CN116326181A

CN116326181A - Discontinuous reception in side link communication

Info

Publication number: CN116326181A
Application number: CN202080106158.0A
Authority: CN
Inventors: 刘勇; 李栋
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2020-10-13
Filing date: 2020-10-13
Publication date: 2023-06-23
Also published as: WO2022077226A1

Abstract

Example embodiments of the present disclosure relate to methods, apparatuses, and computer-readable storage media for discontinuous reception. The method includes determining, at a first device, a first set of resources for transmission of a first sidelink signal to a second device, the first sidelink information indicating that the second device remains in a discontinuous reception mode; and transmitting a first message indicating the first set of resources to a second apparatus in an active mode to cause the second apparatus to detect the first sidelink signal on the first set of resources in a discontinuous reception mode. In this way, the power consumption of the terminal device can be significantly reduced while improving the feasibility and flexibility of the resource selection of the DRX scheme.

Description

Discontinuous reception in side link communication

Technical Field

Embodiments of the present disclosure relate generally to the field of telecommunications and, in particular, relate to methods, apparatuses, and computer-readable storage media for Discontinuous Reception (DRX) mechanisms.

Background

For vehicle-to-anything (V2X) communication in a fifth generation New Radio (NR) network, there are two resource allocation modes. In the first mode (hereinafter also referred to as NR V2X mode 1 or mode 1), one terminal device (e.g., user equipment) can perform V2X communication with another terminal device by using resources allocated by a network device such as a base station. In the second mode (hereinafter also referred to as NR V2X mode 2 or mode 2), one terminal device can perform V2X communication with another terminal device by using a resource autonomously selected by the one terminal device in a resource pool. V2X communication and device-to-device (D2D) communication may be performed based on side link (sidelink) communication techniques. To this end, a side link resource pool and side link channels may be established for vehicles engaged in such communications.

In some communication scenarios of NR networks, for example in public safety and commercial wearable use cases, terminal devices are often sensitive to energy consumption, and thus energy saving mechanisms may be particularly desirable. The DRX scheme may operate as an efficient power saving mechanism. For example, in side-link communications, the terminal device does not always listen or monitor the physical side-link control channel (PSCCH), but rather periodically wakes up and performs blind decoding ON the PSCCH for an ON duration (ON duration) to monitor the PSCCH. Since the on-duration typically includes multiple time slots, performing blind decoding on the PSCCH is not energy efficient. In this case, the feasibility and flexibility of the resource selection of the DRX scheme is also poor.

Disclosure of Invention

In general, example embodiments of the present disclosure provide a solution for a DRX scheme in side-link communication.

In a first aspect, a first apparatus is provided. The first device includes at least one processor; at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the first apparatus at least to: determining a first set of resources for transmission of a first sidelink signal to a second apparatus, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and transmitting a first message indicating the first set of resources to a second apparatus in an active mode to cause the second apparatus to detect the first sidelink signal on the first set of resources in a discontinuous reception mode.

In a second aspect, a second apparatus is provided. The second device includes at least one processor; at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the second apparatus at least to: in an active mode and receiving a first message from a first apparatus comprising a first set of resources for transmission of a first sidelink signal, the first sidelink signal indicating that a second apparatus remains in a discontinuous reception mode; and detecting the first side link signal on the first set of resources in the discontinuous reception mode.

In a third aspect, a third apparatus is provided. The third device includes at least one processor; at least one memory including computer program code; the at least one memory and the computer program code are configured to, with the at least one processor, cause the third apparatus at least to: determining a resource allocation scheme indicating candidate resources for transmission of a first sidelink signal from a first device to a second device, the first sidelink signal indicating that the second device remains in discontinuous reception mode; and transmitting the resource allocation scheme to the first device and the second device.

In a fourth aspect, a method is provided. The method comprises the following steps: determining, at a first device, a first set of resources for transmission of a first sidelink signal to a second device, the first sidelink signal indicating that the second device remains in a discontinuous reception mode; and transmitting a first message indicating the first set of resources to a second apparatus in an active mode to cause the second apparatus to detect the first sidelink signal on the first set of resources in a discontinuous reception mode.

In a fifth aspect, a method is provided. The method comprises the following steps: receiving, at a second apparatus in an active mode and from a first apparatus, a first message indicating a first set of resources for transmission of a first sidelink signal, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and detecting the first side link signal on the first set of resources in the discontinuous reception mode.

In a sixth aspect, a method is provided. The method comprises the following steps: determining, at a third apparatus, a resource allocation scheme indicating candidate resources for transmission of a first sidelink signal from the first apparatus to a second apparatus, the first sidelink signal indicating that the second apparatus remains in discontinuous reception mode; and transmitting the resource allocation scheme to the first device and the second device.

In a seventh aspect, a first apparatus is provided. The first device comprises: determining, at a first device, a first set of resources for transmission of a first sidelink signal to a second device, the first sidelink signal indicating that the second device remains in a discontinuous reception mode; and means for sending a first message to a second apparatus in an active mode indicating a first set of resources to cause the second apparatus to detect a first sidelink signal on the first set of resources in a discontinuous reception mode.

In an eighth aspect, a second apparatus is provided. The second device includes: means for receiving, at a second apparatus in an active mode and from a first apparatus, a first message indicating a first set of resources for transmission of a first sidelink signal, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and means for detecting the first side link signal on the first set of resources in the discontinuous reception mode.

In a ninth aspect, a third apparatus is provided. The third device includes: determining, at the third apparatus, a resource allocation scheme indicating candidate resources for transmission of a first sidelink signal from the first apparatus to the second apparatus, the first sidelink signal indicating that the second apparatus remains in discontinuous reception mode; and means for transmitting the resource allocation scheme to the first device and the second device.

In a tenth aspect, there is provided a computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to the fourth aspect.

In an eleventh aspect, there is provided a computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to the fifth aspect.

In a twelfth aspect, there is provided a computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to the sixth aspect.

Other features and advantages of embodiments of the present disclosure will be apparent from the following description of the particular embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the embodiments of the disclosure.

Drawings

The embodiments of the present disclosure are set forth in an illustrative sense, and the advantages thereof will be explained in more detail below with reference to the drawings, in which

FIG. 1 illustrates an example environment in which example embodiments of the present disclosure may be implemented;

Fig. 2 illustrates an example slot format of a side link channel between a transmitter terminal device and a receiver terminal device according to some example embodiments of the present disclosure;

fig. 3 shows a signaling diagram illustrating a DRX procedure in side link communication according to some example embodiments of the present disclosure;

fig. 4 illustrates an example configuration of a DRX procedure according to some example embodiments of the present disclosure;

fig. 5A illustrates another configuration of a DRX procedure according to some example embodiments of the present disclosure;

fig. 5B illustrates yet another configuration of a DRX procedure according to some example embodiments of the present disclosure;

fig. 6 illustrates a flowchart of an example method for a DRX procedure, according to some example embodiments of the present disclosure;

fig. 7 illustrates a flowchart of an example method for a DRX procedure, according to some example embodiments of the present disclosure;

fig. 8 illustrates a flowchart of an example method for a DRX procedure, according to some example embodiments of the present disclosure;

FIG. 9 illustrates a simplified block diagram of a device suitable for implementing exemplary embodiments of the present disclosure; and

fig. 10 illustrates a block diagram of an example computer-readable medium, according to some embodiments of the disclosure.

The same or similar reference numbers will be used throughout the drawings to refer to the same or like elements.

Detailed Description

Principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described merely for the purpose of illustrating and helping those skilled in the art understand and practice the present disclosure and are not meant to limit the scope of the present disclosure in any way. The disclosure described herein may be implemented in various other ways besides those described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

In this disclosure, references to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms "first" and "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish between functions of the various elements. As used herein, the term "and/or" includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "including," "includes" and/or "including" when used herein, specify the presence of stated features, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

As used in this application, the term "circuitry" may refer to one or more or all of the following:

(a) Pure hardware circuit implementations (such as implementations using only analog and/or digital circuitry), and

(b) A combination of hardware circuitry and software, such as (as applicable):

(i) Combination of analog and/or digital hardware circuit(s) and software/firmware, and

(ii) Any portion of the hardware processor(s) having software, including digital signal processor(s), software, and memory(s), that work together to cause a device, such as a mobile phone or server, to perform various functions, and

(c) Hardware circuit(s) and/or processor(s), such as microprocessor(s) or portion of microprocessor(s), that require software (e.g., firmware) to operate, but software may not exist when operation is not required.

The definition of circuitry is applicable to all uses of that term in this application, including in any claims. As another example, as used in this application, the term circuitry also encompasses hardware-only circuitry or a processor (or multiple processors) or an implementation of a hardware circuit or portion of a processor and its accompanying software and/or firmware. For example, if applicable to the particular claim elements, the term circuitry also encompasses a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as a fifth generation (5G) system, long Term Evolution (LTE), LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), high Speed Packet Access (HSPA), narrowband internet of things (NB-IoT), and so forth. Furthermore, the communication between the terminal device and the network device in the communication network may be performed according to any suitable generation communication protocol, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) New Radio (NR) communication protocols, and/or any other protocol currently known or to be developed in the future. Embodiments of the present disclosure may be applied to various communication systems. In view of the rapid development of communications, there are, of course, future types of communication techniques and systems that can embody the present disclosure. The scope of the present disclosure should not be limited to only the above-described systems.

As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses the network and receives services from the network. A network device may refer to a Base Station (BS) or an Access Point (AP), e.g., a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR next generation node B (gNB), a Remote Radio Unit (RRU), a Radio Header (RH), a Remote Radio Head (RRH), a relay, a low power node (such as femto, pico), etc., depending on the terminology and technology applied. The network device is allowed to be defined as part of the gNB, for example in a CU/DU split, in which case the network device is defined as a gNB-CU or gNB-DU.

The term "terminal device" refers to any terminal device capable of wireless communication. By way of example, and not limitation, a terminal device may also be referred to as a communication device, user Equipment (UE), subscriber Station (SS), portable subscriber station, mobile Station (MS), or Access Terminal (AT). The terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal Digital Assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop in-vehicle devices (LMEs), USB dongles, smart devices, wireless customer premise devices (CPE), internet of things (IoT) devices, watches or other wearable devices, head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in the context of industrial and/or automated processing chains), consumer electronic devices, devices operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Terminal (MT) part of an Integrated Access and Backhaul (IAB) node (also known as a relay node). In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

Although the functionality described herein may be performed in fixed and/or wireless network nodes in various example embodiments, in other example embodiments, the functionality may be implemented in a user equipment device (such as a cell phone or tablet, notebook or desktop, mobile IoT device, or fixed IoT device). For example, the user equipment device may be suitably equipped with corresponding capabilities as described in connection with the fixed and/or wireless network node(s). The user equipment device may be a user equipment and/or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functions include a bootstrapping server function and/or a home subscriber server, which may be implemented in a user equipment device by providing the user equipment device with software configured to cause the user equipment device to perform operations from the perspective of these functions/nodes.

In order to reduce power consumption, the terminal device may operate in a DRX mode in which the terminal device periodically experiences an active state and an inactive state in a DRX cycle (cycle). The DRX cycle includes an opportunity (opportunity) for DRX and an on-duration of DRX. During the occasion for DRX, the terminal device operates in an inactive state and refrains from listening or monitoring channels, such as PSCCH for NR side links. During the on-duration, the terminal device operates in an active state and monitors data transmissions from other terminal devices or network devices. In case there is no suitable resource for a terminal device acting as a transmitter (hereinafter also referred to as transmitter terminal device), the on-duration of DRX typically comprises a plurality of time slots, however, the periodic occurrence of the on-duration may not be efficient in terms of power consumption.

To further reduce the power consumption, a side link wake-up signal similar to WUS at the Uu interface may be configured to wake up a terminal device acting as a receiver (hereinafter also referred to as receiver terminal device). The side link wake-up signal is sent before the on-duration for monitoring the PSCCH. In this way, the receiver terminal device may periodically detect the side link wake-up signal with relatively low power consumption, rather than periodically experiencing the active state and the inactive state in the DRX cycle. If the side link wakeup signal is successfully detected, the receiver terminal device recognizes that a potential control/data transmission may be sent on the PSCCH and physical side link shared channel (PSSCH), and then begins monitoring the corresponding side link channel for a subsequent on duration. Otherwise, if the terminal device fails to detect a sidelink wake-up signal, it may remain in an inactive state instead of monitoring the PSCCH. Resources (e.g., time/frequency/code resources) for the side link wake-up signal may be assigned or coordinated by a network device (e.g., a gNB). Such a scheme may be particularly suitable for mode 1 side link communications.

In 5G NR, a physical side link feedback channel (PSFCH) for side link communication is designated to carry hybrid automatic repeat request (HARQ) feedback over the side link at the physical layer. The Zadoff-Chu sequence may be transmitted in one Physical Resource Block (PRB) that is repeated over two OFDM symbols on the PSFCH, where the first symbol may be used for Automatic Gain Control (AGC), near the end of the side link resources in the slot. The DRX signal may be configured to occupy the same position in the slot as the PSFCH and employ a Zadoff-Chu sequence, e.g., the Zadoff-Jhu sequence may be the same as or different from the Zadoff-Zhu sequence transmitted on the PSFCH. This will reduce standardization effort and thereby promote advocation of the above-described solutions.

For mode 2 side link communication, more than one sender terminal device (whose corresponding receiver terminal device is in DRX mode) may select the same resources, which may result in collisions, since most terminal devices may be in RRC idle state. Thus, there is a need for an enhanced scheme to enable DRX procedures for side link communications.

Embodiments of the present disclosure propose an enhanced DRX scheme suitable for both mode 1 and mode 2 side link communications. In this scheme, one or more side link signals are defined for informing the receiver terminal device to remain in discontinuous reception mode and to wake up to monitor the respective channel. Furthermore, candidate resources for the sidelink signal may be preconfigured from the sidelink resource pool, e.g., by the network device. Even for mode 2 side link communication, the transmitter terminal device can select unoccupied resources for transmission of side link signals and avoid resource collision by sensing the use case (usage) of candidate resources. In this way, the resource selection and signaling mechanisms in the proposed DRX scheme may be more flexible and feasible for both mode 1 and mode 2 side link communications. In addition, the proposed DRX scheme can meet the requirements and data characteristics of V2X communication while significantly reducing power consumption of the terminal device.

FIG. 1 illustrates an example environment 100 in which example embodiments of the present disclosure may be implemented. As shown in fig. 1, the communication network 100 includes a first device 110, a second device 120, a third device 130, and a fourth device 140. The first apparatus 110, the second apparatus 120, and the fourth apparatus 140 may be terminal devices, and the third apparatus 130 may be a network device. The third device 130 may provide radio coverage, i.e., the cell 102, for serving one or more of the first device 110, the second device 120, and the fourth device 140. It should also be understood that the number of network devices, terminal devices and serving cells shown in fig. 1 are given for illustrative purposes and are not meant to be limiting.

In the network 100, the first device 110, the second device 120, and the fourth device 140 may communicate with each other, e.g., via a mode 1 or mode 2 side chain communication. For discussion purposes, in the context of network 100, first apparatus 110 is described as acting as a sender terminal device, second apparatus 120 is described as acting as a receiver terminal device, and communications between first apparatus 110, second apparatus 120, and fourth apparatus 140 are described as mode 2 side link communications. It should be appreciated that the example embodiments are not limited to such particular communication scenarios, but may be applied to any communication scenario including mode 1 side link communication and any other suitable D2D communication.

According to example embodiments of the present disclosure, a sidelink DRX signal may be transmitted from the first apparatus 110 to the second apparatus 120 for guiding the DRX operation of the receiver terminal device. The side link DRX signal may include a first side link signal for indicating that the receiver terminal device remains in discontinuous reception mode. In the case where the second device 120 is in the DRX mode and there is no data traffic to send to the second device, the first device 110 may send the first side link signal on a predetermined resource to keep the second device 120 in the discontinuous reception mode. From the perspective of the second device 120, if the first side link signal is successfully detected, the second device 120 may ignore the subsequent on-duration for monitoring the PSCCH and remain in an inactive state until the next opportunity for detection of the first side link signal. The first side link signal may also cause other terminal devices (e.g., fourth apparatus 140) to sense usage of resources for the side link DRX signal. After sensing, the fourth device 140, which intends to initiate its own DRX procedure, may select unused time/frequency/code resources to send the side link DRX signal.

In some example embodiments of the present disclosure, the sidelink DRX signal may additionally comprise a second sidelink signal for instructing the receiver terminal device to monitor data to be transmitted on a sidelink channel between the transmitter terminal device and the receiver terminal device. For example, in the case where there is control/data to be transmitted on the PSCCH/PSSCH, the first device 110 may transmit a second side link signal to the second device 120. Upon receiving the second sidelink signal, the second device 120 may begin monitoring control/data transmissions on the PSCCH/PSSCH. This will be described in detail below.

It should be appreciated that while unicast communication between the first device 110 and the second device 120 is illustrated in fig. 1, other modes of communication are also applicable to example embodiments of the present disclosure. For example, example embodiments of the present application may relate to multicast communications between one sender terminal device and multiple receiver terminal devices. The scope of the present disclosure is not limited in this regard.

The third apparatus 130 may pre-configure candidate resources from the side link resource pool for transmission of the side link DRX signal. Specifically, the side link DRX signal may occupy the last symbol in the slot, as shown in fig. 2. As shown, the side link DRX signal may be in the form of a Zadoff-Chu sequence and transmitted in multiple PRBs repeated over two OFDM symbols, and the first symbol therein may be used for AGC. The time resource for the side link DRX signal occurs periodically and the period (period) may be set to 50ms, which is suitable for VoIP traffic in the public safety use case. Further, the third means 130 may (pre) configure the on-duration for monitoring the PSCCH to occur after resources for the side link DRX signal, which occupies a plurality of time slots. This resource configuration for the side link DRX signal is flexible frequency division multiplexed and is applicable to existing specifications regarding Transport Block Size (TBS).

Depending on the communication technology, network 100 may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a single carrier frequency division multiple access (SC-FDMA) network, or the like. The communications discussed in network 100 may conform to any suitable standard including, but not limited to, new radio access (NR), long Term Evolution (LTE), LTE evolution, LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), code Division Multiple Access (CDMA), CDMA2000, global system for mobile communications (GSM), and the like. Furthermore, the communication may be performed according to any generation communication protocol currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies described above as well as other wireless networks and radio technologies. For clarity, certain aspects of these techniques are described below for LTE, and LTE terminology is used in much of the description below.

The principles and implementations of the present disclosure will be described in detail below with reference to fig. 3 through 8. Fig. 3 illustrates a signaling diagram of a DRX procedure 300 in side link communication according to some example embodiments of the present disclosure. For ease of discussion, the process 300 will be described with reference to FIG. 1. The process 300 may involve the first device 110, the second device 120, and the third device 130.

As described above in connection with fig. 1-2, in some cases, for example, the first device 110 determines that there are fewer incoming packets for transmission to the second device 120 within a particular period of time, the second device 120 need not continuously monitor the side link channel. For power saving purposes, the first device 110 and the second device 120 may desire to operate in a DRX mode.

The resource allocation scheme is used for side link communication between the first device 110 and the second device 120. The resource allocation scheme indicates at least candidate resources for transmission of the first side link signal. In some example embodiments, the resource allocation scheme may be determined by the third apparatus 130. In these embodiments, the third apparatus 130 may determine candidate resources and send 305 a resource allocation scheme indicating the candidate resources to the first apparatus 110 and the second apparatus 120. In other example embodiments, the resource allocation scheme or alternatively the candidate resources may be preconfigured or predefined at the first apparatus 110 and the second apparatus 120. Other terminal devices (such as the fourth apparatus 140) assigned the same resource pool as the first apparatus 110 and the second apparatus 120 may also utilize the resource allocation scheme. In some example embodiments, the resource allocation scheme may further indicate a correspondence between a first set of resources selected from candidate resources for transmission of the first sidelink signal and a second set of resources for transmission of the second sidelink signal. In some other embodiments, the correspondence between the first set of resources and the second set of resources may be predefined or preconfigured at the first apparatus 110 and the second apparatus 120. This aspect will be described in detail in connection with fig. 4, 5A and 5B.

Since some of the candidate resources may already be occupied by other terminal devices, the first apparatus 110 may determine the use of the candidate resources before instructing the second apparatus 120 to enter the DRX mode. Referring now to fig. 3, to determine the use of candidate resources, the first device 110 may sense over candidate resources in a predetermined sensing window. In this manner, the first apparatus 110 may determine at least one unused resource from the candidate resources and determine a first set of resources from the at least one unused resource for transmission of the first sidelink signal to the second apparatus 120.

The first device 110 determines 310 a first set of resources. For example, the first apparatus 110 may determine the first set of resources from among the candidate resources indicated by the resource allocation scheme. The first device 110 sends 315 a first message to the second device 120 indicating the first set of resources. The first message may cause the second device 120 in DRX mode and detect the first side link signal on the first set of resources. The first side link signal indicates that the second device 120 remains in the DRX mode. Further, the first side link signal may cause a sensing-based resource selection performed by the terminal device. Upon sensing a first sidelink signal from another terminal device, such as the fourth apparatus 140, on a particular candidate resource, the first apparatus 110 will ignore the resource and select from the remaining candidate resources.

It should be appreciated that the determination of the first set of resources by the first apparatus 110 is set forth herein as an example implementation and should not be construed as imposing any limitation on the scope of the present disclosure. In some other example embodiments, the first set of resources may be determined by the receiver terminal device. In this case, the second device 120 determines the first set of resources from the candidate resources indicated by the resource allocation scheme. After determining the first set of resources, the second device 120 may notify the first device 110 of the first set of resources.

In other example embodiments, the first set of resources may be jointly determined by the transmitter terminal device and the receiver terminal device. In this case, the first apparatus 110 and the second apparatus 120 coordinate to determine the first set of resources from the candidate resources indicated by the resource allocation scheme.

Upon receiving the first message, the second device 120 in the active mode may determine a first set of resources and enter 320 a DRX mode. In some example embodiments, the first apparatus 110 may determine 325 that there is no data to send on the side-link channel. In this case, the first device 110 transmits 330 the first sidelink signal to the second device 120 on at least one of the resources in the first set.

The second device 120 detects 335 a first sidelink signal on the first set of resources in the DRX mode. Upon successful detection of the first sidelink signal on at least one of the resources in the first set, the second device 120 knows that there is no data to send and remains 340 in DRX mode until the next DRX cycle. In other words, in this case, the second device 120 does not monitor the PSCCH/PSSCH during the next on-duration and does not decode the information sent on the corresponding channel.

In the event that the first device 110 determines 345 that there is data to transmit on the side link channel, the first device 110 may instruct the second device 120 to monitor the data to transmit on the side link channel. To select an appropriate resource from the resource pool for transmitting data on the side-link channel, the first apparatus 110 may sense data transmissions from other terminal devices, such as the fourth apparatus 140. It should be appreciated that the sensing-based resource selection is given herein as an example implementation, and that many different resource selection mechanisms may also be applied to example embodiments of the present disclosure. The scope of the present disclosure is not limited in this regard.

In some example embodiments, if there is data to send on the side link channel, the first device 110 may suspend 350 transmission of the first side link signal on the first set of resources to instruct the second device 120 to monitor the side link channel, as will be discussed below in connection with fig. 4.

Fig. 4 illustrates an example configuration 400 of a DRX procedure according to some example embodiments of the present disclosure. As shown, the resource pool includes a plurality of frequency time resources { t } for side link communication _i ，f _i Boxes expressed as various patterns (patterns), where n is a positive integer, t _i Representing time resources in the time domain, f _i Representing frequency resources in the frequency domain. Specifically, a box of a grid pattern (grid pattern) represents candidate resources indicated by a resource allocation scheme, and a box of a bar pattern (strip pattern) represents a first set of resources selected from the candidate resources for transmission of a first side link signal.

According to the configuration 400 of the resource pool, it is assumed that the first side link signal is periodically transmitted at a specific frequency, e.g., at time slots T ', T ' +t, … … T ' + (n-1) T, etc., before the corresponding on-duration, where T represents the period for transmission of the side link DRX signal. Once the first side link signal is successfully detected on the corresponding resource in the first group, the second device 120 will remain in DRX mode and ignore the next on-duration 401, that is, not monitor the data transmission on the side link channel for the on-duration 401. In the event that no first sidelink signal is detected on the corresponding resource in the first group (e.g., on the resource at time slot T' + (n-1) T), which indicates that there may be data to send on the sidelink channel, the second device 120 will wake up and monitor for data transmissions on the sidelink channel during the next on-duration 402. For example, the second device 120 may decode the PSCCH/PSSCH during the on-duration 402.

The first side link signal as shown in fig. 4 occupies the same number of PRBs as the subchannel that is the minimum resource unit of the PSSCH. It should be appreciated that such an arrangement is given as an example implementation, and that other arrangements for first side link signals occupying a different number of PRBs than subchannels are also applicable to embodiments of the present disclosure. The number of PRBs for the first side link signal may be configured by a third device (such as a gNB).

Alternatively, in other example embodiments, if there is data to send on the side link channel, the first apparatus 110 may send 355A second side link signal to the second apparatus 120 on a second set of resources, and the second side link signal is configured to instruct the second apparatus 120 to monitor the data to send on the side link channel, as will be discussed in detail in connection with fig. 5A and 5B.

In the above embodiment, the resource allocation scheme may further indicate the first set of resources { t } ₁ ，f ₁ ，c ₁ And the second group of resources { t } ₂ ，f ₂ ，c ₂ The correspondence between { t }, which can be expressed as ₁ ，f ₁ ，c ₁ }＝f({t ₂ ，f ₂ ，c ₂ }) where t _i Representing time resources in the time domain, f _i Representing frequency resources in the frequency domain, c _i Representing code (code) resources. In this way, the terminal device may further obtain a correspondence from the resource allocation scheme and determine the second set of resources from the candidate resources based on the correspondence.

Fig. 5A illustrates another example configuration 510 of a DRX procedure according to some example embodiments of the present disclosure. As shown, the resource pool includes a plurality of frequency/time/code resources { t } for side link communication _i ，f _i ，c _i And boxes represented as various patterns. Similar to configuration 400, the boxes of the grid pattern represent candidate resources indicated by the resource allocation scheme, and the boxes of the bar pattern represent a first set of resources { t } selected from the candidate resources for transmission of the first sidelink signal ₁ ，f ₁ ，c ₁ }. Furthermore, the boxes of the dotted pattern represent the second set of resources { t } ₂ ，f ₂ ，c ₂ }. According to configuration 510, the second set of resources may be determined as follows:

{t ₂ ，f ₂ ，c ₂ }＝{t ₁ +(n-1)T，f ₁ ，c ₂ } (1)

wherein n is a positive integer, and c ₂ ≠c ₁ 。

As shown in configuration 510, the first side-link signal and the second side-link signal are configured to occupy the same frequency resource but different code resources. For example, the first side link signal and the second side link signal may employ the same Zadoff-Chu sequence but different cyclic shifts, and the cyclic shift employed by the second side link signal may be inferred from the cyclic shift employed by the first side link signal. As shown in fig. 5A, the second device 120 successfully detects the first side link signal on the first set of resources prior to the on-duration 501, the second device 120 may remain in DRX mode and ignore the on-duration 501. Subsequently, since the second device 120 fails to detect the first sidelink signal and successfully detects the second sidelink signal on the second set of resources prior to the on-duration 502, the second device 120 may know that there may be potential data to transmit on the sidelink channel and monitor the data transmitted on the sidelink channel during the on-duration 502 accordingly.

Fig. 5B illustrates yet another example configuration 520 of a DRX procedure according to some example embodiments of the present disclosure. As shown, the resource pool includes a plurality of frequency/time/code resources { t } for side link communication _i ，f _i ，c _i And boxes represented as various patterns. Similar to

configurations

400 and 510, the boxes of the grid pattern represent candidate resources indicated by the resource allocation scheme, and the boxes of the bar pattern represent a first set of resources { t } selected from the candidate resources for transmission of the first sidelink signal ₁ ，f ₁ ，c ₁ }. Furthermore, the boxes of the dot pattern represent the second set of resources { t } ₂ ，f ₂ ，c ₂ }. According to configuration 520, the second set of resources may be determined as follows:

{t ₂ ，f ₂ ，c ₂ }＝{t ₁ +(n-1)T，f ₁ +mF，c ₁ } (2)

where n is a positive integer, c ₂ ＝c ₁ mF represents a frequency offset.

As shown in configuration 520, the first side link signal and the second side link signal occupy different frequency resources but have a fixed relationship, e.g., m=3, and F represents the number of RBs occupied by the side link DRX signal, as shown in fig. 5B. As shown in fig. 5B, the second device 120 successfully detects the first sidelink signal on the first set of resources before the on-duration 503, the second device 120 may remain in the DRX mode and ignore the on-duration 503. Subsequently, since the second device 120 fails to detect the first sidelink signal and successfully detects the second sidelink signal on the second set of resources prior to the on-duration 504, the second device 120 may know that there may be potential data to transmit on the sidelink channel and monitor the data transmitted on the sidelink channel during the on-duration 504 accordingly.

It should be understood that the

configurations

510 and 520 shown in fig. 5A and 5B are set forth herein as example implementations and should not be construed as limiting the scope of the present disclosure in any way. Those skilled in the art will appreciate that there are many different correspondences and configurations of the first side link signal and the second side link signal based on actual needs.

Still referring to fig. 3, based on the results of the monitoring, the second device 120 determines 360 that there is data to transmit on the side link channel, for example, blocks represented by the diagonal pattern (slope pattern) shown in fig. 4, 5A and 5B. The second device 120 may enter an active mode and be ready to receive additional data from the first device 110. In some example embodiments, the second device 120 may send 365 a second message to the first device 110 indicating that the second device 120 is in an active mode. The second message includes, but is not limited to, an Acknowledgement (ACK) or Negative Acknowledgement (NACK) for data transmission on a physical side link feedback channel (PSFCH). The resources for data transmission on the side link channel during the on-duration may be selected based on the sensing-based resource selection performed by the first apparatus 110.

If a second message is received from the second device 120, the first device 110 may send 370 additional data to the second device 120 on a side link channel. Otherwise, if the first device 110 fails to receive the second message from the second device 120, the first device 110 may perform 375 retransmission of the second sidelink signal, e.g., until the second message is received from the second device 120. The data transmission between the first device 110 and the second device 120 may then be performed 380, for example, in a continuous reception manner.

In other example embodiments, instead of the receipt of the second message, the first device 110 may send data directly on the side link channel during the subsequent time slot.

The time offset from the time slot containing the second side link signal to the starting time slot of the subsequent on-duration may be (pre) configured by the third device 130 or at the first device 110 and the second device 120.

Alternatively, in other example embodiments, the first device 110 may rely on any suitable upper layer protocol to identify that the second device 120 has received the second side chain signal and entered the active mode.

According to example embodiments of the present disclosure, the period (period) of the DRX procedure, including the period of time that the first device 110 transmits the side link DRX signal (e.g., the first side link signal and/or the second side link signal), may be determined based on the data traffic characteristics and the delay requirements of the side link communication. In contrast to conventional DRX procedures, the period of the proposed DRX procedure may be negotiated between the first device 110 and the second device 120. In some example embodiments, the period of the DRX procedure may be the same as the period of the resources for the side link DRX signal determined by the network device or preconfigured at the terminal device.

In some other example embodiments, the period of the DRX procedure may be different from the period of the resources for the side link DRX signal. The period of the DRX procedure (e.g., 100 ms) may be a multiple of the period of the (pre) configured resources for the side link DRX signal (e.g., 50 ms). The period for transmission of the side link DRX signal at the first device 110 and the corresponding period for detection of the side link DRX signal at the second device 120 may follow a period of the DRX procedure (e.g., 100 ms), i.e., the transmission and reception of the side link DRX signal is performed every 100 ms.

Alternatively, the period for transmission of the side link DRX signal at the first device 110 may follow a period (e.g., 50 ms) of a (pre) configuration of resources for the side link DRX signal. The corresponding period for detection of the side link DRX signal at the second device 120 may also follow a period (e.g., 100 ms) of the DRX procedure. In this way, sensing of resources occupied by side link DRX signals at other terminal devices, such as the fourth apparatus 140, may be facilitated and expedited.

According to an example embodiment of the present disclosure, a solution for a DRX procedure is provided. By means of the side link DRX signal, either a separate first side link signal or a first side link signal and a second side link signal together, the resource selection of the DRX procedure may be more flexible and thus resource conflicts between different terminal devices may be avoided. In this way, the power consumption of the terminal device can be significantly reduced while improving the feasibility and flexibility of the resource selection of the DRX scheme.

Fig. 6 illustrates a flowchart of an example method 600 for a DRX procedure, according to some example embodiments of the present disclosure. The method 600 may be implemented at a terminal device, for example, the first apparatus 110 described with reference to fig. 1. The method 600 may also involve the second device 120, the third device 130, and the fourth device 140. It should be understood that method 600 may include additional acts not shown and/or may omit some acts shown, and the scope of the present disclosure is not limited in this respect. Further, it should be appreciated that although primarily depicted and described herein as being performed serially, at least a portion of the acts of process 600 may be performed contemporaneously with, or in a different order than depicted in fig. 6.

At 610, the first device 110 determines a first set of resources for transmission of a first sidelink signal to the second device 120. The first side link signal indicates that the second device 120 remains in the DRX mode.

In some example embodiments, the first apparatus 110 may determine the first set of resources from among candidate resources indicated by the resource allocation scheme. In this case, the first apparatus 110 may receive the resource allocation scheme from the third apparatus 130. Alternatively, in other example embodiments, the resource allocation scheme indicating the candidate resources may be predefined or preconfigured at the first apparatus 110. Furthermore, terminal devices assigned the same resource pool for side-link communication may utilize the same resource allocation scheme to coordinate resource selection and avoid collisions.

In some example embodiments, the first apparatus 110 may determine at least one unused resource from the candidate resources by sensing over the candidate resources in the sensing window. For example, the first apparatus 110 may sense a first side link signal transmitted by the fourth apparatus 140 on a specific candidate resource, and thus, unused candidate resources may be determined based on the sensing result. The first device 110 may then determine a first set of resources from the at least one unused resource.

At 620, the first device 110 sends a first message indicating the first set of resources to the second device 120 in the active mode. The reception of the first message causes the second device 120 to detect the first side link signal on the first set of resources in the DRX mode.

In some example embodiments, the first device 110 may determine whether there is data to send on a side link channel between the first device 110 and the second device 120. If the first device 110 determines that there is no data to send to the second device 120, the first device 110 may send a first sidelink signal to the second device 120 on at least one of the resources in the first set.

The first sidelink signal may be periodically transmitted to the second device 120. In some example embodiments, if the first device 110 determines that there is data to send on the sidelink channel, the first device 110 may suspend transmission of the first sidelink signal on the first set of resources.

Alternatively, in other example embodiments, if the first device 110 determines that there is data to send on the side link channel, the first device 110 may send a second side link signal to the second device 120 on a second set of resources. The second side link signal is configured to instruct the second device 120 to monitor data to be transmitted on the side link channel.

In some example embodiments, the first apparatus 110 may determine the second set of resources from candidate resources for transmission of the side link signal and based on a correspondence between the first set of resources and the second set of resources. In this case, the side link signals include a first side link signal and a second side link signal, and the second side link signal instructs the second device 120 to monitor data to be transmitted on the side link channel between the first device and the second device.

In some example embodiments, the first apparatus 110 may determine the second set of resources based on a resource allocation scheme indicating candidate resources and correspondence. As described above, the resource allocation scheme may be received from the third apparatus 130 or, alternatively, predefined at the first apparatus 110.

Upon detecting the absence of the first side link signal, or alternatively upon receiving the second side link signal, the second device 120 knows that there is likely to be data to be sent on the next on-duration. In this case, the second device 120 may monitor potential control and data transmissions on the PSCCH and PSSCH during the next on-duration. If the second device 120 determines that the data of interest is transmitted, for example, by decoding the PSCCH and PSSCH, the second device 120 may transmit a second message to the first device 110 indicating that the second device 120 is in an active mode and ready to receive additional data from the first device 110. The second message may include an ACK or NACK for data transmission. In such an embodiment, upon receiving the second message, the first device 110 may send additional data to the second device 120 over the side link channel. Otherwise, if the first device 110 fails to receive the second message from the second device 120 within the predetermined period of time, the first device 110 may perform retransmission of the second side-chain signal.

Fig. 7 illustrates a flowchart of an example method 700 for a DRX procedure, according to some example embodiments of the present disclosure. The method 700 may be implemented at a terminal device, for example, the second apparatus 120 described with reference to fig. 1. For ease of discussion, the method 700 will be described with reference to fig. 1. The method 700 may also involve the first apparatus 110, the third apparatus 130, and the fourth apparatus 140. It should be understood that process 700 may include additional acts not shown and/or may omit some acts shown, and the scope of the present disclosure is not limited in this respect. Further, it should be appreciated that although primarily presented herein as being performed serially, at least a portion of the acts of method 700 may be performed contemporaneously with, or in a different order than, the acts illustrated in fig. 7.

Initially, the second device 120 may be in an active mode. At 710, a first message is received from the first apparatus 110, the first message indicating a first set of resources for transmission of a first sidelink signal. The first side link signal is configured to indicate that the second apparatus 120 remains in the DRX mode.

Upon receiving the first message, the second device 120 detects 720 a first side link signal on a first set of resources in DRX mode. In some example embodiments, the second apparatus 120 remains in the DRX mode in the event that the first side link signal is detected on at least one of the resources in the first set. In the event that the first sidelink signal is not detected on a corresponding resource in the first set of resources, the second device 120 knows that there may be data of interest to send on the sidelink channel during the next on-duration. In this case, the second device 120 monitors the data transmitted on the side-link channel for a preconfigured duration.

In some example embodiments, a resource allocation scheme is used to indicate candidate resources for transmission of side link DRX signals including a first side link signal and a second side link signal, and a correspondence between the first set of resources and a second set of resources for transmission of the second side link signal. The second side-link signal is configured to instruct the second device 120 to monitor the side-link channel. In this case, the second device 120 may receive the resource allocation scheme from the third device 130. Alternatively, in other example embodiments, the resource allocation scheme may be predefined or preconfigured at the second apparatus 120.

In the above-described embodiment, the second apparatus 120 may determine the second set of resources for transmission of the second side link signal according to the candidate resources and based on the correspondence. The second apparatus 120 remains in the DRX mode if the first side link signal is detected on at least one of the resources in the first set. Otherwise, if the first sidelink signal is not detected on a corresponding resource in the first set of resources, the second device 120 knows that there may be data of interest to send on the sidelink channel during the next on-duration. In this case, the second device 120 detects a second side-chain signal on a second set of resources.

Fig. 8 illustrates a flowchart of an example method for a DRX procedure, according to some example embodiments of the present disclosure. The method 800 may be implemented at a network device, for example, the third apparatus 130 described with reference to fig. 1. For ease of discussion, the method 800 will be described with reference to fig. 1. The method 800 may also involve the first device 110 and the second device 120. It should be understood that process 800 may include additional acts not shown and/or may omit some acts shown, and the scope of the present disclosure is not limited in this respect. Further, it should be appreciated that although primarily presented herein as being performed serially, at least a portion of the acts of method 800 may be performed contemporaneously with, or in a different order than, the acts illustrated in fig. 8.

At 810, the third apparatus 130 determines a resource allocation scheme indicating candidate resources for transmission of the first sidelink signal from the first apparatus 110 to the second apparatus 120. In an example embodiment, the first side link signal is configured to instruct the second apparatus 120 to remain in DRX mode. In some example embodiments, the third apparatus 130 may determine a correspondence between the first set of resources and a second set of resources for transmission of the second sidelink signal to the second apparatus 120. As described above, the second sidelink signal is configured to instruct the second device 120 to monitor a sidelink channel, such as a PSCCH or/and a PSSCH, between the first device 110 and the second device 120. In such an embodiment, the third apparatus 130 may determine a resource allocation scheme indicating the correspondence and the candidate resources.

At 820, the third device 130 transmits the resource allocation scheme to the first device 110 and the second device 120.

In some example embodiments, a first apparatus (e.g., first apparatus 110) capable of performing method 600 may include means for performing the respective steps of method 600. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. The first apparatus may be implemented as the first apparatus 110 or included in the first apparatus 110. In some embodiments, the component may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the first apparatus to perform.

In some example embodiments, a first apparatus includes means for determining a first set of resources for transmission of a first sidelink signal to a second apparatus, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and means for sending a first message to a second apparatus in an active mode indicating a first set of resources to cause the second apparatus to detect a first sidelink signal on the first set of resources in a discontinuous reception mode.

In some example embodiments, the means for determining the first set of resources comprises means for determining the first set of resources from candidate resources for transmission of at least one side link signal, the at least one side link signal comprising the first side link signal. In some example embodiments, the candidate resources are indicated by a resource allocation scheme received from the third apparatus or predefined at the first apparatus.

In some example embodiments, the means for determining the first set of resources comprises: means for determining at least one unused resource from the candidate resources by sensing on the candidate resources in the sensing window; and means for determining a first set of resources from the at least one unused resource.

In some example embodiments, the first apparatus further comprises means for transmitting the first sidelink signal to the second apparatus on at least one of the resources in the first set in accordance with a determination that there is no data to transmit on the sidelink channel between the first apparatus and the second apparatus.

In some example embodiments, the first sidelink signal is periodically transmitted to the second apparatus, and the first apparatus further comprises means for suspending transmission of the first sidelink signal on the first set of resources in accordance with a determination that data is to be transmitted on the sidelink channel between the first apparatus and the second apparatus.

In some example embodiments, the first apparatus further comprises: means for determining a second set of resources from the candidate resources for transmission of the side link signals based on a correspondence between the first set of resources and the second set of resources for transmission of the second side link signals, the side link signals including the first side link signal and the second side link signal, and the second side link signal instructing the second device to monitor data to be transmitted on the side link channel between the first device and the second device.

In some example embodiments, the means for determining the second set of resources comprises means for determining the second set of resources based on a resource allocation scheme indicating candidate resources and correspondence, the resource allocation scheme being received from the third apparatus or predefined at the first apparatus.

In some example embodiments, the first apparatus further comprises means for transmitting a second side-link signal to the second apparatus on a second set of resources in accordance with a determination that there is data to transmit on the side-link channel.

In some example embodiments, the first apparatus further comprises: means for transmitting further data to the second device on the side link channel in response to receiving a second message from the second device, the second message comprising an acknowledgement or negative acknowledgement of the transmission of the data; and means for performing retransmission of the second side chain signal in response to failing to receive the second message from the second device within a predetermined period of time.

In some example embodiments, the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

In some example embodiments, a second apparatus (e.g., second apparatus 120) capable of performing method 700 may include means for performing the respective steps of method 700. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. In some embodiments, the component may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the second apparatus to perform. The second apparatus may be implemented as the second apparatus 120 or included in the second apparatus 120.

In some example embodiments, a second apparatus includes means for receiving a first message from a first apparatus in an active mode, the first message indicating a first set of resources for transmission of a first sidelink signal, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and means for detecting the first side link signal on the first set of resources in the discontinuous reception mode.

In some example embodiments, the second apparatus further comprises: means for maintaining in discontinuous reception mode in accordance with a determination that a first sidelink signal is detected on at least one of the resources in the first set; and means for monitoring data transmitted on a side-link channel between the first device and the second device for a pre-configured duration in accordance with a determination that the first side-link signal is not detected on a corresponding resource in the first set of resources.

In some example embodiments, the second apparatus further comprises: means for determining a second set of resources based on a correspondence between the first set of resources and a second set of resources for transmission of a second side-chain signal, the second side-chain signal indicating that the second device monitors a side-chain channel between the first device and the second device.

In some example embodiments, the means for determining the second set of resources comprises: means for determining a second set of resources from candidate resources for transmission of a side link signal from the first device, the side link signal comprising a first side link signal and a second side link signal.

In some example embodiments, the candidate resources and the correspondence are indicated by a resource allocation scheme received from the third apparatus or predefined at the second apparatus.

In some example embodiments, the second apparatus further comprises: means for maintaining in discontinuous reception mode in accordance with a determination that a first sidelink signal is detected on at least one of the resources in the first set; and means for detecting a second side link signal on the second set of resources in accordance with a determination that the first side link signal was not detected on a corresponding resource in the first set of resources.

In some example embodiments, the second apparatus further comprises: means for maintaining in discontinuous reception mode in accordance with a determination that a second side-chain signal is not detected on a corresponding resource in the second set of resources; and means for monitoring data transmitted on the side-link channel for a pre-configured duration in accordance with a determination that a second side-link signal is detected on a corresponding resource in the second set of resources.

In some example embodiments, the second apparatus further comprises: means for determining, based on the monitoring results, that no data is being transmitted on the side-link channel for a preconfigured duration to remain in discontinuous reception mode; and means for entering an active mode in accordance with a determination based on the monitoring that there is data sent on the side-link channel for a preconfigured duration.

In some example embodiments, the second apparatus further comprises means for sending a second message to the first apparatus indicating that the second apparatus is in an active mode in accordance with a determination that data is sent on the side link channel, the second message comprising an acknowledgement or negative acknowledgement of the transmission of the data.

In some example embodiments, a third apparatus (e.g., third apparatus 130) capable of performing method 800 may include means for performing the respective steps of method 800. The component may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules. In some embodiments, the component may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the third apparatus to perform. The third apparatus may be implemented as the third apparatus 130 or included in the third apparatus 130.

In some example embodiments, the third apparatus includes: means for determining candidate resources for transmission of a first sidelink signal from a first device to a second device, the first sidelink signal indicating that the second device remains in a discontinuous reception mode; and means for transmitting a resource allocation scheme indicating the candidate resource to the first apparatus and the second apparatus.

In some example embodiments, the means for determining the resource allocation scheme comprises: means for determining a correspondence between the first set of resources and a second set of resources for transmission of a second side link signal to a second device, the second side link signal indicating that the second device monitors a side link channel between the first device and the second device; and means for determining a resource allocation scheme indicating the correspondence and the candidate resource.

Fig. 9 is a simplified block diagram of a device 900 suitable for implementing embodiments of the present disclosure. The apparatus 900 may be provided to implement a communication device, for example, the first device 110, the second device 120, the third device 130, and the fourth device 140 as shown in fig. 1. As shown, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processors 910, and one or more communication modules 940 coupled to the processors 910.

The communication module 940 is used for two-way communication. The communication module 940 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary to communicate with other network elements.

The processor 910 may be of any type suitable to the local technical network and may include, by way of non-limiting example, one or more of the following: general purpose computers, special purpose computers, microprocessors, digital Signal Processors (DSPs), and processors based on a multi-core processor architecture. The device 900 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock that is synchronized to the master processor.

Memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read-only memory (ROM) 924, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact Disks (CD), digital Video Disks (DVD), and other magnetic and/or optical storage. Examples of volatile memory include, but are not limited to, random Access Memory (RAM) 922 and other volatile memory that does not persist during power outages.

The computer program 930 includes computer-executable instructions that are executed by the associated processor 910. Program 930 may be stored in ROM 920. Processor 910 may perform any suitable actions and processes by loading program 930 into RAM 922.

Embodiments of the present disclosure may be implemented by the program 930 such that the device 900 may perform any of the processes of the present disclosure discussed with reference to fig. 6-8. Embodiments of the present disclosure may also be implemented in hardware or by a combination of software and hardware.

In some embodiments, the program 930 may be tangibly embodied in a computer-readable medium that may be included in the device 900 (such as in the memory 920) or other storage device that the device 900 may access. Device 900 may load program 930 from a computer-readable medium into RAM 922 for execution. The computer readable medium may include any type of tangible, non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Fig. 10 shows an example of a computer readable medium 1000, which may be in the form of a CD or DVD. The computer-readable medium has stored thereon the program 930.

In general, the various embodiments of the disclosure may be implemented using hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product comprises computer executable instructions, such as instructions included in a program module, that are executed in a device on a target real or virtual processor to perform any of the methods 600 to 800 described above with reference to fig. 6-8. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as desired. Machine-executable instructions of program modules may be executed within local or distributed devices. In a distributed device, program modules may be located in both local and remote memory storage media.

Program code for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus such that the program code, when executed by the processor or controller, causes the functions/operations specified in the flowchart and/or block diagram to be implemented. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable an apparatus, device or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are described in a particular order, this should not be construed 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. In some cases, multitasking and parallel processing may be advantageous. Also, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described 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 subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first apparatus at least to:

determining a first set of resources for transmission of a first sidelink signal to a second apparatus, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and

a first message is sent to the second apparatus in an active mode indicating the first set of resources to cause the second apparatus to detect the first sidelink signal on the first set of resources in the discontinuous reception mode.

2. A first apparatus according to claim 1, wherein the first apparatus is caused to determine the first set of resources by:

The first set of resources is determined from candidate resources for transmission of at least one side link signal, the at least one side link signal comprising the first side link signal.

3. The first apparatus of claim 2, wherein the candidate resources are indicated by a resource allocation scheme received from a third apparatus or predefined at the first apparatus.

4. A first apparatus according to claim 1, wherein the first apparatus is further caused to determine the first set of resources by:

determining at least one unused resource by sensing on the candidate resources in the sensing window; and

the first set of resources is determined from the at least one unused resource.

5. The first apparatus of claim 1, wherein the first apparatus is further caused to:

in accordance with a determination that there is no data to send on a sidelink channel between the first device and the second device, the first sidelink signal is sent to the second device on at least one of the resources in the first set.

6. The first apparatus of claim 1, wherein the first sidelink signal is periodically transmitted to the second apparatus, and the first apparatus is further caused to:

In accordance with a determination that there is data to send on a sidelink channel between the first device and the second device, the transmission of the first sidelink signal on the first set of resources is suspended.

7. The first apparatus of claim 1, wherein the first apparatus is further caused to:

the method further includes determining, from candidate resources for transmission of a side link signal, a second set of resources based on a correspondence between the first set of resources and the second set of resources for transmission of the second side link signal, the side link signal including the first side link signal and the second side link signal, and the second side link signal indicating that the second device monitors data to be transmitted on a side link channel between the first device and the second device.

8. The first apparatus of claim 7, wherein the first apparatus is caused to determine the second set of resources by:

the second set of resources is determined based on a resource allocation scheme indicating the candidate resources and the correspondence, the resource allocation scheme being received from a third device or predefined at the first device.

9. The first apparatus of claim 7, wherein the first apparatus is further caused to:

In accordance with a determination that there is data to send on the side link channel, the second side link signal is sent to the second device on the second set of resources.

10. The first apparatus of claim 9, wherein the first apparatus is further caused to:

transmitting further data to the second device on the side link channel in response to receiving a second message from the second device, the second message comprising an acknowledgement or negative acknowledgement of the transmission of the data; and

in response to failing to receive the second message from the second device within a predetermined period of time, a retransmission of the second side-chain signal is performed.

11. The first apparatus according to any of claims 1 to 10, wherein the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

12. A second apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second apparatus at least to:

In an active mode and receiving a first message from a first apparatus, the first message indicating a first set of resources for transmission of a first sidelink signal, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and

the first sidelink signal is detected on the first set of resources in the discontinuous reception mode.

13. A second apparatus according to claim 12, wherein the second apparatus is further caused to:

in accordance with a determination that the first sidelink signal is detected on at least one of the resources in the first set, maintaining in the discontinuous reception mode; and

in accordance with a determination that the first sidelink signal is not detected on a corresponding resource in the first set of resources, data transmitted on a sidelink channel between the first device and the second device is monitored for a preconfigured duration.

14. A second apparatus according to claim 12, wherein the second apparatus is further caused to:

the second set of resources is determined based on a correspondence between the first set of resources and a second set of resources for transmission of a second side link signal that instructs the second device to monitor a side link channel between the first device and the second device.

15. A second apparatus according to claim 14, wherein the second apparatus is caused to determine the second set of resources by:

the second set of resources is determined from candidate resources for transmission of a side link signal from the first device, the side link signal comprising the first side link signal and the second side link signal.

16. The second apparatus of claim 15, wherein the candidate resources and the correspondence are indicated by a resource allocation scheme received from a third apparatus or predefined at the second apparatus.

17. A second apparatus according to claim 14, wherein the second apparatus is further caused to:

in accordance with a determination that the first side-link signal is not detected on a corresponding resource in the first set of resources, the second side-link signal is detected on the second set of resources.

18. A second device according to claim 17, wherein the second device is further caused to:

In accordance with a determination that the second side-chain signal is not detected on a corresponding resource in the second set of resources, maintaining in the discontinuous reception mode; and

and monitoring the data sent on the side-link channel for a preconfigured duration according to the determination that the second side-link signal is detected on the corresponding resource in the second group of resources.

19. A second device according to claim 13 or 18, wherein the second device is further caused to:

determining that no data is transmitted on the side link channel for the preconfigured duration according to the monitoring result, and keeping in the discontinuous reception mode; and

and determining that data is transmitted on the side link channel in the preset duration time according to the result based on the monitoring, and entering the active mode.

20. A second device according to claim 18, wherein the second device is further caused to:

in accordance with a determination that data is sent on the side link channel, a second message is sent to the first device indicating that the second device is in the active mode, the second message including an acknowledgement or negative acknowledgement of the transmission of the data.

21. The second apparatus according to any of claims 14 to 20, wherein the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

22. A third apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third apparatus at least to:

determining candidate resources for transmission of a first side link signal from a first apparatus to a second apparatus, the first side link signal indicating that the second apparatus remains in discontinuous reception mode; and

and transmitting a resource allocation scheme indicating the candidate resource to the first device and the second device.

23. The third apparatus of claim 22, wherein the third apparatus is further caused to:

determining a correspondence between the first set of resources and a second set of resources for transmission of a second side link signal to the second device, the second side link signal indicating that the second device monitors a side link channel between the first device and the second device; and

Wherein the third apparatus is caused to transmit the resource allocation scheme by:

and sending the resource allocation scheme indicating the corresponding relation and the candidate resource.

24. The third apparatus according to claim 22 or 23, wherein the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

25. A method, comprising:

determining, at a first apparatus, a first set of resources for transmission of a first sidelink signal to a second apparatus, the first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode;

26. The method of claim 25, wherein determining the first set of resources comprises:

27. The method of claim 26, wherein the candidate resources are indicated by a resource allocation scheme received from a third apparatus or predefined at the first apparatus.

28. The method of claim 25, further comprising:

29. The method of claim 25, wherein determining the first set of resources comprises:

the first set of resources is determined from the at least one unused resource.

30. The method of claim 25, wherein the first sidelink signal is periodically transmitted to the second device, and the method further comprises:

31. The method of claim 25, further comprising:

32. The method of claim 31, wherein determining the second set of resources comprises:

33. The method of claim 31, further comprising:

34. The method of claim 33, further comprising:

35. A method according to any of claims 25 to 34, wherein the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

36. A method, comprising:

receiving, at a second apparatus in an active mode and from a first apparatus, a first message indicating a first set of resources for transmission of a first side link signal indicating that the second apparatus remains in a discontinuous reception mode; and

37. The method of claim 36, further comprising:

38. The method of claim 36, further comprising:

39. The method of claim 38, wherein determining the second set of resources comprises:

40. The method of claim 39, wherein the candidate resources and the correspondence are indicated by a resource allocation scheme received from a third device or predefined at the second device.

41. The method of claim 38, further comprising:

42. The method of claim 41, further comprising:

43. The method of claim 37 or 42, further comprising:

44. The method of claim 43, further comprising:

45. The method of any one of claims 36 to 44, wherein the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

46. A method, comprising:

at a third apparatus, determining candidate resources for transmission of a first side link signal from a first apparatus to a second apparatus, the first side link signal indicating that the second apparatus remains in discontinuous reception mode; and

47. The method of claim 46, wherein the method further comprises:

wherein transmitting the resource allocation scheme comprises:

48. The method of claim 46 or 47, wherein the first apparatus is a terminal device, the second apparatus is a further terminal device, and the third apparatus is a network device.

49. A first apparatus, comprising:

determining, at the first apparatus, a first set of resources for transmission of a first sidelink signal to a second apparatus, the first sidelink signal indicating that the second apparatus remains in discontinuous reception mode;

Means for sending a first message to the second apparatus in an active mode indicating the first set of resources to cause the second apparatus to detect the first sidelink signal on the first set of resources in the discontinuous reception mode.

50. A second apparatus, comprising:

means for receiving, at the second apparatus in an active mode and from a first apparatus, a first message indicating a first set of resources for transmission of a first sidelink signal indicating that the second apparatus remains in a discontinuous reception mode; and

means for detecting the first sidelink signal on the first set of resources in the discontinuous reception mode.

51. A third apparatus, comprising:

determining, at the third apparatus, candidate resources for transmission of a first sidelink signal from a first apparatus to a second apparatus, the first sidelink signal indicating that the second apparatus remains in discontinuous reception mode; and

52. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any one of claims 25 to 35.

53. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any one of claims 36 to 45.

54. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any one of claims 46 to 48.