Method and apparatus for LCP enhancement using shared COT information

Abstract

The invention relates to a method and apparatus for logical channel prioritization (LCP) enhancements with shared channel occupancy time (COT) information. One embodiment of the present disclosure provides a user equipment (UE) comprising: a physical layer; a media access control (MAC) layer; a transceiver; and a processor coupled with the transceiver, in which the MAC layer is configured to: determine shared COT information for a sidelink (SL) grant; and selecting a destination and a logical channel (LCH).

Description

Technical Field

[0001] The present disclosure relates to wireless communications, and in particular to methods and apparatus for logical channel prioritization (LCP) enhancement utilizing shared channel occupancy time (COT) information. Background Art

[0002] In the NR-U scenario, before any transmission, the BS or UE needs to perform an LBT process, and if the LBT process is successful, the BS or UE can perform the transmission, otherwise the transmission cannot be performed. There are different types of LBT processes, such as an LBT type 1 process or an LBT type 2 process. The BS or UE can obtain channel occupancy (CO) using the LBT type 1 process, and can share the acquired CO. For example, the BS acquires the CO, and it can share the CO with the UE, and vice versa. The CO may be associated with a duration, that is, the CO is acquired by the BS for a certain duration; the CO may be associated with a frequency band, that is, the CO is acquired by the BS for the frequency band, or the CO may be associated with both the duration and the frequency band. In the following of the present disclosure, the term "channel occupation time (COT)" is used to describe the present disclosure, and those skilled in the art know that the terms "COT" and "CO" may also be used interchangeably.

[0003] In COT, a BS or UE may perform an LBT Type 2 procedure instead of an LBT Type 1 procedure before data transmission, which has a much shorter sensing period and results in higher transmission efficiency.

[0004] This is also an advantage of COT sharing for SL-U. That is, SL UE can use LBT Type 2 process to access the channel used for SL transmission, which has much higher transmission efficiency.

[0005] Therefore, it may be desirable to provide a solution for LCP enhancement that takes into account shared COT information. Summary of the invention

[0006] One embodiment of the present disclosure provides a user equipment (UE) comprising: a physical layer; a medium access control (MAC) layer; a transceiver; and a processor coupled to the transceiver, wherein the MAC layer is configured to: determine shared COT information for a side link (SL) grant; and select a destination and a logical channel (LCH).

[0007] In some embodiments, the UE is in resource allocation mode 2, and the MAC layer is configured to: receive a first indication from the physical layer indicating available shared COT information or unavailable shared COT information; and when the first indication indicates the available shared COT information, determine that the available shared COT information is associated with the SL authorization.

[0008] In some embodiments, the UE is in resource allocation mode 2, and the MAC layer is configured to: receive a second indication from the physical layer indicating the shared COT information; determine whether the shared COT information is available for the LCH during the SL authorization selection process; and if the shared COT information is available, determine that the shared COT information is associated with the SL authorization.

[0009] In some embodiments, the UE is in resource allocation mode 2, and the MAC layer is configured to: receive a second indication from the physical layer indicating the shared COT information; determine whether the shared COT information is available for the SL authorization after selecting the SL authorization and before multiplexing a MAC protocol data unit (PDU) for the SL authorization; and perform an LCP process if the shared COT information is available.

[0010] In some embodiments, the UE is in resource allocation mode 1 or resource allocation mode 2, and the MAC layer is configured to: receive a second indication from the physical layer indicating the shared COT information; determine whether the shared COT information is available after selecting the SL authorization and after multiplexing MAC PDU for the SL authorization; and select a type of listen-before-talk (LBT) process based on whether the shared COT information is available.

[0011] In some embodiments, the UE is in resource allocation mode 1 or resource allocation mode 2, and the MAC layer is configured to: receive a first indication from the physical layer indicating available shared COT information or unavailable shared COT information; select the LBT type 2 process when the first indication indicates the available shared COT information; or select the LBT type 1 process when the first indication indicates the unavailable shared COT information.

[0012] In some embodiments, the UE is in resource allocation mode 1, and the shared COT information is received from a base station (BS).

[0013] In some embodiments, the UE is in resource allocation mode 1, and the MAC layer is configured to: receive a second indication indicating the shared COT information from the physical layer; determine whether the shared COT information is available for the SL authorization received from the BS before multiplexing the MAC PDU; and perform an LCP process based on whether the shared COT information is available.

[0014] In some embodiments, the MAC layer is configured to select the destination and the LCH based on the shared COT information if the shared COT information is available, wherein the shared COT information is associated with at least one of: a destination ID allowed in the shared COT; a destination ID associated with at least one LCH with priority allowed in the shared COT; or a LCH with priority allowed in the shared COT.

[0015] In some embodiments, when no destination is selected in the available shared COT or when the SL grant is in an unavailable shared COT, and the MAC layer is configured to perform at least one of the following: discarding the SL grant; considering that data is not multiplexed; triggering a resource reselection process when there are no other reserved resources for the SL grant and the UE is in resource allocation mode 2; instructing the physical layer to transmit a negative acknowledgment (NACK) to the BS when there are no other reserved resources for the SL grant and the UE is in resource allocation mode 1; or when a retransmission associated with another SL grant can be performed in the available shared COT, reassociating the hybrid automatic repeat request (HARQ) process ID of the other SL grant and performing the retransmission.

[0016] In some embodiments, the UE is in resource allocation mode 1, and when no destination is selected in the available shared COT or when the SL authorization is in an unavailable shared COT, the processor is further configured to: transmit a third indication to the BS indicating that no destination is selected in the available shared COT or the SL authorization is in the unavailable shared COT.

[0017] In some embodiments, when the LCP process is performed without considering the shared COT information and the MAC PDU is multiplexed, the MAC layer is configured to: determine the shared COT information for the SL authorization based on at least one of: the destination ID, the priority of the MAC PDU, or the shared COT information received from the physical layer.

[0018] In some embodiments, the MAC layer is configured to perform one of the following: perform an LBT type 2 process if the shared COT information is available; discard the MAC PDU if the shared COT information is not available; or perform an LBT type 1 process if the MAC PDU is not to be transmitted in the shared COT.

[0019] Another embodiment of the present disclosure provides a BS, comprising: a transceiver; and a processor, which is coupled to the transceiver and configured to: receive shared COT information from a first UE; and transmit a SL grant associated with the shared COT information and the shared COT information to a second UE.

[0020] In some embodiments, the processor is further configured to: receive an indication from the UE indicating that the destination is not selected in the available shared COT or that the SL grant is in an unavailable shared COT.

[0021] Yet another embodiment of the present disclosure provides a method performed by a UE, comprising: determining shared COT information for SL authorization; and selecting a destination and an LCH.

[0022] Yet another embodiment of the present disclosure provides a method performed by a BS, comprising: receiving shared COT information from a first UE; and transmitting a SL grant associated with the shared COT information and the shared COT information to a second UE. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to describe the manner in which the advantages and features of the present application can be obtained, the description of the present application is presented with reference to specific embodiments of the present application, which are illustrated in the accompanying drawings. These drawings depict only example embodiments of the present application and therefore should not be considered as limiting the scope thereof.

[0024] Figure 1 A schematic diagram illustrating a wireless communication system according to some embodiments of the present disclosure.

[0025] Figure 2 A scenario of COT sharing for sidelink UE transmissions according to some embodiments of the present disclosure is described.

[0026] Figure 3 A method for wireless communication performed by a UE according to some embodiments of the present disclosure is described.

[0027] Figure 4 A method for wireless communication performed by a BS according to some embodiments of the present disclosure is described.

[0028] Figure 5 A simplified block diagram illustrating an apparatus according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0029] The detailed description of the accompanying drawings is intended as a description of the currently preferred embodiments of the present invention and is not intended to represent the only form in which the present invention can be practiced. It should be understood that the same or equivalent functions can be implemented by different embodiments intended to be included in the spirit and scope of the present invention.

[0030] Although the operations are depicted in a particular order in the drawings, those skilled in the art will readily recognize that such operations need not be performed in the particular order as shown or in a sequential order, or that all of the illustrated operations need to be performed to achieve the desired result; one or more operations may sometimes be skipped. In addition, the drawings may schematically depict one or more example processes in the form of a flow chart. However, other operations not depicted may be incorporated into the schematically illustrated example processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some cases, multitasking and parallel processing may be advantageous.

[0031] Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architectures and new service scenarios, such as cellular telephone networks, networks based on time division multiple access (TDMA), networks based on code division multiple access (CDMA), networks based on orthogonal frequency division multiple access (OFDMA), LTE networks, networks based on the third generation partnership project (3GPP), LTE, advanced LTE (LTE-A), 3GPP 4G, 3GPP 5G NR, 3GPP Release 16 and higher, satellite communication networks, high altitude platform networks, and the like. It is considered that with the development of network architectures and new business scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and in addition, the terms cited in the present disclosure may be changed, which should not affect the principles of the present disclosure.

[0032] The UE in the NR SL-U scenario may be referred to as a SL UE. A SL UE transmitting data on a side link in an unlicensed spectrum may be referred to as a transmitting UE, a transmitting UE, a transmitting SL UE, a Tx SL UE, a Tx UE, a SL Tx UE, a SL BWP Tx UE, a UE, or the like. A SL UE receiving data on a side link in an unlicensed spectrum may be referred to as a receiving UE, a receiving UE, a receiving SL UE, a Rx UE, a Rx SL UE, a SL Rx UE, a UE, or the like.

[0033] SL UEs may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart TVs (e.g., TVs connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle-mounted computers, network devices (e.g., routers, switches, and modems), Internet of Things (IoT) devices, personal computers (PCs), gaming consoles, extended reality (XR) devices, or the like.

[0034] According to some embodiments of the present disclosure, the SL UE may include a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identity module, a personal computer, a selective call receiver, or any other device capable of sending and receiving communication signals on a wireless network.

[0035] According to some embodiments of the present disclosure, the SL UE may include a wearable device, such as a smart watch, a fitness band, an optical head-mounted display, or the like. In addition, the SL UE may be referred to as a subscriber unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terms used in the art. The SL UE may communicate directly with the BS via a communication signal.

[0036] The BS in the NR SL-U scenario may be referred to as a base unit, base, access point, access terminal, macro cell, Node B, enhanced Node B (eNB), gNB, home Node B, relay node, device, remote unit or any other term used in the art. The BS may be distributed throughout a geographic area. Typically, the BS is part of a radio access network, which may include one or more controllers communicatively coupled to one or more corresponding base stations.

[0037] The BS is typically communicatively coupled to one or more packet core networks (PCNs), which may be coupled to other networks, such as a packet data network (PDN) (e.g., the Internet) and a public switched telephone network, among other networks. These and other elements of the radio access and core networks are not illustrated, but are generally well known to those of ordinary skill in the art. For example, one or more BSs may be communicatively coupled to a mobility management entity (MME) or access and mobility management function (AMF), a serving gateway (SGW), a packet data network gateway (PGW), and / or a user plane function (UPF).

[0038] The BS may serve several SL UEs within a service area (eg, a cell or a cell sector) via wireless communication links. The BS may communicate directly with one or more SL UEs via communication signals. For example, the BS may serve SL UEs within a macro cell.

[0039] In the NR SL-U scenario, the sidelink communication between the Tx UE and the receiving (Rx) UE includes multicast communication, unicast communication or broadcast communication.

[0040] Figure 1 A wireless communication system 100 (eg, a SL-U communication system) is described according to some embodiments of the present disclosure.

[0041] like Figure 1 As shown in , the wireless communication system 100 includes a base station (e.g., BS102) and some UEs (e.g., UE101-A, UE 101-B, UE 101-C, and UE 101-D). UE 101-A and UE 101-B are within the coverage of BS102, and UE 101-C and UE 101-D are outside the coverage of BS102. UE 101-A, UE 101-B, UE 101-C, and UE 101-D may perform sidelink unicast transmission, sidelink multicast transmission, or sidelink broadcast transmission in an unlicensed spectrum (e.g., SL BWP). UE 101-A, UE 101-B, UE 101-C, and UE 101-D may be referred to as SL UEs. It is contemplated that according to some other embodiments of the present disclosure, the SL-U communication system may include more BSs and more or fewer SL UEs.

[0042] In addition, despite Figure 1 The SL UE shown in the figure is illustrated in the shape of a mobile phone, but it is considered that according to some other embodiments of the present disclosure, the SL communication system may include any type of UE (e.g., a roadmap device, a mobile phone, a computer, a laptop computer, an IoT device, or other types of devices).

[0043] according to Figure 1 In some embodiments, UE 101-A may be used as a Tx UE, and UE 101-B, UE 101-C, and UE 101-D may be used as Rx UEs. UE 101-A may exchange SL messages with UE 101-B or UE 101-C via a side link using, for example, NR technology or LTE technology, via a PC5 interface as defined in a 3GPP document. UE 101-A may transmit information or data to another (some) UEs within the SL-U communication system via side link unicast, side link multicast, or side link broadcast. For example, UE 101-A may transmit data to UE 101-B in a side link unicast session. UE 101-A may transmit data to UE 101-B and UE 101-C in a multicast group via a side link multicast transmission session. Moreover, UE 101-A may transmit data to UE 101-B and UE 101-C via a side link broadcast transmission session.

[0044] Alternatively, according to Figure 1 In some other embodiments, UE 101-B or UE 101-C may function as a Tx UE and transmit information or data, and UE 101-A may function as a Rx UE and receive information or data from UE 101-B or UE 101-C.

[0045] Figure 1Both UE 101-A and UE 101-B in the embodiment of the present invention can transmit information to BS 102 and receive control information from BS 102, for example, via a Uu interface. BS 102 can define one or more cells, and each cell can have a coverage area. Figure 1 As shown in , both UE 101-A and UE 101-B are within the coverage of BS 102, while UE 101-C and UE 101-D are not within the coverage of BS 102.

[0046] like Figure 1 BS102 described and shown in the figure may not be a specific base station, but may be any base station in the SL-U communication system. For example, assuming that the SL-U communication system includes two BSs, then the situation where UE 101-A is within the coverage area of ​​any one of the two BSs can be referred to as the situation where UE 101-A is within the coverage area of ​​the BS in the SL-U communication system; and the situation where only UE 101-A is outside the coverage area of ​​the two BSs can be referred to as the situation where UE 101-A is outside the coverage area of ​​the BS in the SL-U communication system.

[0047] The UE may operate in different modes. At least the following two sidelink resource allocation modes are defined for sidelink communication: Resource Allocation Mode 1: The BS may schedule sidelink resources for the UE to use for sidelink transmission; and Resource Allocation Mode 2: The UE may determine the sidelink transmission resources within the sidelink resources configured by the BS or the network or the pre-configured sidelink resources. In Resource Allocation Mode 2, the BS may not schedule sidelink resources for the UE. Figure 1 In some embodiments, UE 101-A and UE 101-B may be in resource allocation mode 1, and UE 101-C and UE 101-D may be in resource allocation mode 2. In some other cases, UE 101-A and UE 101-B may also operate in resource allocation mode 2. In the following of the present disclosure, "mode 1" may refer to resource allocation mode 1, and "mode 2" may refer to resource allocation mode 2.

[0048] Figure 2 A scenario of COT sharing for sidelink UE transmissions according to some embodiments of the present disclosure is described.

[0049] exist Figure 2, UE#1 performs a Type 1 LBT procedure for a duration marked by block 210, and for a duration 220, UE#1 performs data transmission. UE#1 may share COT 230 with UE#2. Within the shared COT 230, UE#2 performs a Type 2 LBT procedure for a duration marked by block 211, and performs data transmission for a duration 221. When UE#2 needs to perform data transmission outside the shared COT 230, it performs a Type 1 LBT procedure for a duration marked by block 212, and performs data transmission for a duration 222.

[0050] As can be seen, the LBT Type 2 process is performed for a shorter period compared to the LBT Type 1 process, and therefore the transmission efficiency is higher.

[0051] In summary, the SL UE can perform the LBT Type 2 procedure in the shared COT to access the channel for transmission, which has much higher transmission efficiency.

[0052] During the RAN1#109 meeting discussions, it was agreed that "UE-to-UE COT sharing is supported in NR sidelink operation in a shared channel (SL-U)", which means that the SL UE can obtain the COT and share it with other SL UEs. In addition, during the RAN1#110 meeting, consensus was reached on the following aspects of COT sharing. In general, two aspects were agreed upon: 1) the responding UE can use the COT shared by the initiating UE only when certain conditions are met; and 2) the UE can report COT information to the gNB to assist in mode 1 resource allocation. After the introduction of COT sharing information, SL UEs in both resource allocation mode 1 and resource allocation mode 2 can consider the shared COT information when selecting or scheduling resources for SL transmission. For example, the SL UE or BS can select or schedule resources within the shared COT so that LBT type 2 can be used to improve transmission efficiency. On the other hand, if the shared COT information is not considered during the resource allocation process, the shared COT information can also be considered during the LCP process.

[0053] In this disclosure, several solutions for LCP enhancement consider sharing COT information.

[0054] The SL UE may determine the available shared COT information for SL authorization, for LCH, for MAC PDU, or for resources used for transmission or for data transmission, etc. In the following of the present disclosure, the term "available shared COT information" means that if the responding UE can utilize the shared COT shared by the COT initiating UE according to a specific rule or condition, then the COT may be referred to as an available shared COT, and the information associated with the shared COT means the available shared COT information. On the other hand, if the responding UE cannot utilize the shared COT shared by the COT initiating UE, then the COT may be referred to as an unavailable shared COT, and the information associated with the shared COT means the unavailable shared COT information.

[0055] Specifically, the MAC layer may determine the available shared COT information. In the following of the present disclosure, the MAC layer may be a component, function, member, entity, instance, circuit, virtual device, logic, or the like that may implement the method (or step, operation, or the like) described in the present disclosure. Similarly, the physical layer may also be a component, function, member, entity, instance, circuit, virtual device, logic, or the like that may implement the method (or step, operation, or the like) described in the present disclosure.

[0056] If COT sharing is enabled or if the shared COT information received by the UE is from other SL UEs, the available shared COT information can be used for the LCP process.

[0057] In one embodiment, if COT sharing is enabled for the UE (i.e., the SL UE can receive COT sharing information from another SL UE(s) and can utilize the shared COT when certain conditions are met), the MAC layer determines whether there is shared COT information and whether the shared COT can be utilized by the SL UE.

[0058] The MAC layer may determine whether shared COT information exists and whether the shared COT may be utilized by the SL UE.

[0059] For the SL UE in resource allocation mode 2, i.e., resources are selected autonomously by the SL UE, and the SL UE may determine whether there is shared COT information and whether the shared COT can be utilized by the SL UE under the following options 1 to 4:

[0060] Option 1:

[0061] The physical layer of the SL UE may determine whether shared COT information is available and indicate the available shared COT information together with the available resources for resource selection, and the MAC layer may consider the available shared COT information to be associated with the selected SL grant.

[0062] Specifically, the physical layer of the SL UE may receive shared COT information from another (some) SL UEs and determine whether the shared COT information is available. In the case where the shared COT information is available, the physical layer may indicate to the MAC layer the available shared COT information together with the available resources for resource selection. The physical layer may determine whether the shared COT can be utilized. For example, the physical layer may determine that the shared COT overlaps with the SL authorization, with the MAC PDU, or with resources for data transmission, resources for the LCH, or the like, and the physical layer may determine that the shared COT can be used for the SL authorization, for the MAC PDU, for resources, for data transmission, for the LCH, or the like.

[0063] The physical layer may perform the determination during determination of a resource subset for PSSCH resource selection, wherein the MAC layer may instruct the physical layer to perform the resource selection.

[0064] After the determination, the physical layer may determine the shared COT information that can be received from another SL UE(s) as available or unavailable. The physical layer may transmit information to the MAC layer, that is, the shared COT is available (available shared COT information) or the shared COT is unavailable (unavailable shared COT information).

[0065] In the case where the shared COT is available (i.e., the MAC layer receives an indication from the physical layer indicating available shared COT information), the MAC layer may consider the available shared COT information to be associated with the selected SL grant. In other words, the MAC layer may associate the available shared COT information with the selected SL grant.

[0066] Option 2:

[0067] In this option, the physical layer may indicate to the MAC layer that shared COT information is received, and the MAC layer may determine whether the shared COT information is available during the SL grant selection process. If the COT information is available, the MAC layer may associate the available shared COT information with the selected SL grant.

[0068] Specifically, the physical layer may receive shared COT information from another SL UE(s), and the physical layer may indicate the received shared COT information to the MAC layer. In other words, the physical layer may not be able to determine whether the shared COT can be utilized by the SL UE.

[0069] After receiving the shared COT information from the physical layer, the MAC layer may determine whether the shared COT can be used for the SL UE. The MAC layer may determine whether the shared COT can be utilized, i.e., the MAC layer may perform the determination during a resource selection process or a SL grant selection process. For example, the MAC layer may determine that the shared COT overlaps with the SL grant, with the MAC PDU, or with resources for data transmission, resources for the LCH, or the like, and the MAC layer may determine that the shared COT can be used for the SL grant, for the MAC PDU, for resources, for data transmission, for the LCH, or the like.

[0070] The MAC layer may consider the available shared COT information to be associated with the selected SL grant. In other words, the MAC layer may associate the available shared COT information with the selected SL grant.

[0071] Option 3:

[0072] In this option, the shared COT information is not considered during the resource (reselection) phase, the MAC layer may obtain the shared COT information from the physical layer, and determine whether the shared COT information is available before multiplexing MAC PDUs for SL grant.

[0073] The MAC layer may not be able to determine whether the shared COT information received from the physical layer is available or unavailable during the resource selection (reselection) process or the SL selection process. After the resource selection (reselection) process or the SL selection process, a specific SL grant may be selected. The MAC layer may determine whether the shared COT information (which is received from the physical layer) is available or unavailable for a specific SL grant before multiplexing the MAC PDU for the SL grant. In some other embodiments, the MAC layer may determine whether the shared COT information is available or unavailable for a specific LCH, for a MAC PDU, etc.

[0074] In summary, the MAC layer may determine whether the shared COT information is available or unavailable after selecting a SL grant and before multiplexing a MAC PDU for the SL grant.

[0075] In case the MAC layer determines that the shared COT information is available, the MAC layer may consider the shared COT information for the LCP procedure, ie, the MAC layer may perform the LCP procedure based on the available shared COT information.

[0076] Option 4:

[0077] In this option, the MAC layer may determine whether the shared COT information received from the physical layer is available after the resource selection (reselection) process or the SL grant selection process and after multiplexing the MAC PDU for the SL grant.

[0078] Specifically, the physical layer may receive shared COT information from another (some) SL UE, and the physical layer may indicate the received shared COT information to the MAC layer. After the MAC PDU has been multiplexed (i.e., there is a specific MAC PDU), the MAC layer may determine whether the shared COT can be used for the specific MAC PDU. In the case where the MAC layer determines that the shared COT information is available, the MAC layer may consider the information for LBT type selection and data transmission. Specifically, the MAC layer may instruct the physical layer to perform the LBT type 2 process if the shared COT information is available; or instruct the physical layer to perform the LBT type 1 process if the shared COT information is not available. Furthermore, the MAC layer may determine whether the shared COT can be used for SL authorization, resources for MAC PDU or for data transmission, resources on the LCH, or the like.

[0079] In some other embodiments, the physical layer may determine whether a shared COT can be used for a particular MAC PDU and indicate available COT information or unavailable COT information to the MAC layer. In some other embodiments, the physical layer may determine whether a shared COT can be used for SL grants, resources for MAC PDUs or for data transmission, resources on the LCH, or the like.

[0080] After the MAC layer receives an indication from the physical layer regarding available shared COT information or unavailable shared COT information, the MAC layer may perform LBT type selection.

[0081] For a SL UE in resource allocation mode 1, i.e., SL resources are scheduled and indicated by the BS, the SL UE may determine whether there is shared COT information and whether the shared COT can be utilized by the SL UE under the following options 5 to 7:

[0082] Option 5:

[0083] In resource allocation mode 1, the UE may receive a SL grant and associated available shared COT information from the BS, wherein the MAC layer may store the associated COT information for the SL grant.

[0084] Option 6:

[0085] In this option, the UE may receive a SL grant from the BS, and the BS may not indicate the associated available shared COT information, or the BS may indicate that the COT information is not to be considered. In this case, the UE (i.e., the MAC layer) may not consider the available shared COT information, or may not consider the shared COT information for the SL grant from the BS.

[0086] The MAC layer may determine whether shared COT information (which is received from the physical layer) is available or unavailable for a specific SL grant (which is received from the physical layer) before multiplexing the MAC PDU for the SL grant. In some other embodiments, the MAC layer may determine whether shared COT information is available or unavailable for a specific LCH, for a MAC PDU, etc.

[0087] In summary, the MAC layer may determine whether the shared COT information is available or unavailable after selecting a SL grant and before multiplexing a MAC PDU for the SL grant.

[0088] In case the MAC layer determines that the shared COT information is available, the MAC layer may consider the shared COT information for the LCP procedure, ie, the MAC layer may perform the LCP procedure based on the available shared COT information.

[0089] Option 7:

[0090] In this option, similar to option 6, the UE may receive a SL grant from the BS, and the BS may not indicate the associated available shared COT information, or the BS may indicate that the COT information is not to be considered. In this case, the UE (ie, the MAC layer) may not consider the available shared COT information for the SL grant from the BS.

[0091] Specifically, the physical layer may receive shared COT information from another (some) SL UE, and the physical layer may indicate the received shared COT information to the MAC layer. After the MAC PDU has been multiplexed (i.e., there is a specific MAC PDU), the MAC layer may determine whether the shared COT can be used for the specific MAC PDU. In the case where the MAC layer determines that the shared COT information is available, the MAC layer may consider the information for LBT type selection and data transmission. Specifically, the MAC layer may instruct the physical layer to perform the LBT type 2 process if the shared COT information is available; or instruct the physical layer to perform the LBT type 1 process if the shared COT information is not available. Furthermore, the MAC layer may determine whether the shared COT can be used for SL authorization, resources for MAC PDU or for data transmission, resources on the LCH, or the like.

[0092] In some other embodiments, the physical layer may determine whether a shared COT can be used for a particular MAC PDU and indicate available COT information or unavailable COT information to the MAC layer. In some other embodiments, the physical layer may determine whether a shared COT can be used for SL grants, resources for MAC PDUs or for data transmission, resources on the LCH, or the like.

[0093] After the MAC layer receives an indication from the physical layer regarding available shared COT information or unavailable shared COT information, the MAC layer may perform LBT type selection.

[0094] In options 1 to 7 above, for the case where the SL grant is associated with an available shared COT, the MAC layer may determine the destination ID and the associated LCH with priority allowed to be transmitted in the available shared COT before or during the LCP procedure.

[0095] In the above options 1 to 3, 5 and 6 (where MAC PDUs have not been multiplexed), in the case where the SL grant is associated with an available shared COT, the MAC layer may determine (or select) the destination and LCH taking into account the available shared COT information.

[0096] The shared COT information considered may be associated with at least one of the following restrictions (or conditions):

[0097] - Restrictions (or conditions) on additional destination selection:

[0098] i. Destination IDs that are allowed to transmit in the available shared COT. For example, some destination IDs are allowed in the available shared COT, while others are not.

[0099] ii. A destination ID associated with at least one LCH with priority allowed in the available shared COT. For example, LCHs with priority higher than a predetermined level are allowed in the available shared COT, while LCHs with priority lower than a predetermined level are not allowed in the available shared COT.

[0100] - Restrictions (or conditions) on additional LCH options:

[0101] i. Priority of LCHs allowed in the available shared COT For example, LCHs with a priority higher than a predetermined level are allowed in the available shared COT, while LCHs with a priority lower than a predetermined level are not allowed in the available shared COT.

[0102] For example, if there is an associated available shared COT for a specific SL grant, then before MAC PDU multiplexing or the LCP process, the MAC layer may determine that there is an available shared COT for the SL grant, and the SL UE may perform the LCP process for the SL grant based on the available shared COT information. More specifically, for destination selection during the LCP process, the SL UE may consider the above-mentioned restrictions on additional destination selection.

[0103] An example of the specification is presented as follows, wherein the underlined portion is newly introduced according to the solution of the present disclosure:

[0104]

[0105] Similarly, for LCH selection, the SL UE may consider the above-mentioned restrictions on additional LCH selection. That is, for SL transmissions to be transmitted in the available shared COT, an additional condition needs to be met, namely, the LCH priority associated with the SL transmission is allowed by the available shared COT.

[0106] An example of the specification is as follows, wherein the underlined portion is newly introduced according to the solution of the present disclosure:

[0107]

[0108] In some cases, the SL grant may be associated with an available shared COT, but the destination cannot be selected. In some other cases, a useful shared COT that can be used may be determined before multiplexing the MAC PDU, but the SL grant is in an unavailable shared COT. The present disclosure proposes several solutions for solving these technical problems. In particular, the UE (e.g., the MAC layer) may take at least one of the following operations to solve the above technical problems:

[0109] -Discard SL authorization or ignore SL authorization;

[0110] - Consider that data is not multiplexed;

[0111] - triggering a resource reselection procedure if there are no other reserved resources for SL grant and the UE is in resource allocation mode 2;

[0112] - instruct the physical layer to transmit a negative acknowledgement (NACK) to the BS if there are no other reserved resources for the SL grant and the UE is in resource allocation mode 1; or

[0113] - In case retransmission can be performed in the available shared COT, reassociate the Hybrid Automatic Repeat Request (HARQ) process ID of another SL grant and perform retransmission associated with another SL grant.

[0114] In case that the SL UE is in resource allocation mode 1, the SL UE may also transmit to the BS an indication indicating that no destination is selected in the available shared COT or indicating that the SL is granted in the unavailable shared COT.

[0115] For example, when COT sharing is enabled (i.e., there may be an available shared COT) and the SL grant is associated with the shared COT, but a destination cannot be selected during the LCP process (i.e., the SL UE cannot find a destination that can be transmitted in the associated shared COT for the SL grant); or there is an available shared COT that is determined to be usable before multiplexing the MAC PDU, but the SL grant is in an unavailable shared COT, the SL UE may discard or ignore the SL grant. Alternatively, the SL UE may consider the data not to be multiplexed.

[0116] In another example, the SL UE may check whether there are other reserved resources for the SL authorization (because the SL authorization can reserve more than one resource). If no, that is, there are no other reserved resources for the SL authorization, then the SL UE may trigger resource reselection if the SL UE is in resource allocation 2; or instruct the physical layer to transmit a negative acknowledgment (NACK) to the BS if the SL UE is in resource allocation 1.

[0117] In another example, the SL UE may check whether current resources can be used to transmit another SL-authorized MAC PDU that has yet to be retransmitted. If the SL UE has a MAC PDU that has yet to be retransmitted, the SL UE may determine whether the destination and LCH priority of the MAC PDU that has yet to be retransmitted can be transmitted in the available shared COT based on the above conditions associated with destination selection and / or LCH selection. If the conditions are met, the UE may perform retransmission of another SL-authorized MAC PDU. In some cases, the SL UE may determine that there are multiple MAC PDUs that can be transmitted in the shared COT, and may select the MAC PDU with the highest priority to transmit.

[0118] In the above options 4 and 7, the MAC layer may determine whether the shared COT information received from the physical layer is available after multiplexing the MAC PDU for SL grant. The LCP process is performed without considering the shared COT information.

[0119] That is, after the destination ID and LCH selection process, the SL UE can determine whether the MAC PDU to be transmitted is in the shared COT and whether the shared COT is available or unavailable. Then, the SL UE can determine whether the MAC PDU can be transmitted and the LBT type for MAC PDU transmission under the following operations:

[0120] - In case a MAC PDU is to be transmitted in an available shared COT, the MAC layer may instruct the physical layer to perform an LBT Type 2 procedure and perform transmission of the MAC PDU;

[0121] - discarding the MAC PDU if it is to be transmitted in an unavailable shared COT; and / or

[0122] - In case the MAC PDU is not to be transmitted in the shared COT (available or unavailable), the MAC layer may instruct the physical layer to perform the LBT Type 1 procedure and perform transmission of the MAC PDU.

[0123] Figure 3 A method for wireless communication performed by a UE according to some embodiments of the present disclosure is described.

[0124] In operation 301, the UE may determine shared COT information for a SL grant, and in operation 302, the UE may select a destination and a LCH. In some embodiments, the UE may determine shared COT information for a LCH, for a MAC PDU, for resources for data transmission, or the like.

[0125] In some embodiments, the UE is in resource allocation mode 2, and the MAC layer is configured to: receive a first indication from the physical layer indicating available shared COT information or unavailable shared COT information; and when the first indication indicates available shared COT information, determine that the available shared COT information is associated with the SL authorization.

[0126] In some embodiments, the UE is in resource allocation mode 2, and the MAC layer is configured to: receive a second indication indicating shared COT information from the physical layer; determine whether the shared COT information is available for the LCH during the SL authorization selection process; and if the shared COT information is available, determine that the shared COT information is associated with the SL authorization.

[0127] In some embodiments, the UE is in resource allocation mode 2, and the MAC layer is configured to: receive a second indication from the physical layer indicating shared COT information; determine whether the shared COT information is available for the SL authorization after selecting the SL authorization and before multiplexing the MAC protocol data unit (PDU) for the SL authorization; and perform the LCP process if the shared COT information is available.

[0128] In some embodiments, the UE is in resource allocation mode 1 or resource allocation mode 2, and the MAC layer is configured to: receive a second indication indicating shared COT information from the physical layer; determine whether the shared COT information is available after selecting the SL authorization and after multiplexing the MAC PDU for the SL authorization; and select a type of listen-before-talk (LBT) process based on whether the shared COT information is available.

[0129] In some embodiments, the UE is in resource allocation mode 1 or resource allocation mode 2, and the MAC layer is configured to: receive a first indication from the physical layer indicating available shared COT information or unavailable shared COT information; select the LBT type 2 process when the first indication indicates available shared COT information; or select the LBT type 1 process when the first indication indicates unavailable shared COT information.

[0130] In some embodiments, the UE is in resource allocation mode 1 and the shared COT information is received from a base station (BS).

[0131] In some embodiments, the UE is in resource allocation mode 1 and the MAC layer is configured to: receive a second indication indicating shared COT information from the physical layer; determine whether the shared COT information is available for the SL authorization received from the BS before multiplexing the MAC PDU; and perform the LCP process based on whether the shared COT information is available.

[0132] In some embodiments, the MAC layer is configured to select a destination and LCH based on shared COT information if the shared COT information is available, wherein the shared COT information is associated with at least one of: a destination ID allowed in the shared COT; a destination ID associated with at least one LCH with priority allowed in the shared COT; or a LCH with priority allowed in the shared COT.

[0133] In some embodiments, when no destination is selected in the available shared COT or when the SL grant is in an unavailable shared COT, and the MAC layer is configured to perform at least one of the following: discarding the SL grant; considering that the data is not multiplexed; triggering a resource reselection process when there are no other reserved resources for the SL grant and the UE is in resource allocation mode 2; instructing the physical layer to transmit a negative acknowledgment (NACK) to the BS when there are no other reserved resources for the SL grant and the UE is in resource allocation mode 1; or reassociating the hybrid automatic repeat request (HARQ) process ID of another SL grant and performing retransmission associated with the other SL grant when retransmission can be performed in the available shared COT.

[0134] In some embodiments, the UE is in resource allocation mode 1, and when no destination is selected in the available shared COT or when the SL authorization is in an unavailable shared COT, the processor is further configured to: transmit a third indication to the BS indicating that no destination is selected in the available shared COT or the SL authorization is in the unavailable shared COT.

[0135] In some embodiments, when the LCP process is performed without considering the shared COT information and the MAC PDU is multiplexed, the MAC layer is configured to: determine the shared COT information for SL authorization based on at least one of the following: destination ID, priority of the MAC PDU, or shared COT information received from the physical layer.

[0136] In some embodiments, the MAC layer is configured to perform one of the following: perform an LBT type 2 process if shared COT information is available; discard the MAC PDU if shared COT information is not available; or perform an LBT type 1 process if the MAC PDU is not to be transmitted in the shared COT.

[0137] Another embodiment of the present disclosure provides a BS, comprising: a transceiver; and a processor coupled with the transceiver and configured to: receive shared COT information from a first UE; and transmit a SL grant associated with the shared COT information and the shared COT information to a second UE.

[0138] Figure 4 A method for wireless communication performed by a BS according to some embodiments of the present disclosure is described.

[0139] In operation 401, the BS may receive shared COT information from a first UE, and in operation 402, the BS may transmit SL grant associated with the shared COT information and the shared COT information to a second UE. For example, the first UE may be a COT sharing UE, and the second UE may be a responding UE.

[0140] Figure 5 A simplified block diagram illustrating an apparatus according to some embodiments of the present disclosure.

[0141] like Figure 5 , an example of an apparatus 500 may include at least one processor 504 and at least one transceiver 502 coupled to the processor 504. The apparatus 500 may be a UE, a BS, or any other device having similar functionality.

[0142] Although in this figure, elements such as at least one transceiver 502 and processor 504 are described in singular form, plural forms are contemplated unless limitation to the singular form is explicitly stated. In some embodiments of the present disclosure, transceiver 502 may be divided into two devices, such as a receive circuit system and a transmit circuit system. In some embodiments of the present disclosure, device 500 may further include an input device, a memory, and / or other components.

[0143] In some embodiments of the present disclosure, the device 500 may be a UE. The transceiver 502 and the processor 504 may interact with each other to perform Figures 1 to 4The transceiver 502 and the processor 504 may interact with each other to perform Figures 1 to 4 The operation of a node described in any of .

[0144] In some embodiments of the present disclosure, the apparatus 500 may further include at least one non-transitory computer-readable medium.

[0145] For example, in some embodiments of the present disclosure, the non-transitory computer-readable medium may store thereon computer-executable instructions to cause the processor 504 to implement the method for the UE as described above. For example, when the computer-executable instructions are executed, the processor 504 interacts with the transceiver 502 to perform Figures 1 to 4 Operation of the UE described in any one of .

[0146] In some embodiments of the present disclosure, the non-transitory computer-readable medium may have computer-executable instructions stored thereon to cause the processor 504 to implement the method for the device as described above. For example, when the computer-executable instructions are executed, the processor 504 interacts with the transceiver 502 to perform Figures 1 to 4 The operation of the device described in any one of the above.

[0147] The methods of the present disclosure may be implemented on a programmed processor. However, the controller, flow charts, and modules may also be implemented on a general or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit components, an integrated circuit, a hardware electronic or logic circuit (e.g., a discrete component circuit), a programmable logic device, or the like. In general, any device having a finite state machine capable of implementing the flow charts shown in the figures may be used to implement the processing functions of the present disclosure.

[0148] Although the present disclosure has been described with its specific embodiments, it is apparent that many alternatives, modifications and variations will be apparent to those skilled in the art. For example, the various components of the embodiments may be interchanged, added or replaced in other embodiments. Moreover, all elements shown in each figure are not necessary for the operation of the disclosed embodiments. For example, a person skilled in the art of the disclosed embodiments will be able to make and use the teachings of the present disclosure by simply adopting the elements of the independent claims. Therefore, the embodiments of the present disclosure as described herein are intended to be illustrative and not restrictive. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0149] In the present disclosure, relational terms (such as "first", "second" and the like) can only be used to distinguish one entity or action from another entity or action, and do not necessarily require or imply any actual such relationship or order between such entities or actions. The term "comprises, comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also may include other elements that are not explicitly listed or inherent to this process, method, article or equipment. In the absence of more constraints, an element starting with "a, an" or the like does not exclude the presence of additional identical elements in the process, method, article or equipment including the element. Moreover, the term "another" is defined as at least a second or more. As used herein, the terms "include", "have" and the like are defined as "include".

Claims

1. A user equipment UE, comprising: Physical layer; Media Access Control MAC layer; Transceiver; and a processor coupled to the transceiver, wherein the MAC layer is configured to: Determine shared channel occupation time COT information for side link SL grant; and Select the destination and logical channel LCH.

2. The UE according to claim 1, wherein the UE is in resource allocation mode 2, and the MAC layer is configured to: receiving a first indication from the physical layer indicating that shared COT information is available or that shared COT information is not available; In case the first indication indicates the available shared COT information, it is determined that the available shared COT information is associated with the SL authorization.

3. The UE of claim 1 , wherein the UE is in resource allocation mode 2, and the MAC layer is configured to: receiving a second indication from the physical layer indicating the shared COT information; determining during the SL grant selection procedure whether the shared COT information is available for the logical channel LCH; and In case the shared COT information is available, it is determined that the shared COT information is associated with the SL authorization.

4. The UE of claim 1, wherein the UE is in resource allocation mode 2, and the MAC layer is configured to: receiving a second indication from the physical layer indicating the shared COT information; determining whether the shared COT information is available for the SL grant after selecting the SL grant and before multiplexing a MAC protocol data unit (PDU) for the SL grant; and In case the shared COT information is available, a logical channel prioritization LCP procedure is performed.

5. The UE according to claim 1, wherein the UE is in resource allocation mode 1 or resource allocation mode 2, and the MAC layer is configured to: receiving a second indication from the physical layer indicating the shared COT information; determining whether the shared COT information is available after selecting the SL grant and after multiplexing the MAC PDU for the SL grant; and A type of listen-before-talk (LBT) process is selected based on whether the shared COT information is available.

6. The UE according to claim 1, wherein the UE is in resource allocation mode 1 or resource allocation mode 2, and the MAC layer is configured to: receiving a first indication from the physical layer indicating that shared COT information is available or that shared COT information is not available; In case the first indication indicates the available shared COT information, selecting the LBT Type 2 process; or In a case where the first indication indicates that shared COT information is unavailable, an LBT type 1 process is selected. 7 . The UE according to claim 1 , wherein the UE is in resource allocation mode 1 and the shared COT information is received from a base station BS.

8. The UE of claim 1, wherein the UE is in resource allocation mode 1, and the MAC layer is configured to: receiving a second indication from the physical layer indicating the shared COT information; determining whether the shared COT information is available for the SL grant received from the BS before multiplexing the MAC PDU; and The LCP process is performed based on whether the shared COT information is available.

9. The UE of claim 1 , wherein the MAC layer is configured to select the destination and the LCH based on the shared COT information if the shared COT information is available, wherein the shared COT information is associated with at least one of: The destination IDs allowed in the shared COT; a destination ID associated with at least one LCH with priority allowed in the shared COT; or The LCHs with priority allowed in the shared COT.

10. The UE of claim 1 , wherein in a case where a destination is not selected in an available shared COT or in a case where the SL grant is in an unavailable shared COT, and the MAC layer is configured to perform at least one of the following: discarding the SL authorization; Consider that data is not multiplexed; triggering a resource reselection procedure in the case where there are no other reserved resources for the SL grant and the UE is in resource allocation mode 2; In case there are no other reserved resources for the SL grant and the UE is in resource allocation mode 1, instructing the physical layer to transmit a negative acknowledgement NACK to the BS; or In case a retransmission associated with another SL grant can be performed in the available shared COT, a hybrid automatic repeat request HARQ process ID of the other SL grant is reassociated and the retransmission is performed.

11. The UE of claim 1 , wherein the UE is in resource allocation mode 1, and if no destination is selected in an available shared COT or if the SL grant is in an unavailable shared COT, the processor is further configured to: A third indication indicating that no destination is selected in the available shared COT or that the SL grant is in the unavailable shared COT is transmitted to the BS.

12. The UE according to claim 1, wherein in a case where an LCP process is performed without considering the shared COT information and MAC PDUs are multiplexed, the MAC layer is configured to: The shared COT information is determined for the SL grant according to at least one of: a destination ID, a priority of the MAC PDU, or the shared COT information received from the physical layer.

13. The UE of claim 12, wherein the MAC layer is configured to perform one of the following: In case the shared COT information is available, performing LBT type 2 process; In case the shared COT information is not available, discarding the MAC PDU; or In case the MAC PDU is not to be transmitted in the shared COT, an LBT Type 1 procedure is performed.

14. A base station BS, comprising: Transceiver; and a processor coupled to the transceiver and configured to: receiving shared COT information from a first user equipment UE; and A sidelink SL grant associated with the shared COT information and the shared COT information are transmitted to a second UE.

15. A method performed by a user equipment UE, comprising: Determine the shared channel occupancy time COT information for the side link SL grant; and Select the destination and logical channel LCH.

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