WO2023279265A1

WO2023279265A1 - Mechanism for distributed channel occupancy time sharing

Info

Publication number: WO2023279265A1
Application number: PCT/CN2021/104838
Authority: WO
Inventors: Vinh Van Phan; Ling Yu; Lianghai JI; Nuno Manuel KIILERICH PRATAS; Tao Tao; Yong Liu; Naizheng ZHENG; Torsten WILDSCHEK
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2021-07-06
Filing date: 2021-07-06
Publication date: 2023-01-12
Also published as: CN117643159A

Abstract

Embodiments of the present disclosure relate to distributed channel occupancy time sharing. According to embodiments of the present disclosure, a first device determines a channel occupancy time for sidelink transmission on an unlicensed band. The first device determines at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device. The first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band. The first device transmits at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information. In this way, it achieves efficient channel access to make sure coexistence fairness to other device and system. It can support COT sharing mechanism without any grouping for unlicensed sidelink.

Description

MECHANISM FOR DISTRIBUTED CHANNEL OCCUPANCY TIME SHARING

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for distributed channel occupancy time (COT) sharing.

BACKGROUND

With development of communication technologies, different communication scenarios have been proposed. For example, sidelink communication has been proposed. Sidelink is the special kind of communication mechanism between device and device without going through a network device. The technology of “sidelink” can be applied to various scenarios, for example, vehicle-to-vehicle (V2V) , vehicle-to-everything (V2X) and the like. The device may generally perform a clear channel assessment (CCA) on an unlicensed spectrum band before performing the sidelink communication on the unlicensed spectrum band, in order to determine that the unlicensed spectrum band is not occupied by other device (s) or system (s) . If the CCA is successful, the device can access the channel for a certain period of time which can be represented as “channel occupancy time (COT) . ” It is worthy to study how to share the COT properly.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for distributed channel occupancy time sharing.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to: determine a channel occupancy time for sidelink transmission on an unlicensed band; determine at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band ; and transmit, at the first device, at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to receive, at a second device and from at least one first device, at least one of: at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; determine, at the second device, a target configuration from the at least one of the at least one first configuration and the at least one second configuration; and perform the sidelink communication based on the target configuration.

In a third aspect, there is provided a method. The method comprises determining, at a first device, a channel occupancy time for sidelink transmission on an unlicensed band; determining, at the first device, at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; and transmitting, at the first device, at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information.

In a fourth aspect, there is provided a method. The method comprises receiving, at a second device and from at least one first device, at least one of: at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; determining, at the second device, a target configuration from the at least one of: the at least one first configuration and the at least one second configuration; and performing, at the second device, the sidelink communication based on the target configuration.

In a fifth aspect, there is provided an apparatus. The apparatus comprise means for determining, at a first device, a channel occupancy time for sidelink transmission on an unlicensed band; means for determining, at the first device, at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; and means for transmitting, at the first device, at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information.

In a sixth aspect, there is provided an apparatus. The apparatus comprises means for receiving, at a second device and from at least one first device, at least one of at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; means for determining, at the second device, a target configuration from the at least one of: the at least one first configuration and the at least one second configuration; and means for performing, at the second device, the sidelink communication based on the target configuration.

In a seventh aspect, there is provided a computer readable medium. The computer readable medium comprises program instructions for causing an apparatus to perform at least the method according to any one of the above third or fourth aspect.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1 illustrates a schematic diagram of a COT according to conventional technologies;

Figs. 2A and 2B illustrate schematic diagrams of transmission gaps during the COT according to conventional technologies;

Fig. 3 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

Fig. 4 illustrates a signaling flow for sharing COT according to some example embodiments of the present disclosure;

Fig. 5 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

Fig. 6 illustrates a flowchart of a method implemented at a second apparatus according to some other example embodiments of the present disclosure;

Fig. 7 illustrates a simplified block diagram of an apparatus that is suitable for implementing example embodiments of the present disclosure; and

Fig. 8 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones 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 skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall 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 one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. 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” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

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

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated and Access Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. The term “terminal device” refers to any end device that may be capable of wireless communication. In the following description, the terms “terminal device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As mentioned above, sidelink communication has been proposed. Recently, sidelink communication in unlicensed spectrum, also referred to as unlicensed sidelink for short or denoted as SL-U, is getting more interesting due to the following potential benefits. Stand-alone NR-U is a key enabler for private network in industrial automation. Unlicensed sidelink can provide additional benefits and value-added services in complex industrial scenario: coverage extension for the challenging conditions: high path loss (in coverage hole) , strictly regulated TX power; service reliability enhancement by using multiple transmission paths; potential low latency coming from direct sidelink transmission, no need to convey from gNB.

In sub-7GHz unlicensed bands, the NR coexistence with other systems is ensured via a listen-before-talk (LBT) channel access mechanism. Where, a UE intending to perform a sidelink transmission needs first to successfully complete an LBT check, before being able to initiate that same transmission.

For a UE to pass an LBT check it must observe the channel as available for a number of consecutive Clear Channel Assessment (CCA) slots. In sub-7GHz the duration of each of these slots is 9 μs. The UE deems the channel as available in a CCA slot if the measured power (i.e. the collected energy during the CCA slot) is below a regulatory specified threshold (which can depend on the operating band and geographical region) . The term “listen-before-talk (LBT) ” used herein refers to a technique used in radio communications whereby a radio transmitter first sense its radio environment before it starts a transmission. LBT can be used by a radio device to find a network the device is allowed to operate on or to find a free radio channel to operate on. For example, signal detection (SD) may be used in the LBT. A SD threshold can be sometimes referred to as the preamble carrier sense threshold. Only as an example, the SD threshold can be statistically around 4 dB signal-to-noise ratio (SNR) for most radios to detect and decode a preamble. In other words, a radio can usually decode any incoming preamble transmissions at a received signal at about 4 dB above the noise floor. Alternatively, energy detection may be used in the LBT.

Support for NR-based access to unlicensed spectrum (NR-U) has been introduced. NR operation in unlicensed bands relies on the transmitting device sensing the radio resources (the medium) before commencing transmission. Different types of LBT procedures are defined for NR-based access to unlicensed spectrum. The channel access types supported are summarized in the following table 1.

Table 1

The term “clear channel assessment (CCA) ” used herein refers to a technique to appraise the RF medium. The CCA may involve listening for RF transmissions at the Physical layer radios use a CCA threshold when listening to the RF medium. For example, energy detection may be used in the CCA. The energy detection (ED) threshold is used to detect any other type of RF transmissions during the CCA. If energy detected on the channel is less than an energy detection threshold, the channel can be regarded as available for performing transmissions. If the energy detected on the channel is larger than an energy detection threshold, the channel can be regarded as busy.

When a UE initiates the communication (i.e. the UE takes the role of initiating device) , then this UE has to acquire the “right” to access the channel for a certain period of time –denoted in the regulations as the Channel Occupancy Time (COT) (for example, the duration 120 shown in Fig. 1) –by applying an “extended” LBT procedure where the channel must be deemed as free for the entire duration of a Contention Window (CW) (shown as the duration 110 in Fig. 1) . This “extended” LBT procedure, is commonly known as LBT type 1. Conventionally, it defines 2 LBT schemes: Type 1 and Type 2. Type 1 LBT, also known as Category 4 LBT (Cat. 4 LBT) , is defined as a continuous sensing of the channel activity for, at least, N CCA intervals (N is a random number obtained from a uniform distribution) . Once the channel is declared as idle, the node can access the channel for a maximum time known as the MCOT. During that time, the node (typically the gNB) can grant access to the served UEs and rely on channel occupancy time (COT) sharing. In COT sharing conditions, UEs are allowed to access the channel by performing Type 2 LBT.

The duration of both the COT and CW depends on the Channel Access Priority Class (CAPC) associated with the UE’s traffic, as shown in Table 1. Control plane traffic (such as PSCCH) is transmitted with p=1, while user plane traffic has p>1. In Table 1, it depicts the LBT Type 1 details for the Uu uplink (UL) case, but the downlink (DL) case LBT Type 1 parameters could also in principle be adopted in SL.

Table 2

The UE initiating the transmission (which can be referred to “an initiating device” ) upon successfully completing the LBT Type 1, acquires the COT with duration associated with the corresponding CAPC and performs a transmission. For example, as shown in Fig. 2A, during the COT 201, the initiating device can perform the

transmissions

211 and 212 and there is a gap 202 between the two transmissions. As shown in Fig. 2B, during the COT 211, the initiating device can perform the transmission 213 and the responding device can perform the transmission 221. There is also a gap 203 between the transmission 213 and the transmission 221. The acquired COT is valid even in the case where the initiating device pauses its transmission, although if the initiating device wants to perform a new transmission (within the COT) it is still required to perform a “reduced” LBT procedure.

This “reduced” LBT procedure, is commonly known as LBT Type 2, with the following variants:

Type 2A (25 μs LBT) –for SL transmissions within the initiating device acquired COT in case the gap between two SL transmissions (for example, the gap 202 and the gap 203 for SL transmissions following another SL transmission) is longer than or equal to 25 μs;

Type 2B (16 μs LBT) –for SL transmission within the initiating device acquired COT in case the gap between two SL transmissions (for example, the gap 202 and the gap 203) exactly equal to 16 μs;

Type 2C (no LBT) –for SL transmission within the initiating device acquired COT in case the gap between two SL transmissions (for example, the gap 202 and the gap 203) is shorter than or equal to 16 μs and the allowed duration of the SL transmission is less than or equal to 574 μs.

The initiating device can share its acquired COT with its intended receiver (the responding device) . For this purpose, the initiating device shall inform (e.g. via control signaling) the responding device about the duration of this COT. The responding device uses this information to decide which type of LBT it should apply upon performing a transmission for which the intended receiver is the initiating device. In case the responding device transmission falls outside the COT, then the responding device will have to acquire a new COT using the LBT Type 1 with the appropriate channel access priority class (CAPC) .

SL communications between UEs over PC5 are based on the principle of transmitter (Tx UE) oriented one-to-many broadcast. On one hand, Tx UE transmits SL to a Rx UE or a group of Rx UEs or all Rx UEs in proximity of Tx UE using resources from a (pre-) configured resource pool, at least for transmitting SL control information (SCI) which is used as a scheduling assignment for a SL data transmission. The term “TX UE” used herein can refer to a UE which can transmit data to another UE when performing sidelink communications with the other UE. The term “RX UE” used herein can refer to a UE which can receive data from another UE when performing sidelink communications with the other UE. On the other hand, Rx UE needs to keep monitoring over the (pre-) configured resource pool to receive SL, at least receiving all SCI instances and determining whether a received SCI and corresponding SL data transmission is meant for Rx UE to receive or not based on Source (SRC) and/or Destination (DST) ID (s) indicated in the received SCI instances, SRC is corresponding to Tx side and DST is corresponding to Rx side. This is applied for all casting types over SL: unicast, groupcast or broadcast.

Conventionally, there are two modes of resource allocation, referred to as Mode 1 and Mode 2, specified for a SL transmission. Mode 1 is based on using scheduled resources or grants from a serving BS. This implies that Tx UE may need to be in radio resource control (RRC) CONNECTED state of the serving BS in order to get Mode 1 resources allocated. Mode 2 is based on autonomous allocation or selection of resources from a preconfigured Tx resource pool by Tx UE. The resource selection in Mode 2 can be based on a simple random selection or sensing-based selection. The latter is preferred and used for normal operation while the former is used for exceptional operations or situations with a particular, preconfigured resource pool. Mode 2 can be used for Tx UE being in coverage (IC) or out-of-coverage (OoC) ; in RRC IDLE, RRC INACTIVE or RRC CONNECTED state. Table 3 below specifies SCI which is used for scheduling a SL transmission and facilitating mode 2 sensing based resource allocation according to 3GPP NR standards.

Table 3

For SL operated in unlicensed band, a SL UE can access the channel for the period of channel occupancy time (COT) after successful “extended” LBT procedure, i.e. LBT type 1. The acquired COT can be shared from the initiating device to the responding devices. The shared COT is valid even in the case where the relevant SL UEs pause their transmissions, but a “reduced” LBT procedure is required if the relevant SL UEs want to perform a new transmission after transmission pause within the COT. The term “channel occupancy time (COT) ” used herein can refer to the total time for which eNB/gNB/UE and any eNB/gNB/UE (s) sharing the channel occupancy perform transmission (s) on a channel after an eNB/gNB/UE performs the corresponding channel access procedures described in this clause. For determining a Channel Occupancy Time, if a transmission gap is less than or equal to 25us, the gap duration is counted in the channel occupancy time. A channel occupancy time can be shared for transmission between an eNB/gNB/UE (s) and the corresponding eNB/gNB/UE (s) .

In case of SL communication, either gNB scheduled mode 1 or sensing based mode 2 resource allocation allows frequency division multiplexing (FDM) among SL transmissions from different SL Tx UEs. Considering COT sharing for SL operated in unlicensed band, in principle all SL UEs can share the same COT without introducing interference among SL transmissions from different UEs due to mode 1 or mode 2 resource allocation designed in SL operation. However, utilizing COT sharing mechanism and defining the scope of COT sharing within different group of SL UEs, it becomes possible to manage the load balance between different SL bands in either licensed or unlicensed band. In addition, due to scheduled or sensing based SL resource allocation (mode 1 and mode 2) , the SL transmission from different SL-U UEs may not interfere with each other. The identification of transmission pause/gap during COT as well as LBT measurement may not only take into account the SL-U UEs sharing the same COT but also other SL transmissions in the targeted unlicensed band to some extent. The principle behind the COT sharing mechanism is the sharing of the channel in U-band, acquired by an initiating device via LBT type 1, with responding device (s) for direct communications between the initiating device and responding device (s) . The initiating device provides information of the acquired COT, referred to as COT sharing information, to responding device (s) so that responding device (s) may use the channel to transmit to at least the initiating device using LBT type 2 (which has less overhead than LBT type 1, as discussed in section 2) .

SL communication, as specified in 3GPP for unicast, groupcast or broadcast, is based on one-to-many broadcast principle and used for proximity services (ProSe) . SL communication is distributed in nature at least from Rx UE perspective, as Rx UE needs to monitor over one or more preconfigured resource pool (RP) for SL reception, including reception of SL Control Information (SCI) and then reception of SL Data based on received SCI. SCI comprises a 1st-stage SCI sent in PSCCH and a 2nd-stage SCI sent in PSSCH. The 2nd-stage SCI is sent together with SL Data. For the regular sensing operation in Mode 2, SL UE needs to monitor at least 1st-stage SCI (from other Tx UEs in proximity of SL UE) constantly.

The initiating device or, i.e., COT provider, can be any of authenticated and authorized UEs involved in SL communications in the shared resource pool on unlicensed spectrum band, denoted as RP-U. It is further assumed that the COT sharing information is sent in SCI from the initiating device. Hence, COT sharing information from one or more initiating device (s) may be received by one or more UE (s) which is (are) monitoring the RP-U and in proximity of the one or more initiating device (s) .

According to embodiments of the present disclosure, a first device determines a channel occupancy time for sidelink transmission on an unlicensed band. The first device determines at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device. The first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band. The first device transmits at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information. In this way, it achieves efficient channel access to make sure coexistence fairness to other device and system. It can support COT sharing mechanism without any grouping for unlicensed sidelink.

Fig. 3 illustrates a schematic diagram of a communication environment 300 in which embodiments of the present disclosure can be implemented. The communication environment 300, which is a part of a communication network, further comprises a terminal device 310-1, a terminal device 310-2, ...., a terminal device 310-N, which can be collectively referred to as “terminal device (s) 310. ” The communication environment 300 comprises a network device 320. The number N can be any suitable integer numbers.

The communication environment 300 may comprise any suitable number of devices and cells. In the communication environment 300, the terminal device 310 and the network device 320 can communicate data and control information to each other. A link from the network device 320 to the terminal device 310 is referred to as a downlink (DL) , while a link from the terminal device 310 to the network device 320 is referred to as an uplink (UL) .

It is to be understood that the number of devices and cells and their connections shown in Fig. 3 is given for the purpose of illustration without suggesting any limitations. The communication environment 300 may include any suitable number of devices and networks adapted for implementing embodiments of the present disclosure.

Communications in the communication environment 300 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is now made to Fig. 4, which illustrates a signaling flow 400 for sharing COT according to example embodiments of the present disclosure. The signaling flow 400 may involve an initiating device (i.e., the first device) and a responding device (i.e., the second device) . In some embodiments, the initiating device may be a terminal device (for example, the terminal device 310-1) and the responding device may be another terminal device (for example, the terminal device 310-2) . Alternatively, the initiating device may be a network device (for example, the network device 320) . In other embodiments, the initiating device may be sidelink unlicensed (SL-U) related devices such as a road side unit (RSU) operated in an unlicensed spectrum band. The term “a shared spectrum band” or “an unlicensed spectrum band” can be used interchangeable. Embodiments of the present disclosure are not limited to this aspect. Only for the purpose of illustrations, the signaling flow 400 may involve the terminal device 310-1 and the terminal device 310-2. Only as an example, the terminal device 310-1 acts as the imitating device, and the terminal device 310-2 acts as the responding device. It should be noted that the terminal device 310-1 and the terminal device 310-2 are interchangeable. In other words, the terminal device 310-1 can be the responding device and the terminal device 310-2 can be the initiating device.

The terminal device 310-1 may determine 4010 a channel occupancy time (COT) for sidelink communications on an unlicensed band. In some embodiments, the terminal device 310-1 may acquire the COT using the LBT/CCA mechanism. For example, a conventional LBT mechanism may be used to obtain the COT. Alternatively, the LBT may take SL-U transmissions into account. For example, if the terminal device 310-1 has a SL operation capability (for example, SL-U UE or UE type RSU) , it can monitor the SL-U transmissions and measure energy on the monitored SL-U transmission.

The terminal device 310-1 may determine a result of the LBT (or CCA) on the unlicensed spectrum band based on a difference between the energy of the sidelink transmission on the unlicensed spectrum band and a measured energy of the LBT (or CCA) . For example, if the difference is within a threshold difference, the LBT may be considered as successfully to acquire the COT by the terminal device 310-1. In other words, if the energy detection in the LBT is similar as the calculated energy level of monitored SL-U transmission, the LBT may be considered as successfully to acquire the COT by COT initiating device. Alternatively, if the energy detection in the LBT is higher than the calculated energy level of monitored SL-U transmission beyond the configured threshold, the LBT may be considered as a failure.

The terminal device 310-1 determines 4020 a first sharing of the COT and/or a second sharing of the COT. The first sharing is common to a plurality of sidelink communications on the unlicensed band. In other words, the first sharing can be used for the sidelink communications, regardless of an identity of the terminal device 310-1 (i.e., the initiating UE) or the terminal device 310-2 (i.e., the responding UE) . For example, the identity may be a Source (SRC) ID of the terminal device 310-1. Alternatively or in addition, the identity may be a Destination (DST) ID of the terminal device 310-2.

In some embodiments, the first sharing may be limited within the remaining duration of the present system frame number (SFN) of sidelink communications in which the first sharing is initiated by the first device. It is noted that the system frame of sidelink communications is also referred to as direct device-to-device communication frame or direct frame. The first sharing may also be under a predetermined maximum duration allowed for using the channel on the unlicensed band for SL communications. The predetermined maximum duration (shorter than the duration of the system frame) may be configured by the serving network. Thus, the first sharing of the COT may start from the time instance when the first configuration of the first sharing of the COT is sent/received and last until either the predetermined maximum duration of the first sharing of the COT expires or the present SFN ends, whatever comes first. The remaining duration of the first sharing can be set of the smaller one among the remaining duration of the present SFN and the predetermined maximum duration. Only as an example, if the duration of the system frame is 10 ms, the remaining duration of the present SFN is 3 ms and the predetermined maximum duration is 5ms, the remaining duration of the first sharing is 3 ms. As another example, if the duration of the system frame is 10 ms, the remaining duration of the present SFN is 7 ms and the predetermined maximum duration is 5ms, the remaining duration of the first sharing is 5 ms. In this way, it ensures fairness in sharing the channel on the unlicensed band between sidelink communications and other types of communications or communication systems.

The second sharing is dedicated to a specific sidelink communication on the unlicensed band. In some embodiments, the specific sidelink communication may be a communication of a broadcast. Alternatively, the specific sidelink communication may be a communication of a groupcast. In other embodiments, the specific sidelink communication may be a communication of a unicast. In this situation, the second sharing can be dedicated to the identity of the terminal device 310-1 (i.e., the initiating UE) or the terminal device 310-2 (i.e., the responding UE) , as indicated by the terminal device 310-1 (the first device) in second sidelink control information (e.g., the second stage SCI) .

The second COT sharing can be targeted for one or more responding UE (s) (for example, the terminal device 310-2) which have predefined relationship with the terminal device 310-1 (i.e., the initiating UE) , e.g., peer or group member of the initiating UE. This can be determined based on at least one of the SRC ID and the DST ID indicated in the sidelink control information of the initiating UE (e.g., the second stage SCI) . That is, the targeted responding UEs may use the COT information in the second sharing provided by their related initiating UEs only (for SL transmissions in the unlicensed band) . The COT information in the second sharing may specify the targeted responding UEs or UE groups, either implicitly via the SRC ID and/or the DST ID indicated in the SCI from the initiating UE or explicitly, for example, with a list of DST IDs of the targeted responding UEs or UE groups. The COT duration of the second sharing may not need to be constrained under min (the remaining duration of the current SFN, the predefined maximum duration) , as it is the case for the first sharing. In some embodiments, the COT duration of the second sharing may be up to the maximum COT duration allowed for using the channel in U-band in accordance with the regulation and the COT duration of the second sharing may start from slot j in SFN [n] and last until slot k in SFN [n+1] , assuming that the duration of a system frame is 10ms and the maximum COT duration is a bit less than 10ms.

The terminal device 310-1 may determine to provide either the first sharing or the second sharing or both based on its need of SL communications and criteria or rules configured to it by the serving network.

The terminal device 310-1 transmits at least one of a first configuration of the first sharing and a second configuration of the second sharing. As shown in Fig. 4, the terminal device 310-1 may transmit 4030 a first configuration of the first sharing in first sidelink control information to the terminal device 310-2, if the terminal device 310-1 determines that the first sharing is needed. Alternatively or in addition, if the second sharing is needed, the terminal device 310-1 may transmit 4040 a second configuration of the second sharing in second sidelink control information to the terminal device 310-2. In some embodiments, only the first configuration can be transmitted. Alternatively, only the second configuration can be transmitted. In other embodiments, both the first and second configurations can be transmitted. In this way, it reduces latency. Moreover, the first sharing can be used even if the second sharing is failed. If both the first and second configurations are transmitted, the terminal device 310-1 can be configured to ensure that the remaining duration of the first sharing cannot exceed the remaining duration of the second sharing. That is, the terminal device 310-1 can determine whether to provide the first sharing or not in addition to the second sharing depending on the remaining COT duration of the second sharing. If the remaining COT duration of the second sharing is shorter than a required minimum of the remaining duration of the first sharing, the terminal device 310-1 may determine that the first sharing may not be provided. Alternatively, if he remaining COT duration of the second sharing is longer than the required minimum of the remaining duration of the first sharing, the terminal device 310-1 may determine that the first sharing may be provided.

In some embodiments, the terminal device 310-1 may transmit the first configuration of the first sharing on a physical sidelink control channel. Alternatively, the terminal device 310-1 may transmit the first configuration of the first sharing on a physical sidelink shared channel. In some embodiments, the terminal device 310-1 may transmit the second configuration of the second sharing on a physical sidelink shared channel. Alternatively, the terminal device 310-1 may transmit the second configuration of the second sharing on a physical sidelink control channel.

In some embodiments, the first configuration of the first sharing in the first sidelink control information (e.g., the first stage SCI) may comprise one bit indicating the first sharing. In this situation, if the responding UE (for example, the terminal device 310-2) determines that the first sharing is available based on the received first sidelink control information, the terminal device 310-2 may determine the remaining duration of the first sharing based on a preconfigured configuration (e.g., the predefined maximum duration) and the received first sidelink control information (e.g., the remaining duration of the present SFN) . As discussed above, the remaining COT duration of the first sharing can set to min (the remaining duration of the current SFN, the predefined maximum duration) . This means that the initiating UE may provide the first COT sharing only if the actual remaining COT duration is not less than min (the remaining duration of the current SFN, the predefined maximum duration) .

Alternatively, the first configuration of the first sharing in the first sidelink control information may be associated with other control information elements such as a priority field in the first SCI. In this case, the predefined maximum duration can be derived based on the priority field in the first SCI. For example, higher priorities correspond to lower COT duration, while lower priorities to longer COT duration. This is the case due to higher priority transmission perform the LBT Type 1 for a shorter CW duration and therefore have a shorter COT associated with.

In other embodiments, the first configuration can comprise one or more bits to indicate the remaining COT duration of the first sharing. In this way, it achieves finer resolution for indication of the remaining COT duration (as compared to the use of the preconfigured configuration above) . Moreover, the first sidelink control information may also indicate further COT configuration. In other words, existing control elements or fields, such as priority field, time resource assignment field or resource reservation period field in the 1st-stage SCI as given in Table 3, can be used to derive further COT configuration for either or both of the first sharing and the second sharing.

Alternatively or in addition, some or all of the one or more bits which are used for indicating the remaining COT duration of the first sharing as well as the remaining reserved bits in the first sidelink control information (the first stage SCI) may be used for indicating to what extent the reserved resources indicated in the same first SCI (e.g., the first stage SCI) are under an acquired or shared COT. For examples, those instances of the reserved resources which are under an acquired or shared COT may have higher priority than those which are not under an acquired or shared COT. This can be used by all UEs of SL communications in the unlicensed band, regardless of acting as the initiating UE or the responding UE. In this way, it can enhance Mode 2 sensing and resource allocation over the unlicensed band.

In some embodiments, the terminal device 310-3 may transmit 4050 a third configuration and/or a fourth configuration. Only as an example, the third configuration may be the configuration of the first sharing of a COT provided by the terminal device 310-3 which is common to the plurality of sidelink communications. The fourth configuration may be the configuration of the second sharing of the COT provided by the terminal device 310-3 which is dedicated to the specific sidelink communication. In this case, the terminal device 310-1 and the terminal device 310-3 can be considered as 2 independent COT providers or initiating UEs which may not be in proximity of each other but the terminal device 310-2 is in proximity of both the terminal device 310-1 and the terminal device 310-3. The terminal device 310-3 may be operating as the terminal device 310-1 (i.e., the first device) to provide at least one of the first sharing and the second sharing.

The terminal device 310-2 determines 4060 a target configuration. For example, if the reception of the third configuration is later than the reception of the first configuration and both the third and first configurations are common to the plurality of sidelink communications, the terminal device 310-2 may determine the third configuration as the target configuration. Alternatively, if the remaining COT duration of the fourth configuration is shorter than the remaining COT duration of the second configuration, the terminal device 310-2 may determine the second configuration as the target configuration. If the terminal device 310-1 and the terminal device 310-3 can be considered as 2 independent COT providers or initiating UEs, the terminal device 310-2 is allowed to select and use at least suitable or preferred COT sharing from at least one of the terminal device 310-1 or the terminal device 310-3. In this situation, the terminal device 310-2 may use a combination of provided COT sharings from the terminal device 301-1 and the terminal device 310-3.

The terminal device 310-2 performs 4070 the sidelink communication in the unlicensed spectrum band based on the target configuration. In some embodiments, the terminal device 310-2 may use the second sharing received from one or more related initiating UEs in proximity for SL transmissions for corresponding SL communications. For example, if the one or more initiating UEs (for example, the terminal devices 310-1 and 310-3) and the terminal device 310-2 are all members of the same SL group (for example, broadcast/groupcast) , in this case, the terminal device 310-2 may use a combination of the received COT sharing information. Only as an example, if the terminal devices 310-1, 310-2 and 310-3 are in the same sidelink group of the specific sidelink communication, the terminal device 310-2 may use a combination of the second configuration and the fourth configuration. As an example, the terminal device 310-2 can transmit according to shortest remaining COT duration indicated by initiating UEs. For example, as mentioned above, if the remaining COT duration of the fourth configuration is shorter than the remaining COT duration of the second configuration, the terminal device 310-2 may perform the sidelink transmission based on the fourth configuration. If the remaining COT duration of the first configuration is longer than the remaining COT duration of the third configuration, the terminal device 310-2 may perform the sidelink transmission based on the third configuration. As another example, the terminal device 310-2 can transmit according to longest remaining COT duration indicated by initiating UEs. For example, as mentioned above, if the remaining COT duration of the fourth configuration is shorter than the remaining COT duration of the second configuration, the terminal device 310-2 may perform the sidelink transmission based on the second configuration. If the remaining COT duration of the first configuration is longer than the remaining COT duration of the third configuration, the terminal device 310-2 may perform the sidelink transmission based on the first configuration.

Alternatively or in addition, if the one or more initiating UEs (for example, the terminal devices 310-1 and 310-3) and the terminal device 310-2 are members or peers of different SL groups (unicast/groupcast) , in this case, the terminal device 310-2 may be configured to use: (i) group-specific COT sharing information for SL transmissions for corresponding group of the initiating UE; and, in addition, (ii) cross-group COT sharing information for SL transmissions for any of groups of the responding UE with or without the constraint under min (the remaining duration of the current SFN, the predefined maximum duration) , based on the principle of the first COT sharing.

In some embodiments, the terminal device 310-2 may be configured to avoid selecting resources which are reserved by other Tx UEs of which at least one instance is under an acquired or shared COT. The terminal device 310-2 may select and reserve resources which are reserved by other Tx UEs but not under an acquired or shared COT. For example, the first sidelink control information may indicate some resources are reserved by other devices which are under the COT. The terminal device 310-2 may not select those reserved resources.

In some embodiments, the terminal device 310-1 may also transmit at least one of the first configuration and the second configuration to the terminal device 310-3. In this situation, the terminal device 310-3 which is acting as a COT provider (the initiating UE) may become a COT responder (the responding UE) of another COT provider in proximity, the terminal device 310-1, as soon as the terminal device 310-3 detects the terminal device 310-1 and that the COT provided by the terminal device 310-1 is preferred to the terminal device 310-3. The terminal device 310-3 may release its own COT and become a COT responder of the terminal device 310-1.

Fig. 5 shows a flowchart of an example method 500 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the initiating device. Only for the purpose of illustrations, the method 500 is described with the reference to the terminal device 310-1.

At block 510, the terminal device 310-1 determines a channel occupancy time for sidelink transmission on an unlicensed band.

At block 520, the terminal device 310-1 determines at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device. The first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band.

At block 530, the terminal device 310-1 transmits at least one of: a first configuration of the first sharing on a first sidelink channel and a second configuration of the second sharing on a second sidelink channel. In some embodiments, the first sidelink channel is a physical sidelink control channel and the second sidelink channel is a physical sidelink shared channel.

In some embodiments, the terminal device 310-1 may transmit the first configuration in first sidelink control information, the first configuration comprising one bit indicating that the first sharing, common to a plural of sidelink communications on the unlicensed band, is provided. In this case, the first sharing of the channel occupancy time may be kept within the remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time is no longer than a predetermined duration.

Alternatively or in addition, the terminal device 310-1 may transmit the first configuration in first sidelink control information, the first configuration comprising at least one of: a first bit indicating that the first sharing, common to the plurality of sidelink communications, is provided, one or more second bits indicating of a remaining duration of the first sharing, or one or more third bits indicating one or more resources reserved for the channel occupancy time.

In other embodiments, the terminal device 310-1 may transmit the second configuration in second sidelink control information, the second configuration comprising one or more bits indicating a remaining duration of the second sharing of the channel occupancy time.

Alternatively or in addition, the terminal device 310-1 may transmit the first configuration in first sidelink control information and transmit the second configuration in second sidelink control information. In some embodiments, the terminal device 310-1 may determine whether the second sharing, and therefore the second configuration, is needed based on a first remaining duration of the first sharing and a second remaining duration of the second sharing. If the first remaining duration is shorter than the second remaining duration, the terminal device 310-1 may determine that the second configuration is needed.

Fig. 6 shows a flowchart of an example method 600 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the responding device. Only for the purpose of illustrations, the method 600 is described with the reference to the terminal device 310-2.

At block 610, the terminal device 310-2 receives, from the terminal device 310-1 and/or the terminal device 310-3, at least one of: at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band. The first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band.

In some embodiments, the terminal device 310-2 may receive the first configuration in first sidelink control information. The first configuration comprises one bit indicating that the first sharing, common to a plural of sidelink communications on the unlicensed band, is provided. The first sharing of the channel occupancy time may be within the remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time may be no longer than a predetermined duration.

Alternatively or in addition, the terminal device 310-2 may receive the first configuration in first sidelink control information comprising at least one of: a first bit indicating that the first sharing is provided, one or more second bits indicating of a remaining duration of the first sharing, or one or more third bits indicating one or more resources reserved for the channel occupancy time.

In other embodiments, the terminal device 310-2 may receive the second configuration in second sidelink control information comprising one or more bits indicating a duration of the second sharing.

At block 620, the terminal device 310-2 determines a target configuration from the at least one of the at least one first configuration and the at least one second configuration. For examples, the target configuration may be the latest received first configuration, as selected among the at least one first configuration of at least one channel occupancy time received from (i.e., provided by) at least one first device. The target configuration may be the second configuration of the longest channel occupancy time, as selected among the at least one second configuration of at least one channel occupancy time received from (i.e., provided by) at least one first device.

In some embodiments, the terminal device 310-2 may receive a third configuration of the first sharing of a channel occupancy time. In this case, if the reception of the first configuration is later than the reception of the third configuration, the terminal device 310-2 may determine the first configuration to be the target configuration.

Alternatively or in addition, the terminal device 310-2 may receive a fourth configuration of the second sharing of a channel occupancy time. In this situation, if the channel occupancy time of the second configuration is longer than the channel occupancy time of the four configuration, the terminal device 310-2 may determine the second configuration to be the target configuration.

At block 630, the terminal device 310-2 performs the sidelink communication based on the target configuration. In some embodiments, the terminal device 310-2 may perform the sidelink communication within a duration of the first configuration which is either the remaining duration of the present system frame number or the predetermined duration. The terminal device 310-2 may determine the predetermined duration based on a priority indicated in the first sidelink control information.

In some embodiments, the terminal device 310-2 may perform the sidelink communication with resources which are different from the one or more resources reserved for the channel occupancy time. In some embodiments, the terminal device 310-2 may perform the sidelink communication within the duration of the second sharing.

In an example embodiment, the terminal device 310-2 may receive, from a third device (for example, the terminal device 310-3) , a fourth configuration of the second sharing of a third channel occupancy time which is dedicated to a specific sidelink communication. The first, second and third devices may belong to a same sidelink group of the specific sidelink communication. In this situation, if the second sharing of the first channel occupancy time is provided to the second device 310-2 by the first device 310-1 in the second configuration for the same specific sidelink communication, the terminal device 310-2 may perform the specific sidelink communication with a shortest duration indicated in the second configuration and the fourth configuration. Alternatively, the terminal device 310-2 may perform the specific sidelink communication with a longest duration indicated in the second configuration and the fourth configuration.

Alternatively or in addition, the terminal device 310-2 may receive, from a third device (for example, the terminal device 310-3) , a fourth configuration of the second sharing of a third channel occupancy time which is dedicated to a specific sidelink communication. The first, second and third devices may belong to different sidelink groups. In this situation, if the second sharing of the first channel occupancy time is provided to the second device 310-2 by the first device 310-1 in the second configuration dedicated to a specific sidelink communication different from that of the fourth configuration, the terminal device 310-2 may perform the specific sidelink communication with the first device using the second configuration of the first channel occupancy time and the specific sidelink communication with the third device using the fourth configuration of the third channel occupancy time. Alternatively, the terminal device 310-2 may perform the specific sidelink communication with the first device and with the third device using a first sharing common to a plurality of sidelink communications if the first sharing is provided to the second device by either the first device or the third device or any other device.

In some example embodiments, a first apparatus capable of performing any of the method 500 (for example, the terminal device 310-1) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 310-1. In some example embodiments, the means may comprise at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause performance of the apparatus

In some embodiments, the apparatus comprises means for determining, at a first device, a channel occupancy time for sidelink transmission on an unlicensed band; means for determining, at the first device, at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; and means for transmitting, at the first device, at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information.

In some embodiments, the apparatus further comprises means for transmitting the first configuration of the first sharing in a first sidelink channel and the second configuration of the second sharing in a second sidelink channel.

In some embodiments, the means for transmitting the first configuration of the first sharing comprises: means for transmitting the first configuration in the first sidelink control information, the first configuration comprising one bit indicating that the first sharing, common to a plural of sidelink communications on the unlicensed band, is provided.

In some embodiments, the first sharing of the channel occupancy time is within the remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time is no longer than a predetermined duration.

In some embodiments, the means for transmitting the first configuration of the first sharing comprises: means for transmitting first configuration in the first sidelink control information, the first configuration comprising at least one of: a first bit indicating that the first sharing, common to the plurality of sidelink communications, is provided, one or more second bits indicating of a remaining duration of the first sharing, and one or more third bits indicating one or more resources reserved for the channel occupancy time.

In some embodiments, the means for transmitting the second configuration of the second sharing comprises: means for transmitting the second configuration in second sidelink control information, the second configuration comprising one or more bits indicating a duration of the channel occupancy time.

In some embodiments, the apparatus comprises means for determining whether the second sharing, and therefore the second configuration, is needed based on a first remaining duration of the first sharing and a second remaining duration of the second sharing; and means for, in accordance with a determination that the first remaining duration is shorter than the second remaining duration, determining that the second configuration is needed.

In some embodiments, the first device is a terminal device or a network device, and the second device is another terminal device or another network device.

In some embodiments, the apparatus comprises means for receiving, at a second device and from at least one first device, at least one of: at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; means for determining, at the second device, a target configuration from the at least one of the at least one first configuration and the at least one second configuration; and means for performing, at the second device, the sidelink communication based on the target configuration.

In some embodiments, the apparatus comprises means for receiving, at the second device, a first configuration of the first sharing of a first channel occupancy time and a third configuration of the first sharing of a third channel occupancy time, ; and the means for determining the target configuration comprises: means for, in accordance with a determination that the reception of the first configuration is later than the reception of the third configuration, determining the first configuration to be the target configuration.

In some embodiments, the apparatus comprises means for receiving, at the second device, a second configuration of the second sharing of a second channel occupancy time and a fourth configuration of the second sharing of a fourth channel occupancy time; and the means for determining the target configuration comprises: means for, in accordance with a determination the second channel occupancy time of the second configuration is longer than the fourth channel occupancy time of the fourth configuration, determining the second configuration to be the target configuration.

In some embodiments, the means for receiving the first configuration of the first sharing comprises: means for receiving the first configuration in first sidelink control information, the first configuration comprising one bit indicating that the first sharing, common to a plural of sidelink communications on the unlicensed band, is provided.

In some embodiments, the means for performing the sidelink communication comprises: means for performing the sidelink communication within a duration of the first configuration which is either the remaining duration of the present system frame number or the predetermined duration.

In some embodiments, the apparatus comprises means for determining the predetermined duration based on a priority indicated in the first sidelink control information.

In some embodiments, the means for receiving the first configuration comprises: means for receiving the first configuration in first sidelink control information comprising at least one of: a first bit indicating that the first sharing is provided, one or more second bits indicating of a remaining duration of the first sharing, and one or more third bits indicating one or more resources reserved for the channel occupancy time.

In some embodiments, the means for performing the sidelink communication comprises: means for performing the sidelink communication with resources which are different from the one or more resources reserved for the channel occupancy time.

In some embodiments, the means for receiving the second configuration comprises: means for receiving the second configuration in second sidelink control information comprising one or more bits indicating a duration of the second sharing.

In some embodiments, the means for performing the sidelink communication comprises: means for performing the sidelink communication within the duration of the second sharing.

In some embodiments, the apparatus comprises means for receiving, at the second device and from the first device, a second configuration of the second sharing of a first channel occupancy time dedicated to a specific sidelink communication; means for receiving, at the second device and from a third device, a fourth configuration of the second sharing of a third channel occupancy time which is dedicated to the specific sidelink communication, and wherein the first, second and third devices belong to a same sidelink group of the specific sidelink communication; and the means for performing the sidelink communication comprises: means for in accordance with a determination that the second sharing of the first channel occupancy time and the third channel occupancy time is for the same specific sidelink communication, performing the specific sidelink communication with a shortest duration indicated in the second configuration and the fourth configuration; or means for performing the specific sidelink communication with a longest duration indicated in the second configuration and the fourth configuration.

In some embodiments, the apparatus comprises means for receiving, at the second device from the first device, a second configuration of the second sharing of a first channel occupancy time dedicated to a first specific sidelink communication; means for receiving, at the second device from a third device, a fourth configuration of the second sharing of a third channel occupancy time which is dedicated to a second specific sidelink communication, wherein the first, second and third devices belong to different sidelink groups; and the means for performing the sidelink communication comprises: means for in accordance with a determination that the first channel occupancy time is dedicated to the first specific sidelink communication different from the second specific sidelink communciation, performing the first specific sidelink communication with the first device using the second configuration of the first channel occupancy time and the second specific sidelink communication with the third device using the fourth configuration of the third channel occupancy time; or means for in accordance with a determination that a first sharing is provided to the second device, performing the first specific sidelink communication with the first device and the second specific sidelink communication the third device using a first configuration of the first sharing of a channel occupancy time common to a plurality of sidelink communications, wherein the first configuration of the first sharing is common to the first and second specific sidelink communications.

Fig. 7 is a simplified block diagram of a device 700 that is suitable for implementing example embodiments of the present disclosure. The device 700 may be provided to implement a communication device, for example, the terminal device 310 or the network device 320 as shown in Fig. 3. As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processor 710, and one or more communication modules 740 coupled to the processor 710.

The communication module 740 is for bidirectional communications. The communication module 740 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 740 may include at least one antenna.

The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not latest in the power-down duration.

A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the memory, e.g., ROM 724. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

Example embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to Figs. 4 to 6. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and other magnetic storage and/or optical storage. Fig. 8 shows an example of the computer readable medium 80 in form of an optical storage disk. The computer readable medium has the program 730 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in 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 embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method 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 includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above with reference to Figs. 4 to 7. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes 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 codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a 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 the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but 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 the 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 depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present 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 may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present 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

A first device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to

determine a channel occupancy time for sidelink transmission on an unlicensed band;

determine at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; and

transmit at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information.
The first device of claim 1, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to transmit the first configuration of the first sharing in a first sidelink channel and the second configuration of the second sharing in a second sidelink channel.
The first device of claim 1, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to transmit the first configuration of the first sharing by:

transmitting the first configuration in the first sidelink control information, the first configuration comprising one bit indicating that the first sharing is provided.
The first device of claim 1, wherein the first sharing of the channel occupancy time is within a remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time is no longer than a predetermined duration.
The first device of claim 1, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to transmit the first configuration of the first sharing by:

transmitting first configuration in the first sidelink control information, the first configuration comprising at least one of:

a first bit indicating that the first sharing is provided,

one or more second bits indicating a remaining duration of the first sharing, and

one or more third bits indicating one or more resources reserved for the channel occupancy time.
The first device of claim 1, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to transmit the second configuration of the second sharing by:

transmitting the second configuration in the second sidelink control information, the second configuration comprising one or more bits indicating a duration of the channel occupancy time.
The first device of claim 1, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to:

determine whether the second sharing is needed based on a first remaining duration of the first sharing and a second remaining duration of the second sharing; and

in accordance with a determination that the first remaining duration is shorter than the second remaining duration, determine that the second configuration is needed.
The first device of any one of claims 1-7, wherein the first device is a terminal device or a network device, and the second device is another terminal device or another network device.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

receive, from at least one first device, at least one of: at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band;

determine a target configuration from the at least one of the at least one first configuration and the at least one second configuration; and

perform the sidelink communication based on the target configuration.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

receive, at the second device, a first configuration of the first sharing of a first channel occupancy time and a third configuration of the first sharing of a third channel occupancy time; and

wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to determine the target configuration by:

in accordance with a determination that the reception of the first configuration is later than the reception of the third configuration, determining the first configuration to be the target configuration.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

receive, at the second device, a second configuration of the second sharing of a second channel occupancy time and a fourth configuration of the second sharing of a fourth channel occupancy time; and

wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to determine the target configuration by:

in accordance with a determination the second channel occupancy time of the second configuration is longer than the fourth channel occupancy time of the fourth configuration, determining the second configuration to be the target configuration.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to receive the first configuration of the first sharing by:

receiving the first configuration in first sidelink control information, the first configuration comprising one bit indicating that the first sharing is provided.
The second device of claim 9, wherein the first sharing of the channel occupancy time is within a remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time is no longer than a predetermined duration.
The second device of claim 13, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the sidelink communication by:

performing the sidelink communication within a duration of the first configuration which is either the remaining duration of the present system frame number or the predetermined duration.
The second device of claim 13, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

determine the predetermined duration based on a priority indicated in the first sidelink control information.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to receive the first configuration by:

receiving the first configuration in first sidelink control information comprising at least one of:

a first bit indicating that the first sharing is provided,

one or more second bits indicating a remaining duration of the first sharing, and

one or more third bits indicating one or more resources reserved for the channel occupancy time.
The second device of claim 16, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the sidelink communication by:

performing the sidelink communication with resources which are different from the one or more resources reserved for the channel occupancy time.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to receive the second configuration by:

receiving the second configuration in second sidelink control information comprising one or more bits indicating a duration of the second sharing.
The second device of claim 18, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the sidelink communication by:

performing the sidelink communication within the duration of the second sharing.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

receive, from the first device, a second configuration of the second sharing of a first channel occupancy time dedicated to a specific sidelink communication;

receive, from a third device, a fourth configuration of the second sharing of a third channel occupancy time dedicated to the specific sidelink communication, and wherein the first, second and third devices belong to a same sidelink group of the specific sidelink communication; and

wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the sidelink communication by:

in accordance with a determination that the first channel occupancy time and the third channel occupancy time is dedicated to the specific sidelink communication, performing the specific sidelink communication with a shortest duration of the second sharing indicated in the second configuration and the fourth configuration; or

performing the specific sidelink communication with a longest duration of the second sharing indicated in the second configuration and the fourth configuration.
The second device of claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to:

receive, from the first device, a second configuration of the second sharing of a first channel occupancy time dedicated to a first specific sidelink communication;

receive, from a third device, a fourth configuration of the second sharing of a third channel occupancy time dedicated to a second specific sidelink communication, and wherein the first, second and third devices belong to different sidelink groups; and

wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the sidelink communication by:

in accordance with a determination that the first channel occupancy time is dedicated to the first specific sidelink communication different from the second specific sidelink communication, performing the first specific sidelink communication with the first device with the second configuration and the second specific sidelink communication with the third device with the fourth configuration; or

performing the first specific sidelink communication with the first device and the second specific sidelink communication with the third device with a first configuration of the first sharing of a channel occupancy time received from either the first device, the third device, or a fourth device, wherein the first configuration of the first sharing is common to the first and second specific sidelink communications.
A method, comprising:

determining, at a first device, a channel occupancy time for sidelink transmission on an unlicensed band;

determining, at the first device, at least one of a first sharing and a second sharing of the channel occupancy time to be provided to at least one second device, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band; and

transmitting, at the first device, at least one of: a first configuration of the first sharing in first sidelink control information and a second configuration of the second sharing in second sidelink control information.
The method of claim 11, further comprising

transmitting the first configuration of the first sharing in a first sidelink channel and the second configuration of the second sharing in a second sidelink channel.
The method of claim 22, wherein transmitting the first configuration of the first sharing comprises:

transmitting the first configuration in the first sidelink control information, the first configuration comprising one bit indicating that the first sharing is provided or not.
The method of claim 22, wherein the first sharing of the channel occupancy time is within a remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time is no longer than a predetermined duration.
The method of claim 22, wherein transmitting the first configuration of the first sharing comprises:

transmitting first configuration in the first sidelink control information, the first configuration comprising at least one of:

a first bit indicating that the first sharing is provided,

one or more second bits indicating a remaining duration of the first sharing, and

one or more third bits indicating one or more resources reserved for the channel occupancy time.
The method of claim 22, wherein transmitting the second configuration of the second sharing comprises:

transmitting the second configuration in the second sidelink control information, the second configuration comprising one or more bits indicating a duration of the channel occupancy time.
The method of claim 22, further comprising:

determining whether the second sharing is needed based on a first remaining duration of the first sharing and a second remaining duration of the second sharing; and

in accordance with a determination that the first remaining duration is shorter than the second remaining duration, determining that the second configuration is needed.
The method of any one of claims 22-28, wherein the first device is a terminal device or a network device, and the second device is another terminal device or another network device.
A method, comprising:

receiving, at a second device and from at least one first device, at least one of: at least one first configuration of a first sharing of at least one channel occupancy time for sidelink transmission on an unlicensed band and at least one second configuration of a second sharing of at least one channel occupancy time for sidelink transmission on the unlicensed band, wherein the first sharing is common to a plurality of sidelink communications on the unlicensed band and the second sharing is dedicated to a specific sidelink communication on the unlicensed band ;

determining, at the second device, a target configuration from the at least one of the at least one first configuration and the at least one second configuration; and

performing, at the second device, the sidelink communication based on the target configuration.
The method of claim 30, further comprising:

receiving, at the second device, a first configuration of the first sharing of a first channel occupancy time and a third configuration of the first sharing of a third channel occupancy time; and

wherein determining the target configuration comprises:

in accordance with a determination that the reception of the first configuration is later than the reception of the third configuration, determining the first configuration to be the target configuration.
The method of claim 30, further comprising:

receiving, at the second device, a second configuration of the second sharing of a second channel occupancy time and a fourth configuration of the second sharing of a fourth channel occupancy time; and

wherein determining the target configuration comprises:

in accordance with a determination the second channel occupancy time of the second configuration is longer than the fourth channel occupancy time of the fourth configuration, determining the second configuration to be the target configuration.
The method of claim 30, wherein receiving the first configuration of the first sharing comprises:

receiving the first configuration in first sidelink control information, the first configuration comprising one bit indicating that the first sharing is provided.
The method of claim 30, wherein the first sharing of the channel occupancy time is within a remaining duration of a present system frame number in which the first sharing is provided and the length of the first sharing of the channel occupancy time is no longer than a predetermined duration.
The method of claim 34, wherein performing the sidelink communication comprises:

performing the sidelink communication within a duration of the first configuration which is either the remaining duration of the present system frame number or the predetermined duration.
The method of claim 34, further comprising:

determining the predetermined duration based on a priority indicated in the first sidelink control information.
The method of claim 30, wherein receiving the first configuration comprises:

receiving the first configuration in first sidelink control information comprising at least one of:

a first bit indicating that the first sharing is provided,

one or more second bits indicating a remaining duration of the first sharing, and

one or more third bits indicating one or more resources reserved for the channel occupancy time.
The method of claim 37, wherein performing the sidelink communication comprises:

performing the sidelink communication with resources which are different from the one or more resources reserved for the channel occupancy time.
The method of claim 30, wherein receiving the second configuration comprises:

receiving the second configuration in second sidelink control information comprising one or more bits indicating a duration of the second sharing.
The method of claim 39, wherein performing the sidelink communication comprises:

performing the sidelink communication within the duration of the second sharing.
The method of claim 30, further comprising:

receiving, from a first device, a second configuration of the second sharing of a first channel occupancy time dedicated to a specific sidelink communication;

receiving, from a third device, a fourth configuration of the second sharing of a third channel occupancy time dedicated to the specific sidelink communication, and wherein the first, second and third devices belong to a same sidelink group of the specific sidelink communication; and

wherein performing the sidelink communication comprises:

in accordance with a determination that the first channel occupancy time and the third channel occupancy time is dedicated to the specific sidelink communication, performing the specific sidelink communication with a shortest duration of the second sharing indicated in the second configuration and the fourth configuration; or

performing the specific sidelink communication with a longest duration of the second sharing indicated in the second configuration and the fourth configuration.
The method of claim 30, further comprising:

receiving, from the first device, a second configuration of the second sharing of a first occupancy time dedicated to a first specific sidelink communication;

receiving, from a third device, a fourth configuration of the second sharing of a third channel occupancy time dedicated to a second specific sidelink communication, and wherein the first, second and third devices belong to different sidelink groups; and

wherein performing the sidelink communication comprises:

in accordance with a determination that the first channel occupancy time is dedicated to the first specific sidelink communication different from the second specific sidelink communication, performing the first specific sidelink communication with the first device with the second configuration and the second specific sidelink communication with the third device with the fourth configuration; or

performing the first specific sidelink communication with the first device and the second specific sidelink communication with the third device with a first configuration of the first sharing of a channel occupancy time received from either the first device, the third device, or a fourth device, wherein the first configuration of the first sharing is common to the first and second specific sidelink communications.
A computer readable medium comprising program instructions for causing an apparatus to perform the method of any one of claims 22-29 or any one of claims 30-42.
An apparatus comprises means for performing the method of any one of claims 22-29 or any one of claims 30-42.