NR sidelink DRX design for relay reselection

Abstract

Certain aspects of the present disclosure provide techniques for switching between a first path and a second path when certain selection criteria are met. The first path may be a Uu connection whereby the remote UE is directly connected to the network entity. The second path may be a connection whereby the remote UE is connected to the network entity (i.e., indirectly) via a relay UE (e.g., via a PC5 connection).

Description

Technical Field

[0001] Aspects of the present disclosure relate to wireless communications and, more particularly, to techniques for coordinating a sidelink discontinuous reception (DRX) pattern for a remote UE connected to a relay. Background Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, the Advanced LTE (LTE-A) system, the Code Division Multiple Access (CDMA) system, the Time Division Multiple Access (TDMA) system, the Frequency Division Multiple Access (FDMA) system, the Orthogonal Frequency Division Multiple Access (OFDMA) system, the Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and the Time Division Synchronous Code Division Multiple Access (TD-SCDMA) system, to name a few.

[0003] In some examples, a wireless multiple access communication system may include a number of base stations (BSs), each of which is capable of simultaneously supporting communications for multiple communication devices (also referred to as user equipment (UE)). In an LTE or LTE-A network, a set of one or more base stations may define an eNodeB (eNB, evolved node B). In other examples (e.g., in next-generation, new radio (NR) or 5G networks), a wireless multiple access communication system may include a number of distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmit receive points (TRPs), etc.) communicating with a number of central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), wherein a set of one or more DUs communicating with a CU may define an access node (e.g., which may be referred to as a BS, 5G NB, next-generation NodeB (gNB or gNodeB), transmit receive point (TRP), etc.). A BS or DU may communicate with a set of UEs on downlink channels (eg, for transmissions from the BS or DU to the UEs) and uplink channels (eg, for transmissions from the UEs to the BS or DU).

[0004] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. NR (e.g., New Radio or 5G) is an example of an emerging telecommunication standard. NR is a set of enhancements to the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on the downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0005] Sidelink communication is communication from one UE to another. As demand for mobile broadband access continues to grow, there is a need for further improvements in NR and LTE technologies, including improvements for sidelink communication. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunications standards that employ them. Summary of the Invention

[0006] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," those skilled in the art will understand how the features of this disclosure provide advantages, including improved communication between access points and stations in a wireless network.

[0007] Certain aspects provide a method for wireless communication by a remote user equipment (UE). The method generally includes connecting to a relay node connected to a network entity via a sidelink; sending an indication of a sidelink discontinuous reception (DRX) configuration preference; receiving a sidelink DRX configuration defining at least one sidelink DRX mode after sending the indication; entering a reduced power state during an off-duration of the sidelink DRX mode; and monitoring for discovery messages for relay selection from one or more other relays during an on-duration of the sidelink DRX mode.

[0008] Certain aspects provide a method for wireless communications by a relay node. The method generally includes connecting to a remote user equipment (UE) via a sidelink when the relay node is also connected to a network entity; receiving an indication of a sidelink discontinuous reception (DRX) configuration preference from the remote UE; and after receiving the indication, sending a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE.

[0009] Certain aspects provide a method for wireless communications by a network entity. The method generally includes connecting to a relay node connected to a remote user equipment (UE); receiving an indication of a sidelink discontinuous reception (DRX) configuration preference; and after receiving the indication, sending a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE.

[0010] Aspects generally include methods, apparatus, systems, computer-readable media, and processing systems as fully described with reference to and as illustrated by the accompanying figures.

[0011] To accomplish the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only a few of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order that the manner in which the above-mentioned features of the present disclosure may be understood in detail, a more particular description of the content briefly summarized above may be given by reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and, since the description may admit of other equally effective aspects, are not to be considered as limiting the scope of protection thereof.

[0013] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0014] Figure 2 is a block diagram illustrating an example logical architecture of a distributed radio access network (RAN) in accordance with certain aspects of the present disclosure.

[0015] Figure 3 is a diagram illustrating an example physical architecture of a distributed RAN in accordance with certain aspects of the present disclosure.

[0016] Figure 4 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in accordance with certain aspects of the present disclosure.

[0017] Figure 5 is a high-level path diagram illustrating an example connection path for a remote user equipment (UE) in accordance with certain aspects of the present disclosure.

[0018] Figure 6is an example block diagram illustrating a control plane protocol stack on L3 when no direct connection path exists between a remote UE and a network node, in accordance with certain aspects of the present disclosure.

[0019] Figure 7 is an example block diagram illustrating a control plane protocol stack on L2 when a direct connection path exists between a remote UE and a network node, in accordance with certain aspects of the present disclosure.

[0020] Figure 8 An example layer 3 (L3) relay process is illustrated in accordance with certain aspects of the present disclosure.

[0021] Figure 9 An example layer 2 (L2) relay process is shown in accordance with certain aspects of the present disclosure.

[0022] Figure 10A and Figure 10B An example relay discovery process is shown.

[0023] Figure 11 is a flow diagram illustrating example operations that may be performed by a remote UE in accordance with certain aspects of the present disclosure.

[0024] Figure 12 is a flow diagram illustrating example operations that may be performed by a relay UE in accordance with certain aspects of the present disclosure.

[0025] Figure 13 is a flow diagram illustrating example operations that may be performed by a network entity in accordance with certain aspects of the present disclosure.

[0026] Figure 14-16 An example of sidelink DRX coordination in accordance with certain aspects of the present disclosure is shown.

[0027] Figure 17 1 illustrates how a UE in accordance with certain aspects of the present disclosure may be configured with sidelink DRX for relay discovery for reselection.

[0028] Figure 18

[0066] Illustrated is how a UE sidelink DRX configuration may be switched in accordance with certain aspects of the present disclosure.

[0029] Figure 19A and Figure 19B An example of DRX-assisted fast relay selection in accordance with certain aspects of the present disclosure is shown.

[0030] Figure 20 Some aspects of the present disclosure may include a device configured to perform Figure 11 The operation of the various components of a communications device is illustrated.

[0031] Figure 21 Some aspects of the present disclosure may include a device configured to perform Figure 12 The operation of the various components of a communications device is illustrated.

[0032] Figure 22 Some aspects of the present disclosure may include a device configured to perform Figure 13 The operation of the various components of a communications device is illustrated.

[0033] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0034] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for coordinating a sidelink discontinuous reception (DRX) pattern for a remote UE connected to a relay connected to a network entity (e.g., a gNB).

[0035] The connection between a relay and a network entity may be referred to as a Uu connection or via a Uu path. The connection between a remote UE and a relay (e.g., another UE or "relay UE") may be referred to as a PC5 connection or via a PC5 path. A PC5 connection is a device-to-device connection that can exploit the relative proximity between a remote UE and a relay UE (e.g., when the remote UE is closer to the relay UE than the closest base station). The relay UE may connect to an infrastructure node (e.g., a gNB) via a Uu connection and relay the Uu connection to the remote UE via the PC5 connection.

[0036] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of the elements discussed without departing from the scope of the present disclosure. Various processes or components may be omitted, replaced, or added to each example, as appropriate. For example, the method described may be performed in an order different from the order described, and various steps may be added, omitted, or combined. In addition, the features described with respect to some examples may be combined into some other examples. For example, a device may be implemented or a method may be implemented using any number of aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such devices or methods implemented using other structures, functions, or structures and functions in addition to or different from the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims. 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 or advantageous over other aspects.

[0037] The techniques described herein can be used for various wireless communication technologies, such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers the IS-2000, IS-95, and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, and the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS).

[0038] New Radio (NR) is an emerging wireless communication technology under development in conjunction with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein may be used for the wireless networks and radio technologies mentioned above, as well as other wireless networks and radio technologies. For clarity, although various aspects may be described herein using terminology commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations, such as 5G and beyond, including NR technology.

[0039] New Radio (NR) access (e.g., 5G technology) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or beyond), millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or beyond), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission critical services targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet their respective quality of service (QoS) requirements. In addition, these services can coexist in the same subframe.

[0040] Figure 1 An example wireless communication network 100 is shown in which aspects of the present disclosure may be implemented. For example, Figure 1 The UE 120a and / or BS 110a may be configured to perform the following with reference to Figure 11 、 Figure 12 and Figure 13 Operations 1100, 1200, and 1300 are described to coordinate remote UE sidelink DRX configuration.

[0041] like Figure 1As shown, the wireless communication network 100 may include a number of base stations (BSs) 110a-z (each BS also referred to herein individually as BS110 or collectively as BS110) and other network entities. In aspects of the present disclosure, a roadside service unit (RSU) may be considered a type of BS, and BS110 may be referred to as an RSU. BS110 may provide communication coverage for a particular geographic area (sometimes referred to as a "cell"), which may be stationary or may be mobile depending on the location of the mobile BS110. In some examples, BS110 may be interconnected to each other and / or to one or more other BSs or network nodes (not shown) in the wireless communication network 100 through various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.) using any suitable transport network. Figure 1 In the illustrated example, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more cells. BS 110 communicates with user equipment (UEs) 120a-y (each UE also referred to herein individually or collectively as UEs 120) in wireless communication network 100. UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout wireless communication network 100, and each UE 120 may be stationary or mobile.

[0042] The wireless communication network 100 may also include a relay station (e.g., relay station 110r) (also referred to as a repeater, etc.) that receives transmissions of data and / or other information from an upstream station (e.g., BS110a or UE 120r) and sends transmissions of data and / or other information to a downstream station (e.g., UE 120 or BS110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0043] A network controller 130 may couple to a set of BSs 110 and provide coordination and control for these BSs 110. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with each other (eg, directly or indirectly), for example, via a wireless or wired backhaul.

[0044] UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE may be stationary or mobile. A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, customer premises equipment (CPE), a cellular phone, a smart phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or apparatus, a biometric sensor / device, a wearable device (such as a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music device, a video device, a satellite radio unit, etc.), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node may provide, for example, connectivity to a network (e.g., a wide area network such as the Internet or a cellular network) or to the network via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0045] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing can be 15 kHz and the minimum resource allocation (called a "resource block" (RB)) can be 12 subcarriers (or 180 kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may be further divided into subbands. For example, a subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0046] Although aspects of the examples described herein may be associated with LTE technology, aspects of the present disclosure may be applicable in the context of other wireless communication systems (e.g., NR). NR may utilize OFDM with CP on both the uplink and downlink, and may include support for half-duplex operation using TDD. Beamforming may be supported, and the beam direction may be dynamically configured. MIMO transmission with precoding may also be supported. With up to 8 streams and multi-layer DL transmission of up to 2 streams per UE, the MIMO configuration in the DL may support up to 8 transmit antennas. Multi-layer transmission with up to 2 streams per UE may be supported. Aggregation of multiple cells with up to 8 serving cells may be supported.

[0047] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., BS) allocates resources for communication among some or all devices and apparatuses within its service area or cell. A scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities utilize resources allocated by the scheduling entity. A base station is not the only entity that can act as a scheduling entity. In some examples, a UE may act as a scheduling entity, and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs may utilize resources scheduled by the UE for wireless communications. In some examples, a UE may act as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In the mesh network example, UEs may communicate directly with each other in addition to communicating with the scheduling entity.

[0048] exist Figure 1 , a solid line with double arrows indicates desired transmissions between a UE and a serving BS, which is a BS designated to serve the UE on the downlink and / or uplink. A thin dashed line with double arrows indicates interfering transmissions between the UE and the BS.

[0049] Figure 2 An example logical architecture of a distributed radio access network (RAN) 200 is shown, which may be Figure 1 2. The 5G access node 206 may include an access node controller (ANC) 202. The ANC 202 may be a central unit (CU) of the distributed RAN 200. The backhaul interface to the next generation core network (NG-CN) 204 may terminate at the ANC 202. The backhaul interface to the neighboring next generation access node (NG-AN) 210 may terminate at the ANC 202. The ANC 202 may include one or more TRPs 208 (e.g., cells, BSs, gNBs, etc.).

[0050] The TRP 208 may be a distributed unit (DU). The TRP 208 may be connected to a single ANC (e.g., ANC 202) or to more than one ANC (not shown). For example, for RAN sharing, Radio as a Service (RaaS), and service-specific RAN deployments, the TRP 208 may be connected to more than one ANC. The TRPs 208 may each include one or more antenna ports. The TRPs 208 may be configured to serve traffic destined for the UE individually (e.g., dynamically selected) or jointly (e.g., for joint transmission).

[0051] The logical architecture of the distributed RAN 200 can support fronthaul solutions across different deployment types. For example, the logical architecture can be based on the transmitting network capabilities (e.g., bandwidth, latency, and / or jitter).

[0052] The logical architecture of the distributed RAN 200 may share features and / or components with LTE. For example, the next generation access node (NG-AN) 210 may support dual connectivity with NR and may share a common fronthaul for LTE and NR.

[0053] The logical architecture of the distributed RAN 200 may enable collaboration between and among TRPs 208, eg, within and / or across TRPs via the ANC 202. An inter-TRP interface may not be used.

[0054] Logical functions can be dynamically distributed in the logical architecture of the distributed RAN 200. The radio resource control (RRC) layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer can be adaptively placed at the DU (e.g., TRP 208) or the CU (e.g., ANC 202).

[0055] Figure 3 An example physical architecture of a distributed RAN 300 according to aspects of the present disclosure is shown. A centralized core network unit (C-CU) 302 can host core network functions. The C-CU 302 can be centrally deployed. C-CU 302 functions can be offloaded (e.g., to an enhanced wireless service (AWS)) in an attempt to handle peak capacity.

[0056] The centralized RAN unit (C-RU) 304 can host one or more ANC functions. Alternatively, the C-RU 304 can host core network functions locally. The C-RU 304 can have a distributed deployment. The C-RU 304 can be close to the network edge.

[0057] The DU 306 may host one or more TRPs (edge ​​nodes (EN), edge units (EU), radio heads (RH), smart radio heads (SRH), etc.) The DU may be located at the edge of the network with radio frequency (RF) capabilities.

[0058] Figure 4 BS 110a and UE 120a are shown (as in Figure 1) which may be used to implement aspects of the present disclosure. For example, antenna 452, processors 466, 458, 464, and / or controller / processor 480 of UE 120a and / or antenna 434, processors 420, 430, 438, and / or controller / processor 440 of BS 110a may be used to perform the operations referred to herein. Figure 11 、 Figure 12 and Figure 13 Various techniques and methods are described.

[0059] At BS 110a, a transmit processor 420 may receive data from a data source 412 and control information from a controller / processor 440. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. Data may be for a physical downlink shared channel (PDSCH), etc. The processor 420 may process (e.g., encode and symbol map) the data and control information, respectively, to obtain data symbols and control symbols. The processor 420 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS). A transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 432a through 432t. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and frequency upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 432a through 432t may be transmitted via antennas 434a through 434t, respectively.

[0060] At UE 120a, antennas 452a through 452r may receive downlink signals from base station 110a and may provide received signals to demodulators (DEMODs) 454a through 454r, respectively, in the transceiver. Each demodulator 454 may condition (e.g., filter, amplify, downconvert, and digitize) its respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 456 may obtain received symbols from all demodulators 454a through 454r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 458 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to a data sink 460, and provide decoded control information to a controller / processor 480.

[0061] On the uplink, at UE 120a, a transmit processor 464 may receive and process data from a data source 462 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 480 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 464 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 464 may be precoded by a TX MIMO processor 466 (if applicable), further processed by demodulators 454a through 454r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to the base station 110a. At BS 110a, the uplink signal from UE 120a may be received by antenna 434, processed by modulator 432, detected by MIMO detector 436 (if applicable), and further processed by receive processor 438 to obtain decoded data and control information transmitted by UE 120a. The receive processor 438 may provide decoded data to a data sink 439 and decoded control information to a controller / processor 440 .

[0062] Controllers / processors 440 and 480 may direct the operations at BS 110a and UE 120a, respectively. Processor 440 and / or other processors and modules at BS 110a may execute or direct the operations referred to herein. Figure 11 、 Figure 12 and Figure 13 Execution of the process of describing the technique.

[0063] In some cases, two or more slave entities (e.g., UEs) can communicate with each other using sidelink signals. Real-life applications of such sidelink communications may include public safety, neighbor services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical networks, and / or various other appropriate applications. Generally, a sidelink signal may refer to a signal transmitted from one slave entity (e.g., UE1) to another slave entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be utilized for scheduling and / or control purposes. In some examples, the sidelink signal may be transmitted using a licensed spectrum (unlike a wireless local area network (WLAN), which typically uses an unlicensed spectrum).

[0064] Example UE to NW relay

[0065] Aspects of the present disclosure relate to remote UEs, relay UEs, and networks, such as Figure 5 As shown, Figure 5 This is a high-level path diagram showing example connection paths: a Uu path (cellular link) between a relay UE and a network gNB, and a PC5 path (D2D link) between a remote UE and a relay UE. The remote UE and the relay UE may be in radio resource control (RRC) connected mode.

[0066] like Figure 6 and Figure 7 As shown, a remote UE can typically connect to a relay UE via a Layer 3 (L3) connection (without a Uu connection to the network (and is not visible to the network)) or via a Layer 2 (L2) connection (where the UE supports a Uu access stratum (AS) and a non-AS connection (NAS) to the network).

[0067] Figure 6 3GPP LTE 100 network nodes. The remote UE may not have a Uu application server (AS) connection to the radio access network (RAN) via a relay path. In other cases, the remote UE may not have a direct non-access stratum (NAS) connection to the 5G core network (5GC). The relay UE may report the presence of the remote UE to the 5GC. Alternatively and optionally, the remote UE may be visible to the 5GC via a non-3GPP interworking function (N3IWF).

[0068] Figure 7 is an example block diagram showing the control plane protocol stack on L2 when there is a direct connection path between the remote UE and the network node. The control plane protocol stack refers to the L2 relay option based on NR-V2X connectivity. Both the PC5 control plane (C-plane) and the NR Uu C-plane are on the remote UE, similar to Figure 6 As shown. The PC5 C-plane can establish a unicast link before the relay. The remote UE can support NR Uu AS and NAS connections over the PC5 radio link control (RLC). The NG-RAN can control the PC5 link of the remote UE via the NR radio resource control (RRC). In some embodiments, an adaptation layer may be required to support multiplexing of multiple UE services over the Uu connection of the relay UE.

[0069] Example NR sidelink DRX design for relay reselection

[0070] Certain systems (such as NR) may support standalone (SA) capabilities for sidelink-based UE-to-network and UE-to-UE relay communications, e.g., utilizing Layer-3 (L3) and Layer-2 (L2) relays as described above.

[0071] Various procedures and functions may need to be supported in such a system. An example of such procedures and functions is relay selection and (re)selection criteria and procedures. Aspects of the present disclosure provide mechanisms that can help utilize remote UE-specific sidelink discontinuous reception (DRX) modes to support efficient operation of the discovery model / procedure for sidelink relays.

[0072] Sidelink DRX modes can be used for broadcast, multicast, and unicast operations. The DRX configuration defines the on-duration and off-duration for the sidelink, and specifies corresponding UE procedures. Aspects of the present disclosure may provide mechanisms that can help align sidelink DRX wake-up times among UEs communicating with each other (remote UEs and relay UEs) and / or align sidelink DRX wake-up times with Uu DRX wake-up times for UEs in coverage.

[0073] In NR Release 15, the DRX mechanism is similar to the LTE DRX mechanism. Both are MAC entities. However, in LTE, the time unit of the DRX parameters is time slots, while in NR, the time unit is absolute time (ms). In NR, the Hybrid Automatic Repeat Request (HARQ) Round Trip Time (RTT) timer starts after PUSCH transmission or PDSCH reception, while in LTE, this timer starts after PDCCH reception.

[0074] In Release 16, various changes related to NR DRX are introduced. First, the DRX configuration can be per frequency range (FR, such as FR1 / FR2). Furthermore, to save power, UE Assistance Information (UAI) is introduced on the preferred C-DRX configuration, which can include a long DRX cycle, a short DRX cycle, a DRX Inactivity Timer, or a short DRX Cycle Timer. Furthermore, a wake-up signal (WUS) is also introduced, for example, the WUS indicates whether the UE should actually wake up during the DRX on duration.

[0075] Mechanisms for relay selection and reselection may also be provided. Relay selection generally refers to a process whereby a remote UE, which has not yet been connected to any relay node, discovers relay nodes whose sidelink discovery reference signal received power (SD-RSRP) is higher than a threshold level (possibly higher by a certain amount), and selects the relay node with the best SD-RSRP from among them. Relay reselection generally refers to a process whereby a remote UE is already connected to a relay node (e.g., relay selection has been performed), and when the SD-RSRP of the current relay node drops below a threshold level (possibly dropped by a certain amount), the remote UE discovers relay nodes whose SD-RSRP is higher than the threshold level (possibly higher by a certain amount), and (re)selects the relay node with the best SD-RSRP from among them.

[0076] The specific relay process may depend on whether the relay is an L3 relay or an L2 relay. Figure 8 An example dedicated PDU session for L3 relay is shown. In the illustrated scenario, the remote UE establishes a PC5-S unicast link and obtains an IP address. PC5 unicast link AS configuration is managed using PC5-RRC. The relay UE and remote UE coordinate on the AS configuration. The relay UE can consider information from the RAN to configure the PC5 link. Authentication / authorization of the remote UE for relay access can be completed during PC5 link establishment. In the illustrated example, the relay UE performs L3 relaying.

[0077] Figure 9An example dedicated PDU session for L2 relay is shown. In the scenario shown, there is no PC5 unicast link establishment before relaying. The remote UE sends NR RRC messages on the PC5 signaling radio bearer (SRB) over the sidelink broadcast control channel (SBCCH). The RAN can indicate the PC5 AS configuration to the remote UE and the relay UE independently via NR RRC messages. The NR V2X PC5 stack operation may be changed to support radio bearer processing in NR RRC / PDCP, but support the corresponding logical channels in the PC5 link. In L2 relay, PC5 RLC may need to support interaction with NR PDCP directly.

[0078] In the case of sidelink relay DRX scenarios, there may be various issues to address. One issue relates to supporting remote UE sidelink DRX for relay discovery. In some cases, one assumption for relay discovery is that the relay UE is only in connected mode, not idle / inactive. The remote UE can be in connected, idle / inactive, or out-of-coverage (OOC) mode.

[0079] Discovery can be supported for both relay selection and reselection. Different types of discovery models can be supported. For example, Figure 10A The first model (called Model A Discovery) is shown in FIG. In this case, the UE sends a discovery message (announcement) and other UEs monitor. Figure 10B In the second model shown (referred to as Model B Discovery), a UE (discoverer) sends a request message and waits for a response from a monitoring UE (discovered). Such a discovery message may be sent on a PC5 communication channel (e.g., and not on a separate discovery channel). The discovery message may be carried within the same layer-2 frame as used for other direct communications (including, for example, a destination layer-2 ID that may be set to a unicast, multicast, or broadcast identifier, and a source layer-2 ID that is always set to the unicast identifier of the transmitter), and the frame type indicates that it is a ProSe direct discovery message.

[0080] As described above, for relay selection, the remote UE is not yet connected to any relay node (i.e., no PC5 unicast link is established between the remote UE and the relay node). In this case, it may be desirable to design a DRX mode to reduce the power consumption of the remote UE when monitoring relay discovery messages for relay selection.

[0081] As described above, for relay reselection, the remote UE is already connected to at least one relay node (e.g., with PC5 unicast established between the remote UE and the relay node). For relay reselection, it may be desirable to design a DRX configuration that helps reduce power consumption of the remote UE when monitoring for relay discovery messages for relay reselection and PC5 data transmission.

[0082] Aspects of the present disclosure may help implement such DRX configuration for remote UEs by coordinating with relays connected to a network entity (e.g., a gNB) and / or the network entity itself. Figure 11 、 Figure 12 and Figure 13 Example operations for coordinating a sidelink DRX configuration for a remote UE that may be optimized for relay reselection are illustrated from the perspectives of the remote UE, the relay UE, and a network entity, respectively.

[0083] Figure 11 Example operations 1100 are shown that may be performed by a remote UE to coordinate sidelink DRX configuration in accordance with aspects of the present disclosure. Operations 1100 may be performed, for example, by Figure 1 or Figure 4 UE 120 performs.

[0084] At 1102, operations 1100 begin by connecting to a relay node connected to a network entity via a sidelink. At 1104, the remote UE sends an indication of a sidelink discontinuous reception (DRX) configuration preference. At 1106, the remote UE receives a sidelink DRX configuration defining at least one sidelink DRX mode after sending the indication. At 1108, the remote UE enters a reduced power state during an off-duration of the sidelink DRX mode. At 1110, the remote UE monitors for discovery messages for relay selection from one or more other relays during an on-duration of the sidelink DRX mode.

[0085] Operations 1200 may be performed by a relay node (e.g., a relay UE) to coordinate a request for a remote UE (performing Figure 11 Operation 1100) of the sidelink DRX configuration.

[0086] At 1202, operations 1200 begin by connecting to a remote user equipment (UE) via a sidelink while the relay node is also connected to a network entity. At 1204, the relay node receives an indication of a sidelink discontinuous reception (DRX) configuration preference from the remote UE. At 1206, the relay node, upon receiving the indication, transmits a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE.

[0087] Operations 1300 may be performed by a network entity (e.g., a gNB) connected to a relay node to coordinate a request for a remote UE (performing Figure 11 Operation 1100) of the sidelink DRX configuration.

[0088] At 1302, operations 1300 begin by connecting to a relay node connected to a remote user equipment (UE). At 1304, a network entity receives an indication of a sidelink discontinuous reception (DRX) configuration preference. At 1306, the network entity transmits a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE after receiving the indication.

[0089] As described above, one of the goals of a sidelink (SL) DRX configuration may be to conserve power for remote UEs and / or relay UEs. Without SL DRX, a remote UE may have to keep its receiver always on to monitor for relay discovery messages. However, depending on the SL DRX configuration, a relay UE may turn off its transceiver during the sidelink DRX off duration for power conservation.

[0090] The SL DRX mode may be applied to relay reselection and PC5 data transmission (e.g., after connecting to a relay node). As will be described in more detail below, a remote UE-specific sidelink DRX (e.g., similar to Uu C-DRX) mode may be established by coordination with the remote UE.

[0091] For L3 relay scenarios, the remote UE may report its DRX preferences (e.g., preferred parameters) to the relay node via a PC5 RRC message. The relay node may determine the sidelink DRX configuration of the remote UE (e.g., based on the indicated preferences or some other configuration). Alternatively, the relay node may forward the sidelink DRX preferences of the remote UE to the network, for example, via Sidelink UE Information (SUI) or UE Assistance Information (UAI), and the network entity may determine the remote UE SL DRX configuration.

[0092] For L2 relay scenarios, the remote UE may report its DRX preference directly to the network entity (e.g., via SUI or UAI) for the network entity to make a decision regarding its SL DRX configuration. In this case, the network entity may update both the remote UE and relay UE DRX configurations, e.g., via RRC reconfiguration messages.

[0093] In either scenario (L3 or L2), if SL DRX is configured, the relay node may be required to send a Sidelink Broadcast Channel (SL-BCH) for synchronization of the remote UE SL DRX cycle.

[0094] Figure 14 An alternative approach for SL DRX configuration in an L3 relay scenario is shown. As shown, the remote UE can indicate a specific (preferred) sidelink DRX configuration to the relay (e.g., via PC5 RRC). For example, the preferred sidelink DRX configuration can have a DRX on-duration that is a subset of the remote UE group common DRX on (e.g., used during relay selection). The indicated DRX preference can include a DRX cycle, on-duration timer / offset, and inactivity timer (same as traditional UAI).

[0095] As shown in the figure, in this alternative, the relay node determines the remote UE DRX mode (e.g., based on an indicated preference or otherwise). The relay node can transmit the remote UE-specific sidelink DRX, for example, via a PC5 RRC message. As shown in the figure, the relay node can also forward the remote UE's sidelink DRX configuration to the network, for example, via SidelinkUEinformationNR (SidelinkUE Information NR) (SUI).

[0096] The remote UE may apply a sidelink DRX configuration similar to the Uu C-DRX mode. For example, the remote UE may not monitor any receive resource pool that falls within a dedicated DRX off time. Further, at least the DRX inactivity timer may be running, as well as the HARQ RTT timer. In some cases, the remote UE may apply a dedicated sidelink DRX to all sidelinks (PC5 links) in its sidelinks. In other words, a single remote UE-specific DRX configuration may be applied to all PC5 links in its PC5 links. This may be sufficient because the DRX configuration among different relay nodes (in connected mode) may be coordinated, for example, via inter-node messages.

[0097] Figure 15 Another alternative for SL DRX configuration in L3 relay scenario is shown, where the network entity decides the remote UE DRX mode.

[0098] As in Figure 14In the example of , the remote UE can report its sidelink DRX preference to the relay node via a PC5 RRC message. However, in this case, the relay node forwards the remote UE's sidelink DRX preference to the NW via SidelinkUEinformationNR (SUI) or UEAssistenceInformation (UE Assistance Information) (UAI). The network entity decides the remote UE-specific sidelink DRX configuration and sends it to the relay node via an RRC reconfiguration message. The relay node forwards the sidelink DRX configuration to the remote UE (e.g., via a PC5 RRC message), and the remote UE applies sidelink DRX as described above.

[0099] Figure 16 An example of remote UE specific SL DRX configuration coordination in a scenario involving L2 relay is shown. In this case, it may always be up to the network to decide the remote UE DRX mode.

[0100] As shown, in this case, the remote UE reports its sidelink DRX preference directly to the network entity (eg, via UAI or SUI). As described above, the DRX preference may include preference settings for the DRX cycle, on-duration timer / offset, and inactivity timer.

[0101] The network entity determines the remote UE-specific sidelink DRX configuration and, as shown, may also update the relay UE DRX configuration. The network entity sends the DRX configuration to the remote UE (and possibly the relay node) via an RRC reconfiguration message. The remote UE may apply the new DRX configuration in the same manner as described above for the L3 relay scenario.

[0102] Figure 17 A comparison of a remote UE common DRX configuration (cases 1-2) and a remote UE-specific (dedicated) sidelink DRX configuration (case 2) is shown. As shown, before the UE has connected to a relay, it monitors for relay discovery messages for more relays, with a longer DRX on-duration for relay selection (e.g., to monitor for discovery messages from relays 1, 2, and 3).

[0103] Once the remote UE is connected to the relay UE, the remote UE can request (negotiate) a dedicated SL DRX. In the example shown, the remote UE is connected to relay-1, which sends a dedicated SL DRX to the remote UE via PC5 RRC. As shown, the DRX mode of the dedicated SL DRX may not require the remote UE to monitor for discovery messages from relay-3. Therefore, the on-duration of the dedicated SL DRX cycle may be much shorter than the on-duration of the remote UE common DRX cycle, allowing the remote UE to remain powered down for a longer period of time.

[0104] In addition to power saving, the remote UE SL DRX cycle can be optimized in other ways. For example, in some cases, once the remote UE is connected to the relay UE, the relay UE can adjust the remote DRX cycle to assist the remote UE in performing faster relay reselection.

[0105] For example, Figure 18 As shown, the remote UE can be configured to use a first SL DRX configuration (labeled as DRX Mode 1) for use when the remote UE experiences good relay link quality (e.g., SL-RSRP is above a certain threshold). However, when the relay link quality is below a certain threshold, the remote UE can switch (or be switched) to a second DRX configuration (labeled as DRX Mode 2). As shown, DRX Mode 2 has a much longer DRX on-duration, allowing the UE to monitor for more relay discovery signals than DRX Mode 1 (e.g., DRX Mode 2 covers discovery signals from Relay 2, while DRX Mode 1 does not cover discovery signals from Relay 2).

[0106] There are various options for how to switch the remote UE from one SL DRX mode to another SL DRX mode. According to a first option, the remote UE makes this decision for itself (e.g., the remote UE switches DRX mode autonomously). This option can be applied to L2 or L3 relay scenarios.

[0107] according to Figure 19A In the second option shown, the relay UE can decide to switch the remote UE to a different SL DRX mode. As shown, the relay UE can make the decision based on the SL measurement results reported by the remote UE. The relay UE can instruct the remote UE to switch to a different SL DRX mode via an RRC reconfiguration message. This option may generally only be applied in L3 relay scenarios.

[0108] according to Figure 19BIn the third option shown, the network entity may decide to switch the remote UE to a different SL DRX mode. As shown, this decision may be based on SL measurements reported by the remote UE. The network entity may direct the remote UE to switch to a different SL DRX mode via an RRC reconfiguration message that may also indicate the target cell configuration. This option may be applicable to either L2 or L3 relay scenarios.

[0109] In some cases, the remote UE may need to synchronize its timing for SL DRX mode for relay discovery. For example, remote UE common DRX may require timing synchronization among all remote UEs and relay UEs. In this case, the relay node may always be connected and therefore synchronized with the gNB. On the other hand, the remote UE may need synchronization. If DRX is configured in the SIB and / or pre-configured, the relay node may be required to send the Sidelink Broadcast Channel (SL-BCH) for synchronization of the remote UE. In other words, the remote UE may be able to synchronize its timing and apply it to the DRX mode on and off durations.

[0110] Figure 20 A communication device 2000 is shown that may include devices configured to perform operations for the techniques disclosed herein (such as Figure 11 2. The communication device 2000 includes various components (e.g., corresponding to functional module components) of the communication device 2000. The communication device 2000 includes a processing system 2002 coupled to a transceiver 2008. The transceiver 2008 is configured to transmit and receive signals for the communication device 2000, such as the various signals described herein, via an antenna 2010. The processing system 2002 can be configured to perform processing functions for the communication device 2000, including processing signals received and / or to be transmitted by the communication device 2000.

[0111] The processing system 2002 includes a processor 2004 coupled to a computer-readable medium / memory 2012 via a bus 2006. In some aspects, the computer-readable medium / memory 2012 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2004, cause the processor 2004 to perform Figure 11The operations shown or other operations for switching between a PC5 path and a Uu path. In some aspects, the computer-readable medium / memory 2012 stores code 2014 for connecting to a relay node connected to a network entity via a sidelink; code 2016 for sending an indication of a sidelink discontinuous reception (DRX) configuration preference; code 2018 for receiving a sidelink DRX configuration defining at least one sidelink DRX mode after sending the indication; code 2020 for entering a reduced power state during an off-duration of the sidelink DRX mode; and code 2022 for monitoring discovery messages for relay selection from one or more other relays during an on-duration of the sidelink DRX mode. In some aspects, the processor 2004 has circuitry configured to implement the code stored in the computer-readable medium / memory 2012. Processor 2004 includes circuitry 2024 for connecting to a relay node connected to a network entity via a sidelink; circuitry 2026 for sending an indication of a sidelink discontinuous reception (DRX) configuration preference; circuitry 2028 for receiving a sidelink DRX configuration defining at least one sidelink DRX mode after sending the indication; circuitry 2030 for entering a reduced power state during an off-duration of the sidelink DRX mode; and circuitry 2032 for monitoring for discovery messages for relay selection from one or more other relays during an on-duration of the sidelink DRX mode.

[0112] Figure 21 A communication device 2100 is shown that may include devices configured to perform operations for the techniques disclosed herein (such as Figure 12 2. The communication device 2100 includes various components (e.g., corresponding to functional module components) of the communication device 2100. The communication device 2100 includes a processing system 2102 coupled to a transceiver 2108. The transceiver 2108 is configured to transmit and receive signals for the communication device 2100, such as the various signals described herein, via an antenna 2110. The processing system 2102 can be configured to perform processing functions for the communication device 2100, including processing signals received and / or to be transmitted by the communication device 2100.

[0113] The processing system 2102 includes a processor 2104 coupled to a computer-readable medium / memory 2121 via a bus 2106. In certain aspects, the computer-readable medium / memory 2121 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2104, cause the processor 2104 to perform Figure 12The operations shown or other operations for assisting a remote UE in switching paths. In certain aspects, the computer-readable medium / memory 2112 stores code 2114 for connecting to a remote user equipment (UE) via a sidelink when the relay node is also connected to a network entity; code 2116 for receiving an indication of a sidelink discontinuous reception (DRX) configuration preference from the remote UE; and code 2118 for sending a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE after receiving the indication. In certain aspects, the processor 2104 has circuitry configured to implement the code stored in the computer-readable medium / memory 2112. The processor 2104 includes circuitry 2120 for connecting to a remote user equipment (UE) via a sidelink when the relay node is also connected to the network entity; circuitry 2122 for receiving an indication of a sidelink discontinuous reception (DRX) configuration preference from the remote UE; and circuitry 2124 for sending a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE after receiving the indication.

[0114] Figure 22 A communication device 2200 is shown, which may include devices configured to perform operations for the techniques disclosed herein (such as Figure 13 2. The communication device 2200 includes various components (e.g., corresponding to functional module components) of the communication device 2200. The communication device 2200 includes a processing system 2202 coupled to a transceiver 2208. The transceiver 2208 is configured to transmit and receive signals for the communication device 2200, such as the various signals described herein, via an antenna 2210. The processing system 2202 can be configured to perform processing functions for the communication device 2200, including processing signals received and / or to be transmitted by the communication device 2200.

[0115] The processing system 2202 includes a processor 2204 coupled to a computer-readable medium / memory 2226 via a bus 2206. In some aspects, the computer-readable medium / memory 2226 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2204, cause the processor 2204 to perform Figure 13 The operations shown or other operations are used to assist the remote UE in switching between paths.

[0116] In certain aspects, the computer-readable medium / memory 2212 stores code 2214 for connecting to a relay node connected to a remote user equipment (UE); code 2216 for receiving an indication of a sidelink discontinuous reception (DRX) configuration preference; and code 2218 for sending a sidelink DRX configuration defining at least one sidelink DRX mode to the remote UE after receiving the indication.

[0117] In certain aspects, the processor 2204 has circuitry configured to implement code stored in the computer-readable medium / memory 2212. The processor 2204 includes circuitry 2220 for connecting to a relay node connected to a remote user equipment (UE); circuitry 2222 for receiving an indication of a sidelink discontinuous reception (DRX) configuration preference; and circuitry 2222 for, upon receiving the indication, sending a sidelink DRX configuration defining at least one sidelink DRX pattern to the remote UE.

[0118] The methods disclosed herein include one or more steps or actions for implementing the methods. Method steps and / or actions may be interchangeable with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0119] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to encompass a, b, c, ab, ac, bc, and abc, as well as any combination of multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0120] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or another data structure), ascertaining, etc. Furthermore, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Furthermore, "determine" may include resolving, selecting, choosing, establishing, etc.

[0121] The foregoing description is provided to enable those 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 overall principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but rather to be given the full scope consistent with the language of the claims, wherein, unless otherwise specifically stated, reference to an element in the singular is not intended to mean "one and only one," but rather "one or more." Unless otherwise explicitly stated, the term "some" refers to one or more. 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 included by the claims, and these structural and functional equivalents are known or will become known to those of ordinary skill in the art. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. No claim element is to be interpreted under the provisions of 35 U.S.C. § 112(f) unless the element is explicitly stated using the phrase "means for..." or, in the case of a method claim, the element is stated using the phrase "step for..."

[0122] The various operations of the methods described above may be performed by any appropriate unit capable of performing the corresponding functions. The units may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. Generally, where there are operations shown in the figures, those operations may have corresponding paired functional module components. For example, Figure 11 、 Figure 12 and Figure 13 The various operations shown can be performed by Figure 4 The instructions may be executed by various processors as shown, such as processors 466, 458, 464 and / or controller / processor 480 of UE 120a.

[0123] The various illustrative logic blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or performed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0124] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. In addition, the bus interface may also be used to connect a network adapter to the processing system via the bus. The network adapter may be used to implement signal processing functions at the PHY layer. In the user terminal 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also connect various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described any further. The processor may be implemented using one or more general and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize that how to best implement the functionality described for the processing system depends on the specific application and the overall design constraints imposed on the entire system.

[0125] If implemented in software, the functionality may be stored on or transmitted via a computer-readable medium as one or more instructions or codes. Whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise, software should be broadly interpreted to mean instructions, data, or any combination thereof. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates the transfer of computer programs from one location to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on a machine-readable storage medium. A computer-readable storage medium may be coupled to the processor so that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be an integral part of the processor. For example, the machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium having instructions stored thereon, separate from the wireless node, all of which may be accessed by the processor via a bus interface. Alternatively, or in addition, the machine-readable medium or any portion thereof may be integrated into the processor, such as in the case of a cache and / or general register file. For example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. Machine-readable media may be embodied in a computer program product.

[0126] A software module may include a single instruction or many instructions and may be distributed across several different code segments, among different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a sending module and a receiving module. Each software module may be located in a single storage device or distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During execution of the software module, the processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When referring to the functions of a software module below, it will be understood that such functions are implemented by the processor when executing instructions from the software module.

[0127] Furthermore, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc. Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks utilize lasers to reproduce data optically. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Furthermore, for other aspects, computer-readable media may include transitory computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0128] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein. For example, a computer program product for performing the operations described herein and in Figure 11 、 Figure 12 and Figure 13 The operation instructions are shown in .

[0129] Further, it should be understood that the modules and / or other appropriate units for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station where applicable. For example, such a device can be coupled to a server to facilitate the transmission of the units for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage unit (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.) so that the user terminal and / or base station can obtain the various methods when the storage unit is coupled to or provided to the device. In addition, any other appropriate technology for providing the methods and techniques described herein to a device can be utilized.

[0130] It is to be understood that the claims are not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a remote user equipment (UE), comprising: connecting to a relay node connected to the network entity via a sidelink; Sending an indication of a sidelink discontinuous reception (DRX) configuration preference; After sending the indication, receiving a sidelink DRX configuration defining at least one sidelink DRX pattern, wherein the at least one sidelink DRX pattern is associated with a link quality between the remote UE and the relay node; entering a reduced power state during an off-duration of the sidelink DRX mode; as well as Monitoring is performed during the on-duration of the sidelink DRX mode for discovery messages for relay selection from one or more other relays.

2. The method according to claim 1, wherein The On-Duration of the sidelink DRX pattern comprises a subset of the On-Duration for initial relay selection and a remote UE group common DRX pattern On-Duration.

3. The method according to claim 1, wherein: The remote UE sends the indication of the sidelink DRX configuration preference to the relay node; and The relay node signals the sidelink DRX configuration to the remote UE.

4. The method according to claim 3, wherein: The relay node also determines the sidelink DRX mode.

5. The method according to claim 3, wherein: The sidelink DRX configuration is signaled to the remote UE via a sidelink radio resource control (RRC) message; and The remote UE does not monitor the reception resource pool that falls within the off-duration of the sidelink DRX mode.

6. The method according to claim 5, wherein: The remote UE applies the sidelink DRX pattern to all of its sidelinks.

7. The method according to claim 3, wherein: The relay node forwards the sidelink DRX configuration preference of the remote UE to the network entity; and The network entity determines the sidelink DRX mode and sends it to the relay node to be forwarded to the remote UE.

8. The method according to claim 1, wherein: The remote UE sends the indication of the sidelink DRX configuration preference to the network entity; and The network entity determines the sidelink DRX mode and signals the sidelink DRX configuration to the remote UE.

9. The method according to claim 1, wherein: The DRX configuration indicates at least a first sidelink DRX mode and a second sidelink DRX mode; and The remote UE switches between the first sidelink DRX mode and the second sidelink DRX mode based on one or more criteria.

10. The method according to claim 9, wherein: The one or more criteria are related to sidelink channel quality.

11. The method according to claim 10, wherein: When the sidelink channel quality drops below a threshold, the remote UE switches to a mode with a longer on-duration.

12. The method according to claim 11, wherein The remote UE autonomously decides to switch between the first DRX mode and the second DRX mode.

13. The method according to claim 11, wherein The relay node or the network entity decides to switch the remote UE between the first DRX mode and the second DRX mode based on a sidelink measurement result reported by the remote UE.

14. The method according to claim 1, further comprising: receiving a sidelink broadcast channel from the relay node; as well as Timing of the DRX mode is synchronized based on the sidelink broadcast channel.

15. A method for wireless communication by a relay node, comprising: connecting to a remote user equipment (UE) via a sidelink when the relay node is also connected to a network entity; receiving an indication of a sidelink discontinuous reception (DRX) configuration preference from the remote UE; as well as After receiving the indication, a sidelink DRX configuration defining at least one sidelink DRX pattern is sent to the remote UE, wherein the at least one sidelink DRX pattern is associated with a link quality between the remote UE and the relay node.

16. The method according to claim 15, wherein The sidelink DRX mode On-Duration includes a subset of the remote UE group common DRX mode On-Duration for initial relay selection.

17. The method according to claim 15, wherein: The relay node also determines the sidelink DRX mode.

18. The method of claim 15, wherein: The sidelink DRX configuration is signaled to the remote UE via a sidelink radio resource control (RRC) message.

19. The method of claim 15, wherein: The relay node forwards the sidelink DRX configuration preference of the remote UE to the network entity; and The network entity determines the sidelink DRX mode and sends it to the relay node to be forwarded to the remote UE.

20. The method according to claim 19, wherein The relay node forwards the sidelink DRX configuration preference of the remote UE to the network entity via at least one of Sidelink UE Information (SUI) or UE Assistance Information (UAI).

21. The method of claim 15, wherein: The DRX configuration indicates at least a first sidelink DRX mode and a second sidelink DRX mode; and The remote UE switches between the first sidelink DRX mode and the second sidelink DRX mode based on one or more criteria.

22. The method according to claim 21, wherein The one or more criteria are related to sidelink channel quality.

23. The method according to claim 22, wherein When the sidelink channel quality drops below a threshold, the remote UE switches to a mode with a longer on-duration.

24. The method according to claim 23, wherein The remote UE autonomously decides to switch between the first DRX mode and the second DRX mode.

25. The method according to claim 23, wherein The relay node or the network entity decides to switch the remote UE between the first DRX mode and the second DRX mode based on a sidelink measurement result reported by the remote UE.

26. The method of claim 15, further comprising: A sidelink broadcast channel is transmitted, wherein the remote UE synchronizes timing of the DRX mode based on the sidelink broadcast channel.

27. A method for wireless communication by a network entity, comprising: connecting to a relay node connected to a remote user equipment (UE); receiving an indication of a sidelink discontinuous reception (DRX) configuration preference; as well as After receiving the indication, a sidelink DRX configuration defining at least one sidelink DRX pattern is sent to the remote UE, wherein the at least one sidelink DRX pattern is associated with a link quality between the remote UE and the relay node.

28. The method according to claim 27, wherein The sidelink DRX mode On-Duration includes a subset of the remote UE group common DRX mode On-Duration for initial relay selection.

29. The method of claim 27, wherein: The network entity receives the indication of the sidelink DRX configuration preference from the relay node; and The network entity signals the sidelink DRX configuration to the remote UE via the relay node.

30. The method according to claim 29, wherein The relay node forwards the sidelink DRX configuration preference of the remote UE to the network entity via at least one of Sidelink UE Information (SUI) or UE Assistance Information (UAI).

31. The method of claim 27, wherein: The network entity receives the indication of the sidelink DRX configuration directly from the remote UE; and The network entity determines the sidelink DRX mode and directly signals the sidelink DRX configuration to the remote UE.

32. The method of claim 27, wherein: The DRX configuration indicates at least a first sidelink DRX mode and a second sidelink DRX mode; and The remote UE switches between the first sidelink DRX mode and the second sidelink DRX mode based on one or more criteria.

33. The method according to claim 32, wherein The one or more criteria are related to sidelink channel quality.

34. The method according to claim 33, wherein When the sidelink channel quality drops below a threshold, the remote UE switches to a mode with a longer on-duration.

35. The method according to claim 34, wherein The remote UE autonomously decides to switch between the first DRX mode and the second DRX mode.

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