5 connection with the candidate repeater list. For example, the RSRP of the source repeater maintains a range or meets a threshold. In some aspects, information related to the candidate repeater list can be indicated to the UE in the candidate repeater configuration. In some aspects, the UE measures each candidate repeater in the candidate repeater list such that the UE can select a subset of candidate repeaters from the candidate repeater list to establish a PC5 connection. The subset of candidate repeaters can be less than or equal to the candidate repeater list.

[0070] The UE can send a measurement report to the source repeater. The measurement report may include measurement results from a candidate repeater list and measurement results from the source repeater. In some aspects, the source repeater can send the measurement report received from the UE to the base station. In such aspects, the base station can determine the target repeater based on the measurement report. The base station can then send an indication of the target repeater from the candidate repeater list to the source repeater. The base station can also send a relay handover command to the source repeater to instruct the UE to switch to the target repeater. The source repeater then provides the relay handover command to the UE.

[0071] In some aspects, the source repeater can be configured to determine the target repeater. The source repeater can be configured to determine the target repeater based on measurement reports received from the UE. The source repeater can determine the target repeater even without input from the base station. The source repeater sends a relay handover command to the UE to instruct it to hand over to the target repeater.

[0072] The UE responds to receiving a trunk handover command from the source repeater by switching to the target repeater. The source repeater may send the trunk handover command to the UE in a side link control information (SCI) or a PC5 media access control (MAC) control element (CE) (MAC-CE). The transmission of trunk handover commands using SCI or PC5 MAC-CE includes Layer-1 or Layer-2 signaling that results in a significant reduction in time.

[0073] In some aspects, the measurement report generated by the UE may include Layer-1 measurement results, such as, but not limited to, Layer-1 RSRP of the source repeater's discovery signal. In some aspects, the UE may be event-triggered to perform measurements on the source repeater and candidate repeater lists and to generate a measurement report. For example, the event triggering the UE to perform the measurement may be based on certain conditions of the source repeater, such as, for example, a comparison threshold for the RSRP measurement results. In some aspects, the measurements of the source repeater and candidate repeaters may be configured to be periodic. In some aspects, the measurements of the source repeater and candidate repeaters may be configured to be aperiodic, allowing the UE to be network-triggered to perform the measurement. The source repeater may indicate to the UE which type of measurement report should be utilized by the UE. In some aspects, the measurement report may be carried on the Physical-side Link Control Channel (PSCCH) or the Physical-side Link Shared Channel (PSSCH).

[0074] In some aspects, the configuration of candidate repeaters may include candidate repeaters associated with different base stations. For example, a candidate repeater associated with a base station not connected to the source repeater may be indicated in the candidate repeater configuration. The UE may be configured to measure candidate repeaters associated with different base stations in addition to those associated with the base station having a connection to the source repeater. The UE may establish a PC5 connection with a candidate repeater associated with a base station having a connection to the source repeater, but the UE may not establish a PC5 connection with candidate repeaters associated with different base stations.

[0075] Figure 6 This is a call flow diagram 600 showing the signaling between UE 602, base station 604, and source repeater 606. Base station 604 or source repeater 606 can be configured to provide a cell. UE 602 can be configured to communicate with base station 604 or source repeater 606. For example, in... Figure 1 In the context of this, base station 604 or source repeater 606 may correspond to base station 102 / 180, and therefore the cell may include a geographical coverage area 110 in which communication coverage is provided and / or a small cell 102' having coverage area 110'. Further, UE 602 or source repeater 606 may at least correspond to UE 104. In another example, in Figure 3 In this context, base station 604 or source repeater 606 may correspond to base station 310, and UE 802 or source repeater 606 may correspond to UE 350. Optional aspects are shown using dashed lines.

[0076] As shown at 608, base station 604 can be configured with a candidate relay configuration. Base station 604 can be configured with a candidate relay configuration that includes at least information about candidate repeaters. In some aspects, the candidate relay configuration may include candidate repeaters associated with base station 604 and candidate repeaters associated with a second base station (not shown).

[0077] As shown at 610, base station 604 can transmit candidate relay configurations. Base station 604 can transmit candidate relay configurations to source repeater 606. Source repeater 606 can receive candidate relay configurations from base station 604. Source repeater 606 may have a connection to base station 604. In some aspects, source repeater 606 may include a UE. In some aspects, source repeater 606 may include a base station.

[0078] In some aspects, for example, as shown at 612, source repeater 606 can determine a list of candidate repeaters. Source repeater 606 can determine a list of candidate repeaters for candidate repeater configuration. In such an aspect, source repeater 606 can configure the candidate repeater configuration itself without input from base station 604.

[0079] As shown at 614, source repeater 606 can transmit candidate relay configurations. Source repeater 606 can transmit candidate relay configurations to UE 602. UE 602 can receive candidate relay configurations from source repeater 606. The candidate relay configuration may include at least information about the candidate repeaters. In some aspects, the candidate relay configuration may include candidate repeaters associated with a first base station (e.g., 604) and candidate repeaters associated with a second base station (not shown). Source repeater 606 may have a connection to the first base station (e.g., 604). In some aspects, source repeater 606 may include a UE. In some aspects, source repeater 606 may include a base station.

[0080] As shown at 616, UE 602 can measure the reference signal of the source repeater. UE 602 can also measure the reference signal of each of the candidate repeaters. UE 602 can measure the reference signals of the source repeater 606 and each of the candidate repeaters based on the candidate repeater configuration. In some aspects, the measurement of the reference signal may include measuring the demodulation reference signal (DMRS) of the discovery channel from the source repeater 606 and each of the candidate repeaters. In some aspects, the measurement of the reference signal of the source repeater and each of the candidate repeaters may occur if the quality of the reference signal of the source repeater meets a condition. In some aspects, UE 602 can determine the quality of the reference signal of the source repeater 606. For example, UE 602 may determine that the quality of the reference signal of the source repeater 606 is below a threshold. The threshold may be a pre-configured threshold or may be configured through the candidate repeater configuration.

[0081] In some aspects, UE 602 can rank each candidate repeater among the candidate repeaters. UE 602 can rank each candidate repeater among the candidate repeaters based on a measured reference signal of each candidate repeater among the candidate repeaters. In some aspects, a subset of candidate repeaters can be based on the ranking of each candidate repeater among the candidate repeaters.

[0082] In some aspects, UE 602 can establish connections with candidate repeaters within a subset of candidate repeaters. UE 602 can establish connections with candidate repeaters in the subset if the quality of the reference signal of the source repeater 606 meets certain conditions. In some aspects, the conditions may include a decrease in the quality of the reference signal below a threshold.

[0083] As shown at 618, UE 602 may establish connections with a subset of candidate repeaters. In some aspects, connections with a subset of candidate repeaters may include PC5 connections. In some aspects, UE 602 does not establish connections with candidate repeaters associated with a second base station, wherein the source repeater 606 does not have a connection with the second base station. UE 602 does not establish connections with candidate repeaters associated with base stations not associated with the source repeater 606.

[0084] As shown at 620, UE 602 can send a measurement report of the reference signal of a subset of candidate repeaters. UE 602 can send the measurement report to source repeater 606. Source repeater 606 can receive the measurement report of the subset of candidate repeaters from UE 602. The subset of candidate repeaters can be provided to UE 602 by source repeater 606 in a candidate repeater configuration. The subset of candidate repeaters can be determined by source repeater 606 or base station 604. In some aspects, reception of the measurement report by source repeater 606 can occur if the quality of the reference signal of the source repeater meets a condition. The condition may include the quality of the reference signal of the source repeater being below a threshold. In some aspects, the measurement report may include the measurement results of the Layer-1 Reference Signal Received Power (RSRP) of source repeater 606 and the subset of candidate repeaters. The reporting of the measurement results of the reference signal of each candidate repeater in source repeater 606 and candidate repeaters can be periodic or aperiodic. In some respects, the source repeater 606 can indicate to the UE 602 whether the measurement results should be reported periodically or non-periodically.

[0085] In some aspects, for example, as shown at 622, source repeater 606 can transmit a measurement report received from UE 602. Source repeater 606 can transmit the measurement report received from UE 602 to base station 604. Base station 604 can receive measurement reports of reference signals for a subset of candidate repeaters from source repeater 606. In some aspects, base station 604 may receive a measurement report if the quality of the reference signal of source repeater 606 is below a threshold. In some aspects, the measurement report may include measurement results of the Layer-1 Reference Signal Received Power (RSRP) of the source repeater and a subset of candidate repeaters. In some aspects, the reception of measurement results of the reference signals of each candidate repeater among the source repeater and candidate repeaters by base station 604 may be periodic or aperiodic.

[0086] In some aspects, for example, as shown at 624, base station 604 can select a target repeater from a subset of candidate repeaters. Base station 604 can select a target repeater from a subset of candidate repeaters based on measurement reports.

[0087] In some aspects, for example, as shown at 626, base station 604 can send a relay handover command for UE 602 to hand over to the target relay. Base station 604 can send the relay handover command for UE 602 to hand over to the target relay to source relay 606. Source relay 606 can receive the relay handover command from base station 604. In some aspects, the relay handover command can be sent via Layer-1 or Layer-2 signaling. Layer-1 signaling may include control information or sidelink control information. Layer-2 signaling may include MAC-CE. In some aspects, target relay information may be indicated in the relay handover command.

[0088] In some aspects, source repeater 606 can receive an indication of a target repeater. Source repeater 606 can receive an indication of a target repeater from base station 604. This indication can indicate a target repeater from a subset of candidate repeaters. In some aspects, base station 604 can determine the target repeater from the subset of candidate repeaters based on a measurement report.

[0089] As shown at 628, source repeater 606 can send a relay handover command to UE 602. Source repeater 606 can send a relay handover command to UE 602 for switching to a target repeater from a subset of candidate repeaters. UE 602 can receive the relay handover command from source repeater 606. The relay handover command can be received by UE 602 via Layer-1 or Layer-2 signaling. Layer-1 signaling may include control information or sidelink control information. Layer-2 signaling may include a Media Access Control (MAC) control element (CE) (MAC-CE). Target repeater information may be indicated in the relay handover command. For example, target repeater information may include an identifier of the target repeater. In some aspects, source repeater 606 can determine the target repeater based on a measurement report. In such aspects, source repeater 606 can determine the target repeater from a subset of candidate repeaters on its own and without input from base station 604. In some respects, base station 604 can determine the target repeater from a subset of candidate repeaters based on measurement reports, such that source repeater 606 does not determine the target repeater.

[0090] In some aspects, for example, as shown at 630, UE 602 can switch to a target repeater. UE 602 can switch to a target repeater as indicated in the repeater handover command.

[0091] Figure 7This is a flowchart 700 of a wireless communication method. The method can be performed by a UE or a component of a UE (e.g., UE 104; device 802; cellular baseband processor 804, which may include memory 360, and may be the entire UE 350 or components of UE 350, such as TX processor 368, RX processor 356, and / or controller / processor 359). One or more operations shown may be omitted, interchanged, or performed simultaneously. Optional aspects are shown using dashed lines. The method may allow a UE to establish a connection with one or more candidate repeaters in preparation for switching to a target repeater from one or more candidate repeaters.

[0092] At 702, the UE can receive a candidate relay configuration. For example, 702 can be performed by the candidate relay component 840 of device 802. The UE can receive the candidate relay configuration from the source relay. The candidate relay configuration may include at least information about the candidate relays. In some aspects, the candidate relay configuration includes a candidate relay associated with a first base station and a candidate relay associated with a second base station.

[0093] In some aspects, such as at 704, the UE can determine the quality of the reference signal of the source repeater. For example, 704 can be performed by the quality component 842 of device 802. The UE can determine that the quality of the reference signal of the source repeater is below a threshold.

[0094] At 706, the UE can measure the reference signal of the source repeater. For example, 706 can be performed by the measurement component 844 of device 802. The UE can also measure the reference signal of each of the candidate repeaters. The UE can measure the reference signal of the source repeater and each of the candidate repeaters based on the candidate repeater configuration. In some aspects, the measurement of the reference signal may include measuring the demodulation reference signal (DMRS) of the discovery channel from the source repeater and each of the candidate repeaters. In some aspects, the measurement of the reference signal of each of the source repeaters and candidate repeaters may occur if the quality of the reference signal of the source repeater meets certain conditions.

[0095] In some aspects, such as at 708, the UE can rank each candidate repeater among the candidate repeaters. For example, 708 can be performed by the rank component 846 of device 802. The UE can rank each candidate repeater among the candidate repeaters based on a measured reference signal of each candidate repeater among the candidate repeaters. In some aspects, a subset of candidate repeaters can be based on the ranking of each candidate repeater among the candidate repeaters.

[0096] In some aspects, such as at 710, the UE can establish a connection with a candidate repeater within a subset of candidate repeaters. For example, 710 can be performed by the connection component 848 of device 802. The UE can establish a connection with a candidate repeater in the subset if the quality of the reference signal from the source repeater meets a condition. In some aspects, the condition may include a decrease in the quality of the reference signal below a threshold.

[0097] At point 712, the UE can establish a connection with a subset of candidate repeaters. For example, 712 can be performed by the connection component 848 of device 802. In some aspects, the connection with a subset of candidate repeaters may include a PC5 connection. In some aspects, the UE does not establish a connection with candidate repeaters associated with a second base station. The UE does not establish a connection with candidate repeaters associated with a base station not associated with the source repeater.

[0098] At 714, the UE can send a measurement report of the reference signal of a subset of candidate repeaters. For example, 714 can be performed by the reporting component 850 of device 802. The UE can send a measurement report to the source repeater. In some aspects, the measurement report may include measurement results of the Layer-1 Reference Signal Received Power (RSRP) of the source repeater and a subset of candidate repeaters. Reporting of the measurement results of the reference signal for each candidate repeater in the source repeater and candidate repeaters can be periodic or aperiodic. In some aspects, the source repeater can indicate whether the measurement results should be reported periodically or aperiodically.

[0099] At point 716, the UE can receive a relay handover command for switching to the target relay. For example, 716 can be executed by the handover component 852 of device 802. The UE can receive the relay handover command from the source relay. The UE can receive a relay handover command for switching to the target relay from a subset of candidate relays. The relay handover command can be received via Layer-1 or Layer-2 signaling. Layer-1 signaling may include control information or sidelink control information. Layer-2 signaling may include a Media Access Control (MAC) control element (CE) (MAC-CE). Target relay information can be indicated in the relay handover command. For example, target relay information may include an identifier of the target relay. In some aspects, the base station can determine the target relay from a subset of candidate relays based on a measurement report. In some aspects, the source relay can determine the target relay based on a measurement report.

[0100] In some aspects, such as at 718, the UE can switch to the target repeater. For example, 718 can be performed by the target repeater component 854 of device 802. The UE can switch to the target repeater as indicated in the repeater handover command.

[0101] Figure 8 This is a schematic diagram 800 illustrating an example of a hardware implementation for device 802. Device 802 is a UE, and includes a cellular baseband processor 804 (also referred to as a modem) coupled to a cellular RF transceiver 822, one or more Subscriber Identity Module (SIM) cards 820, an application processor 806 coupled to a Secure Digital Card (SD) card 808 and a screen 810, a Bluetooth module 812, a Wireless Local Area Network (WLAN) module 814, a Global Positioning System (GPS) module 816, and a power supply 818. The cellular baseband processor 804 communicates with the UE 104 and / or BS 102 / 180 via the cellular RF transceiver 822. The cellular baseband processor 804 may include computer-readable media / memory. The computer-readable media / memory may be non-transitory. The cellular baseband processor 804 is responsible for general processing, including the execution of software stored on the computer-readable media / memory. When executed by the cellular baseband processor 804, the software causes the cellular baseband processor 804 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 804 during software execution. The cellular baseband processor 804 also includes a receiving component 830, a communication manager 832, and a transmitting component 834. The communication manager 832 includes one or more of the components shown. Components within the communication manager 832 can be stored in the computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 804. The cellular baseband processor 804 can be a component of the UE 350 and can include at least one of a memory 360 and / or a TX processor 368, an RX processor 356, and a controller / processor 359. In one configuration, the device 802 can be a modem chip and only include the baseband processor 804; in another configuration, the device 802 can be the entire UE (e.g., see [link to relevant documentation]). Figure 3 (350) and additional modules including device 802 discussed above.

[0102] Communication manager 832 includes candidate relay component 840, which is configured to receive candidate relay configurations, such as those in combination with... Figure 7 As described in 702. The communication manager 832 also includes a quality component 842, which is configured to determine the quality of the reference signal of the source repeater, for example, as in conjunction with Figure 7 As described in 704. The communication manager 832 also includes a measurement component 844, which is configured to measure the reference signal of the source repeater, for example, as in combination with Figure 7 As described in 706. The communication manager 832 also includes a ranking component 846, which is configured to rank each candidate repeater among the candidate repeaters, for example, as in combination with... Figure 7As described in 708. The communication manager 832 also includes a connection component 848 configured to establish connections with candidate repeaters within a subset of candidate repeaters. The connection component 848 can be configured to establish connections with a subset of candidate repeaters, for example, as in combination with... Figure 7 As described in 712. The communication manager 832 also includes a reporting component 850, which is configured to send measurement reports of reference signals for a subset of candidate repeaters, for example, as in conjunction with... Figure 7 As described in 714. The communication manager 832 also includes a switching component 852 configured to receive a relay switching command for switching to a target repeater, for example, as in conjunction with... Figure 7 As described in 716. The communication manager 832 also includes a target repeater component 854, which is configured to switch to a target repeater, for example, as in combination with... Figure 7 The description of 718.

[0103] The device may include execution Figure 7 The additional components in each box of the algorithm in the flowchart mentioned above. Accordingly, Figure 7 Each box in the flowchart mentioned above can be executed by a component, and the apparatus can include one or more of those components. A component can be one or more hardware components specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0104] In one configuration, device 802 (particularly cellular baseband processor 804) includes units for receiving candidate relay configurations from a source repeater, the candidate relay configurations including at least information about the candidate repeaters. The device includes units for measuring reference signals of the source repeater and each of the candidate repeaters based on the candidate relay configurations. The device includes units for establishing connections with a subset of the candidate repeaters. The device includes units for sending a measurement report of the reference signals of the subset of candidate repeaters to the source repeater. The device includes units for receiving a relay handover command from the source repeater for switching to a target repeater from the subset of candidate repeaters. The device also includes units for determining that the quality of the reference signal of the source repeater is below a threshold. The device also includes units for ranking each candidate repeater based on the measured reference signals. The device also includes units for establishing connections with the candidate repeaters in the subset if the quality of the reference signal of the source repeater meets a condition. The device also includes units for switching to a target repeater as indicated in the relay handover command. The unit mentioned above can be one or more components of device 802 that are configured to perform the functions described by the unit mentioned above. As described above, device 802 may include TX processor 368, RX processor 356, and controller / processor 359. Accordingly, in one configuration, the unit mentioned above can be TX processor 368, RX processor 356, and controller / processor 359 that are configured to perform the functions described by the unit mentioned above.

[0105] Figure 9 This is a flowchart 900 of a wireless communication method. The method can be performed by a UE or its components (e.g., UE 104; device 1002; cellular baseband processor 1004, which may include memory 360 and may be the entire UE 350 or components of UE 350, such as TX processor 368, RX processor 356, and / or controller / processor 359). The method can also be performed by a base station or its components (e.g., base station 102 / 180; device 1002; cellular baseband unit 1004, which may include memory 376 and may be the entire base station 310 or components of base station 310, such as TX processor 316, RX processor 370, and / or controller / processor 375). One or more of the operations shown may be omitted, interchanged, or performed simultaneously. Optional aspects are shown using dashed lines. The method may allow a source repeater to configure the UE with candidate repeater configurations to switch to a target repeater based on the candidate repeater configurations.

[0106] In some aspects, such as at 902, the source repeater can receive candidate repeater configurations. For example, 902 can be performed by the candidate repeater component 1040 of device 1002. The source repeater can receive candidate repeater configurations from the base station. The source repeater can have a connection to the base station. In some aspects, the base station can determine a list of candidate repeaters for the candidate repeater configurations.

[0107] In some aspects, such as at 904, the source repeater can determine a list of candidate repeaters. For example, 904 can be performed by the determining component 1042 of device 1002. The source repeater can determine a list of candidate repeaters for candidate repeater configuration. In such aspects, the source repeater can configure the candidate repeater configuration itself and without input from the base station.

[0108] At position 906, the source repeater may send candidate relay configurations. For example, position 906 may be performed by the configuration component 1044 of device 1002. The source repeater may send candidate relay configurations to the UE. The candidate relay configurations may include at least information about the candidate repeaters. In some aspects, the candidate relay configurations may include candidate repeaters associated with a first base station and candidate repeaters associated with a second base station. The source repeater may have a connection to the first base station. In some aspects, the source repeater may include a UE. In some aspects, the source repeater may include a base station.

[0109] At 908, the source repeater can receive measurement reports of a subset of candidate repeaters. For example, 908 can be performed by the reporting component 1046 of device 1002. The source repeater can receive measurement reports of a subset of candidate repeaters from the UE. In some aspects, reception of the measurement report can occur if the quality of the source repeater's reference signal meets a condition. The condition may include the quality of the source repeater's reference signal being below a threshold. In some aspects, the measurement report may include measurement results of the Layer-1 Reference Signal Received Power (RSRP) of the source repeater and a subset of candidate repeaters. In some aspects, reception of the measurement report may be periodic or aperiodic. In some aspects, the source repeater may indicate the type of measurement report to be used by the UE to measure the source repeater and candidate repeaters. The subset of candidate repeaters may be provided to the UE in a candidate repeater configuration. The subset of candidate repeaters may be determined by the source repeater or the base station.

[0110] In some aspects, such as at 910, the source repeater can transmit a measurement report received from the UE. For example, 910 can be performed by the reporting component 1046 of device 1002. The source repeater can transmit the measurement report received from the UE to the base station.

[0111] In some aspects, such as at 912, the source repeater can receive an indication of a target repeater. For example, 912 can be performed by the indication component 1048 of device 1002. The source repeater can receive an indication of a target repeater from the base station. This indication can indicate a target repeater from a subset of candidate repeaters. In some aspects, the base station can determine the target repeater from a subset of candidate repeaters based on measurement reports.

[0112] In some aspects, such as at 914, the source repeater can receive a relay handover command. For example, 914 can be executed by the handover component 1050 of device 1002. The source repeater can receive the relay handover command from the base station. In some aspects, the relay handover command can be sent to the UE via Layer-1 or Layer-2 signaling. Layer-1 signaling may include control information or sidelink control information. Layer-2 signaling may include a Media Access Control (MAC) control element (CE) (MAC-CE).

[0113] At point 916, the source repeater can send a relay handover command to the UE. For example, 916 can be performed by the handover component 1050 of device 1002. The source repeater can send a relay handover command to the UE for handing over to a target repeater from a subset of candidate repeaters. Target repeater information can be indicated in the relay handover command. In some aspects, the source repeater can determine the target repeater based on a measurement report. In such aspects, the source repeater can determine the target repeater from a subset of candidate repeaters independently and without input from the base station.

[0114] Figure 10This is a schematic diagram 1000 illustrating an example of a hardware implementation of device 1002. In some aspects, device 1002 is a UE, while in other aspects, device 1002 is a base station. Device 1002 includes a cellular baseband processor 1004 (also referred to as a modem) coupled to a cellular RF transceiver 1022. In the aspect where device 1002 is a UE, device 1002 may include one or more Subscriber Identity Module (SIM) cards 1020, an application processor 1006 coupled to a Secure Digital Card (SD) card 1008 and a screen 1010, a Bluetooth module 1012, a Wireless Local Area Network (WLAN) module 1014, a Global Positioning System (GPS) module 1016, and a power supply 1018. Cellular baseband processor 1004 communicates with UE 104 and / or BS 102 / 180 via cellular RF transceiver 1022. Cellular baseband processor 1004 may include computer-readable media / memory. The computer-readable media / memory may be non-transitory. The cellular baseband processor 1004 is responsible for general processing, including the execution of software stored on a computer-readable medium / memory. When executed by the cellular baseband processor 1004, the software causes the cellular baseband processor 1004 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 1004 during software execution. The cellular baseband processor 1004 also includes a receiving component 1030, a communication manager 1032, and a transmitting component 1034. The communication manager 1032 includes one or more of the components shown. The components within the communication manager 1032 can be stored in a computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 1004. In some aspects, the cellular baseband processor 1004 can be a component of the UE 350 and can include at least one of a memory 360 and / or a TX processor 368, an RX processor 356, and a controller / processor 3510. In one configuration, device 1002 may be a modem chip and include only a baseband processor 1004, while in another configuration, device 1002 may be the entire UE (e.g., see [link to relevant documentation]). Figure 3 (350) and additional modules discussed above, including device 1002. In some aspects, cellular baseband processor 1004 may be a component of base station 310, and may include at least one of memory 376 and / or TX processor 316, RX processor 370 and controller / processor 375.

[0115] Communication manager 1032 includes candidate relay component 1040, which is configured to receive candidate relay configurations, such as those in combination with... Figure 9 As described in 902. The communication manager 1032 also includes a determination component 1042 configured to determine a list of candidate repeaters, for example, as in conjunction with... Figure 9As described in 904. The communication manager 1032 also includes a configuration component 1044, which is configured to send candidate relay configurations, for example, as in conjunction with... Figure 9 As described in 906. The communication manager 1032 also includes a reporting component 1046 configured to receive measurement reports from a subset of candidate repeaters, such as those in conjunction with... Figure 9 As described in 908. Reporting component 1046 can be configured to send measurement reports received from the UE, for example, as in conjunction with Figure 9 As described in 910. The communication manager 1032 also includes an indication component 1048 configured to receive indications to a target repeater, for example, as in conjunction with... Figure 9 As described in 912. The communication manager 1032 also includes a switching component 1040 configured to receive relay switching commands, for example, as in conjunction with... Figure 9 As described in 914. The handover component 1040 can be configured to send a relay handover command to the UE, for example, as in conjunction with... Figure 9 The 916 described.

[0116] The device may include functions that perform Figure 9 The additional components in each box of the algorithm in the flowchart mentioned above. Accordingly, Figure 9 Each box in the flowchart mentioned above can be executed by a component, and the apparatus can include one or more of those components. A component can be one or more hardware components specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0117] In one configuration, apparatus 1002 (particularly cellular baseband processor 1004) includes units for sending candidate relay configurations to a UE. The candidate relay configurations include at least information about candidate relays. The apparatus includes units for receiving measurement reports of a subset of candidate relays from the UE. The apparatus includes units for sending a relay handover command to the UE for switching to a target relay from the subset of candidate relays. The apparatus also includes units for receiving candidate relay configurations from a base station. The apparatus further includes units for determining a list of candidate relays for the candidate relay configurations. The apparatus also includes units for receiving relay handover commands from the base station. The apparatus also includes units for sending measurement reports received from the UE to the base station. The apparatus also includes units for receiving indications from the base station of target relays from the subset of candidate relays. The units mentioned above may be one or more components of apparatus 1002 configured to perform the functions described by the units mentioned above. As described above, apparatus 1002 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Accordingly, in one configuration, the units mentioned above can be TX processor 368, RX processor 356, and controller / processor 359 configured to perform the functions described by the units mentioned above.

[0118] Figure 11 This is a flowchart 1100 of a wireless communication method. The method can be performed by a base station or components of a base station (e.g., base station 102 / 180; device 1202; baseband unit 1204, which may include memory 376, and may be the entire base station 310 or components of base station 310, such as TX processor 316, RX processor 370, and / or controller / processor 375). One or more of the operations shown can be omitted, interchanged, or performed simultaneously. Optional aspects are shown using dashed lines. The method can allow the base station to configure the UE with a candidate relay configuration to switch to a target repeater based on the candidate relay configuration.

[0119] At 1102, the base station can configure a candidate relay configuration. For example, 1102 can be performed by the configuration component 1240 of device 1202. The base station can configure a candidate relay configuration that includes at least information about the candidate repeaters. In some aspects, the candidate relay configuration may include candidate repeaters associated with the base station and candidate repeaters associated with a second base station.

[0120] At 1104, the base station can transmit candidate relay configurations. For example, 1104 can be performed by candidate relay component 1242 of device 1202. The base station can transmit candidate relay configurations to the source relay. In some aspects, the source relay may include a UE. In some aspects, the source relay may include a base station.

[0121] At 1106, the base station can receive a measurement report of the reference signal of a subset of candidate repeaters. For example, 1106 can be performed by the reporting component 1244 of apparatus 1202. The base station can receive a measurement report of the reference signal of a subset of candidate repeaters from the source repeater. In some aspects, the base station can receive a measurement report if the quality of the reference signal of the source repeater is below a threshold. In some aspects, the measurement report may include measurements of the Layer-1 Reference Signal Received Power (RSRP) of the source repeater and subsets of candidate repeaters. In some aspects, the reception of the measurement results of the reference signal of each candidate repeater among the source repeater and candidate repeaters can be periodic or aperiodic.

[0122] At 1108, the base station can select a target repeater from a subset of candidate repeaters. For example, 1108 can be performed by the target repeater component 1246 of device 1202. The base station can select a target repeater from a subset of candidate repeaters based on a measurement report.

[0123] At point 1110, the base station can send a relay handover command for the UE to hand over to the target relay. For example, 1110 can be performed by the handover component 1248 of device 1202. The base station can send the relay handover command to the source relay for the UE to hand over to the target relay. In some aspects, the relay handover command can be sent via Layer-1 or Layer-2 signaling. Layer-1 signaling may include control information or sidelink control information. Layer-2 signaling may include MAC-CE. In some aspects, the target relay information may be indicated in the relay handover command.

[0124] Figure 12This is a schematic diagram 1200 illustrating an example of a hardware implementation of device 1202. Device 1202 is a BS and includes a baseband unit 1204. The baseband unit 1204 can communicate with a UE 104 via a cellular RF transceiver. The baseband unit 1204 may include computer-readable media / memory. The baseband unit 1204 is responsible for general processing, including the execution of software stored on the computer-readable media / memory. When executed by the baseband unit 1204, the software causes the baseband unit 1204 to perform the various functions described above. The computer-readable media / memory can also be used to store data manipulated by the baseband unit 1204 during the execution of the software. The baseband unit 1204 also includes a receiving component 1230, a communication manager 1232, and a transmitting component 1234. The communication manager 1232 includes one or more of the components shown. The components within the communication manager 1232 may be stored in the computer-readable media / memory and / or configured as hardware within the baseband unit 1204. The baseband unit 1204 may be a component of the BS310, and may include at least one of the memory 376 and / or the TX processor 316, the RX processor 370, and the controller / processor 375.

[0125] Communication manager 1232 includes configuration component 1240, which can configure candidate relay configurations, for example, as combined with Figure 11 As described in 1102. The communication manager 1232 also includes a candidate relay component 1242, which can send candidate relay configurations, for example, as in combination with... Figure 11 As described in 1104. The communication manager 1232 also includes a reporting component 1244, which can receive measurement reports of reference signals from a subset of candidate repeaters, for example, as in conjunction with Figure 11 As described in 1106. The communication manager 1232 also includes a target repeater component 1246, which can select a target repeater from a subset of candidate repeaters, for example, as in combination with Figure 11 As described in 1108. The communication manager 1232 also includes a handover component 1248, which can send a relay handover command for the UE to switch to the target repeater, for example, as in combination with... Figure 11 The description of 1110.

[0126] The device may include execution Figure 11 The additional components in each box of the algorithm in the flowchart mentioned above. Accordingly, Figure 11 Each box in the flowchart mentioned above can be executed by a component, and the apparatus can include one or more of those components. A component can be one or more hardware components specifically configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0127] In one configuration, apparatus 1202 (particularly baseband unit 1204) includes units for configuring a candidate relay configuration that includes at least information about candidate relays. The apparatus includes units for sending the candidate relay configuration to a source relay. The apparatus includes units for receiving a measurement report of reference signals from a subset of candidate relays from the source relay. The apparatus includes units for selecting a target relay from the subset of candidate relays based on the measurement report. The apparatus includes units for sending a relay handover command to the source relay for the UE to hand over to the target relay. The units mentioned above may be one or more components of apparatus 1202 configured to perform the functions described by the units mentioned above. As described above, apparatus 1202 may include a TX processor 316, an RX processor 370, and a controller / processor 375. Accordingly, in one configuration, the units mentioned above may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions described by the units mentioned above.

[0128] It should be understood that the specific order or hierarchy of boxes in the disclosed process / flowchart is illustrative. Based on design preferences, it should be understood that the specific order or hierarchy of boxes in the process / flowchart may be rearranged. Furthermore, some boxes may be combined or omitted. The appended method claims give the elements of each box in illustrative order, and do not imply limitation to the given specific order or hierarchy.

[0129] The following examples are merely illustrative and can be combined with, but are not limited to, other embodiments or aspects of the teachings described herein.

[0130] Example 1 is a method for wireless communication at a UE, comprising: receiving a candidate relay configuration from a source repeater, the candidate relay configuration including at least information about the candidate repeaters; measuring a reference signal of the source repeater and each of the candidate repeaters based on the candidate relay configuration; establishing a connection with a subset of the candidate repeaters; sending a measurement report of the reference signal of the subset of candidate repeaters to the source repeater; and receiving a relay handover command from the source repeater for switching to a target repeater from the subset of candidate repeaters.

[0131] In Example 2, the method according to Example 1 further includes: measuring the reference signal includes measuring the DMRS of the discovery channel from the source repeater and each of the candidate repeaters.

[0132] In Example 3, the method according to Example 1 or Example 2 further includes: if the quality of the reference signal of the source repeater meets the condition, then measuring the reference signal of each of the source repeaters and candidate repeaters.

[0133] In Example 4, the method according to any of Examples 1-3 further includes: determining that the quality of the reference signal of the source repeater is below a threshold.

[0134] In Example 5, the method according to any of Examples 1-4 further includes ranking each candidate repeater among the candidate repeaters based on the measured reference signal.

[0135] In Example 6, the method according to any of the examples in Examples 1-5 also includes: a subset of candidate repeaters is based on the ranking of each candidate repeater among the candidate repeaters.

[0136] In Example 7, the method according to any of Examples 1-6 further includes: measuring the results of Layer 1 RSRP measurements, which include a subset of source repeaters and candidate repeaters.

[0137] In Example 8, the method according to any of Examples 1-7 further includes: reporting whether the measurement result of the reference signal of each of the source repeaters and candidate repeaters is periodic or aperiodic.

[0138] In Example 9, the method according to any of Examples 1-8 further includes: the source repeater indicating whether the measurement results are reported periodically or non-periodically.

[0139] In Example 10, the method according to any of Examples 1-9 further includes: the measurement report is carried on the PSCCH or PSSCH.

[0140] In Example 11, the method according to any of the examples 1-10 further includes: if the quality of the reference signal of the source repeater meets the condition, then establishing a connection with the candidate repeaters in the subset.

[0141] In Example 12, the method according to any of the examples in Examples 1-11 further includes the condition that the quality of the reference signal drops below a threshold.

[0142] In Example 13, the method according to any of the examples in Examples 1-12 further includes: the connection to a subset of candidate repeaters includes PC5 connections.

[0143] In Example 14, the method according to any of Examples 1-13 further includes: the relay handover command is received via Layer-1 or Layer-2 signaling.

[0144] In Example 15, the method according to any of Examples 1-14 further includes: Layer-1 signaling including control information or side link control information.

[0145] In Example 16, the method according to any of the examples in Examples 1-15 also includes: Layer-2 signaling including MAC-CE.

[0146] In Example 17, the method according to any of the examples 1-16 also includes: switching to the target repeater as indicated in the repeater switching command.

[0147] In Example 18, the method according to any of Examples 1-17 further includes: the candidate relay configuration includes a candidate repeater associated with a first base station and a candidate repeater associated with a second base station.

[0148] In Example 19, the method according to any of Examples 1-18 further includes: the UE does not establish a connection with the candidate repeater associated with the second base station.

[0149] In Example 20, the method according to any of Examples 1-19 further includes: the target repeater information is indicated in the relay switching command.

[0150] In Example 21, the method according to any of the examples 1-20 further includes: the base station determining the target repeater from a subset of candidate repeaters based on the measurement report.

[0151] In Example 22, the method according to any of the examples in Examples 1-21 further includes: the source repeater determining the target repeater based on the measurement report.

[0152] Example 23 is a device that includes one or more processors; and one or more memories storing instructions that are in electronic communication with the one or more processors, the instructions being executable by the one or more processors to cause a system or apparatus to perform the methods as in any of the examples in Examples 1-22.

[0153] Example 24 is a system or apparatus that includes units for performing a method as in any of the examples in Examples 1-22 or implementing an apparatus as in any of the examples in Examples 1-22.

[0154] Example 25 is a non-transitory computer-readable medium that stores instructions that can be executed by one or more processors to cause one or more processors to implement the methods as in any of the examples in Examples 1-22.

[0155] Example 26 is a method of wireless communication at a source repeater, comprising: sending a candidate repeater configuration to a user equipment (UE), the candidate repeater configuration including at least information about the candidate repeaters; receiving a measurement report of a subset of the candidate repeaters from the UE; and sending a repeater handover command to the UE for switching to a target repeater from the subset of candidate repeaters.

[0156] In Example 27, the method according to Example 26 further includes: sending a measurement report to the base station.

[0157] In Example 28, the method according to Example 26 or Example 27 further includes: the base station determining a list of candidate repeaters for candidate repeater configuration.

[0158] In Example 29, the method according to any of the examples 26-28 further includes: receiving candidate relay configuration from the base station.

[0159] In Example 30, the method according to any of the examples 26-29 further includes: determining a list of candidate repeaters for candidate repeater configuration.

[0160] In Example 31, the method according to any of the examples 26-30 further includes: if the quality of the reference signal of the source repeater meets the conditions, then the reception of a measurement report occurs.

[0161] In Example 32, the method according to any of the examples 26-31 further includes the condition that the quality of the reference signal of the source repeater is below a threshold.

[0162] In Example 33, the method according to any of the examples 26-32 further includes: measuring the results of the Layer-1 RSRP measurement report, which includes a subset of source repeaters and candidate repeaters.

[0163] In Example 34, the method according to any of the examples 26-33 further includes: the receipt of measurement reports is periodic or non-periodic.

[0164] In Example 35, the method according to any of the examples 26-34 further includes: the measurement report is carried on the PSCCH or PSSCH.

[0165] In Example 36, the method according to any of Examples 26-35 further includes: the source repeater indicating the type of measurement report used by the UE to measure the source repeater and the candidate repeater.

[0166] In Example 37, the method according to any of Examples 26-36 further includes: a subset of candidate repeaters is provided to the UE in the candidate repeater configuration.

[0167] In Example 38, the method according to any of the examples 26-37 further includes: the candidate relay configuration includes a candidate repeater associated with a first base station and a candidate repeater associated with a second base station.

[0168] In Example 39, the method according to any of the examples 26-38 further includes: the source repeater is connected to the first base station.

[0169] In Example 40, the method according to any of the examples 26-39 further includes: receiving a relay handover command from a base station.

[0170] In Example 41, the method according to any of Examples 26-40 further includes: the relay handover command is sent to the UE via Layer-1 or Layer-2 signaling.

[0171] In Example 42, the method according to any of the examples 26-41 further includes: Layer-1 signaling including control information or side link control information.

[0172] In Example 43, the method according to any of the examples 26-42 also includes: Layer-2 signaling including MAC-CE.

[0173] In Example 44, the method according to any of the examples 26-43 further includes: the target repeater information is indicated in the repeater switching command.

[0174] In Example 45, the method according to any of Examples 26-44 further includes: sending a measurement report received from the UE to the base station; and receiving from the base station an indication of a target repeater from a subset of candidate repeaters.

[0175] In Example 46, the method according to any of the examples 26-45 further includes: the base station determining the target repeater from a subset of candidate repeaters based on the measurement report.

[0176] In Example 47, the method according to any of the examples 26-46 further includes: the source repeater determining the target repeater based on the measurement report.

[0177] In Example 48, the method according to any of the examples in Examples 26-47 further includes: the source repeater includes the UE.

[0178] In Example 49, the method according to any of the examples 26-48 further includes: the source repeater includes a base station.

[0179] Example 50 is a device that includes one or more processors; and one or more memories storing instructions that are in electronic communication with the one or more processors, the instructions being executable by the one or more processors to cause a system or apparatus to implement the methods as in any of the examples 26-49.

[0180] Example 51 is a system or apparatus that includes units for performing a method as in any of the examples in Examples 26-49 or implementing an apparatus as in any of the examples in Examples 26-49.

[0181] Example 52 is a non-transitory computer-readable medium that stores instructions that can be executed by one or more processors to cause one or more processors to implement the methods as in any of the examples in Examples 26-49.

[0182] Example 53 is a method for wireless communication at a base station, comprising: configuring a candidate relay configuration including at least information about candidate relays; sending the candidate relay configuration to a source relay; receiving a measurement report of reference signals of a subset of candidate relays from the source relay; selecting a target relay from the subset of candidate relays based on the measurement report; and sending a relay handover command to the source relay for the UE to hand over to the target relay.

[0183] In Example 54, the method according to Example 53 further includes: if the quality of the reference signal of the source repeater is below a threshold, a receive measurement report is generated.

[0184] In Example 55, the method according to Example 53 or Example 54 further includes: measuring the results of Layer-1 RSRP measurements, which include a subset of source repeaters and candidate repeaters.

[0185] In Example 56, the method according to any of Examples 53-55 further includes: the reception of the measurement results of the reference signal of each of the source repeaters and candidate repeaters is periodic or aperiodic.

[0186] In Example 57, the method according to any of the examples 53-56 further includes: the measurement report is carried on the PSCCH or PSSCH.

[0187] In Example 58, the method according to any of the examples 53-57 further includes: the relay switching command is sent via Layer-1 or Layer-2 signaling.

[0188] In Example 59, the method according to any of the examples 53-58 further includes: Layer-1 signaling including control information or side link control information.

[0189] In Example 60, the method according to any of the examples 53-59 further includes: Layer-2 signaling including MAC-CE.

[0190] In Example 61, the method according to any of Examples 53-60 further includes: the candidate relay configuration includes a candidate repeater associated with a base station and a candidate repeater associated with a second base station.

[0191] In Example 62, the method according to any of the examples 53-61 further includes: the target repeater information is indicated in the repeater switching command.

[0192] Example 63 is an apparatus comprising: one or more processors; and one or more memories storing instructions that are in electronic communication with the one or more processors, the instructions being executable by the one or more processors to cause a system or apparatus to implement the methods as in any of the examples 53-62.

[0193] Example 64 is a system or apparatus that includes units for performing a method as in any of the examples in Examples 53-62 or implementing an apparatus as in any of the examples in Examples 53-62.

[0194] Example 65 is a non-transitory computer-readable medium that stores instructions that can be executed by one or more processors to cause one or more processors to implement the methods as in any of the examples in Examples 53-62.

[0195] The foregoing description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but are to be consistent with the full scope of the language of the claims, wherein reference to a singular element, unless expressly stated otherwise, is not intended to mean “one and only one,” but rather “one or more.” Terms such as “if,” “when,” and “at the same time as” should be interpreted as meaning “under the condition of,” rather than implying an immediate temporal relationship or reaction. That is, these phrases (e.g., “when”) do not imply an immediate action in response to the occurrence of an action or during the occurrence of an action, but merely that an action will occur if the condition is met, without requiring a specific or immediate temporal constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred over or superior to other aspects. Unless expressly stated otherwise, the term “some” refers to one or more. Combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may contain one or more members of A, B, or C. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure are expressly incorporated herein by reference and are intended to be covered by the claims, and such structural and functional equivalents are known to or will be known later to those skilled in the art. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is explicitly stated in the claims. Terms such as “module,” “mechanism,” “element,” and “device” are not necessarily substitutes for the term “unit.” Accordingly, no claim element should be interpreted as a functional module unless the element is explicitly stated using the phrase “unit for…”.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: Receive candidate relay configurations from the source repeater, the candidate relay configurations including at least information about the candidate repeaters; The reference signal of the source repeater and each of the candidate repeaters is measured based on the candidate repeater configuration. Establish connections with a subset of candidate repeaters, which are selected based on a measured reference signal; A measurement report of the reference signal of a subset of the candidate repeaters is sent to the source repeater; as well as Receive a relay switching command from the source repeater for switching to a target repeater from a subset of the candidate repeaters.

2. The method according to claim 1, wherein, The measurement of the reference signal includes measuring the demodulation reference signal (DMRS) of the discovery channel from the source repeater and each of the candidate repeaters.

3. The method according to claim 1, wherein, If the quality of the reference signal of the source repeater meets the condition, then the measurement of the reference signal of the source repeater and each of the candidate repeaters occurs.

4. The method according to claim 3, further comprising: The quality of the reference signal of the source repeater is determined to be below a threshold.

5. The method according to claim 1, further comprising: Each candidate repeater is ranked based on the measured reference signal, wherein a subset of the candidate repeaters is based on the ranking of each candidate repeater.

6. The method according to claim 1, wherein, The measurement report includes the measurement results of the Layer 1 Reference Signal Received Power (RSRP) of the source repeater and a subset of the candidate repeaters.

7. The method according to claim 1, wherein, The report indicates whether the measurement results of the reference signal of each of the source repeaters and candidate repeaters are periodic or aperiodic, wherein the source repeater indicates whether the measurement results are reported periodically or aperiodically, and wherein the measurement report is carried on the physical side crosslink control channel (PSCCH) or the physical side crosslink shared channel (PSSCH).

8. The method according to claim 1, further comprising: If the quality of the reference signal of the source repeater meets a condition, a connection is established with the candidate repeaters in the subset, wherein the condition includes the quality of the reference signal falling below a threshold.

9. The method according to claim 1, wherein, The connection to the subset of the candidate repeaters includes a PC5 connection.

10. The method according to claim 1, wherein, The relay handover command is received via Layer-1 or Layer-2 signaling, wherein the Layer-1 signaling includes control information or sidelink control information, and the Layer-2 signaling includes a Media Access Control (MAC) control element (CE) (MAC-CE).

11. The method according to claim 1, further comprising: Switch to the target repeater as indicated in the repeater switching command.

12. The method according to claim 1, wherein, The candidate relay configuration includes a candidate relay associated with a first base station and a candidate relay associated with a second base station, wherein the UE does not establish a connection with the candidate relay associated with the second base station.

13. The method according to claim 1, wherein, The target repeater information is indicated in the repeater handover command, wherein the base station determines the target repeater from a subset of the candidate repeaters based on the measurement report, wherein the source repeater determines the target repeater based on the measurement report.

14. An apparatus for wireless communication at a user equipment (UE), comprising: Memory; as well as At least one processor coupled to the memory and configured to perform the method according to any one of claims 1-13.

15. A method for wireless communication at a source repeater, comprising: Send candidate relay configuration to user equipment (UE), the candidate relay configuration including at least information about candidate repeaters; The UE receives a measurement report of reference signals for a subset of candidate repeaters, the subset of candidate repeaters being selected based on the reference signals of each candidate repeater measured by the UE. as well as Send a relay handover command to the UE for switching to a target relay from a subset of the candidate relays.

16. The method of claim 15, further comprising: The measurement report is sent to the base station.

17. The method of claim 16, further comprising: The candidate relay configuration is received from the base station, wherein the base station determines a list of candidate repeaters for the candidate relay configuration.

18. The method of claim 15, further comprising: Determine the list of candidate repeaters for the candidate repeater configuration.

19. The method according to claim 15, wherein, If the quality of the reference signal of the source repeater meets a condition, then the measurement report is received, wherein the condition includes the quality of the reference signal of the source repeater being below a threshold.

20. The method of claim 15, wherein, The measurement report includes the measurement results of the Layer-1 Reference Signal Received Power (RSRP) of the source repeater and a subset of the candidate repeaters, wherein the measurement report is carried on the physical-side cross-link control channel (PSCCH) or the physical-side cross-link shared channel (PSSCH), and wherein the reception of the measurement report is periodic or aperiodic.

21. The method according to claim 15, wherein, The source repeater indicates the type of measurement report used by the UE to measure the source repeater and the candidate repeater.

22. The method according to claim 15, wherein, The subset of candidate repeaters is provided to the UE in the candidate repeater configuration.

23. The method according to claim 15, wherein, The candidate relay configuration includes a candidate repeater associated with a first base station and a candidate repeater associated with a second base station, wherein the source repeater is connected to the first base station.

24. The method of claim 15, further comprising: The relay handover command is received from the base station, wherein the relay handover command is sent to the UE via Layer-1 or Layer-2 signaling, wherein the Layer-1 signaling includes control information or sidelink control information, and wherein the Layer-2 signaling includes a Media Access Control (MAC) control element (CE) (MAC-CE).

25. The method according to claim 15, wherein, The target repeater information is indicated in the repeater switching command.

26. The method of claim 15, further comprising: Send the measurement report received from the UE to the base station; as well as The base station receives an indication of a target repeater from a subset of the candidate repeaters, wherein the base station determines the target repeater from the subset of the candidate repeaters based on the measurement report.

27. The method according to claim 15, wherein, The source repeater determines the target repeater based on the measurement report, wherein the source repeater includes a UE or a base station.

28. An apparatus for wireless communication at a source repeater, comprising: Memory; as well as At least one processor coupled to the memory and configured to perform the method according to any one of claims 15-27.

29. An apparatus for wireless communication at a user equipment (UE), comprising: A unit for receiving candidate relay configurations from a source repeater, the candidate relay configurations including at least information about the candidate repeater; A unit for measuring the reference signal of the source repeater and each of the candidate repeaters based on the candidate repeater configuration; A unit for establishing a connection with a subset of candidate repeaters, the subset of candidate repeaters being selected based on a measured reference signal; A unit for sending a measurement report of a subset of reference signals of the candidate repeaters to the source repeater; as well as A unit for receiving from the source repeater a relay switching command for switching to a target repeater from a subset of the candidate repeaters.

30. The apparatus of claim 29, further comprising: A unit for determining that the quality of the reference signal of the source repeater is below a threshold.

31. The apparatus according to claim 29, wherein, The measurement report includes the measurement results of the Layer-1 Reference Signal Received Power (RSRP) of the source repeater and a subset of the candidate repeaters.

32. The apparatus according to claim 29, wherein, The reception of the measurement results of the reference signal of the source repeater and each of the candidate repeaters is either periodic or aperiodic.

33. The apparatus according to claim 29, wherein, The measurement report is carried on the physical side crosslink control channel (PSCCH) or the physical side crosslink shared channel (PSSCH).

34. The apparatus according to claim 29, wherein, The relay handover command is sent via Layer-1 or Layer-2 signaling, wherein the Layer-1 signaling includes control information or sidelink control information, and the Layer-2 signaling includes a Media Access Control (MAC) control element (CE) (MAC-CE).

35. The apparatus according to claim 29, wherein, The candidate relay configuration includes a candidate relay associated with a first base station and a candidate relay associated with a second base station, wherein the target relay information is indicated in the relay handover command.

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