WO2022151311A1

WO2022151311A1 - Discontinuous reception configuration for sidelink operation

Info

Publication number: WO2022151311A1
Application number: PCT/CN2021/072022
Authority: WO
Inventors: Boyuan ZHANG; Wei Luo; Mengzhen WANG; Lin Chen
Original assignee: Zte Corporation
Priority date: 2021-01-15
Filing date: 2021-01-15
Publication date: 2022-07-21

Abstract

Systems, methods and apparatus for wireless communication are described. One example method of wireless communication includes transmitting, by a first wireless device to a second wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for. The DRX evaluation timer may modify a property of an active reception cycle from a normal DRX operation.

Description

DISCONTINUOUS RECEPTION CONFIGURATION FOR SIDELINK OPERATION

TECHNICAL FIELD

This document is directed generally to wireless communications.

BACKGROUND

Wireless communication technologies are moving the world toward an increasingly connected and networked society. The rapid growth of wireless communications and advances in technology has led to greater demand for capacity and connectivity. Other aspects, such as energy consumption, device cost, spectral efficiency, and latency are also important to meeting the needs of various communication scenarios. In comparison with the existing wireless networks, next generation systems and wireless communication techniques need to provide support for an increased number of users and devices, as well as support an increasingly mobile society.

SUMMARY

This document relates to methods, systems, and devices for allocating preconfigured resources in mobile communication technology, including 5th Generation (5G) , and new radio (NR) communication systems.

In one exemplary aspect, a wireless communication method is disclosed. The method includes transmitting, by a first wireless device to a second wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for.

In another exemplary aspect, a wireless communication method is disclosed. The method includes receiving, by a second wireless device from a first wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for, and determining whether to use the DRX evaluation timer for further operations.

In another exemplary aspect, a wireless communication method is disclosed. The method includes transmitting, by a second wireless device to a first wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer to be used by the first wireless device.

In another exemplary aspect, a wireless communication method is disclosed. The method includes receiving, by a first wireless device from a second wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer to be used by the first wireless device; and determining whether to use the DRX evaluation timer for further operations.

In another exemplary aspect, a wireless communication method is disclosed. The method includes transmitting, by a network node to a wireless device, one or more semi-static timer configurations that include information for one or more discontinuous reception (DRX) evaluation timers by the wireless device.

In yet another exemplary aspect, the above-described methods are embodied in the form of a computer-readable medium storing processor-executable code for implementing the methods.

In yet another exemplary embodiment, a device that is configured or operable to perform the above-described methods is disclosed. The device may include a processor and/or a transceiver.

The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows examples of sidelink communication system configurations.

FIG. 2 shows an example of operation of a timer offset indication.

FIG. 3 shows an example of a timer configuration procedure triggered from a receiving UE.

FIG. 4 shows an example of operation of a feedback of a timer configuration.

FIG. 5 shows an example of a timer configuration procedure triggers by a transmitting UE.

FIG. 6 shows a flowchart of an example method of wireless communication.

FIG. 7 shows a flowchart of an example method of wireless communication.

FIG. 8 shows a flowchart of an example method of wireless communication.

FIG. 9 shows a flowchart of an example method of wireless communication.

FIG. 10 shows a flowchart of an example method of wireless communication.

FIG. 11 is a block diagram representation of a portion of an apparatus that can be used to implement methods and/or techniques of the presently disclosed technology.

FIG. 12 shows an example of a base station (BS) and user equipment (UE) in wireless communication.

DETAILED DESCRIPTION

Section headings are used in the present document only to improve readability and do not limit scope of the disclosed embodiments and techniques in each section to only that section. Certain features are described using the example of Fifth Generation (5G) wireless protocol. However, applicability of the disclosed techniques is not limited to only 5G wireless systems.

In the field of wireless communication, with the rapid development of smart terminals and mobile Internet applications, users have increasingly higher requirements for user experience, high speed, and large data volume availability from the wireless networks. The traditional cellular network with base station as the data transfer node center has obvious limitations in terms of high data rate and proximity service support. Due to this demand, Sidelink technology, which represents the new direction of future communication technology development, has emerged. The technology is also commonly referred to as ProSe technology. The application of Sidelink technology can reduce the burden on the cellular network, reduce the battery power consumption of user equipment, increase the data rate, and improve the robustness of the network infrastructure, which satisfies the requirements of the above-mentioned high data rate services and proximity services.

Sidelink technology usually includes Sidelink discovery technology and Sidelink communication technology.

Sidelink discovery technology refers to the method used to determine/determine the proximity between two or more Sidelink user equipment (for example, within the range where Sidelink direct communication is possible) or to determine/determine that the first user equipment is adjacent to the second user equipment technology. Generally, Sidelink user equipment can discover each other by sending or receiving discovery signals/information. Under the coverage of a cellular network, the network can assist Sidelink user equipment in Sidelink discovery.

Sidelink communication technology refers to a technology in which part or all of the communication data between Sidelink user equipment can be directly communicated (or through a relay device) without going through the network infrastructure.

Sidelink technology can work in licensed or unlicensed frequency bands, allowing multiple user devices that support the Sidelink function to perform direct discovery/direct communication with or without network coverage. Referring to FIG. 1, where different configurations of wireless devices (called UE or user equipment) there are three main types for Sidelink application use cases:

1) UE1 and UE2 perform Sidelink discovery or communication under the coverage of the cellular network, and the user plane data does not pass through the network infrastructure, as shown in use case 1 in FIG. 1. This use case can further include the following two branchs:

(a) Sidelink discovery: It can be further divided into open Sidelink discovery and restricted Sidelink discovery.

(b) Sidelink communication: It can be further divided into Sidelink broadcast communication, Sidelink multicast communication, and Sidelink unicast communication.

UE-to-Network Relay transmission in weak/uncovered areas, as shown in Use Case 2 in the figure below, allows UE4 with poor signal quality to communicate with the network through nearby UE3 with network coverage, which can help operators Expand coverage and increase capacity.

2) In the event of an earthquake or emergency, and the cellular network cannot work normally, multi-hop communication between devices (UE-to-UE Relay) is allowed, as shown in Use Case 3 in FIG. 1, the control plane and user between UE5, UE6 and UE7 One-hop or multi-hop data communication without going through the network infrastructure.

Service continuity: For Sidelink communication in use cases 1, 2 and 3, as the UE moves, the relative distance between the UEs that are in Sidelink communication may change, and it is no longer suitable for Sidelink communication, or the UE may return When there is network coverage, there is no need to relay data through Sidelink. In addition, two UEs that are communicating via cellular find close to each other. In order to reduce the load on the cellular network and reduce transmission delay, it is beneficial that the data communication will be switched from cellular to Sidelink. In these cases, it is necessary to consider switching the traffic between Sidelink UEs between the Sidelink path and the cellular path. In the process of service flow switching, service continuity must be ensured, and users must not feel that the quality of communication service is degraded.

To ensure the normal operation of the UE-to-Network relay and UE-to-UE relay scenarios, the relay UE may need to use a clear base station instruction to determine whether it can perform relay service transmission. As for the remote UE, how to enable it to select a suitable relay UE to transmit relay data is a technical problem for which no solution presently exists. The embodiments disclosed in the present document can solve these problems, and others.

The Internet of Vehicles refers to a large-scale system network for wireless communication and information exchange between cars and cars, pedestrians, roadside equipment and the Internet in accordance with agreed communication protocols and data exchange standards. Through the Internet of Vehicles communication, vehicles can obtain driving safety, improve traffic efficiency, and obtain convenience or entertainment information. Classified from the objects of wireless communication, Internet of Vehicles (IoV) communication includes three different types: vehicle-to-vehicle communication (Vehicle-to-Vehicle, referred to as V2V) , vehicle-to-vehicle communication (Vehicle-to-vehicle, or network infrastructure) to-Infrastructure/Vehicle-to-Network, referred to as V2I/V2N) , and communication between vehicles and pedestrians (Vehicle-to-Pedestrian, referred to as V2P) , collectively referred to as V2X communication.

In the Long Term Evolution (LTE) -based V2X communication research organized by 3GPP (3rd Generation Partnership Project) , based on the direct/sidelink link (Sidelink) between User Equipment (UE) ) The V2X communication method is one of the methods implemented by the V2X standard, that is, the service data is directly transmitted from the source user equipment to the target user equipment through the air interface without being forwarded by the base station and the core network. This V2X communication method Referred to as PC5-based V2X communication or V2X Sidelink communication.

With the advancement of technology and the development of the automation industry, the V2X communication scenario is further extended and has higher performance requirements. Advanced V2X business is mainly divided into 4 categories: vehicle platooning, extended sensors, advanced driving (semi-automated or full-automated driving) and remote driving (remote) driving) . Required performance requirements: The data packet size supports 50 to 12000 bytes, the transmission rate is 2 to 50 messages per second, the maximum end-to-end delay is 3-500 milliseconds, the reliability is 90%-99.999%, and the data rate is 0.5-1000Mbps , And the transmission range supports 50-1000 meters. 3GPP has established a project based on the fifth generation mobile communication technology (5th Generation, referred to as 5G) , but there is no car networking communication based on 5G air interface and car networking based on 5G direct link (sidelink) in related technologies. Communication.

There are two modes for V2X terminals, a mode based on base station control (mode 1) and a mode based on self-resource scheduling (mode 2) . When the terminal is scheduled based on the base station, whenever the terminal needs to communicate, it needs to make a resource request to the base station and report the service type corresponding to the data packet to be transmitted, the required frequency information, the data packet priority information, and the data packet buffer size. The base station allocates appropriate resources to the terminal according to the information for data transmission of the terminal. When the terminal is in the mode of self-resource scheduling, the terminal can sense in the resource pool, judge the congestion degree of the resource pool, and select appropriate resources for data transmission.

In addition, in LTE V2X technology, when the terminal is in the self-resource scheduling mode for carrier selection, the resource pool on each carrier has a corresponding resource pool busyness indicator (CBR) . For each terminal, Different PPPP priority levels (PPPP) have different PPPP-CBR thresholds. Therefore, the terminal will compare the busyness of the current resource pool with the PPPP-CBR thresholds corresponding to different packet priorities to determine whether the current data packet can be sent using this resource pool. If not, the terminal needs to perform carrier reselection.

The sidelink DRX configuration is different from Uu DRX configuration in the sense that in Uu, when downlink control information (e.g., DCI) is configured from network, UE actually cannot exactly know when the following packet will arrive. In such a case, UE may trigger inActivity Timer or Retransmission Timer to monitor for a while, to ensure that all packet can be received. However, in NR sidelink, Tx UE can exactly indicate the time of following transmission opportunity within SCI towards Rx UE. Therefore, Rx UE does not need to activate InActivity Timer or Transmission Timer immediately after a successful reception on physical sidelink control channel (PSCCH) . Instead, in order to enhance power saving, Rx UE can turn into DRX on when the following transmission opportunity is approaching. Furthermore, considering that Tx UE may need to perform re-evaluation or pre-emption to re-select another resource for the following transmission, to ensure Rx UE’s successful reception after Tx UE’s re-evaluation or pre-emption, a timer, named as SL-DRX-ReEvaluateTimer, can be considered to enlarge Rx UE’s active time. Some example embodiments of this configuration evaluation timer are described in the present document.

Embodiment 1: Configuration of evaluation timer by Rx UE

A1) In this case, in order to make Tx UE aware of Rx UE’s SL-DRX-ReEvaluateTimer, Rx UE may send the timer indication towards Tx UE. This indication can be sent via sidelink control information (SCI) or a sidelink medium access control (MAC) control element (CE) . In details, such an indication can carry at least one of the following information:

- SL-startSlot: To indicate which sidelink slot is the starting point of the timer. The slot can be logical slot calculated from resource pool, or physical slot calculated from tdd-DL-UL-configuration, or physical slot calculated from tdd-DL-UL-configuration and excluding synchronization signal block (SSB) slot and reserved slot.

- SL-TimerDuration: To indicate how long the timer duration is left. If SL-startSlot is absent, which means the timer is start at the time point of sending out the indication. The unit can be milliseconds (ms) or slot number.

- SL-Counter: Instead of using the timer, a counter can be used to indicate how many transmission Rx UE can received until counter turns to 0 (for example, every time Rx UE receives one transmission, counter will decrease by 1 (or another integer value) .

- SL-TimerActiveIndication: A Boolean value to simply indicate the state of Rx UE’s timer. When the state is changed, Rx UE should immediate send the indication towards Tx UE.

One step further, after Tx UE receive the indication and decide the timer determined by Rx UE cannot ensure pre-emption or re-evaluation, Tx UE should response to Rx UE to re-configure the timer. In various embodiments, the response can be sent via one or more of the following manner:

- Through an ACK/NACK indicate, if NACK is sent from Tx UE, means Tx UE would like Rx UE to re-configure timer, for the following purpose: to ensure enough time for re-evaluation and pre-emption/to ensure there will be no half-duplex issue existing. Otherwise, Tx UE can feed back an ACK.

- Through a SCI or sidelink MAC CE, if Tx UE think the configuration is not reasonable, it can indicate a preferred configuration within SCI or sidelink MAC CE. For example, some preferred configurations can include one of the following information:

- SL-prefer-startSlot: To indicate which sidelink slot is preferred to be the starting point of the timer. The slot can be logical slot calculated from resource pool, or physical slot calculated from tdd-DL-UL-configuration, or physical slot calculated from tdd-DL-UL-configuration and excluding SSB slot and reserved slot.

- SL-prefer-TimerDuration: To indicate how long the timer duration is preferred to be left. If SL-startSlot is absent, which means the timer is start at the time point of sending out the indication. The unit can be ms or slot number.

- SL-prefer-Counter: Instead of using the timer, a preferred counter can be used to indicate how many transmission Rx UE can received until counter turns to 0 (e.g., very time Rx UE receives one transmission, counter will decrease by 1 (or another integer) .

In some embodiments, if this sidelink MAC CE is sent out, Tx UE should respond ACK in the associated physical sidelink feedback channel (PSFCH) resource if it has received this timer activation. Furthermore, 2 bits can be used to carry the feedback information, one bit can be used to indicate whether the configuration indication is correctly received, the other bit can be used to indicate whether to activate this timer for the following transmission opportunity.

After Tx UE receive this timer configuration indication from Rx UE, it should perform resource reselection due to pre-emption or re-evaluation within the timer period. In various embodiments, there are two ways to implement this purpose:

- By physical layer, to limit Tx UE’s sensing window, in details, Tx UE should only sensing the resource within the window [R1-x, Rn+y] , which is in terms of slot or ms. For example, R1 is the previous first selected resource, Rn is the previous last selected resource, it is possible that R1 is Rn and x=y. Furthermore, in order to ensure Tx UE’s resource reselection to be fall into Rx UE’s timer period, R1-x should larger than SL-startSlot configured by Rx UE, Rn+y should be smaller than SL-startSlot + SL-TimerDuration.

- By MAC layer, when Tx UE receive the timer configuration from Rx UE, it should also configure its own DTX-timer configuration of which, the DTX-startingslot = SL-startSlot, DTX-EndingSlot = SL-startSlot + SL-TimerDuration. MAC entity should randomly select the time and frequency resource within the selection window [DTX-StartingSlot, DTX-EndingSlot] from the resources indicated by the physical layer.

A2) In this case, in order to avoid frequent indication as per A1) approach, it is beneficial to use one indication which is applicable to all transmission, so that to avoid too much signaling exchange.

In various embodiments, at least one of the following information should be included in the configuration of indication:

- Time Offset refer to each transmission opportunity: Instead of indicating the absolute time or slot number, to indicate a time offset refer to each transmission opportunity can be applicable to all transmissions, as shown in FIG. 2.

- Timer duration: To indicate how long this timer will last.

Such configuration can be carried via PC5-RRC signaling transmitted from Rx UE towards Tx UE. When Rx UE would like to activate this timer, a sidelink MAC CE or SCI can be sent from Rx UE to Tx UE to indicate the activation or de-activation state of this timer.

As further depicted in FIG. 2, timer offset indication may indicate a time between the message transmission and first or second upcoming transmission opportunity.

In addition, the detailed PC5-RRC configuration can refer to FIG. 3. The Rx UE may self-determine a semi-static configuration (e.g., a configuration that is valid for multiple transmission opportunities) of parameters related to sidelink DRX timer such as described above. At 302, the Rx UE will send a time configuration indication to the Tx UE. This indication may include a timer offset and/or a timer duration.

At 304, Tx UE sends (and Rx UE receives) a feedback for the timer configuration. The feedback may be ACK or NACK type. If the feedback is an ACK, then Rx UE will apply the configuration. If the feedback is NACK, then Rx UE may re-configure the DRX timer -either based on a proposed timer value from the Tx UE, or by an autonomous determination by Rx UE.

At 306, based on an agreed upon DRX evaluation timer, Rx UE may send (and Tx UE receive) a signal that activates use of the timer. A de-activation signal may similarly be used to deactivate the timer.

In details, if this sidelink MAC CE is sent out, Tx UE should respond ACK in the associated PSFCH resource if it has received this timer activation. Furthermore, 2 bits can be used to carry the feedback information, one bit can be used to indicate to Rx UE whether the configuration indication is correctly received, the other bit can be used to indicate to Rx UE whether to activate this timer for the following transmission opportunity. For example, the two bits can be AB, if A is 0, it means Tx UE does not correctly receive this indication, Rx UE should retransmit this MAC CE again, otherwise, Tx UE correctly receive this indication. If B is 0, means Tx UE due to some reason (re-select resource because of re-evaluation or pre-emption check. ) will transmit the packet out of the timer window, so Rx UE should not activate this timer for the following transmission, as shown in FIG. 4.

In FIG. 4, two scenarios are depicted for example of feedback bit values 1 and 0. The left scenario is when the timer is acceptable for the first transmission opportunity and the second timer (on right) is not acceptable for the second transmission opportunity.

After Tx UE receives this timer configuration indication from Rx UE, it should perform resource reselection due to pre-emption or re-evaluation within the timer period. For example, there are two ways to implement this purpose:

- By physical layer, to limit Tx UE’s sensing window, in details, Tx UE may only sense the resource within the window [R1-x, Rn+y] , which is in terms of slot or ms. In details, R1 is the previous first selected resource, Rn is the previous last selected resource, it is possible that R1 is Rn and x=y. Furthermore, in order to ensure Tx UE’s resource reselection to be fall into Rx UE’s timer period, R1-x should larger than SL-startSlot configured by Rx UE, Rn+y should be smaller than SL-startSlot + SL-TimerDuration.

Embodiment 2: Tx UE sends configuration evaluation timer to Rx UE:

Since Tx UE is the entity which can exactly know when the next packet will be transmitted, so the timer configuration is more appropriate coming from Tx UE. Furthermore, since Tx UE may need to perform resource reselection due to pre-emption or re-evaluation, so it is more appropriate for Tx UE to provide timer configuration so that to align the re-selected resource and timer window.

B1) Currently, within SCI, Tx UE can indicate the time and frequency resource location for up to three transmission opportunities including current transmission. In this case, Tx UE can also indicate the timer configuration for each transmission opportunity within SCI, in details, the configuration can include one of the following information:

- starting time indication

In details, the starting time indication can be implemented through the following alternatives:

- absolute time indication in terms of physical slot, logical slot or ms

- time offset in prior of the following transmission opportunity in terms of physical slot, logical slot or ms.

- timer duration indication in terms of physical slot, logical slot or ms

When Tx UE send the SCI carrying timer configuration towards Rx UE, it needs to be ensured that Rx UE can correctly receive this configuration and is able to apply this configuration. To facilitate this, hybrid automatic repeat request (HARQ) feedback may be enabled for this configuration transmission. In some embodiments, since two transmission opportunities will be carried in the SCI, and two timer configurations are carried corresponding to these two transmission opportunities. Thus, a two-bit feedback may be used. Feedback of each bit is corresponding to whether to apply each timer configuration of each transmission opportunities. E. g. a two-bit PSFCH HARQ feedback can be marked as AB, if bit A is 0, means Rx UE will not apply the timer configuration for transmission opportunity A, otherwise, Rx UE will apply the timer configuration. If bit B is 0, it means Rx UE will not apply the timer configuration for transmission opportunity B, otherwise, Rx UE will apply the timer configuration.

After Tx UE receive feedback of timer configuration indication from Rx UE. It should perform resource reselection due to pre-emption or re-evaluation within the timer period. In details, there are two ways to implement this purpose:

- By physical layer, to limit Tx UE’s sensing window. For example, Tx UE may only sense the resource within the window [R1-x, Rn+y] , which is in terms of slot or ms. In details, R1 is the previous first selected resource, Rn is the previous last selected resource, it is possible that R1 is Rn and x=y. Furthermore, in order to ensure Tx UE’s resource reselection to be fall into Rx UE’s timer period, R1-x should larger than SL-startSlot configured by Rx UE, Rn+y should be smaller than SL-startSlot + SL-TimerDuration.

B2) In order to avoid frequent indication as per B1) approach, the timer configuration can be configured from Tx UE towards Rx UE to carry semi-static configuration,

In details, the semi-static configuration can be carried via PC5-RRC message, sidelink MAC CE or SCI.

In details, the configuration can include at least one of the following information:

- Time offset in prior of each packet transmission.

- Timer duration.

When Tx UE decide to activate this timer for Rx UE, it can activate this timer according to one of the following granularity:

- Per UE granularity: in this case, the activation/deactivation indication can be sent via PC5-RRC message, sidelink MAC CE, or SCI.

- Per sidelink process: in this case, the activation/deactivation indication can be sent via sidelink MAC CE, or SCI.

- Per packet transmission: in this case, within sidelink SCI, for each transmission, there is a field to indicate whether Tx UE would like to activate the timer for Rx UE.

After Rx UE receive this activation indication, it should perform HARQ feedback to indicate whether Rx UE is able to activate the timer.

In details, if the timer is configured as per packet transmission granularity, Rx UE should use two-bit to feedback whether it can activate the timer for each transmission.

Examples of trigger condition of the timer:

At least one of the following conditions can be considered as trigger condition for Rx UE to activate the timer:

- When Rx UE receive the initial packet transmission, or receive the SCI associated to the initial packet transmission.

- When Rx UE receive the timer indication via SCI/MAC CE or PC5-RRC sent from Tx UE

- When the time/slot indicated in the timer indication via SCI/MAC CE or PC5-RRC is arrived

- When Rx UE receive the ACK feedback from Tx UE for the timer indication associated to specific transmission opportunity.

At least one of the following conditions can be considered as stop condition for Rx UE to de-activate the timer:

- When the timer expires according to the timer duration configuration sent from Tx UE.

- When the timer expires according to the timer duration configured by itself.

- When Rx UE successfully receive the packet sent from Tx UE.

- When Rx UE receive the de-activation indication via PC5-RRC, sidelink MAC CE or SCI, sent from Tx UE

Examples of timer configuration for groupcast, broadcast service:

- For in-coverage UE, network can configure the semi-static timer configuration via dedicated radio resource control (RRC) message or SIB message towards the UE, in details, such semi-static timer configuration can include at least one of the following information:

- A timer offset in prior of each transmission

- A timer offset candidate list in priori of each transmission

- A timer duration

- A timer duration candidate list

In details, the configuration can be set via per UE, per destination ID, per resource pool or per transmission granularity

Optionally, when UE receive the network configuration, if the UE is a Tx UE, it can select one set of configuration from the candidate configuration list and send the configuration via SCI to all possible Rx UE. (e.g., SCI is sent via broadcast manner) . If the UE is a Rx UE, it can select one set of configuration by itself and apply the timer according to the configuration.

- For in-coverage UE, the UE can determine timer configuration by itself and report the timer configuration towards network via PC5 RRC message.

- For out of coverage UE, a pre-configured configuration can be set towards the UE, in details, such semi-static timer configuration can include at least one of the following information:

- A timer offset in prior of each transmission

- A timer offset candidate list in priori of each transmission

- A timer duration

- A timer duration candidate list

FIG. 5 shows an example of messages exchanged between Tx UE and Rx UE. At 502, Tx UE sends a timer configuration message that includes a timer offset and/or a timer duration, as described above. This message is received by the Rx UE. At 504, Rx UE provides a feedback to the Tx UE regarding the DRX evaluation timer proposed by Tx UE. If the feedback is an ACK, this indicates that Rx UE can apply the timer. Ix the feedback is a NACK, then Tx UE should re-configure the timer to an acceptable value. Upon arriving at a mutually acceptable value, at 506, the Rx UE may send an activation signal to begin using the timer or a deactivation signal to stop use of the timer.

Embodiment 3

In some embodiments, the following techniques may be used for relay UE selection considering both UE self-determination and network controlling. For example, UE6 depicted in FIG. 1 is a relay UE.

Some embodiments may indicate UE self-determination as Type 1 approach of relay UE selection/reselection.

Some embodiments may indicate network controlling as Type 2 approach of relay UE selection/reselection.

When remote UE accesses into a network, the network may explicit configure the relay UE selection type towards remote UE. The relay UE selection type can include at least one of the following indication:

- Type 1 approach of relay UE selection/reselection

- Type 2 approach of relay UE selection/reselection

When remote UE get the configuration from network, it can switch to the corresponding approach to perform relay UE selection/reselection. Optionally, network does not need to use an explicit indication to indicate a relay UE selection/reselection approach type towards remote UE. Instead, if network would like to configure type 2 approach towards remote UE, it can directly configure a candidate relay UE/candidate relay UE list towards remote UE, so that remote UE will terminate type 1 approach of relay UE selection/reselection

In some embodiments, in order to help network configure a relay UE selection/reselection approach type towards remote UE, the remote UE can report at least one of the following information towards network:

- Remote UE’s resource allocation mode, e.g. mode 1 or mode 2.

- CBR of remote UE’s sidelink transmission/discovery resource pool

- Priority of QoS flow for certain remote UE’s destination ID.

- Remote UE’s Uu reference signal received power (RSRP) measurement value

- Remote UE’s location information, e.g. zone ID

- Remote UE’s selected sidelink frequency

- Remote UE’s UE capability

When remote UE is under network coverage, the network may implicit configure a mapping rule between the relay UE selection/reselection type and certain criteria. For example, the criteria can be at least one of the following information: (the criteria may be communicated)

- Remote UE’s resource allocation mode, e.g. mode 1 or mode 2.

- CBR of remote UE’s sidelink transmission/discovery resource pool

- Priority of QoS flow for certain remote UE’s destination ID.

- Remote UE’s Uu RSRP measurement value

- Remote UE’s location information, e.g. zone ID

- Remote UE’s selected sidelink frequency

- Remote UE’s UE capability

After remote UE has selected the relay UE selection/reselection approach type according to the above criteria, it should report its selected type towards network so that network.

FIG. 11 is a block diagram representation of a portion of an apparatus, in accordance with some embodiments of the presently disclosed technology. An apparatus 1105 such as a base station or a wireless device (or UE) , can include processor electronics 1110 such as a microprocessor that implements one or more of the techniques presented in this document. The apparatus 1105 can include transceiver electronics 1115 to send and/or receive wireless signals over one or more communication interfaces such as antenna (s) 1120. The apparatus 1105 can include other communication interfaces for transmitting and receiving data. Apparatus 1105 can include one or more memories (not explicitly shown) configured to store information such as data and/or instructions. In some implementations, the processor electronics 1110 can include at least a portion of the transceiver electronics 1115. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the apparatus 1105. The apparatus depicted in FIG. 11 may be used to implement the Tx UE or the Rx UE or the network node described in the present document.

FIG. 12 shows an example of a wireless communication system 500 where techniques in accordance with one or more embodiments of the present technology can be applied. A wireless communication system 500 can include one or more network nodes such as base stations (BSs) 505a, 505b, one or

more wireless devices

510a, 510b, 510c, 510d, and a core network 525. A

base station

505a, 505b can provide wireless service to

wireless devices

510a, 510b, 510c and 510d in one or more wireless sectors. In some implementations, a

base station

505a, 505b includes directional antennas to produce two or more directional beams to provide wireless coverage in different sectors. In some implementations, some

wireless devices

510a, 510b, 510c, 510d may be able to communicate using a direct device to device link 530, e.g., a sidelink, for communication.

The core network 525 can communicate with one or

more base stations

505a, 505b. The core network 525 provides connectivity with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information related to the subscribed

wireless devices

510a, 510b, 510c, and 510d. A first base station 505a can provide wireless service based on a first radio access technology, whereas a second base station 505b can provide wireless service based on a second radio access technology. The

base stations

505a and 505b may be co-located or may be separately installed in the field according to the deployment scenario. The

wireless devices

510a, 510b, 510c, and 510d can support multiple different radio access technologies. The techniques and embodiments described in the present document may be implemented by the base stations of wireless devices described in the present document.

The above-described techniques may be preferably adopted by various embodiments, as listed in the following listing of technical solutions. These solutions may be used, at least partly, to solve the technical problems of use of DRX mechanism with sidelink, as is discussed in the present document.

For example, a receiving wireless device of a transmission opportunity may implement the following solutions.

1. A method of wireless communication (e.g., method 600 depicted in FIG. 6) , comprising: transmitting (602) , by a first wireless device to a second wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for. In some embodiments, the transmitting operation may be performed for each transmission opportunity.

2. The method of solution 1, further including: receiving, by the first wireless device in response to the configuration message, a reconfiguration message from the second wireless device including DRX evaluation timer acceptable to the second wireless device; and performing further operations by processing the reconfiguration message. In some embodiments, the reception may be performed for each transmission opportunity.

3. The method of solution 1, further including: receiving, by the first wireless device in response to the configuration message, a feedback message from the second wireless device including a first indication on whether the DRX evaluation timer for is acceptable to the second wireless device a first following transmission; and performing further operations by processing the reconfiguration message.

4. The method of solution 3, further including: receiving, by the first wireless device in response to the configuration message, a feedback message from the second wireless device including a second indication on whether the DRX evaluation timer is acceptable to the second wireless device for a second following transmission; and performing further operations by processing the reconfiguration message.

5. The method of any of solutions 1-4, wherein the DRX evaluation timer indicates a property by which an active reception cycle of the first wireless device is modified from a normal DRX operation.

6. The method of any of solutions 1-5, wherein the configuration message is transmitted for each transmission opportunity.

7. The method of any of solutions 1-5, wherein the configuration message is transmitted to achieve a semi-static configuration for transmission opportunities.

8. The method of any of solutions 1-7, wherein the configuration message includes an indication of a slot that is a starting slot for the DRX evaluation timer.

9. The method of any of solutions 1-8, wherein the configuration message indicates a duration configuration of the DRX evaluation timer.

10. The method of any of solutions 1-9, wherein the configuration message includes a count of transmissions that the first wireless device uses to count down the DRX evaluation timer for each transmission opportunity.

11. The method of any of solutions 1-10, wherein the configuration message includes an indication of a current state of the DRX evaluation timer.

12. The method of any of solutions 1-11, further including: transmitting, by the first wireless device, an indication of a current state of the DRX evaluation timer.

13. The method of any of solutions 2-12, wherein the reconfiguration message is received from the second wireless device after receiving a NACK message from the second wireless device indicating that the first value of the parameter is not acceptable to the second wireless device.

14. The method of any of solutions 2-12, wherein the configuration message or the reconfiguration message is transmitted via a sidelink control information (SCI) .

15. The method of any of solutions 2-12, wherein the configuration message or the reconfiguration message is included in a medium access control (MAC) control element (CE) .

16. The method of any of solution 2-12, wherein the configuration message or the reconfiguration message is included in a PC5-RRC message.

17. The method of any of solutions 2-13, wherein the reconfiguration message includes an indication of a preferred slot that is a starting slot for the DRX evaluation timer.

18. The method of any of solutions 2-17, wherein the reconfiguration message includes an indication of a preferred duration configuration of the DRX evaluation timer.

19. The method of any of solutions 2-18, wherein the reconfiguration message includes an indication of a preferred count of transmissions that the first wireless device uses to count down the DRX evaluation timer.

20. The method of solution 13, wherein the method further includes: receiving, in response to the MAC CE, a feedback information.

21. The method of solution 20, wherein the feedback information includes a bit indicative of whether the MAC CE was correctly received.

22. The method of solution 20-21, wherein the feedback information includes a bit indicative of whether to activate the DRX evaluation timer at the ensuing transmission opportunity.

23. The method of any of solutions 1-22, wherein the configuration message includes an indication of a time offset used to indicate an offset prior to each transmission opportunity.

24. The method of any of solutions 1-23, wherein the configuration message includes an indication of a timer duration indicating how long the evaluation timer will last.

25. The method of any of solutions 1-24, wherein the configuration message is carried in a radio resource control (RRC) message and wherein the configuration is activated by another message carried in a medium access control element or a sidelink control information transmission.

26. The method of any of solutions 1-25, further including: receiving, by the first wireless device, an acknowledgement responsive to the configuration message from the second wireless device, in a physical feedback sidelink control channel (PFSCH) transmission.

27. The method of solution 26, wherein the acknowledgement includes a bit indicative of whether the MAC CE was correctly received.

28. The method of solution 2-27, wherein the acknowledgement includes a bit indicative whether the DRX evaluation timer is to be started at the ensuing transmission opportunity.

For example, a transmitting wireless device of a transmission opportunity may implement the following solutions.

29. A method of wireless communication (e.g., method 700 depicted in FIG. 7) , comprising: receiving (702) , by a second wireless device from a first wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for; and determining (704) whether to use the DRX evaluation timer for further operations. Upon determination that the DRX evaluation timer is suitable, it may be further used for transmission opportunities. Otherwise, a different DRX evaluation timer may be suggested to the first wireless device.

30. The method of solution 29, further including: transmitting, to the first wireless device in response to the configuration message, a reconfiguration message from the second wireless device including DRX evaluation timer acceptable to the second wireless device.

31. The method of solution 29, further including: transmitting, to the first wireless device in response to the configuration message, a feedback message from the second wireless device including a first indication on whether the DRX evaluation timer for is acceptable to the second wireless device a first following transmission.

32. The method of solution 31, further including: transmitting, to the first wireless device in response to the configuration message, a feedback message from the second wireless device including a second indication on whether the DRX evaluation timer is acceptable to the second wireless device for a second following transmission.

33. The method of any of solutions 29-32, wherein the DRX evaluation timer indicates a property by which an active reception cycle of the first wireless device is modified from a normal DRX operation.

34. The method of any of solutions 29-33, wherein the configuration message is transmitted for each transmission opportunity.

35. The method of any of solutions 29-33, wherein the configuration message is transmitted to achieve a semi-static configuration for transmission opportunities.

36. The method of any of solutions 29-35, wherein the configuration message includes an indication of a slot that is a starting slot for the DRX evaluation timer.

37. The method of any of solutions 29-36, wherein the configuration message indicates a duration configuration of the DRX evaluation timer.

38. The method of any of solutions 29-37, wherein the configuration message includes a count of transmissions that the first wireless device uses to count down the DRX evaluation timer for each transmission opportunity.

39. The method of any of solutions 29-38, wherein the configuration message includes an indication of a current state of the DRX evaluation timer.

40. The method of any of solutions 29-39, further including: receiving, by the second wireless device, an indication of a current state of the DRX evaluation timer.

41. The method of any of solutions 2-40, wherein the reconfiguration message is transmitted by the second wireless device after transmitting a NACK message from the second wireless device indicating that the first value of the parameter is not acceptable to the second wireless device.

42. The method of any of solutions 2-40, wherein the configuration message or the reconfiguration message is transmitted via a sidelink control information (SCI) .

43. The method of any of solutions 2-40, wherein the configuration message or the reconfiguration message is included in a medium access control (MAC) control element (CE) .

44. The method of any of solution 2-40, wherein the configuration message or the reconfiguration message is included in a PC5-RRC message.

45. The method of any of solutions 2-41, wherein the reconfiguration message includes an indication of a preferred slot that is a starting slot for the DRX evaluation timer.

46. The method of any of solutions 2-45, wherein the reconfiguration message includes an indication of a preferred duration configuration of the DRX evaluation timer.

47. The method of any of solutions 2-46, wherein the reconfiguration message includes an indication of a preferred count of transmissions that the first wireless device uses to count down the DRX evaluation timer.

48. The method of solution 41, wherein the method further includes: transmitting, in response to the MAC CE, a feedback information.

49. The method of solution 48, wherein the feedback information includes a bit indicative of whether the MAC CE was correctly received.

50. The method of solution 48-49, wherein the feedback information includes a bit indicative of whether to activate the DRX evaluation timer at the ensuing transmission opportunity.

51. The method of any of solutions 29-50, wherein the configuration message includes an indication of a time offset used to indicate an offset prior to each transmission opportunity.

52. The method of any of solutions 29-51, wherein the configuration message includes an indication of a timer duration indicating how long the evaluation timer will last.

53. The method of any of solutions 29-52, wherein the configuration message is carried in a radio resource control (RRC) message and wherein the configuration is activated by another message carried in a medium access control element or a sidelink control information transmission.

54. The method of any of solutions 29-53, further including: transmitting, to the first wireless device, an acknowledgement responsive to the configuration message from the second wireless device, in a physical sidelink control channel (PFSCH) transmission.

55. The method of solution 54, wherein the acknowledgement includes a bit indicative of whether the MAC CE was correctly received.

56. The method of solution 2-55, wherein the acknowledgement includes a bit indicative whether the DRX evaluation timer is to be started at the ensuing transmission opportunity.

57. The method of any of solutions 29-56, further including: performing transmission resource reselection within a time period indicated by the DRX evaluation timer.

58. The method of solution 29, wherein the performing the transmission resource reselection includes: limiting a sensing window at physical layer to sense within a window [R1-x, Rn+y] , which is in terms of slot or ms, where R1 is a previous first selected resource, Rn is the previous last selected resource, R1-x is larger than a starting slot configured by the first wireless device and Rn+y is smaller than the starting slot + the time period indicated by the DRX evaluation timer.

59. The method of solution 29, wherein the performing the transmission resource reselection includes: configure a discontinuous transmission (DTX) timer configuration of the second wireless device such that a starting slot is equal to a starting slot configured by the first wireless device and an ending slot is equal to the starting slot plus the time period indicated by the DRX evaluation timer.

For example, a transmitting wireless device of a transmission opportunity may implement the following solutions, e.g., with reference to embodiment 2 discussed above.

60. A method of wireless communication (e.g., method 800 depicted in FIG. 8) , comprising: transmitting (802) , by a second wireless device to a first wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer to be used by the first wireless device.

61. The method of solution 60, wherein the configuration message is transmitted to control operation of one transmission opportunity.

62. The method of solution 61, wherein the configuration message is transmitted in a sidelink control information (SCI) message.

63. The method of any of solutions 60-62, wherein the configuration message includes a start time indication for the DRX evaluation timer.

64. The method of solution 63, wherein the start time indication is indicated as an absolute time or an offset time.

65. The method of any of solutions 63-64, wherein the configuration message includes a duration of the DRX evaluation timer.

66. The method of solution 65, wherein the duration is indicated in terms of physical slots or logical slots or milliseconds.

67. The method of any of solutions 60-66, wherein the configuration message is transmitted by enabling hybrid automatic repeat request (HARQ) feedback for the configuration message.

68. The method of solution 67, wherein the HARQ feedback includes a first bit indicative of whether the first wireless device will apply the DRX evaluation timer for a first transmission opportunity and a second bit indicative of whether the first wireless device will apply the DRX evaluation timer for a second transmission opportunity.

69. The method of solution 68, wherein the performing the transmission resource reselection includes: limiting a sensing window at physical layer to sense within a window [R1-x, Rn+y] , which is in terms of slot or ms, where R1 is a previous first selected resource, Rn is the previous last selected resource, R1-x is larger than a starting slot configured by the first wireless device and Rn+y is smaller than the starting slot + the time period indicated by the DRX evaluation timer.

70. The method of solution 68, wherein the performing the transmission resource reselection includes: configure a discontinuous transmission (DTX) timer configuration of the second wireless device such that a starting slot is equal to a starting slot configured by the first wireless device and an ending slot is equal to the starting slot plus the time period indicated by the DRX evaluation timer.

71. The method of solution 70, wherein the configuration message is transmitted to semi-statically control DRX operation over a period of time.

72. The method of solution 71, wherein the configuration message is transmitted in a radio resource control (RRC) message or a sidelink medium access control (MAC) message or a sidelink control information (SCI) transmission.

73. The method of any of solutions 70-72, wherein the configuration message includes: a timer offset and or a timer duration indication.

74. The method of any of solutions 59-73, wherein the method includes: activating, by the second wireless device, use of the DRX evaluation timer.

75. The method of solution 74, wherein the activating is performed on a per-wireless device basis by sending an activation message as an RRC message, a sidelink MAC message or an SCI transmission.

76. The method of solution 74, wherein the activating is performed on a per sidelink process basis by sending an activation message as a sidelink MAC message or an SCI transmission.

77. The method of solution 74, wherein the activating is performed on a per packet basis by using a field of an SCI transmission.

78. The method of solution 77, further including: receiving, in response to the activating, a feedback from the first wireless device.

79. The method of solution 74, wherein the activating is performed implicitly based on occurrence of a trigger condition.

80. The method of solution 79, wherein the trigger condition includes the first wireless device receiving an initial packet from the second wireless device or an SCI associated with the initial packet from the second wireless device or a timer indication or a feedback message.

81. The method of any of solutions 74-80, further including: deactivating, by the second wireless device, use of the DRX reconfiguration timer based on occurrence of a deactivation trigger.

82. The method of any of solutions 60-81, wherein a parameter of the DRX evaluation timer represents a property by which an active reception cycle of the first wireless device is modified from a normal DRX operation.

For example, a receiving wireless device of a transmission opportunity may implement the following solutions, e.g., with reference to embodiment 2 discussed above.

83. A method of wireless communication (e.g., method 900 depicted in FIG. 9) , comprising: receiving (902) , by a first wireless device from a second wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer to be used by the first wireless device, and determining (904) whether to use the DRX evaluation timer for further operations.

84. The method of solution 83, wherein the configuration message is transmitted to control operation of one transmission opportunity.

85. The method of solution 84, wherein the configuration message is transmitted in a sidelink control information (SCI) message.

86. The method of any of solutions 83-85, wherein the configuration message includes a start time indication for the DRX evaluation timer.

87. The method of solution 86, wherein the start time indication is indicated as an absolute time or an offset time.

88. The method of any of solutions 86-87, wherein the configuration message includes a duration of the DRX evaluation timer.

89. The method of solution 88, wherein the duration is indicated in terms of physical slots or logical slots or milliseconds.

90. The method of any of solutions 83-89, wherein the configuration message is transmitted by enabling hybrid automatic repeat request (HARQ) feedback for the configuration message.

91. The method of solution 90, wherein the HARQ feedback includes a first bit indicative of whether the first wireless device will apply the DRX evaluation timer for a first transmission opportunity and a second bit indicative of whether the first wireless device will apply the DRX evaluation timer for a second transmission opportunity.

92. The method of solution 91, wherein the performing the transmission resource reselection includes: limiting a sensing window at physical layer to sense within a window [R1-x, Rn+y] , which is in terms of slot or ms, where R1 is a previous first selected resource, Rn is the previous last selected resource, R1-x is larger than a starting slot configured by the first wireless device and Rn+y is smaller than the starting slot + the time period indicated by the DRX evaluation timer.

93. The method of solution 91, wherein the performing the transmission resource reselection includes: configure a discontinuous transmission (DTX) timer configuration of the second wireless device such that a starting slot is equal to a starting slot configured by the first wireless device and an ending slot is equal to the starting slot plus the time period indicated by the DRX evaluation timer.

94. The method of solution 93, wherein the configuration message is transmitted to semi-statically control DRX operation over a period of time.

95. The method of solution 94, wherein the configuration message is transmitted in a radio resource control (RRC) message or a sidelink medium access control (MAC) message or a sidelink control information (SCI) transmission.

96. The method of any of solutions 93-95, wherein the configuration message includes: a timer offset and or a timer duration indication.

97. The method of any of solutions 83-96, wherein the method includes: activating, by the second wireless device, use of the DRX evaluation timer.

98. The method of solution 97, wherein the activating is performed on a per-wireless device basis by sending an activation message as an RRC message, a sidelink MAC message or an SCI transmission.

99. The method of solution 97, wherein the activating is performed on a per sidelink process basis by sending an activation message as a sidelink MAC message or an SCI transmission.

100. The method of solution 97, wherein the activating is performed on a per packet basis by using a field of an SCI transmission.

101. The method of solution 100, further including: receiving, in response to the activating, a feedback from the first wireless device.

102. The method of solution 97, wherein the activating is performed implicitly based on occurrence of a trigger condition.

103. The method of solution 102, wherein the trigger condition includes the first wireless device receiving an initial packet from the second wireless device or an SCI associated with the initial packet from the second wireless device or a timer indication or a feedback message.

104. The method of any of solutions 97-103, further including: deactivating, by the second wireless device, use of the DRX reconfiguration timer based on occurrence of a deactivation trigger.

105. The method of any of solutions 83-104, wherein a parameter of the DRX evaluation timer represents a property by which an active reception cycle of the first wireless device is modified from a normal DRX operation.

For example, a wireless device may implement the following solutions, e.g., to solve the technical problems for DRX evaluation timer implementation in a groupcast/multicast setting.

106. The method of any of solutions 60-105, wherein the second wireless device receives one or more semi-static timer configurations from a network device, and wherein the method includes: selecting, by the second wireless device, the DRX evaluation timer from the one or more semi-static timer configurations; and transmitting the DRX evaluation timer to all user devices of a group.

107. The method of any of solutions 60-105, wherein the first wireless device receives one or more semi-static timer configurations from a network device, and wherein the method includes: selecting, by the first wireless device, the DRX evaluation timer from the one or more semi-static timer configurations.

108. The method of any of solutions 106-107, wherein the one or more semi-static timer configurations include a timer offset for each transmission, a timer offset candidate list for each transmission, a timer duration or a timer duration candidate list.

109. The method of any of solutions 106-108, wherein the one or more semi-static configurations are sent on a per user device basis or a per destination identifier basis or a per resource pool basis or according to a transmission granularity.

For example, a network device may implement the following solutions, e.g., to solve the technical problems for DRX evaluation timer implementation in a groupcast/multicast setting.

110. The method of wireless communication (e.g., method 1000 depicted in FIG. 10) , comprising: transmitting (1002) , by a network node to a wireless device, one or more semi-static timer configurations that include information for one or more discontinuous reception (DRX) evaluation timers by the wireless device.

111. The method of solution 110, wherein the one or more semi-static timer configurations include a timer offset for each transmission, a timer offset candidate list for each transmission, a timer duration or a timer duration candidate list.

112. The method of any of solutions 110-111, wherein the one or more semi-static configurations are sent on a per user device basis or a per destination identifier basis or a per resource pool basis or according to a transmission granularity.

Additional technical solutions generally applicable to the above listing include:

113. A wireless apparatus comprising a processor configured to implement any of the above methods.

114. A computer readable medium having processor-executable code for implementing an above-recited method stored thereon.

In the above-described solutions, the “first wireless device” may be an Rx UE and the “second wireless device” may be a Tx UE.

It will be appreciated that various techniques are described to allow embodiments configure a DRX evaluation timer (e.g., SL-DRX-ReEvaluateTimer for Rx UE) , to help the Rx UE understand when to switch to active time for reception. In another aspect, the disclosed techniques may be used for embodiments in which Tx UE proposes an evaluation timer for use between the Tx UE and an Rx UE. For broadcast and groupcast, with network assistance, configure SL-DRX-ReEvaluateTimer for Rx UE, to help Rx UE understand when to switch to active time for reception. It will further be appreciated that, for sidelink relay, relay UE selection/reselection, when both remote UE self-determination and network controlling are both existing, how to help remote UE select one relay UE selection/reselection approach type.

Some of the embodiments described herein are described in the general context of methods or processes, which may be implemented in one embodiment by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM) , Random Access Memory (RAM) , compact discs (CDs) , digital versatile discs (DVD) , etc. Therefore, the computer-readable media can include a non-transitory storage media. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-or processor-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

Some of the disclosed embodiments can be implemented as devices or modules using hardware circuits, software, or combinations thereof. For example, a hardware circuit implementation can include discrete analog and/or digital components that are, for example, integrated as part of a printed circuit board. Alternatively, or additionally, the disclosed components or modules can be implemented as an Application Specific Integrated Circuit (ASIC) and/or as a Field Programmable Gate Array (FPGA) device. Some implementations may additionally or alternatively include a digital signal processor (DSP) that is a specialized microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functionalities of this application. Similarly, the various components or sub-components within each module may be implemented in software, hardware or firmware. The connectivity between the modules and/or components within the modules may be provided using any one of the connectivity methods and media that is known in the art, including, but not limited to, communications over the Internet, wired, or wireless networks using the appropriate protocols.

While this document contains many specifics, these should not be construed as limitations on the scope of an invention that is claimed or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in this disclosure.

Claims

A method of wireless communication, comprising:

transmitting, by a first wireless device to a second wireless device, a configuration message, for each transmission opportunity, indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for.
The method of claim 1, further including:

receiving, by the first wireless device in response to the configuration message, for each transmission opportunity, a reconfiguration message from the second wireless device including DRX evaluation timer acceptable to the second wireless device; and

performing further operations by processing the reconfiguration message.
The method of claim 1, further including:

receiving, by the first wireless device in response to the configuration message, for each transmission opportunity, a feedback message from the second wireless device including a first indication on whether the DRX evaluation timer for is acceptable to the second wireless device a first following transmission; and

performing further operations by processing the reconfiguration message.
The method of claim 3, further including:

receiving, by the first wireless device in response to the configuration message, a feedback message from the second wireless device including a second indication on whether the DRX evaluation timer is acceptable to the second wireless device for a second following transmission; and

performing further operations by processing the reconfiguration message.
The method of any of claims 1-4, wherein the configuration message includes an indication of a slot that is a starting slot for the DRX evaluation timer.
The method of any of claims 1-5, wherein the configuration message indicates a duration configuration of the DRX evaluation timer.
The method of any of claims 1-6, wherein the configuration message includes an indication of a current state of the DRX evaluation timer.
The method of any of claims 2-7, wherein the reconfiguration message is received from the second wireless device after receiving an ACK/NACK message from the second wireless device indicating whether the first value of the parameter is acceptable to the second wireless device.
The method of claim 8, wherein the method further includes:

receiving, in response to the reconfiguration message, a feedback information.
The method of claim 9, wherein the feedback information includes a bit indicative of whether the MAC CE was correctly received.
The method of claim 9-10, wherein the feedback information includes a bit indicative of whether to activate the DRX evaluation timer at the ensuing transmission opportunity.
The method of any of claims 1-11, wherein the configuration message includes an indication of a time offset used to indicate an offset prior to each transmission opportunity.
The method of any of claims 1-12, wherein the configuration message includes an indication of a timer duration indicating how long the evaluation timer will last.
The method of any of claims 1-13, wherein the configuration message is carried in a radio resource control (RRC) message and wherein the configuration is activated by another message carried in a medium access control element or a sidelink control information transmission.
The method of any of claims 1-14, further including:

receiving, by the first wireless device, an acknowledgement responsive to the configuration message from the second wireless device, in a physical feedback sidelink control channel (PFSCH) transmission.
The method of claim 15, wherein the acknowledgement includes a bit indicative of whether the MAC CE was correctly received.
The method of any of claims 3-4, wherein the acknowledgement includes a bit indicative whether the DRX evaluation timer is to be started at the ensuing transmission opportunity.
A method of wireless communication, comprising:

receiving, by a second wireless device from a first wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer that the first wireless device is configured for; and

determining whether to use the DRX evaluation timer for further operations.
The method of claim 18, further including:

transmitting, to the first wireless device in response to the configuration message, a feedback message from the second wireless device including a first indication on whether the DRX evaluation timer for is acceptable to the second wireless device a first following transmission; and/or

transmitting, to the first wireless device in response to the configuration message, a feedback message from the second wireless device including a second indication on whether the DRX evaluation timer is acceptable to the second wireless device for a second following transmission.
The method of any of claims 18-19, wherein the DRX evaluation timer indicates a property by which an active reception cycle of the first wireless device is modified from a DRX cycle operation.
The method of any of claims 18-20, wherein the configuration message includes an indication of a slot that is a starting slot for the DRX evaluation timer.
The method of any of claims 18-21, wherein the configuration message indicates a duration configuration of the DRX evaluation timer.
The method of any of claims 2-22, wherein the reconfiguration message is transmitted by the second wireless device after transmitting an ACK/NACK message from the second wireless device indicating whether the first value of the parameter is acceptable to the second wireless device.
The method of claim 23, wherein the method further includes:

transmitting, in response to the configuration message, a feedback information.
The method of claim 24, wherein the feedback information includes a bit indicative of whether the MAC CE was correctly received.
The method of claim 24-25, wherein the feedback information includes a bit indicative of whether to activate the DRX evaluation timer at the ensuing transmission opportunity.
The method of any of claims 18-26, wherein the configuration message includes an indication of a time offset used to indicate an offset prior to each transmission opportunity.
The method of claim 18, wherein the configuration message includes an indication of a timer duration indicating how long the evaluation timer will last.
The method of any of claims 18-28, wherein the configuration message is carried in a radio resource control (RRC) message and wherein the configuration is activated by another message carried in a medium access control element or a sidelink control information transmission.
The method of any of claims 18-29, further including:

transmitting, to the first wireless device, an acknowledgement responsive to the configuration message from the second wireless device, in a physical sidelink control channel (PFSCH) transmission.
The method of claim 30, wherein the acknowledgement includes a bit indicative of whether the MAC CE was correctly received.
The method of claim 31, wherein the acknowledgement includes a bit indicative whether the DRX evaluation timer is to be started at the ensuing transmission opportunity.
The method of claim 32, further including:

performing transmission resource reselection within a time period indicated by the DRX evaluation timer.
The method of claim 18, wherein the performing the transmission resource reselection includes:

limiting a sensing window at physical layer to sense within a window [R1-x, Rn+y] , which is in terms of slot or ms, where R1 is a previous first selected resource, Rn is the previous last selected resource, R1-x is larger than a starting slot configured by the first wireless device and Rn+y is smaller than the starting slot + the time period indicated by the DRX evaluation timer.
The method of claim 18, wherein the performing the transmission resource reselection includes:

configure a discontinuous transmission (DTX) timer configuration of the second wireless device such that a starting slot is equal to a starting slot configured by the first wireless device and an ending slot is equal to the starting slot plus the time period indicated by the DRX evaluation timer.
A method of wireless communication, comprising:

transmitting, by a second wireless device to a first wireless device, a configuration message indicative of a discontinuous reception (DRX) evaluation timer to be used by the first wireless device.
The method of claim 36, wherein the configuration message is transmitted by enabling hybrid automatic repeat request (HARQ) feedback for the configuration message.
The method of claim 37, wherein the HARQ feedback includes a first bit indicative of whether the first wireless device will apply the DRX evaluation timer for a first transmission opportunity and a second bit indicative of whether the first wireless device will apply the DRX evaluation timer for a second transmission opportunity.
The method of claim 38, wherein the performing the transmission resource reselection includes:

limiting a sensing window at physical layer to sense within a window [R1-x, Rn+y] , which is in terms of slot or ms, where R1 is a previous first selected resource, Rn is the previous last selected resource, R1-x is larger than a starting slot configured by the first wireless device and Rn+y is smaller than the starting slot + the time period indicated by the DRX evaluation timer.
A wireless apparatus comprising a processor configured to implement a method recited in any one or more of claims 1-39.
A computer readable medium having processor-executable code for implementing a method recited in any one or more of claims 1-39.