WO2023115568A1

WO2023115568A1 - Method, device and computer storage medium for multi-trp communication

Info

Publication number: WO2023115568A1
Application number: PCT/CN2021/141341
Authority: WO
Inventors: Ying Zhao; Gang Wang
Original assignee: Nec Corporation
Priority date: 2021-12-24
Filing date: 2021-12-24
Publication date: 2023-06-29

Abstract

Embodiments of the present disclosure relate to method, device and computer storage medium for multi-TRP communication. A terminal device receives, from a network device, at least one downlink control information indicating at least one channel occupancy time duration corresponding to at least one channel. The at least one channel is associated with at least one transmission configuration indicator. The terminal device performs at least one channel access procedure on the at least one channel. The terminal device further determines a target starting time and a time duration for an uplink transmission on one channel from the terminal device to the network device based on a result of the at least one channel access procedure and the at least one downlink control information. In this way, the terminal device may share a channel occupancy time initiated by the network device or initiated a channel occupancy time by itself for the uplink transmission. Uplink transmission will be enhanced accordingly.

Description

METHOD, DEVICE AND COMPUTER STORAGE MEDIUM FOR MULTI-TRP COMMUNICATION

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to method, device and computer storage medium for multi-Transmission and Reception Point (TRP) communication.

BACKGROUND

In a communication system, such as a new radio (NR) system, a network device may be equipped with multiple TRPs or antenna panels. That is, the network device can communicate with a terminal device via one or more of the multiple TRPs or antenna panels, which is also referred to as “multi-TRP communication” .

In some multi-TRP communication schemes, devices such as terminal devices and network devices may operate in a wide range of frequency bands. For example, devices may perform transmissions in millimeter wave (mmWave) shared spectrum. It has been proposed to use a channel access procedure by the network device/terminal device to initiate a channel occupancy in the mmWave shared spectrum for downlink/uplink (DL/UL) transmissions. Works are ongoing to introduce a channel occupancy time (COT) sharing or channel occupancy initiating mechanism for scheduled uplink (UL) transmission.

SUMMARY

In general, example embodiments of the present disclosure provide methods, devices and computer storage media for multi-TRP communication.

In a first aspect, there is provided a method of communication. The method comprises: receiving, by a terminal device and from a network device, at least one downlink control information (DCI) indicating at least one channel occupancy time duration corresponding to at least one channel. The at least one channel is associated with at least one transmission configuration indicator (TCI) state or one beam. The method further comprises performing at least one channel access procedure on the at least one channel; and determining a target starting time and a time duration for an uplink transmission on one channel from the terminal device to the network device based on a result of the at least one channel access procedure and the at least one downlink control information.

In a second aspect, there is provided a terminal device. The terminal device comprises a processor and a memory. The memory is coupled to the processor and stores instructions thereon. The instructions, when executed by the processor, cause the terminal device to perform the method according to the first aspect of the present disclosure.

In a third aspect, there is provided a computer readable medium having instructions stored thereon. The instructions, when executed on at least one processor, cause the at least one processor to perform the method according to the first aspect of the present disclosure.

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

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

Fig. 1 illustrates an example communication network in which embodiments of the present disclosure can be implemented;

Figs. 2A and 2B illustrate example schemes of multi-TRP DL transmission in accordance with some embodiments of the present disclosure;

Fig. 3 illustrates a signaling flow for communication according to some example embodiments of the present disclosure;

Figs. 4A-4C illustrate some example of UL transmissions according to some example embodiments of the present disclosure;

Figs. 5A-5D illustrate further example of UL transmissions according to some example embodiments of the present disclosure;

Figs. 6A-6B illustrate further example of UL transmissions according to some example embodiments of the present disclosure;

Figs. 7A-7B illustrate further example of UL transmissions according to some example embodiments of the present disclosure;

Fig. 8 illustrates a flowchart of an example method in accordance with some embodiments of the present disclosure; and

Fig. 9 is a simplified block diagram of a device that is suitable for implementing 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 limitations as to the scope of the disclosure. The disclosure 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.

As used herein, the term “network device” or “base station” (BS) refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an Evolved NodeB (eNodeB or eNB) , a NodeB in new radio access (gNB) a Remote Radio Unit (RRU) , a radio head (RH) , a remote radio head (RRH) , a low power node such as a femto node, a pico node, and the like. For the purpose of discussion, in the following, some embodiments will be described with reference to gNB as examples of the network device.

As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of the terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, tablets, wearable devices, internet of things (IoT) devices, Ultra-reliable and Low Latency Communications (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, device on vehicle for V2X communication where X means pedestrian, vehicle, or infrastructure/network, devices for Integrated Access and Backhaul (IAB) , Space borne vehicles or Air borne vehicles in Non-terrestrial networks (NTN) including Satellites and High Altitude Platforms (HAPs) encompassing Unmanned Aircraft Systems (UAS) , eXtended Reality (XR) devices including different types of realities such as Augmented Reality (AR) , Mixed Reality (MR) and Virtual Reality (VR) , the unmanned aerial vehicle (UAV) commonly known as a drone which is an aircraft without any human pilot, devices on high speed train (HST) , or image capture devices such as digital cameras, sensors, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like. The ‘terminal device’ can further has ‘multicast/broadcast’ feature, to support public safety and mission critical, V2X applications, transparent IPv4/IPv6 multicast delivery, IPTV, smart TV, radio services, software delivery over wireless, group communications and IoT applications. It may also incorporated one or multiple Subscriber Identity Module (SIM) as known as Multi-SIM. The term “terminal device” can be used interchangeably with a UE, a mobile station, a subscriber station, a mobile terminal, a user terminal or a wireless device.

The term “network device” refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNB) , a transmission reception point (TRP) , a remote radio unit (RRU) , a radio head (RH) , a remote radio head (RRH) , an IAB node, a low power node such as a femto node, a pico node, a reconfigurable intelligent surface (RIS) , and the like.

The terminal device or the network device may have Artificial intelligence (AI) or Machine learning capability. It generally includes a model which has been trained from numerous collected data for a specific function, and can be used to predict some information.

The terminal or the network device may work on several frequency ranges, e.g. FR1 (410 MHz –7125 MHz) , FR2 (24.25GHz to 71GHz) , frequency band larger than 100GHz as well as Tera Hertz (THz) . It can further work on licensed/unlicensed/shared spectrum. The terminal device may have more than one connection with the network devices under Multi-Radio Dual Connectivity (MR-DC) application scenario. The terminal device or the network device can work on full duplex, flexible duplex and cross division duplex modes.

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. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.

In some examples, values, procedures, or apparatus are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

In one embodiment, the terminal device may be connected with a first network device and a second network device. One of the first network device and the second network device may be a master node and the other one may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs) . In one embodiment, the first network device may be a first RAT device and the second network device may be a second RAT device. In one embodiment, the first RAT device is eNB and the second RAT device is gNB. Information related with different RATs may be transmitted to the terminal device from at least one of the first network device and the second network device. In one embodiment, a first information may be transmitted to the terminal device from the first network device and a second information may be transmitted to the terminal device from the second network device directly or via the first network device. In one embodiment, information related with configuration for the terminal device configured by the second network device may be transmitted from the second network device via the first network device. Information related with reconfiguration for the terminal device configured by the second network device may be transmitted to the terminal device from the second network device directly or via the first network device.

In one embodiment, a terminal device may be directly communicated with another terminal device in a communication network. Information related with configuration for the terminal device may be transmitted from a network device in the communication network or pre-configured. The information may be transmitted via any of the following: Radio Resource Control (RRC) signaling, Medium Access Control (MAC) control element (CE) , Downlink Control Information (DCI) or pre-configuration.

The embodiments of the present disclosure may be performed in test equipment, e.g. signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal device, test network device, channel emulator.

The embodiments of the present disclosure may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, 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, 5.5G, 5G-Advanced networks, or the sixth generation (6G) networks.

Principle and implementations of the present disclosure will be described in detail below with reference to Figs. 1-9.

Example communication environment

Fig. 1 shows an example communication network 100 in which embodiments of the present disclosure can be implemented. The network 100 includes a network device 110, which is coupled with two TRPs/panels 130-1 and 130-2 (collectively referred to as “TRPs 130” or individually referred to as a “TRP 130” ) . The network 100 also includes a terminal device 120 served by the network device 110. The serving area of the network device 110 is called as a cell 102. It is to be understood that the number of network devices, terminal devices and TRPs is only for the purpose of illustration without suggesting any limitations. The network 100 may include any suitable number of network devices, terminal devices and TRPs adapted for implementing embodiments of this aspect of the present disclosure. Although not shown, it is to be understood that one or more terminal devices may be located in the cell 102 and served by the network device 110.

As used herein, the term “TRP” may refer to an antenna array (with one or more antenna elements) available to the network device located at a specific geographical location. For example, a network device may be coupled with multiple TRPs in different geographical locations to achieve better coverage. Alternatively or in addition, multi TRPs may be incorporated into a network device, or in other words, the network device may comprise the multi TRPs. It is to be understood that the TRP may also be referred to as a “panel” , which also refers to an antenna array (with one or more antenna elements) or a group of antennas. It is to also be understood that the TRP may refer to a logical concept which may be physically implemented by various manner.

In the communication network 100, the network device 110 can communicate data and control information to the terminal device 120 and the terminal device 120 can also communication data and control information to the network device 110. A link from the network device 110 to the terminal device 120 is referred to as a downlink (DL) or a forward link, while a link from the terminal device 120 to the network device 110 is referred to as an uplink (UL) or a reverse link.

Depending on the communication technologies, the network 100 may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Address (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency-Division Multiple Access (OFDMA) network, a Single Carrier-Frequency Division Multiple Access (SC-FDMA) network or any others. Communications discussed in the network 100 may use conform to any suitable standards including, but not limited to, New Radio Access (NR) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , cdma2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, 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. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

As shown in FIG. 1, the network device 110 may communicate with the terminal device 120 via the TRPs 130-1 and 130-2. In the following, the TRP 130-1 may be also referred to as the first TRP, while the TRP 130-2 may be also referred to as the second TRP. Each of the TRPs 130 may provide a plurality of beams for communication with the terminal device 120. The first and second TRPs 130-1 and 130-2 may be included in a same serving cell (such as, the cell 102 as shown in Fig. 1) or different serving cells provided by the network device 110.

Although some example embodiments of the present disclosure are described with reference to the first and second TRPs 130-1 and 130-2 within a same serving cell 102 provided by the network device 110, these embodiments are only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations on the scope of the present disclosure. The embodiments of the present disclosure may be implemented in a network where the TRPs 130 are within different serving cells provided by the network device 110. It is to be understood that the present disclosure described herein can be implemented in various manners other than the ones described below.

In some multi-TRP communication schemes, single DCI may be used to schedule more than one physical downlink shared channel (PDSCH) /physical uplink shared channel (PUSCH) or different DCI (also referred to as multiple DCI or multi-DCI) may be used to schedule more than one PDSCH/PUSCH. Figs. 2A and 2B illustrate

example schemes

200 and 250 of multi-TRP DL transmission in accordance with some embodiments of the present disclosure, respectively.

In the scheme 200, DL data 210-1 may be transmitted by the network device 110 via the TRP 130-1 to the terminal device 120. Likewise, DL data 210-2 may be transmitted by the network device 110 via the TRP 130-2 to the terminal device 120. In this single DCI scheme 200, DCI 220 may be transmitted by the network device 110 to the terminal device 120 via the TRP 130-1. No DCI will be transmitted via the TRP 130-2. For example, the network device 110 may schedule two PDSCHs by the single DCI 220 with for example each of the PDSCHs corresponding to one of the two TRPs 130. That is, single PDCSH with different layers transmitted by different TRPs 130 may be scheduled by the single DCI 220. That is, different layers are associated with per TRP. It is to be understood that although the DCI 220 is transmitted by the TRP 130-1 in Fig. 2, the DCI 220 may be transmitted by the TRP 130-2 instead of the TRP 130-1 in other examples. It is to be understood that more than two TRPs 130 can be implemented in the scheme 200.

In the scheme 250, similar to the scheme 200, DL data 210-1 and data 210-2 may be transmitted by the network device 110 via the TRP 130-1 and the TRP 130-2 to the terminal device 120, respectively. Different with the scheme 200, in the scheme 250, DCI 260-1 and DCI 260-2 may be transmitted by the network device 110 to the terminal device 120 via the TRP 130-1 and the TRP 130-2, respectively. For example, the network device 110 may schedule two PDSCHs transmitted by different TRPs 130. Each PDSCH may be scheduled by a single DCI 260 per TRP 130, or also referred to as different transport blocks (TBs) per TRP 130. It is to be understood that more than two TRPs 130 can be implemented in the scheme 250.

As used herein, the term “beam” refers to a resource (s) in the spatial domain and is indicated by a set of parameters. In 3GPP specifications for NR, the beam may be indicated by the quasi-colocation (QCL) type D information, which is included in a Transmission Configuration Indicator (TCI) state. The beam for PDSCH as used herein is used for reception.

As briefly mentioned above, in the multi-TRP communication network, devices may operate in different frequency bands. For example, devices may perform transmissions in an extremely high frequency band (also referred to as millimeter wave (mmWave) shared spectrum) such as above 52.6GHz to 71GHz.

It has been proposed to use a multi-channel channel access procedure by the network device to initiate a channel occupancy in the mmWave shared spectrum for downlink (DL) transmissions. For example, separate channel clear assessment (CCA) may be performed for each channel. For the multi-TRP operation on mmWave shared spectrum, based on multi-channel access procedure, multiple channels corresponding to multiple TRPs may be occupied for multiple DL transmissions. However, UL transmissions corresponding to multi-TRP based DL transmission in the mmWave shared spectrum need to be enhanced. For example, channel occupancy time (COT) sharing between the network device and the terminal device need to be improved considering the requirement of operation on shared spectrum.

In addition, in some scenarios, the network device may not perform a channel access procedure to initiate a COT for DL transmission, while the terminal device needs to perform the channel access procedure for the UL transmission. In such situation, the terminal device cannot share the COT initiated by the network device, such the above mentioned approach cannot be applied. The terminal device needs to initiate a COT by itself. Initiating the COT by the terminal device needs to be supported.

As discussed above, it is very challenging to perform the UL transmission corresponding to multi-TRP based DL transmission in the mmWave shared spectrum. According to embodiments of the present disclosure, there is proposed a solution for the UL transmission to deal with any of the above mentioned problems. The terminal device receives DCI from the network device. The terminal device performs at least one channel access procedure indicated by the DCI on at least one channel. Then, the terminal device determines a target starting time and a time duration for the UL transmission on one channel based on a result of the at least one channel access procedure. By performing the at least one channel access procedure indicated by the network device, the terminal device can determine a target starting time to share a COT initiated by the network device for the UL transmissions, or determine a COT initiated by the terminal device itself for the UL transmissions. In this way, the UL transmissions will be enhanced. To better understand the solution for multi-TRP communication, some embodiments are now described with reference to Figs. 3-9.

Example multi-TRP transmission with channel access procedure

Fig. 3 illustrates a signaling flow 300 for communication according to some example embodiments of the present disclosure. As shown in Fig. 3, the signaling flow 300 involves a terminal device 120 and a network device 110 in Fig. 1. It is to be understood that the signaling flow 300 may involves more devices or less devices, and the number of devices illustrated in Fig. 3 is only for the purpose of illustration without suggesting any limitations.

In operation, the terminal device 110 may transmit DL transmissions to the terminal device 120. For example, the DL transmissions may comprise DCI. As shown in Fig. 3, the network device 110 transmits 305 at least one DCI to the terminal device 120. The DCI indicates at least one COT corresponding to at least one channel. The at least one channel is associated with at least one TCI state. In some example embodiments, the at least one DCI may comprise at least one indication indicating at least one channel access procedure to be performed by the terminal device 120 on the at least one channel.

In some example embodiments, for example in examples shown in the scheme 250, the network device 110 may transmit 305 first DCI via a first channel and second DCI via a second channel to the terminal device 120. As used hereinafter, the term of “the first channel” may be referred to a channel or a beam associated with the TRP 130-1 in Fig. 1, while the term of “the second channel” may be referred to a channel or a beam associated with the TRP 130-2 in Fig. 1. Each channel or each beam may be associated with a TCI state corresponding to a respective TRP. For example, the network device 110 may transmit 305 the first and second DCI in first and second PDCCH to the terminal device 120 through a first and second beams corresponding to first and second TCI states, respectively. The first DCI may indicate a first COT duration on the first channel initiated by the network device 110. Likewise, the second DCI may indicate a second COT duration on the second channel initiated by the network device 110.

In some example embodiments, the first DCI may comprise a first indication indicating a first channel access procedure on the first channel. Likewise, the second DCI may comprise a second indication indicating a second channel access procedure on the second channel.

In some example embodiments, for example in examples shown in the scheme 200, the network device 110 may transmit 305 single DCI to the terminal device 120. For example, the network device 110 may transmit 305 the single DCI via one of a first channel and a second channel. The DCI may be of format DCI 0_0, DCI 0_1 or DCI 2_0 or another format. The DCI may be enhanced with the indication indicating at least one of a first channel access procedure on the first channel and a second channel access procedure on the second channel. As used hereinafter, the term of "the first channel access procedure" refers to the channel access procedure to be performed by the terminal device 120 on the first channel associated with the TRP 130-1. As used herein, the term of "the second channel access procedure" refers to the channel access procedure to be performed by the terminal device 120 on the second channel associated with the TRP 130-2. It is to be understood that the "first" and "second" used in the terms "the first channel access procedure" and "the second channel access procedure" do not mean any temporal relation between these two channel access procedures. The first channel access procedure may be performed in parallel with the second channel access procedure, before the second channel access procedure, or after the second channel access procedure.

For example, the network device 110 may transmit 305 the DCI in a single PDCCH to the terminal device 120 through a beam corresponding to a TCI state for single DCI based multi-TRP cases. The DCI also may comprise the indication indicating at least one of: a first COT on the first channel initiated by the network device 110 and a second COT on the second channel initiated by the network device 110.

It is to be understood that there may be any suitable number of channels (for example, more than two channels) associated with any suitable number of TRPs. For example, taking a network device 110 with M TRPs 130 as an example, the network device 110 may transmit 305 the single DCI via one of M channels corresponding to the M TRPs 130. Each channel may be a beam indicated by a TCI state corresponding to the respective TRP. The value of M could be any suitable number greater than 1.

In some example embodiments, the DCI may be of any suitable format. Example formats of the DCI may comprise but not limited to DCI 0_0, DCI 0_1 and DCI 2_0. Those DCI formats may be enhanced or augmented with multiple indications to the terminal device 120 for the at least one channel access procedure. The multiple indications may comprise the at least one type of the at least one channel access procedure. For example, example types pf the channel access procedure may comprise but not limited to Type 1 (also referred to as Cat 4) , Type 2 (also referred to as Cat 2, Cat 2A, Cat 2B) , Type 3 (also referred to as Cat 2C) . The DCI may further comprise information regarding the at least one COT duration initiated by the network device 110 in the cases where the network device 110 performs the channel access procedure.

Alternatively, or in addition, in some example embodiments, the network device 110 may transmit 315 a radio resource control (RRC) signaling to the terminal device 120. The terminal device 120 may receive 320 the RRC signaling. The RRC signaling may comprise an indication indicating the at least one channel access procedure on the at least one channel. For example, the indication may indicate at least one of: a first channel access procedure to be performed by the terminal device 120 on the first channel and a second channel access procedure to be performed by the terminal device 120 on the second channel. It is to be understood that the network device 110 may transmit the indication via other signaling other than the RRC signaling.

In some example embodiments, the network device 110 and the terminal device 120 may have a same operation mode on shared spectrum in high frequency band, which may be referred to LBT (listen before talk) mode (the channel access procedure is necessary for initiating and/or sharing a channel occupancy) or no-LBT mode (the channel access procedure before transmission is not necessary for any time) . For example, both the network device 110 and the terminal device 120 operating in LBT mode may perform the channel access procedure to initiate and/or share a channel occupancy before transmission. In such cases, the network device 110 may perform at least one channel access procedure to initiate at least one COT for DL transmissions. For example, the network device 110 may initiate the at least one COT duration on at least on channel based on at least one successful CCA associated with the at least one channel access procedure.

In some example embodiments, the network device 110 may perform a Type A multi-channel access for the DL transmissions. For example, the network device 110 may perform independent CCA for each of the first and second channels. As used hereinafter, the term of “CCA” may also be referred to as “extended CCA (eCCA) ” or “LBT” .

Alternatively, in some example embodiments, the network device 110 may perform a Type B multi-channel access for DL transmissions. For example, the network device 110 may determine a primary channel from the first and second channels. The network device 110 may perform a CCA (for example a Type 1 CCA) on the primary channel, while performing a Type 2 CCA such as Cat 2 LBT for the other channel in the last observation slot of the CCA on the primary channel.

In the cases where the terminal device 110 initiating the at least one COT duration, the network device 110 may transmit 305 the at least one DCI on the at least one channel during the at least one COT duration initiated by the network device 110. For example, in the example where the network device 110 initiates a first COT duration on the first channel and a second COT duration on the second channel, the network device 110 may transmit 305 first DCI on the first channel during the first COT duration and second DCI on the second channel during the second COT duration. Alternatively, the network device 110 may transmit 305 the single DCI on one of the first and second channels on the respective channel during a respective COT duration. For another example where the network device 110 initiates a first COT duration on the first channel without a second COT duration on the second channel, the network device may transmit 305 the single DCI on the first channel during the first COT duration.

In some example embodiments, the network device 110 and the terminal device 120 may have different operation modes on shared spectrum in high frequency band, which may be referred to LBT mode and no-LBT mode. For example, the terminal device 120 may perform the channel access procedure to initiate a channel occupancy while the network device 110 may not perform the channel access procedure to initiate a channel occupancy. In such cases, the network device 110 may transmit 305 the DCI to the terminal device 120 without performing the channel access procedure to initiate a COT.

In responsive to receiving 310 the DCI from the network device 110, the terminal device 120 performs 325 the at least one channel access procedure on the at least one channel. The at least one channel access procedure is indicated by the indication comprised in the at least one DCI or the RRC signaling. For example, in some example embodiments, the terminal device 120 may perform 325 the first channel access procedure on the first channel and the second channel access procedure on the second channel in parallel. It is to be understood that in those examples with more than two TRPs (that is, more than two channels or beams) , the terminal device 120 may perform 325 more than two channel access procedures indicated by the DCI on corresponding channels in parallel.

Alternatively, in some example embodiments, the terminal device 120 may perform 325 the first and second channel access procedures orderly. For example, the terminal device 120 may perform the first channel access procedure on the first channel and the second channel access procedure on the second channel. In some example embodiments, the terminal device 120 may select one from the first and second channel access procedures to be performed randomly or based on priorities of the first and second channels. It is to be understood that the priorities of the first and second channels may also be referred to as the priorities of the TRPs 130-1 and 130-2.

In some example embodiments, the priorities of the first and second channels may be predetermined by the terminal device 120 or predetermined or preconfigured by the network device 110. Alternatively, or in addition, the priorities of the first and second channels may be based on whether the DCI is transmitted via a given channel of the first and second channels. For example, if the DCI is transmitted via the first channel instead of the second channel, the priority of the first channel may be higher than the second channel.

Alternatively, the priorities of the first and second channels may be based on a length of a remaining portion of a COT initiated by the network device 110 of the given channel. For example, in the examples where the network device 110 initiates a first COT on the first channel and a second COT on the second channel, if the remaining portion of the first COT is longer than the remaining portion of the second COT, then the priority of first channel may be higher than the priority of the second channel.

In some example embodiments, if the terminal device 120 performs 325 one of the first and second channel access procedures and the result of this channel access procedure shows that the respective channel associated with this channel access procedure is sensed to be not idle, the terminal device 120 may perform another channel access procedure of the first and second channel access procedures subsequently. For example, taking the first channel access procedure as an example of the target channel access procedure, if the first channel access procedure showing the first channel is not idle, then the terminal device 120 may perform the second channel access procedure subsequently. Otherwise, if the respective channel is sensed to be idle based on the result of the target channel access procedure, the terminal device 120 may not perform the other channel access procedure.

It is to be understood that in those examples where a set of TRPs 130 (for example, more than two TRPs) are associated with the network device 110, the DCI may indicate a set of channel access procedures on a set of channels. In such cases, the terminal device 120 may order the set of channel access procedures based on a descending order of the priorities of the set of channels. The terminal device 120 may perform the set of channel access procedures according to the descending order one by one, until a certain channel access procedure in the set of channel access procedures is successful. That is, the certain channel access procedure shows the respective channel associated with the certain channel access procedure is sensed to be idle and available for transmission.

The terminal device 120 determines 330 a target starting time and a time duration for a transmission on one channel from the terminal device 120 to the network device 110 based on a result of the at least one channel access procedure, corresponding DCI (s) and network configuration (s) . The terminal device 120 then may transmit 335 a transmission to the network device 110 on the channel from the target starting time within duration. The network device 110 may receive 340 the UL transmission from the terminal device 120 accordingly.

For example, in the situation where the network device 110 may transmit the DL transmission without performing the channel access procedure, if the at least one channel is sensed to be idle based on a Type 1 channel access procedure performed by the terminal device 120, the terminal device 120 may determine a starting time of a channel occupancy time duration after the at least one channel access procedure and the channel occupancy time duration to be the target starting time and the time duration.

By using the signaling flow 300, the terminal device 120 may perform at least one channel access procedure before performing a UL transmission to the network device 110. In this way, the terminal device 120 may either use a remaining portion of a COT initiated by the network device for the UL transmission, or initiate a COT by the terminal device itself for the UL transmission.

Some example embodiments regarding how to perform the multi-TRP UL transmissions based on the at least one channel access procedure and the at least one DCI, for example how to determine the target starting time and the time duration will be described with respect to Figs. 4A–7B below.

Example UL transmissions with channel access procedure corresponding to multi-TRP DL transmission

Fig. 4A illustrates example architecture 400-1 and 400-2 of UL transmissions according to some example embodiments of the present disclosure. In the architecture 400-1 and 400-2, a first channel or a first beam is associated with the TRP 130-1 in Fig. 1, and a second channel or a second beam is associated with the TRP 130-2 in Fig. 1. As shown in Fig. 4A, the network device 110 may transmit single DCI 410 through a first channel associated with the TRP 130-1. The DCI 410 may indicate that the terminal device 120 may share the COT corresponding to the TRP 130-1 initiated by the network device 110. That is, the terminal device 120 may be expected to transmit a UL transmission scheduled only for the TRP 130-1. No UL transmission will be performed on the second channel associated with the TRP 130-2.

As shown in Fig. 4A, the network device 110 may perform a channel access procedure on the first channel. For example, the network device 110 may perform a Type 1 CCA 405 (also referred to as a Type 1 channel access procedure or a Cat 4 LBT or a Type 1 eCCA) on the first channel associated with the TRP 130-1. In some example embodiments, the Type 1 CCA may comprise a Cat 4 LBT. If the Type 1 CCA 405 is successful, the network device 110 may transmit DL transmissions to the terminal device 120. For example, the network device 110 may transmit the DCI 410 and a PDSCH 415 to the terminal device 120. The DCI 410 may be carried by a PDCCH. A COT 402 corresponding to the TRP 130-1 initiated by the network device 110 may start from the beginning of the slot where the DCI 410 is detected.

Likewise, the network device 110 may perform a further channel access procedure on the second channel. For example, the network device 110 may perform a further Type 1 CCA 435 on the second channel associated with the TRP 130-2. If the Type 1 CCA 435 is successful, the network device 110 may transmit a PDSCH 440 to the terminal device 120. A COT duration (also referred to as a COT) 404 corresponding to the TRP 130-2 initiated by the network device 110 may start from the beginning of the first DL slot corresponding to the TRP 130-2.

In the examples shown in Fig. 4A, a time gap 420 between the last DL transmission corresponding to all the TRPs 130 and a first scheduled UL transmission is determined. In Fig. 4A, the time gap 420 is greater than a threshold time gap. The threshold time gap may be predetermined by the network device 110 or terminal device 120 or preconfigured by the network device 110. In the situation that the time gap 420 is greater than the threshold time gap, the terminal device 120 may perform a channel access procedure on the first channel where a UL transmission is scheduled based on the DCI 410. For example, the terminal device 120 may perform a Type 2 CCA 425 (also referred to as a Type channel access procedure or a Cat 2 LBT or Type 2 eCCA) . In some example embodiments, the Type 2 CCA may comprise the Cat 2 LBT, or the Type 2/2A/2B channel access procedures.

As shown in the architecture 400-1, if the Type 2 CCA 425-1 is successful, the terminal device 120 may perform a UL transmission (TX) 430 on the first channel associated with the TRP 130-1. Otherwise, as shown in the architecture 400-2, if the Type 2 CCA 425-2 fails, the terminal device 120 may not transmit a UL transmission on the first channel.

Fig. 4B illustrates some example architecture 450-1, 450-2, 450-3 and 450-4 of UL transmissions according to some example embodiments of the present disclosure. In Fig 4B, similar to Fig. 4A, a first channel or a first beam is associated with the TRP 130-1 in Fig. 1, and a second channel or a second beam is associated with the TRP 130-2 in Fig. 1. As shown in Fig. 4A, the network device 110 may transmit single DCI 460 through a first channel associated with the TRP 130-1. Different from the DCI 410, the DCI 460 may further comprise the indication that indicates a first channel access procedure on the first channel and a second channel access procedure on the second channel. That is, the terminal device 120 may be expected to transmit UL transmissions scheduled for the TRPs 130-1 and 130-2. The scheduled UL transmissions scheduled for different TRPs 130 may be overlapped or partly overlapped in time. Only one UL transmission corresponding to only one TRP 130 may occur finally based on result (s) of the channel access procedure (s) on those channels associated with the TRPs 130.

For example, the DCI 460 may comprise multiple indications of the channel access procedure types of the terminal device (for example, Type 1/2/3 channel access procedure or Cat 4/2/2CLBT) and COT durations corresponding to the multiple TRPs 130. The channel access types may be preconfigured by the network device 110 via radio resource control or indicated by the network device 110 through scheduling DCI.

In the architecture 450-1, 450-2 and 450-3, similar to Fig. 4A, the network device 110 performs a Type 1 CCA 405 on the first channel which is successful, and performs a Type 1 CCA 435 on the second channel which is also successful. The time gap 420 is greater than the threshold time gap.

In the architecture 450-1, the terminal device 120 may perform a Type 2 CCA 470-1 on the first channel and a Type 2 CCA 475 on the second channel in parallel. The terminal device 120 may determine to transmit a UL transmission corresponding to a certain TRP 130 according to the results of the Type 2

CCAs

470 and 475. For example, in the architecture 450-1, the Type 2 CCA 470 is failed while the Type 2 CCA 475 is successful, then the terminal device 120 may transmit a UL transmission 480 via the second channel associated with the TRP 130-2. The terminal device 120 may determine a starting point of a slot after the Type 2 CCA 475 as a starting time of the UL transmission 480. The terminal device 120 may determine the remaining portion of the COT duration 404 starting from the starting point of the UL transmission 480 to be a time duration for the UL transmission 480.

Alternatively, or in addition, in some example embodiments, if both the above two Type 2 CCAs are successful, the terminal device 120 may select a target channel of the first and second channels based on priorities of these two channels. The priorities of these two channels may be predetermined by the network device 110 or terminal device 120 or predetermined or preconfigured by the network device 110. Alternatively, the priorities of the first and second channels may be based on whether the DCI is transmitted via a given channel of the first and second channels. In the architecture 450-1, the DCI is transmitted via the first channel instead of the second channel, then the priority of the first channel may be higher than the second channel. Alternatively, the priorities of the first and second channels may be based on a length of a remaining portion of a COT duration initiated by the network device 110 of the given channel. In the architecture 450-1, the remaining time of the COT duration 404 is longer than that of the COT 402, then the priority of the second channel is higher than the priority of the first channel.

In some example embodiments, the first and second channel access procedures may be performed in sequence. For example, the terminal device 120 may choose a target channel access procedure based on the priorities of the first and second channels. Alternatively, the terminal device 120 may select a target channel access procedure randomly.

In the architecture 450-2, the terminal device 120 determines the first channel access procedure associated with the TRP 130-1 to be the target channel access procedure. The terminal device 120 performs the Type 2 CCA 470 which is failed. In the situation that the target channel access procedure is failed, the terminal device 120 may further perform a Type 2 CCA 475 on the second channel subsequently. If the Type 2 CCA 475 is successful, the terminal device 120 may perform a UL transmission 480 via the second channel. The terminal device 120 may determine a starting point of a slot after the Type 2 CCA 475 as a starting time of the UL transmission 480. The terminal device 120 may determine the remaining portion of the COT 404 starting from the starting point of the UL transmission 480 to be a time duration for the UL transmission 480.

In the architecture 450-3, the terminal device 120 determines the second channel access procedure associated with the TRP 130-2 as the target channel access procedure. The terminal device 120 may perform the Type 2 CCA 475 first. In the architecture 450-3, the Type 2 CCA 475 is successful, then the terminal device 120 may transmit the UL transmission 480 without performing a subsequent Type 2 CCA 470. The terminal device 120 may determine a starting point of a slot after the Type 2 CCA 475 as a starting time of the UL transmission 480. The terminal device 120 may determine the remaining portion of the COT 404 starting from the starting point of the UL transmission 480 to be a time duration for the UL transmission 480.

In the architecture 450-4, the network device 110 performs a Type 1 CCA 405 on the first channel which is successful. However, the network device 110 performs a Type 1 CCA 435 on the second channel which is failed. That is, the COT duration 402 is initiated by the network device 110 on the first channel. The second channel is sensed to be not idle based on the Type 1 CCA 435. In such situation, , the terminal device 120 may perform at least one of: a Type 2 channel access procedure on the first channel, and a Type 1 channel access procedure on the second channel. As shown in the architecture 450-4, the terminal device 120 may perform a Type 2 CCA 470 on the first channel, and a Type 1 CCA 485 on the second channel in parallel. In the example shown in the architecture 450-4, the Type 2 CCA 470 is failed, while the Type 1 CCA 485 is successful, thus the terminal device 120 may transmit the UL transmission 480 in the second channel. The terminal device 120 may determine a starting point of a slot after the Type 1 CCA 485 as a starting time of the UL transmission 480. The terminal device 120 may initiate a COT 406 starting from the starting time for the UL transmission 480.

It is to be understood that if both the Type 1 CCA 485 and the Type 2 CCA 470 are successful, the terminal device 120 may choose a channel based on the priorities of these two channels or choose a channel randomly for the UL transmission. It is to be understood that although the architecture 450-4 shows that the Type 1 CCA 485 and the Type 2 CCA 470 are performed in parallel, in some example embodiments, the Type 1 CCA 485 and the Type 2 CCA 470 may be performed in sequence. The order of these two CCAs may be determined based on the priorities of the channels or determined randomly. By performing the channel access procedure on the second channel where the channel access procedure performed by the network device is failed, the terminal device may have the opportunity to use the resource on the second channel.

Fig. 4C illustrates another example architecture 450-5 of UL transmissions according to some example embodiments of the present disclosure. Those elements with same reference number in Fig. 4B will not be repeated here. In the architecture 450-5, similar to Figs. 4A and 4B, the network device 110 performs a Type 1 CCA 405 on the first channel which is successful, and performs a Type 1 CCA 435 on the second channel which is also successful. Unlike Figs. 4A and 4B, the time gap 490 is less than the threshold time gap. In such situation, the terminal device 120 may transmit a UL transmission 480 by using a remaining portion of the at least one COT duration initiated by the network device 110 without performing a channel access procedure. For example, the terminal device 120 may use the remaining portion of the COT duration 402 on the first channel for the UL transmission 480 as shown in the architecture 450-5. It is to be understood that the terminal device 120 may also use the remaining portion of the COT duration 404 on the second channel for the UL transmission 480.

In some example embodiments, the terminal device 120 may select one COT of the

COTs

402 and 404 based on the priorities of the first and second channels. Alternatively, the terminal device 120 may select one of the

COT durations

402 and 404 randomly. The terminal device 120 may perform the UL transmission using a remaining portion of the selected COT duration.

As discussed above, the priorities of these two channels may be predetermined by the terminal device 120 or predetermined or preconfigured by the network device 110. Alternatively, the priorities of the first and second channels may be based on whether the DCI is transmitted via a given channel of the first and second channels. Alternatively, the priorities of the first and second channels may be based on a length of a remaining portion of a COT duration initiated by the network device 110 of the given channel.

Examples regarding the UL transmission based on the channel access procedures indicated by a single DCI in accordance with the present disclosure have been described with respect to Figs. 4A-4C. By using the single DCI to indicate the channel access procedure to be performed by the terminal device, the terminal device may share the COT duration initiated by the network device for UL transmission.

Some examples regarding the UL transmission based on the channel access procedures indicated by multiple DCIs in accordance with the present disclosure have been described with respect to Figs. 5A-5D.

Fig. 5A illustrates example architecture 500-1 and 500-2 of UL transmissions according to some example embodiments of the present disclosure. In the architecture 500-1 and 500-2, a first channel or a first beam is associated with the TRP 130-1 in Fig. 1, and a second channel or a second beam is associated with the TRP 130-2 in Fig. 1. As shown in Fig. 5A, the network device 110 may transmit first DCI 510 through the first channel associated with the TRP 130-1 and second DCI 540 through the second channel associated with the TRP 130-2. The DCI 510 may indicate that the terminal device 120 may share the first COT duration corresponding to the TRP 130-1 initiated by the network device 110. The DCI 510 may indicate that the terminal device 120 may share the second COT corresponding to the TRP 130-1 initiated by the network device 110. In the example shown in Fig. 5A, the terminal device 120 is expected to transmit a UL transmission scheduled only for the TRP 130-1. No UL transmission will be performed on the second channel associated with the TRP 130-2.

In some example embodiments, the terminal device 120 may determine to transmit the UL transmission scheduled for the TRP 130-1 instead of the TRP 130-2 based on the priorities of the TRPs 130-1 and 130-2 (also referred to as the priorities of the first and second channels) . The priorities of the first and second channels may be predetermined by the terminal device 120 or predetermined or preconfigured by the network device 110. Alternatively, or in addition, the priorities of the first and second channels may be based on whether the DCI is transmitted via a given channel of the first and second channels.

If the priority of the first channel is higher than the priority of the second channel, the terminal device 120 may determine to transmit the UL transmission scheduled for the TRP 130-1 instead of the TRP 130-2. Alternatively, the terminal device 120 may select the first channel from the first and second channels randomly.

As shown in Fig. 5A, the network device 110 may perform a channel access procedure on the first channel. For example, the network device 110 may perform a Type 1 CCA 505 (also referred to as a Type 1 channel access procedure or a Cat 4 LBT or a Type 1 eCCA) on the first channel associated with the TRP 130-1. If the Type 1 CCA 505 is successful, the network device 110 may transmit the DCI 510 and a PDSCH 515 to the terminal device 120. The DCI 510 may be carried by a PDCCH. A COT duration 502 corresponding to the TRP 130-1 initiated by the network device 110 may start from the beginning of the slot where the DCI 510 is detected.

Likewise, For example, the network device 110 may perform a Type 1 CCA 535 (also referred to as a Type 1 channel access procedure or a Cat 4 LBT or a Type 1 eCCA) on the first channel associated with the TRP 130-2. If the Type 1 CCA 535 is successful, the network device 110 may transmit the DCI 540 and a PDSCH 545 to the terminal device 120. The DCI 540 may be carried by a PDCCH. A COT duration 504 corresponding to the TRP 130-2 initiated by the network device 110 may start from the beginning of the slot where the DCI 540 is detected.

In the examples shown in Fig. 5A, a time gap 520 between the last DL transmission corresponding to all the TRPs 130 and a first scheduled UL transmission is determined. In Fig. 5A, the time gap 520 is greater than a threshold time gap. The threshold time gap may be predetermined by the network device 110 or terminal device 120 or preconfigured by the network device 110. In the situation that the time gap 520 is greater than the threshold time gap, the terminal device 120 may perform a channel access procedure on the first channel where a UL transmission is scheduled based on the DCI 410. For example, the terminal device 120 may perform a Type 2 CCA 525 (also referred to as a Type 2 channel access procedure or Cat 2 LBT or Type 2 eCCA) .

As shown in the architecture 500-1, if the Type 2 CCA 525-1 is successful, the terminal device 120 may perform a UL transmission (TX) 530 on the first channel associated with the TRP 130-1. Otherwise, as shown in the architecture 500-2, if the Type 2 CCA 425-2 fails, the terminal device 120 may not transmit a UL transmission on the first channel.

Fig. 5B illustrates some example architecture 550-1 and 550-2 of UL transmissions according to some example embodiments of the present disclosure. In Fig 5B, similar to Fig. 5A, a first channel or a first beam is associated with the TRP 130-1 in Fig. 1, and a second channel or a second beam is associated with the TRP 130-2 in Fig. 1. As shown in Fig. 5, the network device 110 may transmit DCI 560 through the first channel associated with the TRP 130-1 and DCI 565 through the second channel associated with the TRP 130-2. In the example of Fig. 5B, the terminal device 120 may be expected to transmit UL transmissions scheduled for the TRPs 130-1 and 130-2. The scheduled UL transmissions scheduled for different TRPs 130 may be overlapped or partly overlapped in time. Only one UL transmission corresponding to only one TRP 130 may occur finally based on result (s) of the channel access procedure (s) on those channels associated with the TRPs 130.

For example, the DCI 560 and DCI 565 may comprise a first and second indications of the channel access types (for example, Type 1/2/3 channel access procedure or Cat 4/2/2C LBT) to be performed by the terminal device 120 and COT information corresponding to the multiple TRPs 130. The channel access types may be preconfigured by the network device 110 via radio resource control (RRC) or indicated by the network device 110 through scheduling DCI.

In the architecture 550-1 and 550-2, similar to Fig. 5A, the network device 110 performs a Type 1 CCA 505 on the first channel which is successful, and performs a Type 1 CCA 535 on the second channel which is also successful. The time gap 520 is greater than the threshold time gap.

In the architecture 550-1, the terminal device 120 may perform a Type 2 CCA 570 on the first channel and a Type 2 CCA 575 on the second channel in parallel. The terminal device 120 may determine to transmit a UL transmission corresponding to a certain TRP 130 according to the results of the Type 2

CCAs

570 and 575. For example, in the architecture 550-1, the Type 2 CCA 570 is failed while the Type 2 CCA 575 is successful, then the terminal device 120 may transmit a UL transmission 580 via the second channel associated with the TRP 130-2. The terminal device 120 may determine a starting point of a slot after the Type 2 CCA 575 as a starting time of the UL transmission 580. The terminal device 120 may determine the remaining portion of the COT duration 504 starting from the starting point of the UL transmission 580 to be a time duration for the UL transmission 580.

Alternatively, or in addition, in some example embodiments, if both the above two Type 2 CCAs are successful, the terminal device 120 may select a target channel from the first and second channels based on priorities of these two channels. The priorities of these two channels may be predetermined by the network device 110 or terminal device 120 or predetermined or preconfigured by the network device 110. Alternatively, the priorities of the first and second channels may be based on whether the DCI is transmitted via a given channel of the first and second channels. Alternatively, the priorities of the first and second channels may be based on a length of a remaining portion of a COT duration initiated by the network device 110 of the given channel.

In some example embodiments, the first and second channel access procedures may be performed in sequence. For example, the terminal device 120 may choose a target channel access procedure based on the priorities of the first and second channels. Alternatively, the terminal device 120 may select a target channel access procedure associated with a channel randomly.

In the architecture 550-2, the terminal device 120 determines the first channel access procedure associated with the TRP 130-1 to be the target channel access procedure. The terminal device 120 performs the Type 2 CCA 570 which is failed. In the situation that the target channel access procedure is failed, the terminal device 120 may further perform a Type 2 CCA 575 on the second channel subsequently. If the Type 2 CCA 575 is successful, the terminal device 120 may perform a UL transmission 580 via the second channel. The terminal device 120 may determine a starting point of a slot after the Type 2 CCA 575 as a starting time of the UL transmission 580. The terminal device 120 may determine the remaining portion of the COT 504 starting from the starting point of the UL transmission 480 to be a time duration for the UL transmission 580.

Fig. 5C illustrates further example architecture 550-3 and 550-4 of UL transmissions according to some example embodiments of the present disclosure. Elements having the same reference number with Fig. 5B will not be repeated.

In the architecture 550-3 and 530-4, the Type 1 CCA 535 on the second channel performed by the network device 110 is failed. That is, the second channel is sensed to be not idle. In such cases, the network device 110 may transmit enhanced DCI 585 to the terminal device 120. The enhanced DCI 585 may comprise indication indicating the first channel access procedure on the first channel and the second channel access procedure on the second channel. For example, the enhanced DCI 585 may comprise indication indicating a Type 2 CCA 570 on the first channel and a Type 1 CCA 585 on the second channel to be performed by the terminal device 120.

In the architecture 550-3, the Type 2 CCA 570 is successful, then the terminal device 120 may transmit the UL transmission 580 without performing the subsequent Type 1 CCA 585. The terminal device 120 may determine a starting point of a slot after the Type 2 CCA 570 as a starting time of the UL transmission 580. The terminal device 120 may determine the remaining portion of the COT duration 502 starting from the starting point of the UL transmission 580 to be a time duration for the UL transmission 580.

In the architecture 550-4, the terminal device 120 may perform the Type 2 CCA 570 on the first channel, and the Type 1 CCA 585 on the second channel in parallel. As shown in the architecture 550-4, the Type 2 CCA 570 is failed, while the Type 1 CCA 585 is successful, thus the terminal device 120 may transmit the UL transmission 580 in the second channel. The terminal device 120 may determine a starting point of a slot after the Type 1 CCA 585 as a starting time of the UL transmission 580. The terminal device 120 may initiate a COT duration 506 starting from the starting time for the UL transmission 580.

It is to be understood that if both the Type 1 CCA 585 and the Type 2 CCA 570 are successful, the terminal device 120 may choose a channel based on the priorities of these two channels or choose a channel randomly for the UL transmission. It is to be understood that although the architecture 550-4 shows that the Type 1 CCA 585 and the Type 2 CCA 570 are performed in parallel, in some example embodiments, the Type 1 CCA 585 and the Type 2 CCA 570 may be performed in sequence. The order of these two CCAs may be determined based on the priorities of the channels or determined randomly. By performing the channel access procedure on the second channel where the channel access procedure performed by the network device is failed, the terminal device may have the opportunity to use the resource on the second channel.

Fig. 5D illustrates another example architecture 550-5 of UL transmissions according to some example embodiments of the present disclosure. Those elements with same reference number in Fig. 5B will not be repeated here. In the architecture 550-5, similar to Figs. 5A and 5B, the network device 110 performs a Type 1 CCA 505 on the first channel which is successful, and performs a Type 1 CCA 535 on the second channel which is also successful. Unlike Figs. 5A and 5B, the time gap 590 is less than the threshold time gap. In such situation, the terminal device 120 may transmit a UL transmission 580 by using a remaining portion of the at least one COT duration initiated by the network device 110 without performing a channel access procedure. For example, the terminal device 120 may use the remaining portion of the COT duration 502 on the first channel for the UL transmission 580 as shown in the architecture 550-5. It is to be understood that the terminal device 120 may also use the remaining portion of the COT duration 504 on the second channel for the UL transmission 580.

In some example embodiments, the terminal device 120 may select one COT of the

COT durations

502 and 504 based on the priorities of the first and second channels. Alternatively, the terminal device 120 may select one of the

COT durations

502 and 504 randomly. The terminal device 120 may perform the UL transmission using a remaining portion of the selected COT duration.

It is to be understood that in the example where M (the value of M being greater than 2) TRPs are applied, the terminal device 120 may receive at least one but no more than M DCI from the network device 110. The terminal device 120 may perform at least one channel access procedure indicated by the at least one but no more than M DCI for the UL transmission.

Examples regarding the UL transmission based on the channel access procedures indicated by multiple DCIs in accordance with the present disclosure have been described with respect to Figs. 5A-5D. By using the multiple DCIs to indicate the channel access procedure to be performed by the terminal device, the terminal device may share the COT duration initiated by the network device for UL transmission.

Further examples regarding the UL transmission based on the channel access procedures indicated by single DCI in accordance with the present disclosure will be described with respect to Figs. 6A-6B. Fig. 6A illustrates example architecture 600-1 and 600-2 of UL transmissions according to some example embodiments of the present disclosure.

In the architecture 600-1 and 600-2, the network device 110 may perform the DL transmission without performing the channel access procedure. For example, the network device 110 may transmit DCI 605 and PDSCH 610 to the terminal device via a first channel associated with the TRP 130-1. The network device 110 may transmit PDSCH 615 to the terminal device 120 via a second channel associated with the TRP 130-2. As shown in Fig. 6A, in such cases the network device 110 transmits single DCI 605 to the terminal device 120. In such cases, the terminal device 120 may be expected to transmit a UL transmission scheduled for only one TRP, for example the TRP 130-1 as shown in Fig. 6A.

The network device 110 operating in no-LBT mode may indicate the terminal device 120 to operate in LBT mode (also referred to as CCA mode) . That is, the terminal device 120 may need to perform a channel access procedure before performing the UL transmission. For example, the terminal device 120 may perform at least one channel access procedure on at least one channel associated with at least one TRP 130, no matter whether there is a gap between the DL transmission and the UL transmission. In the examples of Fig. 6A, only DCI 605 is transmitted by the first channel, thus the terminal device 120 may perform a Type 1 CCA 625 in the first channel, without performing a CCA in the second channel.

As shown in Fig. 6A, in the architecture 600-1, if the Type 1 CCA 625-1 is successful, the terminal device 120 may perform a UL transmission (TX) 630 on the first channel associated with the TRP 130-1. That is, if the first channel is sensed to be idle or available for transmission, the terminal device 120 may perform a UL transmission (TX) 630 on the first channel associated with the TRP 130-1. Otherwise, in the architecture 600-2, if the Type 1 CCA 625-2 fails, the terminal device 120 may not transmit a UL transmission on the first channel. That is, if the first channel is sensed to be not idle or busy, the terminal device 120 may not perform a UL transmission (TX) 630 on the first channel associated with the TRP 130-1.

Fig. 6B illustrates further architecture 650-1 and 650-2 of UL transmissions according to some example embodiments of the present disclosure. In the architecture 650-1 and 650-2, the network device 110 may perform DL transmission without performing the channel access procedure. For example, the network device 110 may transmit DCI 655 and PDSCH 610 to the terminal device via a first channel associated with the TRP 130-1. The network device 110 may transmit PDSCH 615 to the terminal device 120 via a second channel associated with the TRP 130-2. As shown in Fig. 6B, in such cases the network device 110 transmits single DCI 655 to the terminal device 120. The network device 110 operating in no-LBT mode may indicate the terminal device 120 to operate in LBT mode (also referred to as CCA mode) .

Different with Fig. 6A, the DCI 655 may be enhanced DCI 655 which comprises multiple indications of channel access types (such as Type 1) to be performed by the terminal device 120 and additional information. That is, the terminal device 120 may need to perform multiple channel access procedures indicated by the DCI 655 before performing the UL transmission. In such cases, the terminal device 120 may be scheduled to transmit a UL transmission for multiple candidate TRPs (or channels) . UL transmission corresponding to only one TRP may occur finally. For example, the terminal device 120 may perform the channel access procedures on the first channel associated with the TRP 130-1 and the second channel associated with the TRP 130-2, no matter whether there is a gap between the DL transmission and the UL transmission.

As shown in Fig. 6B, in the architecture 650-1, the terminal device 120 may perform the Type 1 CCA 660 on the first channel and the Type 1 CCA 665 on the second channel in parallel. For example, if the terminal device 120 has the capability to simultaneously sense in different beams (or channels) corresponding to different TRPs, the terminal device 120 may perform concurrent multiple channel access procedures (such as the Type 1 CCA 660 and Type 1 CCA 665) corresponding to different TRPs (such as TRP 130-1 and TRP 130-2) . The terminal device 120 may determine to transmit a UL transmission corresponding to a certain TRP based on the results of the multiple channel access procedures.

In the architecture 650-1, if the Type 1 CCA 660 is failed while the Type 1 CCA 665 is successful, the terminal device 120 may initiate a COT duration 674 starting from the ending slot of the Type 1 CCA 665. The terminal device 120 may perform a UL transmission (TX) 630 on the second channel associated with the TRP 130-2 during the COT duration 674. That is, if the second channel is sensed to be idle or available for transmission, the terminal device 120 may perform a UL transmission (TX) 630 on the second channel associated with the TRP 130-2. It is to be understood that if both the Type 1 CCA 660 and Type 1 CCA 665 are successful, that is, if both the first and second channels are idle, then the terminal device 120 may select one channel from those two channels randomly or based on the priorities of the first and second channels.

In some example embodiments, as shown in the architecture 650-2, the terminal device 120 may perform multiple channel access procedures in sequence instead of in parallel. For example, the terminal device 120 may determine the order of the multiple channel access procedures randomly or based on the priorities of channels. In some example embodiments, the priorities of channels may be configured by RRC signaling from the network device 110 or indicated by the network device 110 though scheduling DCI. Alternatively, the priorities of channels may be determined based on whether the (enhanced) DCI is transmitted via a certain channel.

As shown in architecture 650-2, the terminal device 120 may first perform the Type 1 CCA 660 on the first channel associated with the TRP 130-1. If the Type 1 CCA 660 fails, the terminal device 120 may not transmit a UL transmission on the first channel. That is, if the first channel is sensed to be not idle or busy, the terminal device 120 may not perform a UL transmission on the first channel associated with the TRP 130-1. The terminal device 120 may subsequently perform the Type 1 CCA 665 on the second channel associated with the TRP 130-2. If the Type 1 CCA 665 is successful, that is, the second channel is sensed to be idle, the terminal device 120 may perform the UL transmission 630 on the second channel associated with the TRP 130-2. It is to be understood that in the architecture 650, if the Type 1 CCA 660 is successful (not shown) , the terminal device 120 may transmit the UL transmission in the first channel without performing a subsequent Type 1 CCA 665.

It is to be understood that in the example with M (the value of M being greater than 2) TRPs 130, the terminal device 120 may receive one enhanced DCI from the network device 110 indicating K channel access procedures to be performed by the terminal device 120. The value of K may be greater than one but not exceeding M. The terminal device 120 may perform K channel access procedures indicated by the DCI for the UL transmission. For example, the terminal device 120 may perform K Type 1 CCA on K channels associated with K TRPs, and select one channel with a successful Type 1 CCA for UL transmission randomly or based on the priorities. For another example, the terminal device 120 may determine an order of the K Type 1 CCAs randomly or based on the priorities of corresponding channels. The terminal device 120 may perform the K Type 1 CCAs one by one according to the order, until a certain Type 1 CCA is successful. The terminal device 120 may then use the channel (or the TRP) associated with the certain Type 1 CCA to transmit the UL transmission.

Examples regarding the UL transmission based on the channel access procedures indicated by single DCI in accordance with the present disclosure have been described with respect to Figs. 6A-6B. By using the single DCI to indicate the channel access procedure to be performed by the terminal device, the terminal device may initiate a COT duration for UL transmission.

Further examples regarding the UL transmission based on the channel access procedures indicated by multiple DCI in accordance with the present disclosure will be described with respect to Figs. 7A-7B. Fig. 7A illustrates example architecture 700-1 and 700-2 of UL transmissions according to some example embodiments of the present disclosure.

In the architecture 700-1 and 700-2, the network device 110 may perform DL transmission without performing the channel access procedure. For example, the network device 110 may transmit DCI 705 and PDSCH 710 to the terminal device via a first channel associated with the TRP 130-1. The network device 110 may transmit DCI 715 and PDSCH 720 to the terminal device 120 via a second channel associated with the TRP 130-2. As shown in Fig. 7A, in such cases the network device 110 transmits

multiple DCI

705 and 715 to the terminal device 120. In the examples of Fig. 7A, the terminal device 120 may be expected to transmit a UL transmission scheduled for only one TRP, for example the TRP 130-1 as shown in Fig. 7A.

The network device 110 may indicate the terminal device 120 that the connection between the network device 110 and the terminal device 120 is operating in LBT mode (also referred to as CCA mode) . That is, the terminal device 120 may need to perform a channel access procedure before performing the UL transmission. For example, the terminal device 120 may perform at least one channel access procedure on at least one channel associated with at least one TRP 130, no matter whether there is a gap between the DL transmission and the UL transmission. In the examples of Fig. 7A, the terminal device 120 may be indicated to perform a scheduled UL transmission on the first channel associated with the TRP 130-1. The terminal device 120 thus may perform a Type 1 CCA 725 in the first channel, without performing a CCA in the second channel.

As shown in Fig. 7A, in the architecture 700-1, if the Type 1 CCA 725-1 is successful, the terminal device 120 may perform a UL transmission (TX) 730 on the first channel associated with the TRP 130-1. That is, if the first channel is sensed to be idle or available for transmission, the terminal device 120 may perform a UL transmission (TX) 730 on the first channel associated with the TRP 130-1. Otherwise, in the architecture 700-2, if the Type 1 CCA 725-2 fails, the terminal device 120 may not transmit a UL transmission on the first channel. That is, if the first channel is sensed to be not idle or busy, the terminal device 120 may not perform a UL transmission (TX) 730 on the first channel associated with the TRP 130-1.

Fig. 7B illustrates example architecture 750-1 and 750-2 of UL transmissions according to some example embodiments of the present disclosure.

In the architecture 750-1 and 750-2, the network device 110 may perform DL transmission without performing the channel access procedure. For example, the network device 110 may transmit DCI 705 and PDSCH 710 to the terminal device via a first channel associated with the TRP 130-1. The network device 110 may transmit DCI 715 and PDSCH 720 to the terminal device 120 via a second channel associated with the TRP 130-2. As shown in Fig. 7B, in such cases the network device 110 transmits

multiple DCI

705 and 715 to the terminal device 120. The network device 110 operating in no-LBT mode may indicate the terminal device 120 to operate in LBT mode.

In the examples of Fig. 7B, the terminal device 120 may be expected to transmit a UL transmission scheduled for multiple candidate TRPs, for example the TRP 130-1 and the TRP 130-2 as shown in Fig. 7B. For example, multiple scheduling DCI (such as the DCI 705 and 710) through different channels (beams) associated with multiple TRPs (such as the TRPs 130-1 and 130-2) respectively may indicate UL transmission scheduled for multiple candidate TRPs. In such cases, UL transmission corresponding to only one TRP 130 may occur finally.

In the example of Fig. 7B, the terminal device 120 may need to perform multiple channel access procedures indicated by the DCI 705 and DCI 710 before performing the UL transmission. For example, the terminal device 120 may perform the channel access procedures on the first channel associated with the TRP 130-1 and the second channel associated with the TRP 130-2, no matter whether there is a gap between the DL transmission and the UL transmission.

As shown in Fig. 7B, in the architecture 750-1, the terminal device 120 may perform the Type 1 CCA 725 on the first channel and the Type 1 CCA 760 on the second channel in parallel. For example, if the terminal device 120 has the capability to simultaneously sense in different beams (or channels) corresponding to different TRPs, the terminal device 120 may perform concurrent multiple channel access procedures (such as the Type 1 CCA 725 and Type 1 CCA 760) corresponding to different TRPs (such as TRP 130-1 and TRP 130-2) . The terminal device 120 may determine to transmit a UL transmission corresponding to a certain TRP based on the results of the multiple channel access procedures.

In the architecture 750-1, if the Type 1 CCA 725 is failed while the Type 1 CCA 760 is successful, the terminal device 120 may initiate a COT duration 764 starting from the ending slot of the Type 1 CCA 760. The terminal device 120 may perform a UL transmission (TX) 730 on the second channel associated with the TRP 130-2 during the COT duration 764. That is, if the second channel is sensed to be idle or available for transmission, the terminal device 120 may perform a UL transmission (TX) 730 on the second channel associated with the TRP 130-2. It is to be understood that if both the Type 1 CCA 725 and Type 1 CCA 760 are successful, that is, if both the first and second channels are idle, then the terminal device 120 may select one channel from those two channels randomly or based on the priorities of the first and second channels.

In some example embodiments, as shown in the architecture 750-2, the terminal device 120 may perform multiple channel access procedures in sequence instead of in parallel. For example, the terminal device 120 may determine the order of the multiple channel access procedures randomly or based on the priorities of channels. In some example embodiments, the priorities of channels may be configured by RRC signaling from the network device 110 or indicated by the network device 110 though scheduling DCI. Alternatively, the priorities of channels may be determined based on whether the (enhanced) DCI is transmitted via a certain channel.

As shown in architecture 750-2, the terminal device 120 may first perform the Type 1 CCA 725 on the first channel associated with the TRP 130-1. If the Type 1 CCA 725 fails, the terminal device 120 may not transmit a UL transmission on the first channel. That is, if the first channel is sensed to be not idle or busy, the terminal device 120 may not perform a UL transmission on the first channel associated with the TRP 130-1. The terminal device 120 may subsequently perform the Type 1 CCA 760 on the second channel associated with the TRP 130-2. If the Type 1 CCA 760 is successful, that is, the second channel is sensed to be idle, the terminal device 120 may perform the UL transmission 730 on the second channel associated with the TRP 130-2. It is to be understood that in the architecture 750-2, if the Type 1 CCA 725 is successful (not shown) , the terminal device 120 may transmit the UL transmission in the first channel without performing a subsequent Type 1 CCA 760.

It is to be understood that in the example with M (the value of M being greater than 2) TRPs 130, the terminal device 120 may receive K DCI from the network device 110 indicating K channel access procedures to be performed by the terminal device 120. The value of K may be greater than one but not exceeding M. The terminal device 120 may perform K channel access procedures indicated by the DCI for the UL transmission. For example, the terminal device 120 may perform K Type 1 CCA on K channels associated with K TRPs, and select one channel with a successful Type 1 CCA for UL transmission randomly or based on the priorities. For another example, the terminal device 120 may determine an order of the K Type 1 CCAs randomly or based on the priorities of corresponding channels. The terminal device 120 may perform the K Type 1 CCAs one by one according to the order, until a certain Type 1 CCA is successful. The terminal device 120 may then use the channel (or the TRP) associated with the certain Type 1 CCA to transmit the UL transmission.

Examples regarding the UL transmission based on the channel access procedures indicated by multiple DCIs in accordance with the present disclosure have been described with respect to Figs. 7A-7B. By using the multiple DCI to indicate the channel access procedure to be performed by the terminal device, the terminal device may initiate a COT duration for UL transmission.

Example method and device

Fig. 8 illustrates a flowchart of an example method 800 in accordance with some embodiments of the present disclosure. The method 800 can be implemented at a terminal device 120 as shown in Fig. 1. It is to be understood that the method 800 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard. For the purpose of discussion, the method 800 will be described from the perspective of the terminal device 120 with reference to Fig. 1.

At block 810, the terminal device 120 receives, from the network device 110, at least one DCI indicating at least one COT duration corresponding to at least one channel. The at least one channel is associated with at least one TCI state. In some example embodiments, the terminal device 120 may receive an indication comprised in the at least one DCI. The indication indicates the at least one channel access procedure on the at least one channel.

In some example embodiments, the terminal device 120 may further receive an indication indicating the at least one channel access procedure on the at least one channel. For example, the terminal device 120 may receive the indication by a higher layer signaling.

In some example embodiments, the terminal device 120 may receive a first indication via a first channel and a second indication via a second channel. The first indication indicates a first channel access procedure on the first channel. The second indication indicates a second channel access procedure on the second channel.

In some example embodiments, the terminal device 120 may receive the indication via one of a first channel and a second channel. The indication indicates at least one of a first channel access procedure on the first channel and a second channel access procedure on the second channel.

At block 820, the terminal device 120 performs at least one channel access procedure on the at least one channel. For example, the terminal device 120 may perform the first channel access procedure on the first channel and the second channel access procedure on the second channel in parallel.

In some example embodiments, the terminal device 120 may perform the first channel access procedure on the first channel or the second channel access procedure on the second channel. For example, the terminal device 120 may perform the first channel access procedure on the first channel or the second channel access procedure on the second channel based on priorities of the first and second channels.

In some example embodiments, the priorities of the first and second channels are predetermined by the terminal device or the network device. In some example embodiments, the priorities of the first and second channels are based on at least one of: whether the at least one downlink control information is transmitted via a given channel of the first and second channels, or a length of a remaining portion of a channel occupancy time duration of the given channel initiated by the network device.

In some example embodiments, the terminal device 120 may perform the second channel access procedure on the second channel, after the first channel is sensed to be not idle based on the first channel access procedure.

In some example embodiments, the at least one DCI is transmitted by the network device 110 on the at least one channel during the at least one channel occupancy time duration. The at least one channel occupancy time duration is initiated by the network device 110 based on at least one successful channel clear assessment.

In some example embodiments, if a time gap between a last transmission transmitted by the network device and a subsequent uplink transmission to be transmitted by the terminal device exceeds a threshold time gap, the terminal device 120 may perform the at least one channel access procedure on the at least one channel during at least one remaining portion of the at least one channel occupancy time duration initiated by the network device 110.

In some example embodiments, the at least one channel occupancy time duration initiated by the network device 110 comprises a first channel occupancy time duration on a first channel. A channel is sensed to be not idle based on a channel access procedure on a second channel performed by the network device 110. In performing the at least one channel access procedure, the terminal device 120 may perform at least one of: a Type 2 channel access procedure on the first channel; or a Type 1 channel access procedure on the second channel.

In some example embodiments, if a time gap between a last transmission transmitted by the network device 110 and a subsequent uplink transmission to be transmitted by the terminal device 120 is below a threshold time gap, the terminal device 120 may perform the transmission using a remaining portion of the at least one channel occupancy time duration initiated by the network device 110 without performing the at least one channel access procedure.

In some example embodiments, the at least one channel occupancy time duration initiated by the network device 110 comprises a first channel occupancy time duration on a first channel and a second channel occupancy time duration on a second channel. In performing the transmission using a remaining portion of the at least one channel occupancy time duration, the terminal device 120 may perform the transmission using a remaining portion of the first channel occupancy time duration on the first channel or a remaining portion of the second channel occupancy time duration on the second channel based on priorities of the first and second channels.

In some example embodiments, the priorities of the first and second channels are predetermined by the terminal device 120 or the network device 110. Alternatively, the priorities of the first and second channels are based on at least one of: whether the at least one downlink control information is transmitted via a given channel of the first and second channels, or a length of a remaining portion of a channel occupancy time duration of the given channel initiated by the network device 110.

At block 830, the terminal device 120 determines a target starting time and a time duration for an UL transmission on one channel from the terminal device 120 to the network device 110 based on a result of the at least one channel access procedure and the at least one DCI.

In some example embodiments, in determining a target starting time and a time duration based on a result of the at least one channel access procedure, if the at least one channel is sensed to be idle based on the at least one channel access procedure, the terminal device 120 may determine a starting time of the at least one remaining portion of the at least one channel occupancy time duration initiated by the network device 110 to be the target starting time; and determine the at least one remaining portion of the at least one channel occupancy time duration initiated by the network device 110 to be the time duration.

In some example embodiments, the at least one downlink control information is transmitted by the network device 110 without performing a channel access procedure.

In some example embodiments, the at least one channel access procedure comprises a Type 1 channel access procedure by a terminal device. In determining a target starting time and a time duration for a transmission, if the at least one channel is sensed to be idle based on a channel access procedure, the terminal device 120 may determine a starting time of a channel occupancy time duration after the at least one channel access procedure and the channel occupancy time duration to be the target starting time and the time duration.

Details for UL transmission enhancement according to the present disclosure have been described with reference to Figs. 1-8. Now an example implementation of the terminal device 120 will be discussed below. In some embodiments, a terminal device (for example, the terminal device 120) comprises circuitry configured to: receive, from a network device, at least one DCI indicating at least one COT duration corresponding to at least one channel. The at least one channel is associated with at least one TCI state. The circuitry is further configured to perform at least one channel access procedure on the at least one channel; and determine a target starting time and a time duration for an UL transmission on one channel from the terminal device to the network device based on a result of the at least one channel access procedure and the at least one DCI.

In some example embodiments, the circuitry is further configured to receive an indication indicating the at least one channel access procedure on the at least one channel. In some example embodiments, in receiving the indication, the circuitry is configured to receive the indication by a higher layer signaling.

In some example embodiments, in receiving the at least one downlink control information, the circuitry is further configured to receive an indication comprised in the at least one DCI. The indication indicates the at least one channel access procedure on the at least one channel.

In some example embodiments, in receiving the indication, the circuitry is configured to receive a first indication via a first channel and a second indication via a second channel. The first indication indicates a first channel access procedure on the first channel. The second indication indicates a second channel access procedure on the second channel.

In some example embodiments, in receiving the indication, the circuitry is configured to receive the indication via one of a first channel and a second channel. The indication indicates at least one of a first channel access procedure on the first channel and a second channel access procedure on the second channel.

In some example embodiments, in performing at least one channel access procedure, the circuitry is configured to perform the first channel access procedure on the first channel and the second channel access procedure on the second channel in parallel.

In some example embodiments, in performing at least one channel access procedure, the circuitry is configured to perform the first channel access procedure on the first channel or the second channel access procedure on the second channel. In some example embodiments, in performing the first channel access procedure on the first channel or the second channel access procedure on the second channel, the circuitry is configured to perform the first channel access procedure on the first channel or the second channel access procedure on the second channel based on priorities of the first and second channels.

In some example embodiments, in performing the at least one channel access procedure, the circuitry is configured to perform the second channel access procedure on the second channel, after the first channel is sensed to be not idle based on the first channel access procedure.

In some example embodiments, the at least one DCI is transmitted by the network device on the at least one channel during the at least one channel occupancy time duration. The at least one channel occupancy time duration is initiated by the network device based on at least one successful channel clear assessment.

In some example embodiments, in performing the at least one channel access procedure, the circuitry is configured to: in accordance with a determination that a time gap between a last transmission transmitted by the network device and a subsequent uplink transmission to be transmitted by the terminal device exceeds a threshold time gap, perform the at least one channel access procedure on the at least one channel during at least one remaining portion of the at least one channel occupancy time duration initiated by the network device.

In some example embodiments, in determining a target starting time and a time duration based on a result of the at least one channel access procedure and the at least one DCI, the circuitry is configured to: in accordance with a determination that the at least one channel is sensed to be idle based on the at least one channel access procedure, determine a starting time of the at least one remaining portion of the at least one channel occupancy time duration initiated by the network device to be the target starting time; and determine the at least one remaining portion of the at least one channel occupancy time duration initiated by the network device to be the time duration.

In some example embodiments, the at least one channel occupancy time duration initiated by the network device comprises a first channel occupancy time duration on a first channel. A channel is sensed to be not idle based on a channel access procedure on a second channel performed by the network device. In performing the at least one channel access procedure, the circuitry is configured to perform at least one of: a Type 2 channel access procedure on the first channel; or a Type 1 channel access procedure on the second channel.

In some example embodiments, the circuitry is further configured to in accordance with a determination that a time gap between a last transmission transmitted by the network device and a subsequent uplink transmission to be transmitted by the terminal device is below a threshold time gap, perform the transmission using a remaining portion of the at least one channel occupancy time duration initiated by the network device without performing the at least one channel access procedure.

In some example embodiments, the at least one channel occupancy time duration initiated by the network device comprises a first channel occupancy time duration on a first channel and a second channel occupancy time duration on a second channel. In performing the transmission using a remaining portion of the at least one channel occupancy time duration, the circuitry is configured to perform the transmission using a remaining portion of the first channel occupancy time duration on the first channel or a remaining portion of the second channel occupancy time duration on the second channel based on priorities of the first and second channels.

In some example embodiments, the priorities of the first and second channels are predetermined by the terminal device or the network device. Alternatively, the priorities of the first and second channels are based on at least one of: whether the at least one downlink control information is transmitted via a given channel of the first and second channels, or a length of a remaining portion of a channel occupancy time duration of the given channel initiated by the network device.

In some example embodiments, the at least one downlink control information is transmitted by the network device without performing a channel access procedure. In some example embodiments, the at least one channel access procedure comprises a Type 1 channel access procedure by a terminal device. In determining a target starting time and a time duration for a transmission, the circuitry is configured to: in accordance with a determination that the at least one channel is sensed to be idle based on a channel access procedure, determine a starting time of a channel occupancy time duration after the at least one channel access procedure and the channel occupancy time duration to be the target starting time and the time duration.

Fig. 9 is a simplified block diagram of a device 900 that is suitable for implementing embodiments of the present disclosure. The device 900 can be considered as a further example implementation of the network device 110 or the terminal device 120 as shown in Fig. 1. Accordingly, the device 900 can be implemented at or as at least a part of the network device 110 or the terminal device 120.

As shown, the device 900 includes a processor 910, a memory 920 coupled to the processor 910, a suitable transmitter (TX) and receiver (RX) 940 coupled to the processor 910, and a communication interface coupled to the TX/RX 940. The memory 910 stores at least a part of a program 930. The TX/RX 940 is for bidirectional communications. The TX/RX 940 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the eNB, Un interface for communication between the eNB and a relay node (RN) , or Uu interface for communication between the eNB and a terminal device.

The program 930 is assumed to include program instructions that, when executed by the associated processor 910, enable the device 900 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Fig. 1-8. The embodiments herein may be implemented by computer software executable by the processor 910 of the device 900, or by hardware, or by a combination of software and hardware. The processor 910 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 910 and memory 920 may form processing means 950 adapted to implement various embodiments of the present disclosure.

The memory 920 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 920 is shown in the device 900, there may be several physically distinct memory modules in the device 900. The processor 910 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 900 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.

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 representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to Fig. 3 and/or Fig. 8. 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.

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine 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 machine 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 language 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 method of communication comprising:

receiving, by a terminal device and from a network device, at least one downlink control information indicating at least one channel occupancy time (COT) duration corresponding to at least one channel, wherein the at least one channel is associated with at least one transmission configuration indicator (TCI) state;

performing at least one channel access procedure on the at least one channel; and

determining a target starting time and a time duration for an uplink transmission on one channel from the terminal device to the network device based on a result of the at least one channel access procedure and the at least one downlink control information.
The method of claim 1, further comprising:

receiving an indication indicating the at least one channel access procedure on the at least one channel.
The method of claim 2, wherein receiving the indication comprises:

receiving the indication by a higher layer signaling.
The method of claim 1, wherein receiving the at least one downlink control information comprises

receiving an indication indicating the at least one channel access procedure on the at least one channel comprised in the at least one downlink control information.
The method of claim 2 or claim 4, wherein receiving the indication comprises:

receiving a first indication via a first channel and a second indication via a second channel, the first indication indicating a first channel access procedure on the first channel, and the second indication indicating a second channel access procedure on the second channel.
The method of claim 2 or claim 4, wherein receiving the indication comprises:

receiving the indication via one of a first channel and a second channel, the indication indicating at least one of a first channel access procedure on the first channel and a second channel access procedure on the second channel.
The method of claim 5 or claim 6, wherein performing the at least one channel access procedure comprises:

performing the first channel access procedure on the first channel and the second channel access procedure on the second channel in parallel.
The method of claim 5 or claim 6, wherein performing the at least one channel access procedure comprises:

performing the first channel access procedure on the first channel or the second channel access procedure on the second channel.
The method of claim 8, wherein performing the first channel access procedure and/or the second channel access procedure comprises:

performing the first channel access procedure on the first channel or the second channel access procedure on the second channel based on priorities of the first and second channels.
The method of claim 9, wherein the priorities of the first and second channels are predetermined by the terminal device or the network device; or

wherein the priorities of the first and second channels are based on at least one of:

whether the at least one downlink control information is transmitted via a given channel of the first and second channels, or

a length of a remaining portion of a channel occupancy time duration of the given channel initiated by the network device.
The method of claim 5 or claim 6, wherein performing the at least one channel access procedure further comprises:

performing the second channel access procedure on the second channel, after the first channel is sensed to be not idle based on the first channel access procedure.
The method of any of claims 1-11, wherein the at least one downlink control information is transmitted by the network device on the at least one channel during the at least one channel occupancy time duration, the at least one channel occupancy time duration being initiated by the network device based on at least one successful channel clear assessment.
The method of claim 12, wherein performing the at least one channel access procedure comprises:

in accordance with a determination that a time gap between a last transmission transmitted by the network device and a subsequent uplink transmission to be transmitted by the terminal device exceeds a threshold time gap, performing the at least one channel access procedure on the at least one channel during at least one remaining portion of the at least one channel occupancy time duration initiated by the network device.
The method of claim 13, wherein determining a target starting time and a time duration based on a result of the at least one channel access procedure comprises:

in accordance with a determination that the at least one channel is sensed to be idle based on the at least one channel access procedure,

determining a starting time of the at least one remaining portion of the at least one channel occupancy time duration initiated by the network device to be the target starting time; and

determining the at least one remaining portion of the at least one channel occupancy time duration initiated by the network device to be the time duration.
The method of claim 13, wherein the at least one channel occupancy time duration initiated by the network device comprises a first channel occupancy time duration on a first channel, and a channel is sensed to be not idle based on a channel access procedure on a second channel performed by the network device , and

wherein performing the at least one channel access procedure comprises at least one of:

performing a Type 2 channel access procedure on the first channel; or

performing a Type 1 channel access procedure on the second channel.
The method of claim 12, further comprising:

in accordance with a determination that a time gap between a last transmission transmitted by the network device and a subsequent uplink transmission to be transmitted by the terminal device is below a threshold time gap, performing the transmission using a remaining portion of the at least one channel occupancy time duration initiated by the network device without performing the at least one channel access procedure.
The method of claim 16, wherein the at least one channel occupancy time duration initiated by the network device comprises a first channel occupancy time duration on a first channel and a second channel occupancy time duration on a second channel, and

wherein performing the transmission using a remaining portion of the at least one channel occupancy time duration comprises:

performing the transmission using a remaining portion of the first channel occupancy time duration on the first channel or a remaining portion of the second channel occupancy time duration on the second channel based on priorities of the first and second channels.
The method of claim 17, wherein the priorities of the first and second channels are predetermined by the terminal device or the network device; or

wherein the priorities of the first and second channels are based on at least one of:

whether the at least one downlink control information is transmitted via a given channel of the first and second channels, or

a length of a remaining portion of a channel occupancy time duration of the given channel initiated by the network device.
The method of any of claims 1-11, wherein the at least one downlink control information is transmitted by the network device without performing a channel access procedure.
The method of claim 19, wherein the at least one channel access procedure comprises a type 1 channel access procedure by a terminal device; and

wherein determining a target starting time and a time duration for a transmission comprises:

in accordance with a determination that the at least one channel is sensed to be idle based on a channel access procedure, determining a starting time of a channel occupancy time duration after the at least one channel access procedure and the channel occupancy time duration to be the target starting time and the time duration.
A terminal device comprising:

circuitry configured to perform the method according to any of claims 1 to 20.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to perform the method according to any of claims 1 to 20.