Sidelink transmission enabled by the receiving user equipment (UE)

Abstract

Certain aspects provide a method for wireless communication by a first user equipment (UE). The method may include determining whether to receive data from one or more second UEs, transmitting at least one enabling signal instructing the one or more second UEs to transition to an active operating mode to transmit data, and monitoring for data in response to the at least one enabling signal during a receive phase of the UE.

Description

Technical Field

[0001] Aspects of the present disclosure relate to wireless communications and, more particularly, to techniques for sidelink communications. Background Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services, such as telephony, video, data, messaging, broadcast, and the like. 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, and the like). Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, 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, to name a few.

[0003] 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, or even global level. New radio (e.g., 5G NR) 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.

[0004] However, as demand for mobile broadband access continues to increase, further improvements to NR and LTE technologies are needed. Preferably, these improvements should also be applicable to other multi-access technologies and the telecommunication standards that employ them. Summary of the Invention

[0005] 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," one will understand how the features of the present disclosure provide advantages, including improved sidelink communications.

[0006] Certain aspects provide a method for wireless communications by a first user equipment (UE). The method may include determining whether to receive data for at least one application or service from one or more second UEs using at least one sidelink communication, sending at least one enable signal instructing the one or more second UEs to transition to an active operating mode to transmit the data, and, in response to the at least one enable signal, monitoring, during a reception phase of the UE for the at least one application or service using the at least one sidelink communication, the data in response to the at least one enable signal.

[0007] Certain aspects provide a method for wireless communications by a first UE. The method may include receiving an enablement signal from a second UE instructing the first UE to transition to an active operating mode to transmit data for at least one application or service using at least one sidelink communication; determining, based on the enablement signal, whether to transmit data to the second UE during a transmit phase; and transmitting, based on the determination, the data for the at least one application or service to the second UE using the at least one sidelink communication during the transmit phase.

[0008] Aspects of the present disclosure provide units, devices, processors, and computer-readable media for performing the methods described herein.

[0009] To accomplish the foregoing and related ends, the one or more aspects include 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 the one or more aspects. However, these features are indicative of but some of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order that the above-mentioned features of the present disclosure may be understood in detail, reference may be made to a more particular description of the various aspects briefly summarized above, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the disclosure and are therefore not to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0011] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0012] Figure 2 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.

[0013] Figure 3A and 3BA diagrammatic representation of an example vehicle-to-everything (V2X) system is shown, in accordance with aspects of the present disclosure.

[0014] Figure 4 An example sidelink discontinuous reception (SL DRX) configuration for a UE in some aspects is shown.

[0015] Figure 5 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0016] Figure 6 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0017] Figure 7A A sidelink DRX protocol managed by a receiving (RX) UE using periodic enable signaling in accordance with certain aspects of the present disclosure is illustrated.

[0018] Figure 7B A sidelink DRX protocol managed by an RX UE using aperiodic enable signaling in accordance with certain aspects of the present disclosure is illustrated.

[0019] Figure 8A and 8B A sidelink DRX protocol managed by an RX UE for unicast communications is illustrated in accordance with certain aspects of the present disclosure.

[0020] Figure 9A and 9B A sidelink DRX protocol managed by an RX UE for multicast or broadcast communications is illustrated in accordance with certain aspects of the present disclosure.

[0021] Figure 10 Transmission of transmit enable (TxEn) indications using a sequence-based approach in accordance with certain aspects of the present disclosure is illustrated.

[0022] Figure 11 Transmission of TxEn indications using a sidelink control information (SCI) based approach is illustrated in accordance with certain aspects of the present disclosure.

[0023] Figure 12 Transmission of TxEn indications using a medium access control (MAC) control element (CE) based approach is illustrated in accordance with certain aspects of the present disclosure.

[0024] Figure 13 A communications device is shown that may include various components configured to perform the operations of the techniques disclosed herein.

[0025] 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

[0026] Various aspects of the present disclosure provide apparatuses, methods, processing systems, and computer-readable media for implementing sidelink (SL) transmission enablement. For example, certain aspects provide techniques for a receiver (Rx) UE to manage sidelink transmissions to save power. For example, an Rx UE may send one or more enable signals (also known as transmission enable (TxEn) indications) to one or more transmitter (Tx) UEs, requesting one or more Tx UEs to transmit data to the Rx UE. In some embodiments, the Rx UE may send TxEn signals periodically (e.g., during a corresponding DRX on phase) or aperiodically, as described in more detail herein.

[0027] The following description provides an example of a configuration for sidelink (SL) communication in a communication system and does not limit the scope, applicability or examples set forth in the claims. The functions and arrangements of the elements discussed may be changed without departing from the scope of the present disclosure. Various examples may appropriately omit, replace or add various processes or components. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted or combined. In addition, the features described with respect to some examples may be combined in some other examples. For example, a device or 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 that are practiced using other structures, functions or structures and functions in addition to or in addition to the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of the claims. The word "exemplary" is used herein to mean "used 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.

[0028] In general, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, subcarrier, frequency channel, frequency tone, subband, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, 5G NR RAT networks can be deployed.

[0029] Figure 1 An example wireless communication network 100 is shown in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a NR system (e.g., a 5G NR network).

[0030] like Figure 1 As shown, the wireless communication network 100 may include multiple base stations (BSs) 110a-z (each BS also individually referred to herein as BS 110 or collectively referred to as BS 110) and other network entities. BS 110 may provide communication coverage for a particular geographic area, sometimes referred to as a "cell," which may be stationary or may move depending on the location of the mobile BS 110. In some examples, BS 110 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 via 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 UE 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.

[0031] According to certain aspects, UE 120 may be configured to manage the sidelink in a discontinuous reception (DRX) mode of operation. Figure 1As shown, UE 120a includes a transmission manager 121. In some cases, UE 120a may be an Rx UE. In this case, transmission manager 121 may be configured to: determine whether to receive data for at least one application or service from one or more second UEs using at least one sidelink communication; send at least one enable signal instructing the one or more second UEs to transition to an active operating mode to transmit data; and monitor, during a receive phase of the UE, for data for at least one application or service using at least one sidelink communication in response to the at least one enable signal. In some cases, UE 120t may include a transmission manager 122. UE 120t may be a Tx UE. Transmission manager 122 may be configured to: receive an enable signal from a second UE instructing the first UE to transition to an active operating mode to transmit data for at least one application or service using at least one sidelink communication; determine, based on the enable signal, whether to transmit data to the second UE during a transmit phase; and, based on the determination, transmit data for the at least one application or service to the second UE using at least one sidelink communication during the transmit phase.

[0032] The wireless communication network 100 may also include a relay station (e.g., relay station 110r), also referred to as a relay, etc., which 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., UE120 or BS110), or relays transmissions between UEs 120 to facilitate communication between devices.

[0033] 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) via a wireless or wired backhaul.

[0034] Figure 2 1 shows a BS 110a and a UE 120a (eg, in FIG. 1 ) that may be used to implement aspects of the present disclosure. Figure 1 Example components of the wireless communication network 100).

[0035] At BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller / processor 240. 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), or the like. Data may be for a physical downlink shared channel (PDSCH), or the like. The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 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 230 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) 232a-232t. Each modulator 232 can process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can 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 232a-232t can be transmitted via antennas 234a-234t, respectively.

[0036] At UE 120a, antennas 252a-252r can receive downlink signals from BS 110a and can provide received signals to demodulators (DEMODs) 254a-254r in the transceiver, respectively. Each demodulator 254 can condition (e.g., filter, amplify, downconvert, and digitize) its respective received signal to obtain input samples. Each demodulator can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 can obtain received symbols from all demodulators 254a-254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 258 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120a to a data sink 260, and provide decoded control information to a controller / processor 280.

[0037] On the uplink, at UE 120a, a transmit processor 264 may receive and process data from a data source 262 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 280 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by demodulators 254a-254r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to BS 110a. At BS 110a, the uplink signal from UE 120a may be received by antenna 234, processed by modulator 232, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information sent by UE 120a. The receive processor 238 may provide decoded data to a data sink 239 and decoded control information to a controller / processor 240 .

[0038] Memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively.A scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0039] The controller / processor 280 and / or other processors and modules at the UE 120a may perform or direct the execution of processes for the techniques described herein. Figure 2 As shown in FIG, the controller / processor 280 of the UE 120 has a transmission manager 121 (or transmission manager 122). Although shown at the controller / processor, other components of the UE 120a may be used to perform the operations described herein.

[0040] Figure 3A and 3B A diagrammatic representation of an example vehicle-to-everything (V2X) system is shown according to some aspects of the present disclosure. For example, Figure 3A and 3B The UE shown in FIG. 4 may communicate via a sidelink channel and may perform sidelink CSI reporting as described herein.

[0041] Figure 3A and 3B The V2X system provided in [1] provides two complementary transmission modes. Figure 3A The first transmission mode shown as an example in relates to direct communication (e.g. also called sidelink communication) between participants that are close to each other in a local area. Figure 3BThe second transmission mode shown as an example in FIG involves network communication through the network, which can be implemented through the Uu interface (e.g., a wireless communication interface between a radio access network (RAN) and a UE). As shown, UEs 352 and 354 can communicate with each other using a sidelink (SL) 398.

[0042] refer to Figure 3A , shows a V2X system 300 (e.g., including vehicle-to-vehicle (V2V) communications) with two UEs 302, 304 (e.g., vehicles). A first transmission mode allows direct communication between different participants in a given geographic location. As shown, the vehicles can have a wireless communication link 306 with individuals (V2P) (e.g., via the UE) through a PC5 interface. Communication between the UEs 302 and 304 can also occur through the PC5 interface 308. In a similar manner, communication can occur from the UE 302 to other highway components (e.g., highway components 310) (e.g., traffic signals or signs (V2I)) through the PC5 interface 312. Figure 3A Each communication link shown enables bidirectional communication between elements, so each element can be both a sender and receiver of information. V2X system 300 can be a self-managed system implemented without assistance from network entities. This self-managed system can achieve improved spectrum efficiency, reduced costs, and increased reliability because no network service interruptions occur during handover operations between moving vehicles. The V2X system can be configured to operate in either licensed or unlicensed spectrum, so any vehicle equipped with the system can access common frequencies and share information. This coordinated / common spectrum operation allows for safe and reliable operation.

[0043] Figure 3B A V2X system 350 is shown for communicating between a UE 352 (e.g., a vehicle) and a UE 354 (e.g., a vehicle) via a network entity 356. These network communications can occur via discrete nodes, such as base stations (e.g., eNBs or gNBs), that send and receive information to and from the UEs 352, 354 (e.g., relay information between the UEs 352, 354). Network communications via vehicle-to-network (V2N) links (e.g., Uu links 358 and 310) can be used, for example, for long-range communications between vehicles, such as for communicating the presence of an accident some distance ahead along a road or highway. Nodes can also send other types of communications to vehicles, such as traffic flow conditions, road hazard warnings, environmental / weather reports, and service station availability, among other examples. Such data can be obtained from cloud-based sharing services.

[0044] In some cases, two or more subordinate entities (e.g., UEs) can use sidelink signals to communicate with each other. As described above, V2V and V2X communications are examples of communications that can be sent via a sidelink. Other applications of sidelink communications may include public safety or service announcement communications, communications for proximity services, communications for UE to network relay, device to device (D2D) communications, Internet of Everything (IoE) communications, Internet of Things (IoT) communications, mission-critical mesh communications, and other suitable applications. Generally, a sidelink may refer to a direct link between one subordinate entity (e.g., UE1) and another subordinate entity (e.g., UE2). Therefore, even if a scheduling entity (e.g., BS) can be used for scheduling or control purposes, a sidelink may be used to send and receive communications (also referred to herein as "sidelink signals") without relaying the communications through the scheduling entity. In some examples, licensed spectrum may be used to convey sidelink signals (unlike wireless local area networks that typically use unlicensed spectrum).

[0045] Various sidelink channels may be used for sidelink communications, including a physical sidelink discovery channel (PSDCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), and a physical sidelink feedback channel (PSFCH). The PSDCH may carry discovery expressions that enable neighboring devices to discover each other. The PSCCH may carry control signaling, such as sidelink resource configuration and other parameters for data transmission, and the PSSCH may carry data transmission. The PSFCH may carry feedback, such as an acknowledgement (ACK) or negative acknowledgement (NACK) for hybrid automatic repeat request (HARQ) feedback or channel state information (CSI) related to the sidelink channel quality.

[0046] Discontinuous Reception (DRX) on the sidelink

[0047] In a discontinuous reception (DRX) mode of operation, the UE may enter a low-power ("sleep") mode (also referred to herein as a "sleep phase") (which may also be referred to as a low-power state) for a period of time (referred to as a DRX off phase or duration) and wake up again during a DRX on (e.g., wake-up phase) duration (also referred to as a DRX on phase) to check if there is any data to be received. This cycle of sleep and wake-up (DRX on and DRX off) durations repeats over time, allowing the UE to save power while maintaining communications.

[0048] Currently, DRX is not defined for sidelink operation, and therefore, the receiving (Rx) UE must monitor the sidelink control information (SCI) for each time slot, resulting in high power consumption, which is particularly harmful for battery power-constrained UEs (such as pedestrian UEs for vehicle-to-person (V2P) services on the sidelink or UEs for public safety services on the sidelink). Therefore, a SL DRX design is needed to save power for sidelink communications. Compared with the communication between the UE and the base station (BS) on the Uu interface, the sidelink communication between different UEs is more diverse. For example, a UE may simultaneously participate in different vehicle-to-everything (V2X) services with different quality of service (QoS) requirements (e.g., reliability, latency, etc.) and different communication types (e.g., broadcast, groupcast, and unicast). Therefore, a one-size-fits-all SL DRX design may not be optimal for both saving power and meeting different QoS requirements.

[0049] Figure 4 An example SL DRX configuration 400 for a UE is shown. As shown, the SL DRX configuration 400 may include SL DRX On phases 402, 404. As described herein, the SL DRX On phase repeats during each DRX cycle. For example, the DRX On phase 402 is during a DRX cycle 406, as shown. A unicast receiver (Rx) UE or a broadcast or multicast Rx UE wakes up during the DRX On phases 402, 404 to communicate with one or more Tx UEs for unicast broadcast or multicast (e.g., one (or more) Rx UEs monitor signaling that may be received from one (or more) Tx UEs), and one (or more) Rx UEs are in a low power state (e.g., a sleep phase) at other times (also referred to as an SL DRX sleep phase), during which one (or more) Tx UEs may communicate with one (or more) other Rx UEs in another service, group, or UE pair, or one (or more) Tx UEs may also be in a low power state. In addition, when a UE in a service, group or UE pair has a packet to be sent on the sidelink to other UEs in the service or group or another UE in the UE pair, the UE becomes a TxUE on the sidelink. Therefore, unlike DRX for a UE to monitor downlink control information (DCI) from a base station at the Uu interface, SL DRX is bidirectional on the sidelink for both the Tx UE and one (or more) Rx UEs in a service, group or UE pair, and thus SL DRX forms the sidelink traffic pattern for the service, group or UE pair.

[0050] Example SL DRX Operation

[0051] As described herein, sidelink discontinuous reception (SL DRX) can be formed to assist an Rx UE for unicast, broadcast, or multicast in determining when to monitor one (or more) sidelink control information (SCI) from a Tx UE, which schedules sidelink transmissions to one (or more) Rx UEs. Therefore, SL DRX allows one (or more) Rx UEs to save power by discontinuously monitoring the SCI. As described herein, SL DRX is bidirectional and also forms a service mode for the Tx UE. That is, when one (or more) Rx UEs are not in the SL DRX on state for monitoring one (or more) SCIs, the Tx UE may not transmit. That is, if one (or more) Rx UEs are not in the DRX on phase, the Rx UE may be in a sleep operation mode and may not monitor the SCI. Therefore, the Tx UE may also give up transmissions to other UEs that are not in the DRX on phase.

[0052] If different SL DRXs are formed for different communication types, the UEs participating in different sidelink communication types may be woken up based on one or more DL DRX configurations or based on one or more wake-up indications (also referred to herein as wake-up signals) before the SL DRX on phase to monitor the SCI for each sidelink DRX on phase. These communication types may include: communication between all UEs with an application or service using broadcast, communication between UEs within a group using groupcast, and / or communication between UE pairs using unicast. Therefore, the Rx UE may monitor one (or more) SCIs from one or more Tx UEs for one or more communications of an application or service, group or UE pair in each sidelink DRX on phase based on one or more DL DRX configurations or based on one or more wake-up indications before the SL DRX on phase. This may result in high power consumption at the Rx UE because the Rx UE must wake up frequently to monitor different scheduled SCIs from different Tx UEs for different communications. Certain aspects of the present disclosure relate to a sidelink DRX communication protocol managed by the Rx UE.

[0053] There are various use cases where an Rx UE can manage sidelink traffic to achieve greater power savings (e.g., resulting in less frequent wakeups) and better performance. In this way, the Rx UE can avoid half-duplex or hidden node issues that can impact sidelink performance. One use case may involve a UE being triggered to wake up to collect sensor-shared data from all other nearby UEs, e.g., when the UE is about to undergo a mobility trajectory change. Another use case may involve a pedestrian UE being triggered to wake up to obtain safety messages from all other nearby UEs, e.g., when the UE is about to cross a street. Another use case may include a roadside unit (RSU) sending a data pull request, e.g., for assisting sensing or positioning measurements from other UEs. Another use case may include calling a group leader or cluster leader for reports from UEs within a group or cluster. For these example use cases, it may be more efficient for power conservation if the Rx UE can enable (e.g., manage) sidelink traffic, e.g., initiating sidelink transmissions. Furthermore, it may be beneficial for overall performance if the Rx UE can also assist with resource selection for enabled sidelink transmissions, e.g., by providing possible resources or measurements.

[0054] Certain aspects of the present disclosure provide techniques for enabling sidelink transmissions for an Rx UE to reduce power consumption and improve performance. For example, certain aspects provide apparatus and methods for an Rx UE to enable sidelink transmissions, for example, to pull data from at least one Tx UE used for sidelink communication. Certain aspects also provide various design details for sending an enablement indication so that the Rx UE enables one or more sidelink transmissions. For example, a UE may participate in one or more sidelink communications with the same or different UEs. In this case, if the Rx UE can enable and disable sidelink services, for example, periodically (e.g., as configured) or aperiodically (e.g., triggered by an event) sending a transmission enablement indication to one (or more) Tx UEs, it may be more efficient for power saving, as described in more detail herein.

[0055] Figure 5 5 is a flow diagram illustrating example operations 500 for wireless communication in accordance with certain aspects of the present disclosure. Operations 500 may be performed, for example, by a first UE (e.g., such as UE 120a in wireless communication network 100 or UE 120t outside wireless communication network 100) (such as an Rx UE). An Rx UE generally refers to a UE that receives during a DRX on phase.

[0056] Operation 500 may be implemented as a process on one or more processors (e.g., Figure 2 In addition, the UE may transmit and receive signals in operation 500 by, for example, one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (eg, controller / processor 280) that obtain and / or output signals.

[0057] Operations 500 may begin at block 505 with a first UE (e.g., an Rx UE) determining whether to receive data for at least one application or service from one or more second UEs (e.g., Tx UEs) using at least one sidelink communication, and at block 510, transmitting at least one enable signal (e.g., also referred to herein as a transmit enable (TxEn) indication) instructing the one or more second UEs to transition to an active operating mode to transmit data. For example, the indication to transition to the active operating mode may include an indication to activate a transmit chain to transmit data from the one or more second UEs.

[0058] At block 515, the first UE may monitor for data in response to the at least one enable signal during a receive phase of the UE. In some aspects, the first UE may activate a receive chain to monitor for data during the receive phase of the first UE. In some aspects, the first UE may receive data for at least one application or service communicated using at least one sidelink from one or more second UEs during the receive phase of the first UE.

[0059] In some aspects, the first UE may receive an indication during a receive phase that no data is to be sent by one or more second UEs, and in response to the indication, deactivate the UE's receive chain to end the receive phase. The first UE may also send at least one disable signal to the one or more second UEs, the at least one disable signal indicating that the one or more second UEs can transition to an inactive operating state, as described in more detail herein.

[0060] In some aspects, at least one enable signal may be sent during a sidelink DRX On phase, and the first UE may extend the sidelink DRX On phase to monitor another transmission. When the extended sidelink DRX On phase expires, the first UE may send a transmission disable signal indicating that one or more second UEs can transition to an inactive operating state.

[0061] Figure 6 is a flow chart illustrating example operations 600 for wireless communication according to certain aspects of the present disclosure. Operations 600 may be understood as Figure 5 Operation 600 may be performed, for example, by a UE (e.g., such as UE 120a in the wireless communication network 100 or UE 120t outside the wireless communication network 100) (such as a Tx UE). A Tx UE generally refers to a UE that transmits during a DRX on phase.

[0062] Operation 600 may be implemented as a process on one or more processors (e.g., Figure 2 In addition, the UE may transmit and receive signals in operation 600, for example, through one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (eg, controller / processor 280) that obtain and / or output signals.

[0063] Operations 600 may begin at block 605 with a first UE (e.g., a Tx UE) receiving an enable signal from a second UE (e.g., a Rx UE) instructing the first UE to transition to an active operating mode to transmit data for at least one application or service using at least one sidelink communication. For example, the indication to transition to the active operating mode may include an indication to activate a transmit chain to transmit data.

[0064] At block 610, the first UE may determine, based on the enable signal, whether to transmit data to the second UE during a transmit phase. The first UE may activate a transmit chain to transmit data during the transmit phase of the first UE based on the determination. At block 615, the first UE may transmit data for at least one application or service to the second UE using at least one sidelink communication during the transmit phase based on the determination.

[0065] In some aspects, the first UE may transmit an indication that no data is to be transmitted during the transmit phase based on the determination.The first UE may then receive at least one disabling signal from the second UE indicating that the first UE can transition to an inactive operating state.

[0066] In certain aspects, an enable signal may be sent during a sidelink DRX-on phase. The first UE may send sidelink control information along with the data, which allocates resources for another transmission after the sidelink DRX-on phase. In this case, the first UE may extend the sidelink DRX-on phase (also the TX-on phase) to send another transmission.

[0067] Figure 7AA sidelink DRX protocol managed by an Rx UE using periodic enable signaling according to certain aspects of the present disclosure is shown. As shown, the Rx UE may periodically send a transmit enable (TxEn) indication, for example, utilizing the Rx UE's SL DRX cycle. The Rx UE may wake up and enter the SL DRX on phase and send TxEn to one (or more) Tx UEs to pull data during the SL DRX on phase (e.g., SL DRX on phases 760 and 762). The Rx UE decides whether to remain in RX active operating mode during the SL DRX on phase based on the Tx UE's response. When the Rx UE is in RX active 764 and 706, the UE's receive chain may be turned on, allowing the Rx UE to monitor SCI. Otherwise, the Rx UE may deactivate the Rx UE's receive chain to save power. The UE may determine to remain in RX activity 764 based on whether any data is pending (as indicated in the Tx UE's Sidelink Buffer Status Report (SL-BSR) 702) or whether any reservations are made for one (or more) transmissions or one (or more) retransmissions (as indicated in the Tx UE's Scheduled SCI 702). For example, the UE may determine that no further data transmission will occur during the SL DRX On phase (e.g., SL DRX On phase 762) and terminate the SL DRX On phase early, as shown. For example, the UE may receive an indication 704 that there is no further data to be sent or that pending data is not reported in the SL BSR, based on which the Rx UE may terminate the SL DRX On phase early. That is, the RX activity duration 706 may be less than the configured duration of the SL DRX On phase 762. In this case, the first UE may send a transmit disable signal indicating that one or more second UEs may transition to an inactive operating state before the end of the SL DRX On duration.

[0068] The Rx UE may decide whether to extend the active state at the end of the SL DRX On phase based on the response of the Tx UE, for example, whether any data is pending (as indicated in the Sidelink Buffer Status Report (SL-BSR)) or whether there are any reservations for one (or more) transmissions or one (or more) retransmissions (as indicated in the scheduling SCI). For example, if the SCI sent with the data 702 allocates resources for a retransmission after the SL DRX On phase 760, the SL DRX Inactivity Timer may be used to extend the SL DRX On phase 760 so that the Rx UE can monitor the retransmission, as shown. That is, the TxEn duration 764 (e.g., the RX Active Duration) may be longer than the duration of the SL DRX On phase 760. In this case, when there is only one second UE scenario, the first UE and the second UE can transition to the inactive operating state when the SL DRX on duration timer expires (i.e., ending the SL DRX on duration without extension) or when the SL DRX inactivity timer expires (i.e., ending the extension of the SL DRX on phase); when there are more second UEs, the first UE can send a transmission disable signal indicating that one or more second UEs are able to transition to the inactive operating state.

[0069] Figure 7BA sidelink DRX protocol managed by an Rx UE using aperiodic enable signaling according to certain aspects of the present disclosure is shown. For example, a TxEn indication 770 may be triggered by a higher layer of the UE (herein, until further description, the higher layer is the application layer, the V2X service layer, or the access stratum (AS) layer) or by detecting a wake-up indication from a Tx UE. That is, the Rx UE may receive a trigger to pull data from its higher layer (e.g., the application layer) or detect a wake-up indication from a Tx UE with available data, and then send "TxEn=1" to enable other Tx UEs to transmit data. The Rx UE decides to remain active (e.g., "TxEn=1") or not to remain active ("TxEn=0") based on the response of the Tx UE, for example, whether any data is pending (as indicated in the Tx UE's Sidelink Buffer Status Report (SL-BSR)) or whether there is any reservation for one (or more) transmissions or one (or more) retransmissions (as indicated in the Tx UE's Scheduling SCI). Alternatively, the Rx UE ends the TxEn duration 772 (active window, also referred to as the transmission enablement window) with another TxEn 774 ("TxEn=0") based on the Tx UE's response, for example, no data is pending (as indicated in its Sidelink Buffer Status Report (SL-BSR)) or no reservation for one (or more) transmissions or one (or more) retransmissions (as indicated in its Scheduling SCI). In the absence of a response from the Tx UE, the Rx UE may remain active for the minimum TxEn duration (if configured). For example, after sending the TxEn indication 708, no Tx UE may have data to send to the Rx UE, as shown. However, the Rx UE may remain active for the configured minimum TxEn duration 710, during which it may monitor the SCI.

[0070] Figure 8A and 8B A sidelink DRX protocol managed by an Rx UE for one (or more) unicast communications according to certain aspects of the present disclosure is shown. A UE may participate in one or more unicast communications with the same or different UEs. In this case, the UE may send a TxEn indication to the paired UE, such as Figure 8A As shown, or send one or more TxEn indications to multiple paired UEs, such as Figure 8B shown.

[0071] like Figure 8AAs shown in FIG, in step 0, a first UE (e.g., Rx UE) establishes a first PC5 radio resource control (RRC) link with a second UE (e.g., Tx UE1) for two unicasts, and a second PC5 RRC link with a third UE (e.g., Tx UE2). This includes setting up the sidelink DRX configuration (if available), transmission enablement configuration, and so on. In step 1, the first UE (e.g., Rx UE) enters the sidelink DRX on phase (if configured or triggered by higher layers to pull data) and decides to send a TxEn indication to Tx UE1. In step 2, the first UE (e.g., Rx UE1) sends TxEn1 to Tx UE1. In step 3, the second UE (e.g., Tx UE1) determines whether there is any data available for transmission. If no data is available, Tx UE1 remains in an inactive state. Otherwise, Tx UE1 may transmit data. For example, as shown in step 4, the second UE (e.g., Tx UE1) transmits data according to the TxEn indication. Tx UE1 may keep transmitting until the TxEn duration ends, as described herein. At step 5, the first UE (eg, Rx UE1) exits the SL DRX On phase or ends the TxEn duration (eg, TxEn phase) based on the response of Tx UE1.

[0072] As shown, the Rx UE may enter another SL DRX On phase (e.g., SL DRX On 2), which may be triggered by higher layers, as described. At step 7, the Rx UE may send a second TxEn indication (e.g., TxEn2) to Tx UE2, as shown. At step 8, Tx UE2 determines whether there is any data to be sent. For example, if Tx UE2 has no data to send, it may not send data at step 9, as shown. At step 10, the first UE (e.g., Rx UE1) exits the SL DRX On phase or ends the TxEn duration based on Tx UE2's response.

[0073] like Figure 8BAs shown in FIG, at step 0, a first UE (e.g., Rx UE) establishes a first PC5 RRC link with a second UE (e.g., Tx UE1) and a second PC5 RRC link with a third UE (e.g., Tx UE2) for two unicasts, respectively. This includes setting up the sidelink DRX configuration (if applicable), transmission enablement configuration, etc., as described. At step 1, the first UE (e.g., Rx UE) enters the sidelink DRX on-duration (if configured or triggered by higher layers for pulling data) and decides to send a TxEn indication to its UE pair. At step 2, the first UE (e.g., Rx UE1) sends a TxEn to each UE in its UE pair (e.g., TxEn1 to Tx UE1 and TxEn2 to Tx UE2), or sends a TxEn to all its UE pairs (e.g., TxEn to both Tx UE1 and Tx UE2). At steps 3A and 3B, the second UE (e.g., Tx UE1) or the third UE (e.g., Tx UE2) determines whether there is any data available for transmission. If there is no data, the Tx UE remains inactive. At steps 4A and 4B, the second UE (e.g., Tx UE1) or the third UE (e.g., Tx UE2) transmits data according to the TxEn indication. The Tx UE may continue transmitting until the TxEn duration ends. At step 5, the first UE (e.g., Rx UE1) exits the SL DRX On Duration or ends the TxEn duration based on the Tx UE's response.

[0074] Figure 9A and 9B A sidelink DRX protocol managed by an Rx UE for groupcast (e.g., group 1 or 2) or broadcast (e.g., service 1 or 2) communications according to certain aspects of the present disclosure is shown. A UE may participate in one or more groupcasts or broadcasts (e.g., services) with the same UE or different UEs. In this case, the Rx UE may send one (or more) TxEn indications to each group or service, such as Figure 9A As shown in , or send one or more TxEn indications to multiple groups or services, as shown in Figure 9BAs shown in . For example, at step 2, one (or more) TxEn indications may be sent to the Tx UEs of group 1 or service 1 during a first SL DRX on phase (e.g., SL DRX on 1). Each Tx UE of group 1 or service 1 may determine whether there is any data to be sent at step 3, and one or more Tx UEs of group 1 or service 1 may send data at step 4, as shown. During a second DRX on phase (e.g., SL DRX on 2), at step 7, one (or more) TxEn indications may be sent to the Tx UEs of group 2 or service 2. At step 8, each Tx UE of group 2 or service 2 may determine whether there is any data to be sent. At step 9, if the Tx UE does not have any data to be sent, the Tx UEs of group 2 or service 2 may not send data at step 9.

[0075] like Figure 9B As shown, during the same SL DRX on phase, one (or more) TxEn indications may be sent to both the Tx UEs of group 1 or service 1 and the Tx UEs of group 2 or service 2. As shown, each of the Tx UEs of group 1 or service 1 and group 2 or service 2 may determine whether there is any data to be sent at step 3, and send the data in sequence at steps 4A and 4B.

[0076] Figure 10 The transmission of a TxEn indication using a sequence-based design according to certain aspects of the present disclosure is shown. As shown, the Rx UE can send the same or different sequence-based TxEn indications to different Tx UEs. That is, the TxEn indication can be a sequence-based signaling (e.g., a Zadoff-Chu (ZC) sequence) sent at the physical layer and at the last few symbols of the time slot (e.g., a 1-bit sequence with TxEn=1 for enabling transmission and TxEn=0 (also known as a disable signal) for disabling transmission) (e.g., as shown in FIG. Figure 101002). The TxEn indication may include the identities of the Rx UE and Tx UE (e.g., an identifier (ID) or source ID of the Rx UE, an ID of the Tx UE, or a destination ID of a UE pair, group, or service, etc.) within the initial value or cyclic shift of the sequence. All Tx UEs may monitor the TxEn indication at monitoring opportunities according to the TxEn configuration and decide whether to wake up to transmit data based on whether there is any data available in their buffers during the time interval (e.g., the Transmission Enabled Duration) during which the Rx UE is pulling data, which is triggered by a wake-up indication from a higher layer or the Tx UE or during the SL DRX On phase. For example, TxEn1 may pull data from a UE in a pair using unicast, from a UE in a group using multicast, or from a UE in a service using broadcast during TxEn duration 1002, and TxEn2, TxEn3, TxEn4, and TxEn5 may pull data from a UE in a pair, group, or service during TxEn duration 1004, as shown.

[0077] In some aspects, the TxEn indication may be sent at different resource locations at the last few symbols of the slot, e.g., Figure 10 The sequence may include at least an Rx UE ID (e.g., an ID of the Rx UE or a source ID) within an initial value or a cyclic shift value, and a transmission position (e.g., resource allocation) may be mapped with a Tx UE ID or a destination ID of a UE pair, group, or service (so that the Tx UE can monitor the TxEn at the corresponding position).

[0078] Different sequence-based TxEn indications can be code division multiplexed (CDMed) with different initial sequences or different cyclic shifts for different Tx UEs (e.g., TxEn1). One (or more) Tx UEs blindly detect each TxEn indication using different initial sequences or cyclic shifts associated with different Tx UEs. In some cases, the TxEn indications can be frequency division multiplexed (e.g., TxEn2 and TxEn3, TxEn4 and TxEn5) or time division multiplexed (TDMed) (e.g., TxEn2 and TxEn4, TxEn3 and TxEn5), or can be sent using a combination of FDM, TDM, and CDM. One (or more) Tx UEs detect each TxEn indication at a different resource allocation. If CDM is used for combining, the Tx UEs blindly detect each TxEn indication at a different resource allocation.

[0079] Figure 11The figure illustrates the transmission of a TxEn indication using an SCI-based design according to certain aspects of the present disclosure. As shown, an Rx UE can use the SCI to send different TxEn indications to a Tx UE. For an Rx UE that sends TxEn indications to different Tx UEs, the TxEn indication can be SCI-based signaling at the physical layer and sent at the start symbol of a time slot (e.g., TxEn1 and TxEn2) or at the end symbol of a time slot (e.g., TxEn3, TxEn4, TxEn5, TxEn6), as shown. The TxEn indication can be included in various SCI fields within one phase of the SCI or across two phases of the SCI. The various SCI fields may include: both Rx UE ID and Tx UE ID (e.g., Rx UE's ID or source ID, Tx UE's ID or destination ID, etc.); TxEn duration, e.g., the time interval for the transmission enabling window or the number of SL DRX cycles (e.g., quantity); the location and communication range of the Rx UE (e.g., the range to which the TxEn indication applies); selected resources for transmission or blocked resources for transmission (assistance from the Rx UE); sidelink carrier indication and / or sidelink bandwidth part (SLBWP) indication; measurements such as CBR, RSRP, RSSI, or SINR from the Rx UE; or any combination thereof. All Tx UEs can monitor one (or more) TxEn indications at monitoring opportunities according to the TxEn configuration and decide whether to wake up to transmit data based on whether the Tx UE's ID is indicated, whether any data is available in the buffer during the time interval (e.g., TxEn duration), and whether the Tx UE is within communication range (e.g., as indicated by the SCI field from the Rx UE and determined based on the Rx UE's location). Different SCI-based TxEn indications can be frequency-division multiplexed (e.g., TxEn1 and TxEn2, TxEn3 and TxEn5) or time-division multiplexed (e.g., TxEn3 and TxEn5, TxEn4 and TxEn6), or combined with both FDM and TDM. One (or more) Tx UEs detect each TxEn indication at a different resource allocation.

[0080] Figure 12The transmission of a TxEn indication using a design based on a Medium Access Control (MAC) Control Element (CE) according to certain aspects of the present disclosure is shown. An Rx UE can use a MAC CE to send different TxEn indications to a Tx UE. For example, TxEn2 can be sent to a Tx UE using MAC CE 1220 on a sidelink data channel with an SCI, as shown. For an Rx UE to send a TxEn indication to different Tx UEs, the TxEn indication can be based on a MAC CE at the MAC layer and sent in a time slot before the TxEn duration, as shown. The TxEn indication can include the following information within a single SCI phase or across two phases of the SCI: both the Rx UE ID and the Tx UE ID (e.g., the Rx UE ID or source ID, the Tx UE ID or destination ID, etc.); the Rx UE's location and communication range; selected resources for transmission or blocked resources for transmission; a sidelink carrier indication and / or a sidelink bandwidth part (SL BWP) indication; or any combination thereof.

[0081] The TxEn indication may contain more information with different MAC CEs or MAC CE fields, such as the active TxEn interval during which each Tx UE will transmit data (e.g., Tx1 on phase for the first Tx UE and Tx2 phase for the second Tx UE), selected or blocked resources, and / or channel quality measurements (CBR, RSRP, RSSI, or SINR). All Tx UEs may monitor one (or more) TxEn indications at monitoring opportunities according to the TxEn configuration and decide whether to wake up to transmit data based on whether the Tx UE's ID is indicated, whether there is any data available in the buffer during the TxEn duration of the Tx UE, whether the Tx UE is within communication range, and whether the indicated resources can be used. Different MAC CE-based TxEn indications can be frequency-division multiplexed (e.g., TxEn1 and TxEn2, TxEn3 and TxEn4) or time-division multiplexed (e.g., TxEn3 and TxEn5, TxEn4 and TxEn6), or combined using both FDM and TDM. One (or more) Tx UEs detect each TxEn at different resource allocations.

[0082] Figure 13 The diagram shows that a method may include operations configured to perform the techniques disclosed herein (such as Figure 5 and 613. The communication device 1300 includes various components (e.g., corresponding to means plus functional components) of FIG. 13. The communication device 1300 includes a processing system 1302 coupled to a transceiver 1308. The transceiver 1308 is configured to transmit and receive signals for the communication device 1300, such as the various signals described herein, via an antenna 1310. The processing system 1302 may be configured to perform processing functions for the communication device 1300, including processing signals received and / or to be transmitted by the communication device 1300.

[0083] The processing system 1302 includes a processor 1304 coupled to a computer-readable medium / memory 1312 via a bus 1306. In some aspects, the computer-readable medium / memory 1312 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1304, cause the processor 1304 to perform Figure 5 and 6 . In some aspects, computer-readable medium / memory 1312 stores code for determining 1314; code for transmitting 1316; code for monitoring / receiving 1318; and code for activating / deactivating 1320. In some aspects, processor 1304 has circuitry configured to implement the code stored in computer-readable medium / memory 1312. Processor 1304 includes circuitry for determining 1322; code for transmitting 1324; code for monitoring / receiving 1326; and code for activating / deactivating 1330.

[0084] Example aspects

[0085] Aspect 1. A method for wireless communication by a first user equipment (UE), comprising: determining whether to receive data for at least one application or service from one or more second UEs using at least one sidelink communication; sending at least one enabling signal instructing the one or more second UEs to switch to an active operating mode to send the data; and monitoring the data in response to the at least one enabling signal during a reception phase of the UE for the at least one application or service using the at least one sidelink communication.

[0086] Aspect 2. The method according to aspect 1, wherein the indication regarding transitioning to the active operating mode comprises: an indication regarding activating a transmit chain to send the data from the one or more second UEs.

[0087] Aspect 3. The method according to any one of aspects 1-2 further includes: activating a reception chain to monitor the data during the reception phase of the first UE.

[0088] Aspect 4. The method according to any one of aspects 1-3 further includes: receiving the data from the one or more second UEs during the reception phase of the first UE.

[0089] Aspect 5. The method according to any one of Aspects 1-4 further includes: receiving an indication during the receiving phase that the one or more second UEs have no data to send; and deactivating the receiving chain of the UE in response to the indication to end the receiving phase.

[0090] Aspect 6. The method according to aspect 5 further includes: sending at least one disabling signal to the one or more second UEs, the at least one disabling signal indicating that the one or more second UEs can transition to an inactive operating state.

[0091] Aspect 7. The method according to any one of aspects 1-6 further includes: receiving a wake-up signal from a third UE, wherein the sending of the at least one enable signal is in response to the wake-up signal.

[0092] Aspect 8. The method according to aspect 7, wherein the third UE is a second UE among the one or more second UEs.

[0093] Aspect 9. The method according to any one of aspects 1-8, wherein the sending of the at least one enabling signal is in response to a trigger from a higher layer of the UE.

[0094] Aspect 10. The method according to aspect 9, wherein the higher layer comprises an application layer of the UE.

[0095] Aspect 11. The method according to any one of aspects 1-10, wherein the at least one enabling signal is sent during a sidelink discontinuous reception (DRX) on phase.

[0096] Aspect 12. The method according to Aspect 11 further includes: receiving control information together with the data, the control information allocating resources for another transmission after the sidelink DRX on phase, and the method further includes: extending the sidelink DRX on phase to monitor the another transmission.

[0097] Aspect 13. The method according to aspect 12, wherein the another transmission comprises a retransmission of the data.

[0098] Aspect 14. A method according to any one of Aspects 1-13, wherein the one or more second UEs include multiple UEs, and wherein sending the at least one enabling signal includes: sending a first enabling signal to one of the multiple UEs during a first DRX on phase; and sending a second enabling signal to another UE of the multiple UEs during a second DRX on phase.

[0099] Aspect 15. A method according to any one of Aspects 1-14, wherein the one or more second UEs include multiple UEs, and wherein sending the at least one enabling signal includes: sending an enabling signal to each of the multiple UEs during a sidelink DRX on phase.

[0100] Aspect 16. A method according to any one of Aspects 1-15, wherein the one or more second UEs include a first UE set associated with a group or service and a second UE set associated with another group or another service, and wherein sending the at least one enabling signal includes: sending at least one first enabling signal to the first UE set during a first sidelink DRX on phase; and sending at least one second enabling signal to the second UE set during a second sidelink DRX on phase.

[0101] Aspect 17. A method according to any one of Aspects 1-16, wherein the one or more second UEs include a first UE set associated with a group or service and a second UE set associated with another group or another service, and wherein the at least one enabling signal is sent to the first UE set and the second UE set during a sidelink DRX on phase.

[0102] Aspect 18. The method according to any one of Aspects 1-17, wherein sending the at least one enabling signal comprises sending a plurality of enabling signals, and the plurality of enabling signals are multiplexed in at least one of the following ways: code division multiplexing, frequency division multiplexing, or time division multiplexing.

[0103] Aspect 19. The method according to any one of aspects 1-18, wherein each of the at least one enabling signal comprises a sequence associated with a service, a UE group, or a UE pair.

[0104] Aspect 20. The method according to any one of aspects 1-19, wherein the at least one enabling signal is included in at least one sidelink control information (SCI) or medium access control (MAC) control element (CE).

[0105] Aspect 21. A method according to any one of Aspects 1-20, wherein each of the at least one enabling signal indicates at least one of the following: an identifier of the first UE; an identifier of a corresponding second UE among the one or more second UEs; the duration of a transmission enabling window during which the data will be sent; the number of sidelink DRX cycles to be used for sending the data; the location of the first UE; resources for sending the data; resources blocked for sending the data; an indication of a sidelink carrier for sending the data; an indication of a sidelink bandwidth part (SL BWP) for sending the data; or a channel quality measurement.

[0106] Aspect 22. A method for wireless communication by a first user equipment (UE), comprising: receiving an enable signal from a second UE instructing the first UE to switch to an active operating mode to utilize at least one sidelink communication to send data for at least one application or service; determining whether to send data to the second UE during a sending phase based on the enable signal; and based on the determination, sending the data for the at least one application or service to the second UE during the sending phase using the at least one sidelink communication.

[0107] Aspect 23. The method of aspect 22, wherein the indication to transition to the active operating mode comprises an indication to activate a transmit chain to transmit the data.

[0108] Aspect 24. The method according to any one of aspects 22-23 further comprises: based on the determination, activating a transmit chain during the transmit phase of the first UE to transmit the data.

[0109] Aspect 25. The method according to any one of aspects 22-24 further includes: based on the determination, sending the data to the second UE during the transmission phase.

[0110] Aspect 26. The method according to any one of aspects 22-25 further comprises: based on the determination, sending an indication that there is no data to send during the sending phase.

[0111] Aspect 27. The method according to aspect 26 further includes: receiving at least one disabling signal from the second UE, the at least one disabling signal indicating that the first UE can transition to an inactive operating state.

[0112] Aspect 28. The method according to any one of aspects 22-27, wherein the enabling signal is sent during a sidelink discontinuous reception (DRX) on phase.

[0113] Aspect 29. The method according to Aspect 28 further includes: sending control information together with the data, the control information allocating resources for another transmission after the sidelink DRX on phase, and the method further includes: extending the sidelink DRX on phase to send the another transmission.

[0114] Aspect 30. The method of aspect 29, wherein the another transmission comprises a retransmission of the data.

[0115] Aspect 31. The method according to any one of aspects 22-30, wherein the enabling signal is multiplexed with one or more other enabling signals by at least one of the following methods: code division multiplexing, frequency division multiplexing, or time division multiplexing.

[0116] Aspect 32. The method according to any one of aspects 22-31, wherein the enabling signal comprises a sequence associated with a service, a UE group, or a UE pair.

[0117] Aspect 33. The method according to any one of aspects 22-32, wherein the enabling signal is included in at least one sidelink control information (SCI) or medium access control (MAC) control element (CE).

[0118] Aspect 34. A method according to any one of Aspects 22-33, wherein the enabling signal indicates at least one of: an identifier of the second UE; an identifier of the first UE; the duration of a transmission enabling window during which the data will be sent; the number of sidelink DRX cycles to be used for sending the data; the location of the UE; resources for sending the data; resources blocked for sending the data; an indication of a sidelink carrier for sending the data; an indication of a sidelink bandwidth part (SL BWP) for sending the data; or a channel quality measurement.

[0119] Aspect 35. The method according to any one of Aspects 22-34 further includes: determining whether the first UE is within the communication range with the second UE based on the location of the second UE, and the method further includes: ignoring the enabling signal if the first UE is not within the communication range.

[0120] The techniques described herein can be used for various wireless communication technologies such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), 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 IS-2000, IS-95, and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (WiFi), 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). LTE and 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). NR is an emerging wireless communication technology under development.

[0121] The techniques described herein can 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 terms commonly associated with 3G, 4G, and / or 5G wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations.

[0122] In 3GPP, the term "cell" can refer to the coverage area of a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and "base station," next-generation Node B (gNB or gNodeB), access point (AP), distributed unit (DU), carrier, or transmit / receive point (TRP) are used interchangeably. A base station (BS) can provide communication coverage for macrocells, picocells, femtocells, and / or other types of cells. A macrocell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access to UEs with service subscriptions. A picocell can cover a relatively small geographic area and can allow unrestricted access to UEs with service subscriptions. A femtocell can cover a relatively small geographic area (e.g., a home) and can allow restricted access to UEs associated with the femtocell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). A base station for a macrocell can be referred to as a macro BS. A base station for a picocell can be referred to as a pico BS. A base station for a femtocell can be referred to as a femto BS or a home BS.

[0123] 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 smartphone, 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 medical equipment, 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 device, 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 can communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node can provide, for example, a connection to a network (e.g., a wide area network such as the Internet or a cellular network) or to a network via a wired or wireless communication link. Some UEs can be considered Internet of Things (IoT) devices, which can be narrowband IoT (NB-IoT) devices.

[0124] 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 (referred to as 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 can also be divided into subbands. For example, a subband may cover 1.8 MHz (e.g., 6 RBs), 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.In LTE, the basic transmission time interval (TTI) or packet duration is a 1 ms subframe.

[0125] NR can utilize OFDM with CP on both the uplink and downlink and includes support for half-duplex operation using TDD. In NR, the subframe is still 1ms, but the basic TTI is called a slot. Depending on the subcarrier spacing, a subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, ... slots). An NR RB is 12 contiguous frequency subcarriers. NR can support a basic subcarrier spacing of 15kHz, and other subcarrier spacings can be defined relative to this basic subcarrier spacing, such as 30kHz, 60kHz, 120kHz, 240kHz, etc. Symbol and slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing. Beamforming can be supported, and the beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. In some examples, MIMO configurations in the DL can support up to 8 transmit antennas, with multi-layer DL transmission of up to 8 streams and up to 2 streams per UE. In some examples, multi-layer transmission with up to 2 streams per UE can be supported. Aggregation of multiple cells with up to 8 serving cells can be supported.

[0126] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., BS) allocates resources for communicating between 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, the subordinate entities utilize the resources assigned by the scheduling entity. The base station is not the only entity that can be used 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 the 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.

[0127] In some examples, two or more subordinate entities (e.g., UEs) can communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical grids, and / or various other suitable applications. Generally, a sidelink signal can refer to a signal that is transmitted from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be used for scheduling and / or control purposes. In some examples, the sidelink signal can be transmitted using licensed spectrum (unlike wireless local area networks that typically use unlicensed spectrum).

[0128] 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. That is, 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.

[0129] 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. As an example, "at least one of: a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0130] As used herein, the term "determining" includes a variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or another data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Furthermore, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0131] The previous description is provided to enable those skilled in the art to practice 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 may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but should be given the full scope consistent with the language of the claims, wherein, unless otherwise specified, reference to an element in the singular is not intended to mean "one and only one", but rather "one or more". Unless otherwise specifically 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 that are known or will later be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, the content disclosed herein is not intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. No claim element should be interpreted according to the provisions of 35 U.S.C. § 112(f) unless the element is explicitly stated using the phrase "unit for..." or, in the case of a method claim, the phrase "step for..." is used to state the element.

[0132] The various operations of the above method can be performed by any appropriate unit that can perform the corresponding function. The unit 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, when there are operations shown in the figures, those operations can have corresponding corresponding units plus functional components with similar numbers.

[0133] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or performed with 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, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

[0134] 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. The bus interface may be used to connect a network adapter, etc., to the processing system via the bus. The network adapter may be used to implement the signal processing functions of 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 link 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 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 capable of executing software. Those skilled in the art will recognize how best to implement the described functionality of the processing system, which depends on the specific application and the overall design constraints imposed on the entire system.

[0135] If implemented in software, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Software should be broadly interpreted to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms. Computer-readable media include 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 executing 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 the storage medium and write information to the storage medium. In an alternative, the storage medium may be integrated into the processor. As an 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 that is separate from the wireless node, all of which can be accessed by the processor via a bus interface. Alternatively or additionally, the machine-readable medium or any portion thereof may be integrated into the processor, for example, in the case of a cache and / or general register file. As examples, 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. The machine-readable medium may be embodied in a computer program product.

[0136] A software module may include a single instruction or many instructions and may be distributed across several different code segments, in 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 transmission module and a reception module. Each software module may reside in a single storage device or be distributed across multiple storage devices. As an example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During execution of a software module, the processor may load some 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 instructions from that software module are executed.

[0137] 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. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks reproduce data optically using lasers. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, 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.

[0138] 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 stored thereon (and / or encoded thereon) instructions, the instructions being executable by one or more processors to perform the operations described herein, e.g., instructions for performing the operations described herein.

[0139] In addition, 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, as applicable. For example, such a device can be coupled to a server to facilitate the transfer 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 after coupling or providing the storage unit to the device. In addition, any other suitable technology for providing the methods and techniques described herein to a device can be utilized.

[0140] It should be understood, however, that the claims are not limited to the precise configuration and components illustrated above, and that 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 first user equipment (UE), comprising: determining whether to receive data for at least one application or service from one or more second UEs using at least one sidelink communication; In response to a trigger from a higher layer, transmitting at least one enabling signal instructing the one or more second UEs to transition to an active operation mode to transmit the data, the higher layer comprising an application layer, a vehicle-to-everything (V2X) service layer, or an access stratum (AS) layer; as well as monitoring, during a reception phase of the first UE, for the at least one application or service, for the data in response to the at least one enabling signal using the at least one sidelink communication, Wherein, the method further comprises: receiving, during the receiving phase, an indication that the one or more second UEs have no data to send; In response to the indication that the one or more second UEs have no data to send, deactivating a receive chain of the first UE to end the receive phase; and In response to the indication that the one or more second UEs have no data to send, at least one disabling signal is sent to the one or more second UEs, the at least one disabling signal indicating that the one or more second UEs can transition to an inactive operating state.

2. The method according to claim 1, wherein The indication to transition to the active mode of operation includes an indication to activate a transmit chain to send the data from the one or more second UEs.

3. The method according to claim 1, further comprising: activating a receive chain during the receive phase of the first UE to monitor the data; as well as The data is received from the one or more second UEs during the reception phase of the first UE.

4. The method according to claim 1, wherein The indication that there is no data to send comprises a sidelink buffer status report.

5. The method according to claim 1, further comprising: A wake-up signal is received from a third UE, wherein the sending of the at least one enable signal is in response to the wake-up signal, wherein the third UE is one of the one or more second UEs.

6. The method according to claim 1, further comprising: In case no response is received from the one or more second UEs, remaining active for a configured minimum transmission enabled duration.

7. The method according to claim 1, wherein The one or more second UEs include a plurality of UEs, wherein sending the at least one enabling signal includes: sending a first enabling signal to one of the plurality of UEs during a first DRX on phase; and A second enabling signal is sent to another UE of the plurality of UEs during a second DRX on phase.

8. The method according to claim 7, further comprising: receiving, along with the data, control information allocating resources for another transmission from one of the one or more second UEs after the sidelink DRX on phase; as well as The sidelink DRX on phase is extended to monitor the other transmission from the one of the one or more second UEs, wherein the other transmission includes a retransmission of the data.

9. The method according to claim 1, wherein The one or more second UEs include a first set of UEs associated with a group or service and a second set of UEs associated with another group or another service, and wherein sending the at least one enabling signal includes: sending at least one first enabling signal to the first set of UEs during a first sidelink DRX on phase; and At least one second enabling signal is sent to the second set of UEs during a second sidelink DRX on phase.

10. The method according to claim 1, wherein Sending the at least one enabling signal includes sending a plurality of enabling signals, wherein the plurality of enabling signals are multiplexed in at least one of the following ways: code division multiplexing, frequency division multiplexing, or time division multiplexing.

11. The method according to claim 1, wherein Each of the at least one enabling signal comprises a sequence associated with a service, a UE group, or a UE pair.

12. The method according to claim 1, wherein The at least one enabling signal is included in at least one sidelink control information (SCI) or medium access control (MAC) control element (CE).

13. The method according to claim 1, wherein Each of the at least one enable signal indicates at least one of the following: an identifier of the first UE; an identifier of a corresponding one of the one or more second UEs; the duration of a transmission enabled window during which the data is to be sent; the number of sidelink DRX cycles to be used for sending the data; a location of the first UE; resources for transmitting said data; resources that are blocked from sending said data; an indication of a sidelink carrier to be used for transmitting the data; an indication of a sidelink bandwidth part (SL BWP) for transmitting the data; or Channel quality measurement.

14. A method for wireless communication by a first user equipment (UE), comprising: receiving an enablement signal from a second UE instructing the first UE to transition to an active mode of operation to transmit data for at least one application or service utilizing at least one sidelink communication; determining whether to transmit data to the second UE during a transmit phase based on the enable signal; as well as Based on the determination, transmitting the data for the at least one application or service to the second UE using the at least one sidelink communication during the transmission phase, The method further comprises: Based on determining that there is no data to be sent to the second UE during the transmission phase, sending an indication that there is no data to be sent during the transmission phase; and At least one disabling signal based on the indication that there is no data to send is received from the second UE, the at least one disabling signal indicating that the first UE can transition to an inactive operating state.

15. The method according to claim 14, wherein The indication to transition to the active mode of operation includes an indication to activate a transmit chain to send the data during the transmit phase of the first UE based on the determination.

16. The method according to claim 14, wherein said indication that there is no data to send comprises a sidelink buffer status report, or The enabling signal is sent during a sidelink discontinuous reception (DRX) on phase of the second UE, or The activation signal is sent by the second UE in response to a trigger from a higher layer, and the higher layer includes an application layer, a vehicle-to-everything (V2X) service layer, or an access stratum (AS) layer.

17. The method according to claim 14, wherein: The enabling signal is multiplexed with one or more other enabling signals by at least one of the following methods: code division multiplexing, frequency division multiplexing, or time division multiplexing.

18. The method according to claim 17, further comprising: sending control information together with the data, the control information allocating resources for another transmission after the sidelink DRX on phase; as well as The sidelink DRX on phase is extended to send the another transmission, wherein the another transmission includes a retransmission of the data.

19. The method according to claim 14, further comprising: determining whether the first UE is within communication range with the second UE based on the location of the second UE; as well as If the first UE is not within the communication range, the enabling signal is ignored.

20. A first user equipment (UE) configured for wireless communication, comprising: a memory comprising computer-executable instructions; as well as a processor configured to execute the computer-executable instructions and cause the first UE to perform the following operations: determining whether to receive data for at least one application or service from one or more second UEs using at least one sidelink communication; In response to a trigger from a higher layer, transmitting at least one enabling signal instructing the one or more second UEs to transition to an active operation mode to transmit the data, the higher layer comprising an application layer, a vehicle-to-everything (V2X) service layer, or an access stratum (AS) layer; as well as monitoring, during a reception phase of the first UE, for the at least one application or service, for the data in response to the at least one enabling signal using the at least one sidelink communication, The processor is configured to execute the computer-executable instructions and further cause the first UE to perform the following operations: receiving, during the receiving phase, an indication that the one or more second UEs have no data to send; In response to the indication that the one or more second UEs have no data to send, deactivating a receive chain of the first UE to end the receive phase; as well as In response to the indication that the one or more second UEs have no data to send, at least one disabling signal is sent to the one or more second UEs, the at least one disabling signal indicating that the one or more second UEs can transition to an inactive operating state.

21. The first UE according to claim 20, wherein: The indication to transition to the active mode of operation includes an indication to activate a transmit chain to send the data from the one or more second UEs.

22. The first UE according to claim 20, wherein: The processor is configured to execute the computer-executable instructions and further cause the first UE to perform the following operations: activating a receive chain during the receive phase of the first UE to monitor the data; and The data is received from the one or more second UEs during the reception phase of the first UE.

23. The first UE according to claim 20, wherein: The indication that there is no data to send comprises a sidelink buffer status report.

24. The first UE according to claim 20, wherein: The processor is configured to execute the computer-executable instructions and further cause the first UE to perform the following operations: receive a wake-up signal from a third UE, wherein the sending of the at least one enabling signal is in response to the wake-up signal, wherein the third UE is a second UE among the one or more second UEs.

25. The first UE according to claim 20, wherein: The processor is configured to execute the computer-executable instructions and further cause the first UE to perform the following operations: In case no response is received from the one or more second UEs, remaining active for a configured minimum transmission enabled duration.

26. The first UE according to claim 20, wherein: The one or more second UEs include a plurality of UEs, wherein the processor is configured to execute the computer-executable instructions and cause the first UE to send the at least one enabling signal, comprising: the processor is configured to execute the computer-executable instructions and cause the first UE to perform the following operations: sending a first enabling signal to one of the plurality of UEs during a first DRX on phase; and A second enabling signal is sent to another UE of the plurality of UEs during a second DRX on phase.

27. The first UE according to claim 26, wherein: The processor is configured to execute the computer-executable instructions and further cause the first UE to perform the following operations: receiving, along with the data, control information allocating resources for another transmission from one of the one or more second UEs after the sidelink DRX on phase; as well as The sidelink DRX on phase is extended to monitor the other transmission from the one of the one or more second UEs, wherein the other transmission includes a retransmission of the data.

28. The first UE according to claim 20, wherein: The one or more second UEs include a first set of UEs associated with a group or service and a second set of UEs associated with another group or another service, and wherein the processor is configured to execute the computer-executable instructions and cause the first UE to send the at least one enabling signal includes: the processor is configured to execute the computer-executable instructions and cause the first UE to perform the following operations: sending at least one first enabling signal to the first set of UEs during a first sidelink DRX on phase; and At least one second enabling signal is sent to the second set of UEs during a second sidelink DRX on phase.

29. The first UE according to claim 20, wherein: The processor is configured to execute the computer-executable instructions and cause the first UE to send the at least one enabling signal, including: the processor is configured to execute the computer-executable instructions and cause the first UE to perform the following operations: sending multiple enabling signals, and the multiple enabling signals are multiplexed in at least one of the following ways: code division multiplexing, frequency division multiplexing or time division multiplexing.

30. A first user equipment (UE) configured for wireless communication, comprising: a memory comprising computer-executable instructions; as well as a processor configured to execute the computer-executable instructions and cause the first UE to perform the following operations: receiving an enablement signal from a second UE instructing the first UE to transition to an active mode of operation to transmit data for at least one application or service utilizing at least one sidelink communication; determining whether to transmit data to the second UE during a transmit phase based on the enable signal; as well as Based on the determination, transmitting the data for the at least one application or service to the second UE using the at least one sidelink communication during the transmission phase; The processor is configured to execute the computer-executable instructions and further cause the first UE to perform the following operations: sending an indication that there is no data to send during the transmission phase based on determining that there is no data to send to the second UE during the transmission phase; as well as At least one disabling signal based on the indication that there is no data to send is received from the second UE, the at least one disabling signal indicating that the first UE can transition to an inactive operating state.

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