Autonomous retransmission for SL MCSt

Abstract

Aspects of the present disclosure relate to a user equipment (UE), a processor for wireless communication, a method, and a computer readable medium for autonomous retransmission of sidelink (SL) multi-continuous slot transmissions (MCSt). In one aspect, for SL MCSt transmissions, a UE determines whether to retransmit transport blocks (TBs) on a plurality of contiguous resources for SL MCSt transmissions. The TB is associated with a dropped transmission caused by at least one LBT failure. Based on determining to retransmit the TB, the UE retransmits the TB on a resource of the plurality of contiguous resources. In this manner, autonomous transmission or retransmission for SL MCSt is enabled, and transmission reliability is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to wireless communications, and more particularly, to a user equipment (UE), a processor for wireless communications, a method, and a computer readable medium for autonomous retransmission for sidelink (SL) multi-consecutive slot transmission (MCSt). BACKGROUND

[0002] A wireless communication system can include one or more network communication devices, such as a base station, which can also be referred to as an eNodeB (eNB), a next generation NodeB (gNB), or other suitable terminology. Each network communication device, such as a base station, can support wireless communication for one or more user communication devices, which can also be referred to as user equipment (UE), or other suitable terminology. A wireless communication system can support wireless communication with one or more user communication devices by utilizing resources of the wireless communication system, for example, time resources (e.g., symbols, slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers). Additionally, a wireless communication system can support wireless communication across various wireless access technologies, including third generation (3G) wireless access technologies, fourth generation (4G) wireless access technologies, fifth generation (5G) wireless access technologies, and other suitable wireless access technologies applicable to 5G and beyond (e.g., sixth generation (6G)).

[0003] A work item (WI) for sidelink enhancements for Rel-18 has been approved. One target is to study the impact of unlicensed channel access mechanisms on sidelink resource reservation schemes for sidelink (SL) transmissions over unlicensed bands. A UE needs to perform listen-before-talk (LBT) to monitor and access the channel before a sidelink transmission over unlicensed bands. If LBT is successful, the UE can access the channel for transmission for a period of time called “channel occupancy time (COT).” To keep the channel as long as possible and to reduce or even skip channel sensing time, multi-consecutive slot transmission (MCSt) is also introduced for SL-U transmissions. SUMMARY

[0004] The present disclosure relates to a UE, a processor for wireless communications, a method, and a computer readable medium for autonomous retransmission for sidelink (SL) multi-consecutive slot transmission (MCSt). Embodiments of the present disclosure can enable autonomous transmission or retransmission for MCSt over sidelink in case of a listen-before-talk (LBT) failure(s), and thus can improve transmission reliability.

[0005] In a first aspect, a UE is provided. The UE includes: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: determine, for a side-link (SL) multi-continuous slot transmission (MCSt) transmission, whether to retransmit a transport block (TB) on a plurality of contiguous resources for the SLMCSt transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-tell (LBT) failure; and based on the determination to retransmit the TB, retransmit the TB on the resources of the plurality of contiguous resources via the transceiver.

[0006] In a second aspect, a processor for wireless communication is provided. The processor includes: at least one memory; and a controller coupled to the at least one memory and configured such that the controller: at a user equipment (UE) and for side-link (SL) multi-continuous time-slot transmission (MCSt) transmission, determines whether to retransmit a transport block (TB) on a plurality of consecutive resources for SL MCSt transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-tell (LBT) failure; and based on the determination to retransmit the TB, retransmits the TB on resources among the plurality of consecutive resources.

[0007] In the third aspect, a method performed by a UE is provided. The method includes: for a side-link (SL) multi-continuous slot transmission (MCSt) transmission, determining whether to retransmit a transport block (TB) on multiple contiguous resources used for the SL MCSt transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-talk (LBT) failure; and retransmitting the TB on resources among the multiple contiguous resources based on the determination to retransmit the TB.

[0008] In a fourth aspect, a computer-readable medium is provided that stores instructions which, when executed by a processor of a device, cause the device to perform the method according to a third aspect of the present disclosure.

[0009] In the methods described in this paper and some implementations of the UE, determining whether to retransmit the TB may include: determining the retransmission TB based on whether the autonomous transmission or retransmission configuration is enabled at the UE.

[0010] In the methods described in this paper and in some implementations of the UE, determining whether to retransmit the TB may include: determining whether to retransmit the TB based on the remaining packet delay budget (PDB) of the TB.

[0011] In the methods described in this paper and some implementations of the UE, determining whether to retransmit the TB based on the remaining PDB may include: determining to retransmit the TB based on the fact that the remaining PDB of the determined TB is less than a threshold.

[0012] In the methods described herein and some implementations of the UE, determining whether to retransmit a TB based on the remaining PDB may include: comparing the remaining PDB of the TB with the remaining PDB of the generated TB, or the remaining PDB of the data in the buffer used for MCSt transmission that would be discarded due to the retransmission of the TB; and determining to retransmit the TB based on the determination that the remaining PDB of the TB is less than the remaining PDB of the generated TB or the remaining PDB of the data in the buffer.

[0013] In the methods described in this paper and some implementations of the UE, determining whether to retransmit the TB may include: determining to retransmit the TB based on the fact that the priority of the TB is greater than a threshold.

[0014] In the methods described in this paper and in some implementations of the UE, multiple contiguous resources can be multiple configuration authorization (CG) resources.

[0015] In the methods described herein and in some implementations of the UE, the processor is also configured to reuse the same SL procedure and corresponding procedure identifier (ID) for retransmission of TB as for the discarded transmission.

[0016] In the methods described herein and some implementations of the UE, the reuse of the same SL procedure and corresponding procedure ID for retransmission of TB can be based on determining one or more of the following: a previous SL grant for the SL procedure, at least one indication of LBT failure is received; the Media Access Control (MAC) Protocol Data Unit (PDU) size of the TB matches the SL grant size; or the configuration grant in the next resource belongs to the list of configuration grants allowed by the SL.

[0017] In the methods described herein and some implementations of the UE, TB is the first TB, and the processor can also be configured to: based on the determination not to retransmit the first TB and via the transceiver, send the second TB on the resource.

[0018] In the methods described in this paper and in some implementations of the UE, the processor can also be configured to trigger resource reselection.

[0019] In the methods described herein and some implementations of the UE, resource reselection may be triggered based on determining one of the following: at least one LBT failure indication is received from the UE's physical (PHY) layer; no more resources are reserved for SL MCSt transmissions; the number of resources for the next SL MCSt transmission is less than the current SL MCSt transmission or a threshold; the resources for the next SL MCSt transmission exceed the remaining PDB of the generated TB or the remaining PDB of the data in the buffer for MCSt transmissions; the remaining PDB of the generated TB or the remaining PDB of the data in the buffer is less than a threshold; or the number of transmissions for the generated TB has not reached the maximum value of transmissions authorized for SL configuration.

[0020] In the methods and some implementations of the UE described herein, resource reselection can be triggered when an indication of at least one LBT failure is received from the UE's PHY layer. In the methods and some implementations of the UE described herein, resource reselection can be triggered when an indication of LBT success is received from the UE's PHY layer. In the methods and some implementations of the UE described herein, resource reselection can be triggered after the SL MCSt transmission is completed.

[0021] In the methods described herein and in some implementations of the UE, multiple consecutive resources can be one of the following: symbols, time slots, or subframes. Attached Figure Description

[0022] Figure 1 Examples of wireless communication systems in which some embodiments of this disclosure can be implemented are illustrated.

[0023] Figure 2 Examples of process flows according to some exemplary embodiments of the present disclosure are illustrated.

[0024] Figure 3 The illustration shows a schematic diagram of an exemplary contiguous resource for MCSt transmission according to some example embodiments of the present disclosure.

[0025] Figure 4 The illustration shows an exemplary retransmission of a transport block (TB) according to some example embodiments of the present disclosure.

[0026] Figure 5 The illustration shows a schematic diagram of an exemplary resource reselection trigger according to some example embodiments of the present disclosure.

[0027] Figure 6 The illustration shows a schematic diagram of timing for resource reselection triggering according to some example embodiments of the present disclosure.

[0028] Figure 7 Examples of devices suitable for implementing some embodiments of this disclosure are illustrated.

[0029] Figure 8 Examples of processors suitable for implementing some embodiments of this disclosure are illustrated.

[0030] Figure 9 The diagram illustrates a flowchart of a method performed by a user equipment according to aspects of this disclosure.

[0031] In the various figures, the same or similar reference numerals indicate the same or similar elements. Detailed Implementation

[0032] The principles of this disclosure will now be described with reference to some embodiments. It should be understood that these embodiments are described for illustrative purposes only and to assist those skilled in the art in understanding and implementing this disclosure, and do not imply any limitation on the scope of this disclosure. This disclosure described herein can be implemented in various ways other than those described below. In the following specification and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0033] References to "an embodiment," "example embodiment," "embodiment," "some embodiments," etc., in this disclosure indicate that the embodiments described may include specific features, structures, or characteristics, but not every embodiment necessarily includes such specific features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiments. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, it should be understood that, whether explicitly described or not, incorporating other embodiments to affect such a feature, structure, or characteristic is within the knowledge of those skilled in the art.

[0034] It should be understood that although terms such as “first” and “second” may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may also be referred to as a second element without departing from the scope of the embodiments, and similarly, a second element may also be referred to as a first element. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms. In some examples, values, processes, or devices are referred to as “best,” “lowest,” “highest,” “minimum,” “maximum,” etc. It should be understood that such descriptions are intended to indicate that a selection can be made from a number of functional alternatives used, and that such selection is not necessarily better, smaller, higher, or more preferred than other options.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the embodiments. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprises,” “comprising,” “has,” “having,” “includes,” and / or “including,” when used herein, specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. For example, the term “comprising” and variations thereof should be interpreted as open-ended terms meaning “including, but not limited to.” The term “based on” should be interpreted as “at least partially based on.” The terms “one embodiment” and “embodiment” should be interpreted as “at least one embodiment.” The term “another embodiment” should be interpreted as “at least one other embodiment.” The use of expressions such as “A and / or B” can mean “A only,” “B only,” or “both A and B.” Other explicit or implicit definitions may be included below.

[0036] At a recent 3GPP RAN meeting, a work item (WI) for Rel-18 sidelink enhancements was approved. One objective is to address sidelink (SL) transmissions on unlicensed frequency bands, specifically by investigating the impact of unlicensed channel access mechanisms on sidelink resource reservation schemes.

[0037] To coexist with other Radio Access Technologies (RATs) (e.g., WiFi), the New Radio (NR)-SL needs to perform a Listen-Before-Speak (LBT) procedure to monitor and access the channel before transmitting on unlicensed frequency bands. If the LBT is successful, the UE can access the channel and perform a transmission. If the LBT fails, the UE will discard the transmission. Furthermore, if LBT type-1 is successful, the UE can occupy the channel for a period known as Channel Occupancy Time (COT). The length of the COT depends on the Channel Access Priority Class (CAPC) for transmitting data and the LBT duration.

[0038] Furthermore, after COT is initiated, to maintain the channel for as long as possible and to reduce or even skip channel sensing time, Multi-Consecutive-Slot Transmission (MCSt) is introduced for SL-U transmission. For UEs utilizing Mode 2 resource allocation (i.e., resources are selected by the UE), the UE will reserve multiple consecutive resources for MCSt transmission, and these resources can be used for the same transport block (TB) or different TBs. On the other hand, for UEs utilizing Mode 1 resource allocation, the resources used for MCSt transmission are dynamically scheduled or semi-statically configured by the gNB, such as sidelink configuration of authorized resources.

[0039] For Configuration Grant (CG) transmissions, if there is a potential LBT failure for downlink (DL) feedback or scheduling, the UE can autonomously retransmit the TB in the next CG resource after the CG retransmission timer expires, using the same HARQ procedure. When the CG retransmission timer is configured, autonomous retransmission is enabled, and the UE will automatically select the HARQ procedure ID for the CG.

[0040] Technical solutions for autonomous transmission or retransmission of SL MCSt transmissions have not been discussed and require further investigation. According to embodiments of this disclosure, a novel scheme for SL MCSt on unlicensed frequency bands is proposed. According to embodiments of this disclosure, the UE transmits transport blocks (TBs) on contiguous resources for SL MCSt transmission. Contiguous resources can be at the granularity of symbols, time slots, subframes, etc. When a listen-before-speak (LBT) for SL MCSt transmission fails, the UE can determine whether to transmit a TB associated with the dropped transmission caused by the LBT failure in a subsequent resource. If so, the UE can retransmit the TB on a subsequent resource after the LBT succeeds. In this way, autonomous transmission or retransmission of MCSt on the side link is enabled when multiple listen-before-speak (LBT) failures occur, and the reliability of SL MCSt transmission is improved. In some embodiments, the UE can also trigger resource reselection for multiple TBs or data not transmitted on resources for MCSt transmission. In this way, the reliability of SL MCSt transmission can be further improved.

[0041] Figure 1Examples of wireless communication systems 100 that may be implemented in some embodiments of this disclosure are illustrated. The wireless communication system 100 may include one or more network entities 102 (also referred to as network devices (NEs)), one or more UEs 104, a core network 106, and a packet data network 108. The wireless communication system 100 may support various wireless access technologies. In some implementations, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-A network. In some other implementations, the wireless communication system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communication system 100 may be a combination of 4G and 5G networks, or other suitable radio access technologies, including: IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), and IEEE 802.20. The wireless communication system 100 may support wireless access technologies beyond 5G. Additionally, the wireless communication system 100 may support technologies such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or Code Division Multiple Access (CDMA).

[0042] One or more network entities 102 may be distributed throughout a geographic area to form a wireless communication system 100. One or more network entities among the network entities 102 described herein may be, include, or may be referred to as network nodes, base stations, network elements, radio access networks (RANs), base transceivers, access points, NodeBs, eNodeBs (eNBs), next-generation NodeBs (gNBs), or other suitable terms. Network entities 102 and UE 104 may communicate via communication link 110, which may be a wireless or wired connection. For example, network entities 102 and UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) via a Uu interface. In a 3GPP non-terrestrial network (NTN), network entity 102 in satellite form may communicate directly with UE 104 using an NR / LTE Uu interface.

[0043] Network entity 102 can provide a geographic coverage area 112 for which it can provide services (e.g., voice, video, packet data, messaging, broadcasting, etc.) to one or more UEs 104 within the geographic coverage area 112. For example, network entity 102 and UE 104 can support wireless communication of signals associated with services (e.g., voice, video, packet data, messaging, broadcasting, etc.) according to one or more radio access technologies. In some implementations, network entity 102 can be mobile, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies can overlap, but different geographic coverage areas 112 can be associated with different network entities 102. The information and signals described herein can be represented using any variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned in this specification can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0044] One or more UEs 104 may be distributed throughout the geographical area of ​​the wireless communication system 100. UE 104 may include or be referred to as a mobile device, wireless device, remote device, remote unit, handheld device, or subscriber device, or some other suitable term. In some implementations, UE 104 may be referred to as a unit, station, terminal, or client, etc. Additionally or alternatively, UE 104 may be referred to as an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a Machine Type Communication (MTC) device, etc. In some implementations, UE 104 may be stationary within the wireless communication system 100. In some other implementations, UE 104 may be mobile within the wireless communication system 100.

[0045] One or more UEs 104 can be devices in different forms or with different capabilities. Some examples of UEs 104 are shown in... Figure 1 The diagram is shown in the image. Figure 1 As shown, UE 104 can communicate with various types of devices, such as network entity 102, other UE 104, or network devices (e.g., core network 106, packet data network 108, relay devices, integrated access and backhaul (IAB) nodes, or another network device). Additionally or alternatively, UE 104 can support communication with other network entities 102 or UE 104, which can act as relays in the wireless communication system 100.

[0046] UE 104 can also support direct wireless communication with other UE 104s via communication link 114. For example, UE 104 can support direct wireless communication with another UE 104 via a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular V2X deployments, communication link 114 may be referred to as a side link. For example, UE 104 can support direct wireless communication with another UE 104 via a PC5 interface.

[0047] Network entity 102 may support communication with core network 106, or with another network entity 102, or both. For example, network entity 102 may be connected to core network 106 via one or more backhaul links 116 (e.g., via S1, N2, N3, or other network interfaces). Network entities 102 may communicate with each other via backhaul links 116 (e.g., via X2, Xn, or another network interface). In some implementations, network entities 102 may communicate directly with each other (e.g., between network entities 102). In some other implementations, network entities 102 may communicate with each other or indirectly (e.g., via core network 106). In some implementations, one or more network entities 102 may include sub-components, such as access network entities, which may be examples of access node controllers (ANCs). The ANC may communicate with one or more UEs 104 via one or more other access network transport entities, which may be referred to as a wireless head, a smart wireless head, or a transmit-receive point (TRP).

[0048] In some implementations, network entity 102 can be configured in a de-converging architecture that can utilize a protocol stack physically or logically distributed across two or more network entities 102, such as an Integrated Access Backhaul (IAB) network, an Open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a Virtualized RAN (vRAN) (e.g., a Cloud RAN (C-RAN)). For example, network entity 102 may include one or more of the following: a Central Unit (CU), a Distributed Unit (DU), a Radio Unit (RU), a RAN Intelligent Controller (RIC) (e.g., a Near-RT RIC, a Non-RT RIC), a Service Management and Orchestration (SMO) system, or any combination thereof.

[0049] An RU can also be referred to as a radio head, intelligent radio head, remote radio head (RRH), remote radio unit (RRU), or transmit-receive point (TRP). In a de-converging RAN architecture, one or more components of network entity 102 can be co-located, or one or more components of network entity 102 can be located in distributed locations (e.g., separate physical locations). In some implementations, one or more network entities 102 in a de-converging RAN architecture can be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0050] The division of functions among CU, DU, and RU can be flexible and can depend on the different functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combination thereof) performed at the CU, DU, or RU. For example, the functional division of the protocol stack can be adopted between the CU and DU, such that the CU can support one or more layers of the protocol stack, and the DU can support one or more different layers of the protocol stack. In some implementations, the CU can host higher-layer protocol (e.g., Layer 3 (L3), Layer 2 (L2)) functions and signaling (e.g., Radio Resource Control (RRC), Serving Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU can be connected to one or more DUs or RUs, and one or more DUs or RUs can host lower-layer protocol, such as Layer 1 (L1) (e.g., Physical Layer (PHY)) or L2 (e.g., Radio Link Control (RLC), Media Access Control (MAC)) functions and signaling, and each can be at least partially controlled by the CU 160.

[0051] Alternatively or additionally, the functional division of the protocol stack can be adopted between DU and RU, such that DU can support one or more layers of the protocol stack, and RU can support one or more different layers of the protocol stack. DU can support one or more different cells (e.g., via one or more RUs). In some implementations, the functional division between CU and DU, or between DU and RU, can be within the protocol layer (e.g., some functions for the protocol layer can be performed by one of CU, DU, or RU, while other functions of the protocol layer are performed by another of CU, DU, or RU).

[0052] The CU can be further functionally divided into CU control plane (CU-CP) and CU user plane (CU-UP) functions. The CU can be connected to one or more DUs via mid-range communication links (e.g., F1, F1-c, F1-u), and the DUs can be connected to one or more RUs via front-end communication links (e.g., open front-end (FH) interfaces). In some implementations, the mid-range or front-end communication links can be implemented based on interfaces (e.g., channels) between layers of a protocol stack supported by corresponding network entities 102 in communications conducted via such communication links.

[0053] Core network 106 can support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. Core network 106 can be an evolved packet core (EPC) or a 5G core network (5GC), and can include control plane entities that manage access and mobility (e.g., Mobility Management Entity (MME), Access and Mobility Management Functions (AMF)) and user plane entities that route or interconnect packets to external networks (e.g., Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Functions (UPF)). In some implementations, control plane entities can manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management (e.g., data bearers, signaling bearers, etc.) for one or more UEs 104 served by one or more network entities 102 associated with core network 106.

[0054] Core network 106 can communicate with packet data network 108 via one or more backhaul links 116 (e.g., via S1, N2, N3, or another network interface). Packet data network 108 may include application server 118. In some implementations, one or more UEs 104 may communicate with application server 118. UE 104 may establish a session (e.g., Protocol Data Unit (PDU) session, etc.) with core network 106 via network entity 102. Core network 106 can use the established session (e.g., an established PDU session) to route traffic (e.g., control information, data, etc.) between UE 104 and application server 118. A PDU session may be an example of a logical connection between UE 104 and core network 106 (e.g., one or more network functions of core network 106).

[0055] In the wireless communication system 100, network entity 102 and UE 104 can use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, etc.) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some implementations, network entity 102 and UE 104 can support different resource structures. For example, network entity 102 and UE 104 can support different frame structures. In some implementations, such as in 4G, network entity 102 and UE 104 can support a single frame structure. In some other implementations, such as in 5G and other suitable radio access technologies, network entity 102 and UE 104 can support various frame structures (i.e., multi-frame structures). Network entity 102 and UE 104 can support various frame structures based on one or more digital schemes.

[0056] One or more digital schemes may be supported in the wireless communication system 100, and the digital schemes may include subcarrier spacing and cyclic prefixes. A first digital scheme (e.g., =0) can be associated with the first subcarrier spacing (e.g., 15 kHz) and the normal cyclic prefix. In some implementations, the first digital scheme (e.g., 15 kHz) associated with the first subcarrier spacing (e.g., 15 kHz) =0) allows each subframe to utilize one time slot. The second digital scheme (e.g., =1) can be associated with the second subcarrier spacing (e.g., 30 kHz) and the normal cyclic prefix. The third digital scheme (e.g., =2) can be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal or extended cyclic prefix. A fourth digital scheme (e.g., =3) can be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth digital scheme (e.g., =4) can be associated with the fifth subcarrier spacing (e.g., 240 kHz) and the normal cyclic prefix.

[0057] Time intervals for resources (e.g., communication resources) can be organized according to frames (also known as radio frames). Each frame can have a duration, for example, 10 milliseconds (ms). In some implementations, each frame can include multiple subframes. For example, each frame can include 10 subframes, and each subframe can have a duration, for example, 1 ms. In some implementations, each frame can have the same duration. In some implementations, each subframe of a frame can have the same duration.

[0058] Alternatively or concurrently, the time intervals of resources (e.g., communication resources) can be organized according to time slots. For example, a subframe may include multiple (e.g., a certain number) time slots. The number of time slots in each subframe may also depend on one or more digital schemes supported in the wireless communication system 100. For example, the first, second, third, fourth, and fifth digital schemes associated with corresponding subcarrier intervals of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz (i.e., =0、 =1、 =2、 =3、 =4) Each subframe can utilize a single time slot, two time slots, four time slots, eight time slots, or 16 time slots, respectively. Each time slot can include multiple (e.g., a certain number) symbols (e.g., OFDM symbols). In some implementations, the number (e.g., quantity) of time slots used for a subframe can depend on the digital scheme. For a normal cyclic prefix, a time slot can include 14 symbols. For an extended cyclic prefix (e.g., for a 60 kHz subcarrier spacing), a time slot can include 12 symbols. The relationship between the number of symbols per time slot for the normal and extended cyclic prefixes, the number of time slots per subframe, and the number of time slots per frame can depend on the digital scheme. It should be understood that the first digital scheme (e.g., ...) associated with the first subcarrier spacing (e.g., 15 kHz) is... =0) can be used interchangeably between subframes and time slots.

[0059] In wireless communication system 100, the electromagnetic (EM) spectrum can be divided into various categories, frequency bands, frequency channels, etc., based on frequency or wavelength. For example, wireless communication system 100 may support one or more operating frequency bands, such as frequency ranges FR1 (410 MHz – 7.125 GHz), FR2 (24.25 GHz – 52.6 GHz), FR3 (7.125 GHz – 24.25 GHz), FR4 (52.6 GHz – 114.25 GHz), FR4a or FR4-1 (52.6 GHz – 71 GHz), and FR5 (114.25 GHz – 300 GHz). In some implementations, network entity 102 and UE 104 may perform wireless communication on one or more operating frequency bands. In some implementations, FR1 may be used by network entity 102 and UE 104, as well as other devices or equipment, for cellular communication traffic (e.g., control information, data). In some implementations, FR2 can be used by network entity 102 and UE104, as well as other devices or equipment, for short-range, high-data-rate capabilities.

[0060] FR1 can be associated with one or more number schemes (e.g., at least three number schemes). For example, FR1 can be associated with a first number scheme (e.g., =0) is associated with a 15 kHz subcarrier spacing; a second digital scheme (e.g., =1), which includes a 30 kHz subcarrier spacing; and a third digital scheme (e.g., =2), which includes a 60 kHz subcarrier spacing. FR2 can be associated with one or more digital schemes (e.g., at least two digital schemes). For example, FR2 can be associated with a third digital scheme (e.g., =2) is associated with, which includes a 60 kHz subcarrier spacing; and a fourth digital scheme (e.g., =3), which includes a 120 kHz subcarrier spacing.

[0061] Figure 2 An example of a process flow according to some exemplary embodiments of the present disclosure is illustrated. Process flow 200 may relate to user equipment (UE) 201 and base station 202. Process flow 200 may refer to Figure 1 Applied to the wireless communication system 100, for example, UE 201 and UE 202 can be UE 104, which communicates via side link 114. It should be understood that process flow 200 can be applied to other communication scenarios, which will not be elaborated here.

[0062] UE 201 can be configured to perform SL transmissions on unlicensed frequency bands using either Mode 2 (i.e., UE autonomous resource selection mode) or Mode 1 (i.e., gNB scheduled resource mode). UE 201 is required to perform LBT and acquire Channel Occupancy Time (COT) before each sidelink transmission. UE 201 is configured or enabled for Multi-Consecutive Time Slot (MCSt) transmissions and reserves (in Mode 2), schedules (in Mode 1), or configures (in Mode 1 CG) multiple consecutive resources for MCSt transmissions (retransmissions).

[0063] For side-link (SL) multi-continuous slot transmission (MCSt) transmissions, UE 201 determines whether to retransmit transport blocks (TBs) on multiple contiguous resources for SL MCSt transmissions. TBs are associated with transmissions dropped due to at least one listen-before-talk (LBT) failure.

[0064] UE 201 retransmits TB 225 on resources in multiple consecutive resources based on the determined retransmission TB 225 and via the transceiver. Correspondingly, UE 202 receives 230 TB 225 on the SL channel between UE 201 and UE 202.

[0065] Figure 3 The illustration shows a schematic diagram of exemplary contiguous resources for MCSt transmission according to some example embodiments of the present disclosure. Figure 3 In this configuration, eight resources are reserved. The first four consecutive resources (resource #1, resource #2, resource #3, resource #4) are used for the initial transmission of different TBs (e.g., TB #1, TB #2, TB #3, TB #4), and the next four consecutive resources (resource #5, resource #6, resource #7, resource #8) are used for retransmission of different TBs (e.g., TB #1, TB #2, TB #3, TB #4). The reserved resources can be at the granularity of symbols, time slots, subframes, etc., and can also be referred to as the next transmission resource / unit / opportunity / (multiple) time slots.

[0066] Figure 4 The illustration shows an exemplary retransmission of a Transport Block (TB) according to some example embodiments of the present disclosure. UE 201 may perform a Transport Block Transmission (LBT) before transmission. If the LBT succeeds, UE 201 may generate and transmit TB #1, TB #2, TB #3, and TB #4 on reserved contiguous resources #1, #2, #3, and #4. If the LBT fails, for example, if the Media Access Control (MAC) layer of UE 201 receives an LBT failure indication from the Physical (PHY) layer, UE 201 may discard the transmission on resource #1 and continue performing the LBT.

[0067] like Figure 4 As shown, UE 201 can determine to send the TB associated with the discarded transmission. This means that UE 201 will autonomously retransmit the TB of the discarded transmission. In this case, if LBT succeeds and if the UE determines to retransmit TB #1, the UE will send TB #1, TB #2, and TB #3 on reserved resources #2, #3, and #4. TB #4 will not be sent on MCSt resources #1 to #4. If LBT fails, UE 201 can discard the next transmission and continue with LBT. The same process continues for the next reserved resource (if available). On the other hand, if UE 201 determines or prefers to send a new TB (e.g., TB #2), the UE attempts to send TB #2, TB #3, and TB #4 on reserved resources #2, #3, and #4. If the next LBT succeeds, TB #2, TB #3, and TB #4 will be sent, and TB #1 will not be sent on MCSt resources #1 to #4.

[0068] Regarding autonomous retransmission, it is possible that a dropped TB may be retransmitted in a resource following the next reserved resource. For example, if the transmission of TB #1 in the first reserved resource #1 is dropped, UE 201 may retransmit TB #1 in any reserved resource of reserved resource #2, reserved resource #3, or reserved resource #4.

[0069] Combination Figure 4 Reference Figure 2 In determination 210, UE 201 can determine the retransmission TB (e.g., TB #1) based on the determination of autonomous transmission or retransmission configuration when UE 201 is enabled. For example, UE 201 can be (pre-)configured with parameters that enable autonomous transmission (retransmission) of TBs dropped due to LBT failure. For example, parameters (e.g. sl-autonomousTx or sl- autonomousReTx The parameter is (pre-)configured for UE 201. It can be (pre-)configured for SLUE along with the MCSt transmission. The parameter can be 1 bit, where a value of 1 means that UE 201 will perform an autonomous retransmission of the TB dropped due to LBT failure in subsequent reserved resources.

[0070] exist Figure 4 If the LBT fails before the first reserved resource, and UE 201 discards the transmission for the associated TB#1, then UE 201 will retransmit TB#1 in reserved resource #2. On the other hand, a value of 0 means that UE 201 will not perform autonomous retransmission of the TB discarded due to the LBT failure. Figure 4 If the LBT fails before the first reserved resource and UE201 discards the transmission for TB #1, then UE201 will send a new TB in reserved resource #2, for example, TB #2. Alternatively or additionally, the autonomous transmission or retransmission configuration can be pre-configured or specified as enabled by default.

[0071] Alternatively or additionally, UE 201 may determine whether to retransmit a TB (e.g., TB #1) based on the remaining packet delay budget (PDB) of the TB, or the remaining PDB of data in the buffer used for MCSt transmission. In some embodiments, if the remaining PDB of the TB associated with the dropped transmission is less than a (pre)configured threshold, discretionary retransmission may be determined to be enabled, and the first TB will be retransmitted in the next resource (if available). For example, in Figure 4 If LBT fails before the first reserved resource, and UE 201 discards the transmission for TB #1, and if the remaining PDB of TB #1 is less than threshold_value PDB_remain_droppedTBIf so, UE 201 can retransmit TB #1 in reserved resource #2. Otherwise, UE 201 can send a new TB (e.g., TB #2) in reserved resource #2.

[0072] In some embodiments, UE 201 may compare the TB (e.g., TB #1) associated with the dropped transmission (e.g., ...). PDB_remain_untransmitTB The remaining PDB, and the generated TB that will not be sent (e.g., TB #4) (e.g., PDB_remain_bufferreddata PDB_remain_droppedTB < PDB_remain_untransmitTB The remaining PDB of data in the cache, or the remaining PDB of data in the cache (e.g., PDB_remain_droppedTB < PDB_remain_bufferreddata Figure 4 ).if Figure 4 , or if threshold_value sl-AllowedCG-List Then the UE can determine to retransmit TB #1 in reserved resource #2, such as Figure 2 As shown in the diagram. Otherwise, UE 201 may determine not to send TB #1 and send a new TB (e.g., TB #2) in reserved resource #2.

[0073] Alternatively or additionally, UE 201 can determine whether to retransmit a TB (e.g., TB #1) based on its priority. If the priority of the TB associated with the dropped transmission is greater than a (pre)configured threshold, UE 201 can determine that autonomous retransmission is enabled and determine to retransmit the TB. Therefore, TB #1 will be retransmitted in the next resource (if available). For example, in Figure 5 If LBT fails before the first reserved resource #1, and UE 201 discards the transmission on that resource for TB #1, and if the priority of TB #1 is greater than... sl-CG-MaxTransNum If successful, UE 201 can retransmit TB #1 in reserved resource #2 (if available) after a successful LBT. Otherwise, UE 201 can send a new TB (e.g., TB #2) in reserved resource #2.

[0074] As previously mentioned, in Mode 1, the resources used for MCSt transmission can be Configuration Grant (CG) resources. That is, continuous resources are scheduled or configured by the base station (e.g., gNB) for SL MCSt transmission. In some embodiments, CG resources may be permitted for retransmission in SL MCSt.

[0075] When an LBT fails, for example, when the MAC layer of UE 201 receives an indication of LBT failure for an MCSt transmission from a lower layer (e.g., the physical layer), UE 201 may discard the transmission of a TB (e.g., TB #1) on an upcoming resource (e.g., resource #1). Optionally, UE 201 may then consider the SL procedure for the Hybrid Automatic Repeat Request (HARQ) associated with the discarded transmission to be pending (the SL procedure may also be referred to as the Side Link (SL) HARQ procedure), meaning that no new TB can be sent during this SL procedure.

[0076] If the reserved resources for MCSt are subsequently used for retransmission, UE 201 can reuse the same SL procedure and corresponding procedure identifier (ID) for the retransmission of TB as it did for the discarded transmission. UE 201 further retransmits TB on the subsequent MCSt resources in the same SL procedure, or in other words, retransmits TB on the subsequent reserved resources for the MCSt transmission, even if the resources were reserved for the initial transmission, or even if they are SL-CG resources for MCSt.

[0077] In some embodiments, the reuse of the SL procedure and corresponding ID for retransmission may occur when one or more of the following conditions are met: at least one indication of LBT failure is received for a previous SL grant used for the SL procedure; or the Media Access Control (MAC) Protocol Data Unit (PDU) size of the TB matches the SL grant size (e.g., equal to or less than). Alternatively or additionally, when the resource is a CG resource, the condition may require that the configuration grant in the next resource belongs to the list of SL-allowed configuration grants for the logical channel in the TB (e.g., ...). sl-CG-MaxTransNum ).

[0078] refer to Figure 6 UE 201 may optionally trigger resource reselection 240. When the LBT fails before MCSt transmission and UE 201 discards transmissions on one or more reserved resources intended for MCSt transmission, UE 201 may also trigger resource reselection for buffered data or generated TB(s) that should have been transmitted on the resources for MCSt transmission but were not. In this document, the generated TB may be in the form of a MAC PDU and includes multiplexed data from multiple logical channels retrieved from the buffer. Therefore, the generated TB may also be referred to as a multiplexed TB.

[0079] Figure 2 to Figure 6The illustration shows an exemplary resource reselection triggering according to some example embodiments of the present disclosure. As shown, due to the retransmission of TB #1 on resource #2, the generated TB #4 or data in the cache is not sent. UE 201 can trigger resource reselection for the generated TB #4 or data in the cache. If TB #1 is not retransmitted, UE 201 can trigger resource reselection for TB #1.

[0080] In some embodiments, UE 201 may trigger resource reselection when one or more of the following conditions are met: at least one LBT failure indication is received from the physical (PHY) layer; no more resources are reserved for SL MCSt transmission; the number of slots for the next MCSt resource is insufficient, for example, less than the current MCSt resource, or less than a threshold; the next MCSt resource is too late, for example, exceeding or exceeding the remaining PDB of the generated TB, or the remaining PDB of the cached data; the remaining PDB of the generated TB, or the remaining PDB of the cached data is less than a threshold; or the time slots for a particular SL procedure have not been reached. Figure 7 Figure 8 . Figure 9 This indicates the maximum value of the transfer used for SL configuration authorization.

[0081] Figure 1 The illustration shows a schematic diagram of timing for resource reselection triggering according to some example embodiments of the present disclosure. As shown, for case 1, resource reselection can be triggered whenever an indication of at least one LBT failure is received from the UE's PHY layer. Alternatively, resource reselection can be triggered when an indication of LBT success is received from the UE's PHY layer. Alternatively, resource reselection can be triggered after the SL MCSt transmission is completed.

[0082] According to the reference Figure 1 In some of the embodiments discussed, the UE can perform autonomous retransmission for sidelink MCSt transmissions on unlicensed frequency bands with enabled LBTs. When an LBT failure occurs, the UE can determine whether to retransmit the TB associated with the transmission dropped by the LBT failure. If so, the UE can retransmit the TB on subsequently available resources after a successful LBT. This improves the reliability of SL MCSt transmissions.

[0083] ​Another example of a device suitable for implementing some embodiments of this disclosure is illustrated. Device 700 may be an example of UE 104 as described herein. Device 700 may support wireless communication with one or more network entities 102, UE 104, or any combination thereof. Device 700 may include components for bidirectional communication, including components for transmitting and receiving communications, such as processor 702, memory 704, transceiver 706, and (optionally) I / O controller 708. These components may communicate electronically or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0084] Processor 702, memory 704, transceiver 706, or various combinations thereof or various components thereof may be examples of components for performing various aspects of this disclosure as described herein. For example, processor 702, memory 704, transceiver 706, or various combinations thereof or components thereof may support methods for performing one or more of the operations described herein.

[0085] In some implementations, processor 702, memory 704, transceiver 706, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuitry system). The hardware may include: a processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, configured to or otherwise supporting components for performing the functions described herein. In some implementations, processor 702 and memory 704 coupled to processor 702 may be configured to perform one or more of the functions described herein (e.g., instructions stored in memory 704 are executed by processor 702).

[0086] For example, processor 702 may support wireless communication at device 700 according to examples disclosed herein. Processor 702 may be configured to operate to support: means for determining whether to retransmit a transport block (TB) on multiple consecutive resources for SL MCSt transmission for sidelink (SL) transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-tell (LBT) failure; and means for retransmitting the TB on resources among the multiple consecutive resources based on the determination to retransmit the TB and via transceiver 706.

[0087] Processor 702 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some implementations, processor 702 may be configured to operate a memory array using a memory controller. In some other embodiments, the memory controller may be integrated into processor 702. Processor 702 may be configured to execute computer-readable instructions stored in memory (e.g., memory 704) to cause device 700 to perform various functions of this disclosure.

[0088] Memory 704 may include random access memory (RAM) and read-only memory (ROM). Memory 704 may store computer-readable, computer-executable code, which includes instructions that, when executed by processor 702, cause device 700 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some implementations, the code may not be directly executed by processor 702, but may cause a computer (e.g., at compile and execution time) to perform the functions described herein. In some implementations, memory 704 may, among other things, include a basic I / O system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0089] I / O controller 708 can manage input and output signals for device 700. I / O controller 708 can also manage peripheral devices not integrated into device 700. In some embodiments, I / O controller 708 can represent a physical connection or port to an external peripheral device. In some implementations, I / O controller 708 can utilize an operating system such as iOS®, ANDROID®, MS-WINDOWS®, OS / 2®, UNIX®, LINUX®, or another known operating system. In some implementations, I / O controller 708 can be implemented as part of a processor (such as processor 702). In some implementations, a user can interact with device 700 via I / O controller 708 or via hardware components controlled by I / O controller 708.

[0090] In some implementations, device 700 may include a single antenna 710. However, in other implementations, device 700 may have more than one antenna 710 (i.e., multiple antennas), including multiple antenna panels or antenna arrays capable of concurrently transmitting or receiving multiple wireless transmissions. Transceiver 706 may communicate bidirectionally via one or more antennas 710, wired or wireless links, as described herein. For example, transceiver 706 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 706 may also include a modem for modulating packets, providing modulated packets to one or more antennas 710 for transmission, and demodulating packets received from one or more antennas 710. Transceiver 706 may include one or more transmit chains, one or more receive chains, or combinations thereof.

[0091] The transmission chain can be configured to generate and transmit signals (e.g., control information, data, packets). The transmission chain may include at least one modulator for modulating data onto a carrier signal to prepare the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes, such as phase shift keying (PSK) or quadrature amplitude modulation (QAM). The transmission chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. The transmission chain may also include one or more antennas 710 for transmitting the amplified signal over the air or wireless medium.

[0092] The receiver chain can be configured to receive signals (e.g., control information, data, packets) via a wireless medium. For example, the receiver chain may include one or more antennas 710 for receiving signals over the air or via a wireless medium. The receiver chain may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain may include at least one demodulator configured to demodulate the received signal and acquire the transmitted data by reversing the modulation techniques applied during signal transmission. The receiver chain may include at least one decoder for decoding and processing the demodulated signal to receive the transmitted data.

[0093] ​An example of a processor 800 suitable for implementing some embodiments of the present disclosure is illustrated. Processor 800 may be an example of a processor configured to perform various operations according to the examples described herein. Processor 800 may include a controller 802 configured to perform various operations according to the examples described herein. Processor 800 may optionally include at least one memory 804. Additionally or alternatively, processor 800 may optionally include one or more arithmetic logic units (ALUs) 800. One or more of these components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0094] Processor 800 may be a processor chipset and includes a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receive, acquire, retrieve, send, output, forward, store, determine, identify, access, write, read) according to the examples described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory native to or included in the processor chipset (e.g., processor 800), or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), static random access memory (SRAM), ferroelectric random access memory (FeRAM), magnetic random access memory (MRAM), resistive random access memory (RRAM), flash memory, phase-change memory (PCM), etc.).

[0095] Controller 802 can be configured to manage and coordinate various operations of processor 800 (e.g., signaling, receiving, acquiring, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, and reading) to enable processor 800 to support various operations according to examples described herein. For example, controller 802 can operate as a control unit of processor 800, generating control signals that manage the operation of various components of processor 800. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating the timing of operations.

[0096] Controller 802 can be configured to fetch (e.g., obtain, retrieve, receive) instructions from memory 804 and determine subsequent instructions(s) to be executed, enabling processor 800 to support various operations as described herein. Controller 802 can be configured to track memory addresses of instructions associated with memory 804. Controller 802 can be configured to decode instructions to determine the operations to be performed and the operands involved. For example, controller 802 can be configured to interpret instructions and determine control signals to be output to other components of processor 800, enabling processor 800 to support various operations as illustrated in the examples described herein. Additionally or alternatively, controller 802 can be configured to manage data flow within processor 800. Controller 802 can be configured to control data transfers between registers, arithmetic logic unit (ALU), and other functional units of processor 800.

[0097] Memory 804 may include one or more caches (e.g., memory local to or included in the processor 800) or other memories such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, memory 804 may be located inside or on the processor chipset (e.g., local to the processor 800). In some other implementations, memory 804 may be located outside the processor chipset (e.g., remotely to the processor 800).

[0098] Memory 804 may store computer-readable, computer-executable code, including instructions that, when executed by processor 800, cause processor 800 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. Controller 802 and / or processor 800 may be configured to execute computer-readable instructions stored in memory 804 to cause processor 800 to perform various functions (e.g., functions or tasks supporting transmit power prioritization). For example, processor 800 and / or controller 802 may be coupled to or coupled to memory 804, and processor 800, controller 802, and memory 804 may be configured to perform the various functions described herein. In some examples, processor 800 may include multiple processors, and memory 804 may include multiple memories. One or more processors in a multiprocessor system may be coupled to one or more memories in a multi-memory system, which may be configured individually or collectively to perform the various functions described herein.

[0099] One or more ALU 806s can be configured to support various operations as described herein. In some implementations, one or more ALU 806s may be located within or on a processor chipset (e.g., processor 800). In some other implementations, one or more ALU 806s may be located outside the processor chipset (e.g., processor 800). One or more ALU 806s can perform one or more operations on data, such as addition, subtraction, multiplication, and division. For example, one or more ALU 806s can receive input operands and an operand code that determines the operation to be performed. One or more ALU 806s are configured with various logic and arithmetic circuitry, including adders, subtractors, shifters, and logic gates, to process and manipulate data according to the operations. Additionally or alternatively, one or more ALU 806s may support logical operations such as AND, OR, XOR, NOR, and NAND, thereby enabling one or more ALU 806s to handle conditional operations, comparisons, and bitwise operations.

[0100] Processor 800 may support wireless communication according to examples disclosed herein. Processor 802 may be configured to support means for determining whether to retransmit a transport block (TB) on multiple consecutive resources for SLMCSt transmission for side link (SL) transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-tell (LBT) failure; and means for retransmitting the TB on resources among the multiple consecutive resources based on the determination to retransmit the TB and via a transceiver.

[0101] ​ A flowchart illustrating method 900 performed by a UE according to aspects of this disclosure is shown. Operation of method 900 may be implemented by a device or its components, as described herein. For example, operation of method 900 may be performed by UE 104, as described herein. In some implementations, the device may execute a set of instructions to control functional elements of the device to perform the described functions. Additionally or alternatively, the device may use dedicated hardware to perform aspects of the described functions.

[0102] At 910, the method may include: for a side-link (SL) multi-continuous slot transmission (MCSt) transmission, determining whether to retransmit a transport block (TB) on multiple contiguous resources used for the SL MCSt transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-talk (LBT) failure. The operation at 910 may be performed according to examples as described herein. In some implementations, aspects of the operation at 910 may be performed by UE 104, as referenced in [reference]. ​ As described.

[0103] At 920, the method may include: retransmitting the TB on resources across multiple consecutive resources based on a determined retransmission TB. The operation at 920 can be performed according to the examples described herein. In some implementations, aspects of the operation at 920 can be performed by UE 104, as referenced... ​ As described.

[0104] In some embodiments, determining whether to retransmit the TB may include: determining to retransmit the TB based on the determination that autonomous transmission or retransmission configuration is enabled at the UE.

[0105] In some embodiments, determining whether to retransmit a TB may include: determining whether to retransmit the TB based on the remaining packet delay budget (PDB) of the TB.

[0106] In some embodiments, determining whether to retransmit a TB based on the remaining PDB may include: determining to retransmit the TB based on the fact that the remaining PDB of the determined TB is less than a threshold.

[0107] In some embodiments, determining whether to retransmit a TB based on the remaining PDB may include: comparing the remaining PDB of the TB with the remaining PDB of the generated TB, or the remaining PDB of data in the buffer used for MCSt transmission that would be discarded due to the retransmission of the TB; and determining to retransmit the TB based on the determination that the remaining PDB of the TB is less than the remaining PDB of the generated TB or the remaining PDB of the data in the buffer.

[0108] In some embodiments, determining whether to retransmit a TB may include: determining to retransmit the TB based on the determination that the priority of the TB is greater than a threshold.

[0109] In some embodiments, multiple contiguous resources may be multiple configuration license (CG) resources.

[0110] In some embodiments, the method further includes: for retransmission of TB, reusing the same SL procedure and corresponding procedure identifier (ID) as for the discarded transmission.

[0111] In some embodiments, the reuse of the same SL procedure and corresponding procedure ID for retransmission of TB may be based on determining one or more of the following: a previous SL authorization for the SL procedure, at least one indication of LBT failure is received; the Media Access Control (MAC) Protocol Data Unit (PDU) size of TB matches the SL authorization size; or the configuration authorization in the next resource belongs to the list of configuration authorizations allowed by SL.

[0112] In some embodiments, TB is a first TB, and the processor may also be configured to: based on the determination not to retransmit the first TB and via the transceiver, send the second TB on the resource.

[0113] In some embodiments, the method may include triggering resource reselection.

[0114] In some embodiments, resource reselection may be triggered based on determining one of the following: at least one LBT failure indication is received from the UE's physical (PHY) layer; no more resources are reserved for SL MCSt transmissions; the number of resources for the next SL MCSt transmission is less than the current SL MCSt transmission or a threshold; the resources for the next SL MCSt transmission exceed the remaining PDB of the generated TB or the remaining PDB of the data in the cache for MCSt transmissions; the remaining PDB of the generated TB or the remaining PDB of the data in the cache is less than a threshold; or the number of transmissions for the generated TB has not reached the maximum value for transmissions authorized for SL configuration.

[0115] In some embodiments, resource reselection can be triggered when an indication of at least one LBT failure is received from the UE's PHY layer. In some implementations of the methods and UEs described herein, resource reselection can be triggered when an indication of LBT success is received from the UE's PHY layer. In some implementations of the methods and UEs described herein, resource reselection can be triggered after the SL MCSt transmission has been completed.

[0116] In some embodiments, multiple consecutive resources may be one of the following: symbols, time slots, or subframes.

[0117] It should be noted that the methods described in this paper describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are possible. Furthermore, aspects from two or more methods can be combined.

[0118] The various exemplary frames and components described in this disclosure can be implemented or performed using a general-purpose processor, DSP, ASIC, CPU, FPGA, or other programmable logic device, discrete gate or transistor logic circuit, discrete hardware component, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors incorporating a DSP core, or any other such configuration).

[0119] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the function can be stored on or transmitted via a computer-readable medium as one or more instructions or code. Other examples and implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Features implementing the function can also be physically located in various locations, including being distributed across different physical locations, such that portions of the function are implemented at different physical locations.

[0120] Computer-readable media include both non-transitory computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Non-transitory storage media can be any available medium that can be accessed by a general-purpose computer or a special-purpose computer. By way of example, non-transitory computer-readable media can include: RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, optical disc (CD) ROM, or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code components in the form of instructions or data structures, and such other non-transitory medium can be accessed by a general-purpose computer or a special-purpose computer, or a general-purpose processor or a special-purpose processor.

[0121] As used herein, including in the claims, the article “a (a)” preceding an element is unrestricted and is understood to refer to “at least one” or “one or more” of those elements. The terms “a (a),” “at least one,” “one or more,” and “at least one of one or more” are used interchangeably. As used herein, including in the claims, the use of “or” in a list of items (e.g., a list of items beginning with phrases such as “at least one,” or “one or more,” or “one or two”) indicates an inclusive list, such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase “based on” should not be construed as a reference to a closed set of conditions. For example, an example step described as “based on condition A” could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase “based on” should be interpreted in the same manner as the phrase “at least partially based on.” Moreover, as used herein, including in the claims, “set” can include one or more elements.

[0122] The description herein is provided to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be given the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE), comprising: processor; as well as The transceiver is coupled to the processor. The processor is configured as follows: For a side link (SL) multi-continuous slot transmission (MCSt) transmission, determine whether to retransmit a transport block (TB) on multiple consecutive resources used for the SL MCSt transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-talk (LBT) failure; as well as Based on the determination to retransmit the TB, the TB is retransmitted on resources among the plurality of consecutive resources via the transceiver.

2. The UE according to claim 1, wherein determining whether to retransmit the TB includes: Based on the determination that autonomous transmission or retransmission configuration is enabled at the UE, the retransmission of the TB is determined.

3. The UE according to claim 1, wherein determining whether to retransmit the TB includes: Whether to retransmit the TB is determined based on the remaining packet delay budget (PDB) of the TB.

4. The UE according to claim 3, wherein determining whether to retransmit the TB based on the remaining PDB includes: Based on the determination that the remaining PDB of the TB is less than a threshold, it is determined to retransmit the TB.

5. The UE according to claim 3, wherein determining whether to retransmit the TB based on the remaining PDB comprises: The remaining PDB of the TB is compared with the remaining PDB of the generated TB, or the remaining PDB of data in the buffer used for MCSt transmission that will be discarded due to the retransmission of the TB; as well as Based on the determination that the remaining PDB of the TB is less than the remaining PDB of the generated TB or the remaining PDB of the data in the cache, the TB is retransmitted.

6. The UE of claim 1, wherein determining whether to retransmit the TB comprises: Based on the determination that the priority of the TB is greater than the threshold, it is determined to retransmit the TB.

7. The UE according to claim 1, wherein the processor is further configured to: For the retransmission of the TB, the same SL procedure and corresponding procedure identifier (ID) as for the discarded transmission are reused.

8. The UE of claim 7, wherein the reuse of the same SL procedure and the corresponding procedure ID for the retransmission of the TB is based on determining one or more of the following: An indication of failure of at least one LBT is received in relation to a previous SL authorization for the SL process; The size of the Media Access Control (MAC) Protocol Data Unit (PDU) of the TB matches the SL license size; or The configuration license in the next resource belongs to the list of configuration licenses allowed by SL.

9. The UE of claim 1, wherein the TB is a first TB, and the processor is further configured to: Based on the determination not to retransmit the first TB and via the transceiver, the second TB is transmitted on the resource.

10. The UE of claim 1, wherein the processor is further configured to trigger resource reselection.

11. The UE of claim 10, wherein the triggering of the resource reselection is based on determining one of the following: The indication of at least one LBT failure is received from the physical (PHY) layer of the UE; No more resources are reserved for SL MCSt transfers; The number of resources in the next SL MCSt transmission is less than the current SL MCSt transmission or the threshold; The resources of the next SL MCSt transmission exceed the remaining PDB of the generated TB or the remaining PDB of data in the cache used for MCSt transmission; The remaining PDB of the generated TB or the remaining PDB of the data in the cache is less than a threshold; or The number of transmissions generated in the TB did not reach the maximum number of transmissions allowed for SL configuration authorization.

12. The UE according to claim 11, wherein: The resource reselection is triggered when an indication of failure of at least one LBT is received from the PHY layer of the UE; The resource reselection is triggered when a successful LBT indication is received from the PHY layer of the UE. or The resource reselection is triggered after the SL MCSt transmission is completed.

13. A processor for wireless communication, comprising: At least one memory; as well as A controller, coupled to the at least one memory and configured such that the controller: At the user equipment (UE) and for side link (SL) multi-continuous slot transmission (MCSt) transmission, determine whether to retransmit transport blocks (TBs) on multiple consecutive resources used for the SL MCSt transmission, wherein the TBs are associated with a dropped transmission caused by at least one listen-before-talk (LBT) failure. as well as Based on the determination to retransmit the TB, the TB is retransmitted on resources among the plurality of consecutive resources.

14. A method performed by a user equipment, the method comprising: For a side link (SL) multi-continuous slot transmission (MCSt) transmission, determine whether to retransmit a transport block (TB) on multiple consecutive resources used for the SL MCSt transmission, wherein the TB is associated with a dropped transmission caused by at least one listen-before-talk (LBT) failure; as well as Based on the determination to retransmit the TB, the TB is retransmitted on resources among the plurality of consecutive resources.

15. A computer-readable medium storing instructions that, when executed by a processor of a device, cause the device to perform the method according to claim 14.

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