Methods and mobile devices

Abstract

A method is disclosed for a first user equipment (UE) to determine whether a data unit is not transmitted in any of the resources for data units associated with the process of sidelink communication between the first UE and the second UE for multiple consecutive time resource transmissions due to listen-before-talk (LBT) failures, and if a data unit is not transmitted in any of the resources for data units associated with the process of sidelink communication between the first UE and the second UE for multiple consecutive time resource transmissions, to trigger a selection procedure for resources for data units associated with the process of sidelink communication for multiple consecutive time resource transmissions.

Description

[Technical Field]

[0001] This disclosure relates to a communication system. [Background technology]

[0002] This disclosure is particularly relevant to, but not limited to, wireless communication systems and devices operating in accordance with the 3rd Generation Partnership Project (3GPP®) standard or equivalent standards, or derivative standards thereof (including LTE Advanced, Next Generation or 5G networks, Future Generation, and beyond). This disclosure is particularly relevant, though not necessarily exclusive, to data transmission via multiple consecutive slots for sidelinks.

[0003] The evolution of 3GPP standards to date has been known as Evolved Packet Core (EPC) networks, specifically Long-Term Evolution (LTE) and Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), commonly referred to as "4G." More recently, the terms "5G" and "new radio" (NR) have begun to be used to refer to evolving communication technologies expected to support a variety of applications and services. Various details of 5G networks are described in the "NGMN 5G White Paper" V1.0 by the Next Generation Mobile Networks (NGMN) Alliance, which can be obtained, for example, from https: / / www.ngmn.org / 5g-white-paper.html. 3GPP intends to support 5G through the so-called Next Generation (NextGen) Radio Access Network (RAN) and the 3GPP Next Generation Core Network.

[0004] Under the 3GPP standard, a NodeB (or eNB in ​​LTE, gNB in ​​5G) is a Radio Access Network (RAN) node (or simply an “access node,” “access network node,” or “base station”) through which communication devices (user equipment, i.e., “UE”) connect to the core network and communicate with other communication devices or remote servers. For simplicity, this application uses the terms access network node, RAN node, or base station to refer to any such access node.

[0005] For simplicity, this application uses the terms mobile device, user device, or UE to refer to any communication device that can connect to a core network via one or more base stations. While this application may refer to mobile devices in its description, it should be understood that the described technology can be implemented on any communication device (mobile and / or fixed) that can connect to a communication network to transmit / receive data, whether such communication device is controlled by human input or by software instructions stored in memory.

[0006] In current 5G architectures, the structure of a gNB can be divided into two or more parts. In some RAN implementations, there are two parts, known as a Central Unit (CU) or gNB-CU, sometimes called a “control unit,” and a Distributed Unit (DU) or gNB-DU, connected by an F1 interface. This allows for the use of a “split” architecture, typically separating a “higher” CU layer (e.g., not necessarily or not exclusively, such as the Packet Data Convergence Protocol (PDCP) layer and the Radio Resource Control (RRC) layer) from a “lower” DU layer (e.g., not necessarily or not exclusively, such as the Radio Link Control (RLC) layer, the Medium (or “Multiple Mediums”) Access Control (MAC) layer, and the Physical (PHY) layer), between a particular CU and one or more DUs connected to and controlled by that CU via the F1 interface. Therefore, for example, each gNB can locally and individually maintain lower-layer DU functions while centrally implementing the upper-layer CU functions of several gNBs (for example, by a single processing unit, or in a cloud-based or virtualized system).

[0007] Current communication technologies also offer various ways for UEs to communicate data directly with each other without using base station resources (although in some cases UEs require at least some control signaling from base stations). Such communication is often called direct UE communication, device-to-device (D2D) communication, or sidelink communication. D2D communication was initially defined in 3GPP specification releases 12 and 13 as part of the Proximity Service (ProSe) service. A new D2D interface was introduced as part of the ProSe service. This D2D interface is called "PC5" or "sidelink" at the physical layer. Sidelink provides a direct link for device-to-device communication with or without network coverage. As D2D technology has developed, sidelink has been further improved for vehicle use cases to address high-speed (up to 250 km / h along roads and up to 500 km / h along railways) and high-density (thousands of nodes) scenarios.

[0008] Sidelink has several application areas / use cases, particularly proximity services, public safety, IoT including machine-type communications and sensors, and wearable devices. The term Vehicle-to-Everything (V2X) covers a specific application area of ​​Sidelink / PC5 aimed at vehicle-to-vehicle communication using direct links. V2X encompasses at least the following categories: Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), Vehicle-to-Pedestrian (V2P), Vehicle-to-Home (V2H), and enhanced Vehicle-to-Everything (eV2X).

[0009] Sidelink communication, including direct communication between UEs, supports a variety of use cases where UEs are not necessarily within base station coverage. These use cases include in-coverage use cases where both UEs, including sidelink communication, are within base station coverage; partial-coverage use cases where one UE, including sidelink communication, is within base station coverage while the other is not; and out-of-coverage use cases where neither UE, including sidelink communication, is within base station coverage. Naturally, a given UE can move between in-coverage, partial-coverage, and out-of-coverage scenarios.

[0010] Sidelink communication between UEs uses a physical channel similar to the corresponding physical channel used for communication between the base station and the UE. These sidelink physical channels include the Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Feedback Channel (PSFCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Control Channel (PSCCH). Control information for controlling sidelink communication, called sidelink control information (SCI), can be transmitted directly between UEs. SCI is transmitted in two parts (called "stages"). The first stage is carried by the PSCCH, and the second stage is carried by the corresponding PSSCH associated with the PSCCH.

[0011] When a UE is within a base station's coverage, the base station can use communication from the base station to the UE via an air interface (such as a so-called Uu interface) to allocate and manage resources used for sidelink communication (such as V2V communication) from that UE to another UE. In NR, this network-managed resource allocation is known as Mode 1 resource allocation, which is similar to the type of (V2X) resource allocation known as Mode 3 in LTE. In network-controlled resource allocation, sidelink radio resources can be allocated from a sidelink-only licensed carrier or from a licensed carrier that shares resources between UE-to-UE sidelinks and UE-to-base station uplinks. In NR, scheduling in network-controlled resource allocation mode (Mode 1) can include dynamic grant (DG) scheduling (similar to LTE V2X Mode 3 scheduling) or configured grant (CG) scheduling (whereas LTE V2X Mode 3 uses semi-persistent scheduling (SPS)).

[0012] In DG scheduling, the UE requests resources from the base station for each transport block (TB) transmission (and for each possible blind or hybrid automatic repeat request (HARQ) retransmission). Specifically, the UE sends a scheduling request (SR) to the base station on the uplink using the physical uplink control channel (PUCCH). The base station responds using the physical downlink control channel (PDCCH) with downlink control information (DCI) indicating the allocated sidelink resources (e.g., time resources in the form of one or more slots and frequency resources in the form of one or more subchannels). The allocated sidelink resources can be used for transmitting a TB and for up to two possible retransmissions of the same TB. Thus, DG scheduling offers high flexibility in resource scheduling and relatively low latency, but some delay is introduced and signaling overhead is increased because of the need to request resources.

[0013] In CG scheduling, the base station allocates a set of sidelink resources (called configured grants (CGs)) to the UE that can be used (permanently or semi-permanently) to transmit several TBs. A CG is configured using a set of parameters, including a CG index, at least one time-frequency allocation, and the periodicity of the allocated SL resources. To support CG scheduling, the UE can provide UE-aiding information to the base station. Thus, CG scheduling can reduce signaling overhead and latency compared to DG, but at the expense of resource scheduling flexibility.

[0014] When a UE is outside the coverage of any base station, the network cannot allocate and manage resources used for sidelink communication. Therefore, to enable sidelink communication by an out-of-coverage UE, the UE can apply autonomous resource selection techniques (distributed scheduling protocols in which resource allocation is effectively performed by the UE itself). In NR, this autonomous resource selection is known as Mode 2 (or "NR V2X Mode 2") resource allocation, which is similar to the type of (V2X) resource allocation known as Mode 4 in LTE. Specifically, when operating in autonomous resource selection mode, a UE can autonomously select sidelink resources (one or more subchannels) from a resource pool that can be pre-configured and / or configured by base stations when the UE is within network coverage. NR autonomous mode (Mode 2) resource allocation supports dynamic scheduling and semi-persistent scheduling (SPS) schemes. When using the dynamic scheme, the UE can select a new resource for each TB and reserve the resource (by notifying on-range UEs) only for future retransmissions of that TB. The semi-persistent method can be enabled or disabled within a given resource pool by (pre)configuration. When a UE reserves resources for future transmissions, it notifies nearby ("adjacent") UEs using a first-stage SCI that is sent directly from one UE to another using the physical sidelink control channel (PSCCH). When using the SPS method, a UE can select and reserve resources for several TB transmissions (and their retransmissions).

[0015] In autonomous mode (mode 2), the UE can select a new sidelink resource when generating a new TB. It can also trigger a selection for the SPS scheme if the new TB is too large to be sent with a previously reserved resource. To select a new (either dynamic or semi-persistent) sidelink resource, the UE first sets up a time interval (corresponding to a set of slots) called a selection window, which contains resources (called candidate resources) from which the new sidelink resource will be selected for sending the TB.

[0016] When not transmitting, the UE performs a detection operation to identify available candidate resources. This detection operation takes place during a time interval called a detection window, which corresponds to a set of slots. In the detection process, the UE decodes the first-stage SCI received from other UEs on the detected sidelink resources. Each first-stage SCI received from each UE indicates the sidelink resources reserved for the retransmission of the TB associated with the first-stage SCI, and the resources reserved for the initial transmission and retransmission of the next TB. The UE also measures the transmission associated with each first-stage SCI received from other UEs (e.g., reference signal received power (RSRP)). The UE stores the detected information (decoded first-stage SCI and RSRP measurements) and, based on the detected information, determines which candidate resources should be excluded from the selection window (and therefore which candidate resources can be selected) when a new selection is triggered.

[0017] Autonomous mode (mode 2) detection-based SPS can be used, for example, for periodic traffic. Specifically, a detection-based SPS UE can reserve resources (subchannels) in the frequency domain for any number of consecutive periodic transmissions in the time domain. The selected set of slots on which resources are reserved is then repeated periodically for a configured period known as the resource reservation period. The transmitting UE includes information indicating this reservation period in the first-stage SCI sent to other UEs so that other UEs can estimate which resources may be reserved in the future. The number of slots for transmission (and retransmission) within each periodic resource reservation period depends on the number of blind retransmissions (if any) and the resource selection procedure. The number of reserved subchannels per slot depends on the size of the data to be transmitted. After using the reserved resources for a configured number of transmissions (corresponding to a parameter called the Sidelink Resource Reselection Counter (SLRRC)), the UE determines, based on a pre-configured probability value known as the "probability of resource keeping," whether the same selection should be retained or whether a new resource selection procedure should be triggered.

[0018] Sidelink radio resources can be configured so that network-controlled (mode 1) resource allocation and autonomous (mode 2) resource selection use separate resource pools. However, sidelink radio resources can also be configured so that network-controlled (mode 1) resource allocation and autonomous (mode 2) resource allocation share the same resource pool. Pool sharing has the advantage of potentially increasing resource efficiency, but at the cost of conflicts (e.g., potential collisions) between scheduled transmissions using different modes. To address this, a UE operating in network-controlled resource allocation mode can inform other autonomous resource selection mode UEs of the resources allocated for their future (re)transmissions using, for example, a first-stage SCI transmitted directly from one UE to another using a PSCCH as described above.

[0019] Sidelink communication (e.g., in the case of NR V2X) supports Hybrid Automatic Receive reQuest (HARQ) procedures to improve the reliability of sidelink communication. The HARQ procedures are supported for unicast and groupcast messages, for example, which can provide higher reliability for these traffic types.

[0020] HARQ operates in both the MAC layer and the PHY layer. Retransmissions are performed in the MAC layer, but the PHY layer (of the receiver) combines one or more transmissions to increase the likelihood of correct decoding.

[0021] Sidelink HARQ feedback (i.e., including acknowledgement (ACK) and / or negative acknowledgement (NACK)) is provided on the PSFCH and may be in the form of ACK / NACK-based feedback or NACK-only feedback. ACK / NACK-based feedback is transmitted on the PSFCH based on the success or failure of reception of an entire transport block (i.e., ACK or NACK respectively) using a single PSFCH transmission-side UE-dedicated resource. If reception fails at that UE, NACK-only feedback is provided by the UE on the PSFCH, and if reception is successful, no signal on the PSFCH by that UE is transmitted. NACK-only feedback is particularly useful for groupcast / broadcast services as it reduces the number of resources required when there are multiple receiver UEs and they need to transmit feedback simultaneously. NACK-only feedback may be provided, for example, on a resource shared by multiple PSFCH transmission-side UEs.

[0022] In addition to feedback-based retransmission, the possibility of blind retransmission (which does not require explicit feedback from the receiving UE) is introduced. In broadcast communication, only blind retransmission is currently supported, but in unicast and groupcast communication, both blind and feedback-based retransmission can be used.

[0023] In the case of blind retransmission, HARQ is actually implemented only at the receiver for retransmission combining. The transmitting UE selects the resources to be used for retransmission within the resource reservation period. The transmitting UE pre-determines the number of retransmissions up to a maximum of 31 retransmissions (i.e., a total of 32 transmissions) based on the configured value. Nevertheless, blind retransmission may be resource-inefficient, especially when the initial transmission is successful.

[0024] In the case of feedback-based retransmission, HARQ is actually implemented at the transmitter for efficient retransmission and at the receiver for retransmission combining. Feedback-based retransmission is generally more resource-efficient because the transmitting UE generally only requires resources for retransmission when the original transmission has been NACKed, but blind retransmission may reduce the latency associated with feedback-based retransmission because the transmitting UE does not need to wait for HARQ feedback before transmitting a retransmission.

Prior Art Documents

Non-Patent Documents

[0025]

Non-Patent Document 1

[0026] As part of the development of sidelink communication technology, efforts are being made to support sidelink communication over unlicensed spectrum (SL-U). This typically requires the use of appropriate channel access mechanisms to ensure that different devices using unlicensed bandwidths coexist fairly with one another and comply with local regulatory requirements regarding the use of such spectrum.

[0027] One such channel access mechanism is "listen-before-talk" (LBT), in which the transmitting device (UE / base station) is expected to perform some form of clear channel assessment (CCA), which generally involves "sensing" the medium to detect any transmissions from other nodes before obtaining channel occupancy time (COT) to transmit, provided the channel is clear / available. CCA may include, for example, energy sensing (i.e., measuring the received energy level of any signal transmitted from other devices) and determining whether the channel is idle or busy based on the detected energy. There are various scenarios to suit various LBT requirements, including several scenarios in which channel access can be performed immediately (without requiring a sensing / listening step).

[0028] For this purpose, four LBT categories are currently defined for (dynamic) channel access for NR communications in license-free bandwidth. - Cat 4 LBT (also known as "Type 1") with conflicting windows Cat 2 LBT (also known as "Type 2A") with a -25μs gap Cat 2 LBT (T is also known as "Type 2B") with a -16μs gap. - Cat 1 LBT (also known as "Type 2C") with a gap of 16 μs or less, without channel detection / LBT. In uplink (UL) / downlink (DL) communication, both the base station and the UE can acquire the COT using Cat 4 LBT, but the base station or UE can share the COT acquired by other nodes under different conditions with Cat 2 or Cat 1 LBT.

[0029] Therefore, in the case of sidelink communication (e.g., V2X), the transmitting UE can support operation on the unlicensed spectrum by using an appropriate LBT channel access procedure according to one of these Type 1 or Type 2 categories to access a channel on which one or more transmissions are performed. A Type 1 LBT channel access procedure would require the transmitting UE to perform periodic channel detection (as described by the physical layer specification). For a Type 2A "UL" channel access procedure, the transmitting UE can transmit immediately after detecting that the channel has been idle for at least 25 μs detection intervals. For a Type 2B "UL" channel access procedure, the transmitting UE can transmit immediately after detecting that the channel has been idle for at least 16 μs detection intervals. For a Type 2C "UL" channel access procedure, the UE can transmit without detecting the channel before transmitting. In the case of a resource-shared COT, the UE only needs to perform a Type 2 LBT channel access procedure and therefore does not need to pass a Type 1 LBT check to use the resources of that channel.

[0030] Currently, it is assumed that the existing side-link autonomous mode (mode 2) resource allocation scheme will be supported as the baseline for SL-U resource allocation. In this regard, the question arises as to whether detection-based resource selection should be triggered before or after LBT is triggered.

[0031] Additionally, support is being developed for sidelink communication where transmissions can occur in several consecutive slots (called multiple consecutive slots transmission (MCSt)). Besides the potential to increase the capacity of sidelink transmissions, the motivations for developing MCSt include the possibility of reducing the need and / or frequency of LBT to access the channel after the UE has acquired COT, and the possibility of holding COT to transmit the UE's data as quickly as possible (i.e., in subsequent slots). Guard symbols between adjacent slots in MCSt can ensure that there are no gaps between transmissions within adjacent slots, or that the gaps are 16μs or less (i.e., corresponding to type 2C / no LBT required).

[0032] In the autonomous mode (mode 2) resource selection procedure used for sidelink communication, the upper layers of the transmitting UE (e.g., the MAC layer) provide a set of parameters to trigger the physical layer (layer 1 / L1) to report a subset of candidate single-slot resources that may be selected for transmission. These parameters include, for example, Layer 1 (L1) priority (prio_TX), (remaining) packet delay budget (PDB), number of subchannels (L_"subCH"), and reservation periodicity (P_"rsvp_TX"). Resources are then randomly selected at the MAC layer for the initial transmission and retransmission of a single TB. Therefore, in the context of MCSt, it is not possible to guarantee that the selected resource may or may not reside in a contiguous slot.

[0033] Furthermore, MCSt can support the transmission of multiple TBs (in addition to a single TB transmission). Historically, in the case of multiple TB transmissions, multiple sets of upper-layer parameters can be provided to L1 for candidate resource reporting (assuming the upper layers can simultaneously trigger resource (re)selection processes for multiple TBs).

[0034] In the case of SL-U, in the context of MCSt operation, when L1 is triggered by the upper (MAC) layer to report a subset of candidate resources for MCSt, the question arises as to whether only a single parameter set (e.g., prio_TX, remaining PDBs, L_"subCH", and P_"rsvp_TX") should be provided by the upper (MAC) layer for the resource selection procedure at L1 (for sending a single or multiple TB), or whether multiple parameter sets (prio_TX, remaining PDBs, L_"subCH", and P_"rsvp_TX") can be provided for the resource selection procedure (e.g., for sending multiple TBs). The possibility of multiple parameter sets provides flexibility, while providing a single parameter set has the advantage of reducing complexity.

[0035] Similarly, there are several possible options for L1 to report a subset of candidate resources from MCSt to the MAC layer (for resource reservation). For example, L1 could report candidate multi-slot resources to candidate resource set S. A It can be reported as follows, and each candidate multi-slot resource consists of a set of temporally consecutive single-slot resources (in this case, the question of whether each resource in the set of single-slot resources within the candidate multi-slot resource can have a different L_"subCH" size must also be considered). Alternatively, L1 is the candidate resource set S, similar to existing resource selection procedures. A It can report candidate single-slot resources within (in this case, it becomes the responsibility of the upper (MAC) layer to select a set of single-slot resources within a contiguous logical slot). Alternatively, L1 can report candidate resource set S. A You may report consecutive single-slot candidate resources within the same instance.

[0036] At the physical layer, the enhancement of autonomous mode (mode 2) resource selection for MCSt primarily relates to the selection of time and frequency resources in consecutive slots.

[0037] In previous releases, for NR communication over unlicensed spectrum (NR-U), as with license-assisted access (LAA) for using unlicensed spectrum, each data radio bearer (DRB) could have its own channel access priority class (CAPC). Signaling radio bearers (SRBs) carrying control signals such as RRC messages and non-access stratum (NAS) messages always use the highest priority CAPC (except for SRB2). Base stations typically assign CAPCs to DRBs by considering the 5G QoS identifiers (5QIs) of all QoS flows multiplexed on that DRB, while taking into account fairness between different traffic types and transmissions. Certain standardized CAPCs may be used for QoS flows, and QoS flows have 5QIs that form part of a standardized set of 5QIs to which a particular CAPC is mapped. QoS flows corresponding to non-standard 5QIs (e.g., operator-specific 5QIs) may use the CAPC of a standard 5QI that best matches the QoS characteristics of the non-standard 5QI. The UE can use this configuration to determine the CAPC if it is not explicitly signaled directly by the base station. This applies to all CG transmissions and some dynamic grants, in which case the UE selects the CAPC with the lowest priority among the multiplexed data flows. The exception is when signaling data is transmitted, in which case the CAPC of the associated packet is the same as the CAPC of the highest priority signaling bearer.

[0038] For SL-U, a similar procedure is used to determine the CAPC of the sidelinkDRB (SL-DRB) or sidelinkSRB (SL-SRB). Specifically, the CAPC mapping can be determined in a similar manner to that described for NR-U above, using a special 5QI, the so-called PC5 QoS identifier (PQI). For SL-DRB, the CAPC value is (pre)configurable per DRB, as in the case of NR-U. For all SL-SRB, the CAPC value is fixed to the highest priority (i.e., the lowest CAPC value). For all SL MAC control elements (CE), the CAPC value is fixed to the highest priority (i.e., the lowest CAPC value). In the case of PQI-based CAPC mapping, at least the PDB (and possibly other parameters) can be used as a criterion for determining the CAPC. Furthermore, as with NR-U for unstandardized PQI, the CAPC of the standardized PQI that best matches the QoS characteristics of the unstandardized PQI can be used (as a baseline).

[0039] The UE determines the CAPC for the sidelink TB if the CAPC is not indicated in the DCI. If only one or more SL MAC CEs are included in the sidelink TB, the highest priority sidelink CAPC is used. If a sidelink control channel (SCCH) service data unit (SDU) is included in the sidelink TB, the highest priority sidelink CAPC is used.

[0040] While work on MCSt for sidelink communication is ongoing, there are several areas that could benefit from further development, particularly in the context of SL-U, to provide improved UE and related methods / devices as needed. For example, one or more detailed mechanisms to be implemented at the physical layer for MCSt are not yet clear. One or more mechanisms to be implemented at the MAC layer, and coordination between the physical and MAC layers, have also not been considered in detail.

[0041] For example, in the case of a single-slot resource-based transmission, the UE triggers a resource (re)selection if a PSSCH transmission is not performed due to an LBT failure from L1. However, this type of LBT failure handling is not suitable for MCSt because if an LBT failure occurs in the first slot, the UE can still attempt additional LBTs in subsequent slots within the MCSt slot group.

[0042] Furthermore, MCSt transmission carries the risk of potentially blocking data with lower CAPC levels (i.e., higher priority).

[0043] Therefore, there are several areas for possible development / improvement, which include, but are not limited to, resource selection procedures for MCSt, HARQ behavior for MCSt, LBT procedures for MCSt (e.g., failure handling), and / or logical channel prioritization and CAPC assignment in the context of MCSt. [Means for solving the problem]

[0044] This disclosure aims to provide apparatus and related methods that contribute, at least in part, to addressing the above-mentioned problems / needs.

[0045] In one embodiment, a method is provided which is performed by a first user equipment (UE), the method comprising: providing information from a first protocol layer to a second protocol layer to be used when selecting resources for transmitting data using direct inter-UE communication across a plurality of consecutive time resources; receiving information from the second protocol layer in the first protocol layer indicating a set of candidate resources for direct inter-UE communication across a plurality of consecutive time resources, selected based on the information; and transmitting data to the second UE via direct inter-UE communication using at least a subset of the candidate resources across a plurality of consecutive time resources, wherein the information is at least one of the following: resource selection At least one parameter associated with an autonomous mode, where the data includes data from each of several different data sources, each parameter of the at least one parameter is based on a corresponding attribute associated with data from one of the several different data sources, and each parameter of the at least one parameter includes at least one parameter, transmission pattern information identifying at least one intended transmission pattern for transmitting data via direct inter-UE communication, and / or size information indicating the estimated total size of the transmitted data, the estimated total size being based on both the initial transmission of the data and any intended retransmission of the data.

[0046] If the information includes at least one parameter, at least one parameter may include a priority parameter indicating a second protocol layer priority. If the data includes data from each of several different data sources, the priority parameter may indicate that the second protocol layer priority is based on the corresponding priority-related attribute associated with the data from the data source with the highest associated priority among the several different data sources. The corresponding priority-related attribute associated with the data from the data source may be a channel access priority class (CAPC), and the priority parameter may be based on the CAPC associated with the data source with the lowest associated CAPC among the several different data sources.

[0047] If the information includes at least one parameter, at least one parameter may include a packet delay budget (PDB) parameter indicating the remaining PDBs. If the data includes data from each of several different data sources, the PDB parameter may be based on the corresponding PDB-related attribute associated with the data from the data source with the lowest remaining PDB among the several different data sources.

[0048] If the data includes data from each of several different data sources, the multiple data sources may include at least one direct UE-to-UE media access control (MAC) control element (CE). If the data includes data from each of several different data sources, the multiple data sources may include at least one direct UE-to-UE logical channel (LCH).

[0049] If the data contains more data than can be transmitted using the set of candidate resources, the method may include the first protocol layer triggering the second protocol layer to perform further selection of resources for transmitting at least a portion of the data. If the set of candidate resources contains more resources than are required to transmit the data, the method may include dropping at least a subset of resources that are not required to transmit the data. If the set of candidate resources contains more resources than are required to transmit the data, the method may include performing a logical channel prioritization (LCP) procedure to transmit the data or further data to at least one further UE using at least a subset of resources that are not required to transmit the data to a second UE via direct inter-UE communication.

[0050] If the information includes transmission pattern information, the transmission pattern information may include at least one of the following: an instruction for the number of transport blocks (TB) for transmitting data, an instruction for a hybrid automatic repeat request (HARQ) transmission mechanism, and / or the number of slots to be occupied for blind retransmission.

[0051] If the transmission pattern information includes instructions for the HARQ transmission mechanism, the instructions for the HARQ transmission mechanism may indicate at least one of the following: whether the HARQ transmission mechanism is feedback-based or blind retransmission-based; the number of direct UE-to-UE HARQ processes to be used for the intended HARQ transmission; and / or the number of blind retransmissions for at least one TB.

[0052] The data may be sent to the second UE in multiple different transport blocks (TBs) using a common hybrid automatic repeat request (HARQ) process, with each TB being sent using different time resources from among multiple consecutive time resources.

[0053] The data may be sent to a second UE using a common hybrid automatic repeat request (HARQ) process in at least one transport block (TB), and at least one TB may be sent using two or more time resources from a plurality of consecutive time resources.

[0054] The data may be sent to a second UE in at least one transport block (TB) using a common hybrid automatic repeat request (HARQ) process, where at least one TB may be sent in a first time resource of a plurality of consecutive time resources and then retransmitted in at least one further time resource of the plurality of consecutive time resources.

[0055] This method may include providing instructions from the first protocol layer to the second protocol layer for each TB transmission and / or retransmission of at least one of the redundant versions and / or time resources to be used.

[0056] The data may be sent to the second UE in a single transport block (TB) using a hybrid automatic repeat request (HARQ) process, and the single TB may be sent using at least one time resource from a group of consecutive time resources.

[0057] This method may include receiving at least one of HARQ feedback and / or data transmissions from a second UE in at least one other time resource among a plurality of consecutive time resources. The at least one other time resource may form at least a portion of channel occupancy time (COT). This method may include sending COT sharing information indicating at least one other time resource to the second UE. Data may be sent to the second UE in a plurality of transport blocks (TBs), each TB may be sent using a different hybrid automatic repeat request (HARQ) process. Each TB may be sent in a different time resource among a plurality of consecutive time resources. Each TB may carry data of the same priority. Data may be sent using a feedback-based HARQ retransmission mechanism. Data may be sent using a blind retransmission-based HARQ retransmission mechanism, and each TB may be retransmitted in a different time resource among a plurality of consecutive time resources.

[0058] The first of multiple TBs may be transmitted and blind-retransmitted across multiple consecutive time resources in a manner interleaved with the transmission and blind-retransmission of the second of multiple TBs. The first of multiple TBs may be transmitted and blind-retransmitted across multiple consecutive time resources, and the second of multiple TBs may be transmitted and blind-retransmitted across multiple consecutive time resources.

[0059] The first protocol layer may be the media access control (MAC) layer. The second protocol layer may be the physical (PHY / L1) layer.

[0060] In one embodiment, a method is provided which is performed by first user equipment (UE), the method comprising: receiving information from a second protocol layer in a first protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across a plurality of consecutive time resources; transmitting data to a second UE via direct inter-UE communication using at least a subset of the candidate resources across a plurality of consecutive time resources, wherein if the data contains more data than could be transmitted using the set of candidate resources, the first protocol layer triggers the second protocol layer to perform further selection of resources for transmitting at least a portion of the data; and if the set of candidate resources contains more resources than required for transmitting the data, the method performs a logical channel prioritization (LCP) procedure to drop at least a subset of resources not required for transmitting the data, and / or to further transmit the data or further data to at least one further UE using at least a subset of resources not required for transmitting the data to the second UE via direct inter-UE communication.

[0061] At least one additional UE may be selected as at least one destination UE for further transmission, regardless of whether the priority associated with at least one additional UE is higher than the priority associated with another potential destination UE.

[0062] In one embodiment, a method is provided which is performed by first user equipment (UE), the method comprising: receiving information from a second protocol layer in a first protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across multiple consecutive time resources; sequentially performing each listen-before-talk (LBT) for each time resource in multiple consecutive time resources until the LBT result for the corresponding time resource of the multiple consecutive time resources indicates that data transmission can be initiated in the corresponding time resource, or until each LBT fails in all time resources of the multiple consecutive time resources; and at least The present invention provides that if at least one LBT fails for a corresponding time resource among a plurality of consecutive time resources, the second protocol layer indicates at least one LBT failure to the first protocol layer, wherein indicating at least one LBT failure includes indicating a single LBT failure provided when each LBT fails for any of the multiple consecutive time resources, indicating each LBT failure provided for each LBT that fails for a corresponding time resource among the multiple consecutive time resources, or indicating an LBT failure that identifies at least one time resource among the multiple consecutive time resources that the LBT failed for.

[0063] Upon receiving indication of at least one LBT failure from the second protocol layer, the first protocol layer can adapt the planned transmission or retransmission of data based on the indication of at least one LBT failure from the second protocol layer.

[0064] In one embodiment, a method is provided which is performed by first user equipment (UE), the method comprising: receiving information from a second protocol layer to the first protocol layer indicating a set of candidate resources for transmitting existing data using direct inter-UE communication across a plurality of consecutive time resources; and transmitting existing data to the second UE via direct inter-UE communication in at least one transport block (TB) using at least a subset of the candidate resources across a plurality of consecutive time resources, wherein the existing data comprises a plurality of different data, each of which has a different priority level from a plurality of possible priority levels, the plurality of different data having different priority levels are contained in at least one TB, regardless of whether the same TB contains different data having different priority levels, and the plurality of different data having different priority levels are contained in at least one TB, in a manner that ensures that each TB contains data having a common priority level, or that each TB contains only data having a priority level within a particular range of priority levels.

[0065] Regardless of whether the same TB contains different data each having a different priority level, if at least one TB contains multiple different data with different priority levels, and the UE has new data to send before all existing data has been sent, the UE may wait to send the new data until the existing data has been sent, regardless of whether the new data has a higher priority level than the existing data.

[0066] If multiple TBs contain multiple different data with different priority levels, in a manner that ensures each TB contains data with a common priority level, and the UE has new data to send before all existing data has been sent, the UE may delay sending at least one unsent TB containing existing data with a lower priority level than the new data, and send the new data with priority over that at least one unsent TB.

[0067] In a manner that ensures each TB contains only data having a priority level within a specific priority level range, if at least one TB contains multiple different data with different priority levels, and before the transmission of all existing data is complete, the UE has new data with a priority level higher than the specific priority level range for transmission, the UE may delay the transmission of at least one unsent TB containing existing data with a priority level within the specific priority level range and may transmit the new data with priority over that at least one unsent TB.

[0068] Each priority level may be associated with a different channel access priority class (CAPC), with lower CAPCs corresponding to higher priority levels.

[0069] In one embodiment, a first user equipment (UE) is provided, which includes means for providing information from a first protocol layer to a second protocol layer for use in selecting resources for transmitting data using direct inter-UE communication across a plurality of consecutive time resources; means for receiving information from the second protocol layer to the first protocol layer indicating a set of candidate resources for direct inter-UE communication across a plurality of consecutive time resources, selected based on the information; and means for transmitting data to the second UE via direct inter-UE communication using at least a subset of the candidate resources across the plurality of consecutive time resources, wherein the information includes at least one parameter associated with an autonomous mode of resource selection, and if the data includes data from each of a plurality of different data sources, each parameter of the at least one parameter is based on a corresponding attribute associated with data from one of the plurality of different data sources, transmission pattern information identifying at least one intended transmission pattern for transmitting data via direct inter-UE communication, and / or size information indicating an estimated total size of the data to be transmitted, the estimated total size being based on both the initial transmission of the data and any intended retransmissions of the data.

[0070] In one embodiment, a first user equipment (UE) is provided, comprising means for receiving information in a first protocol layer from a second protocol layer indicating a set of candidate resources for transmitting data across a plurality of consecutive time resources using direct inter-UE communication, and means for transmitting data to a second UE via direct inter-UE communication using at least a subset of the candidate resources across the plurality of consecutive time resources, wherein the first protocol layer is configured to trigger the second protocol layer to perform further selection of resources for transmitting at least a portion of the data if the data contains more data than can be transmitted using the set of candidate resources, and if the set of candidate resources contains more resources than are required to transmit the data, the UE is configured to drop at least a subset of resources not required to transmit the data, and / or to perform a logical channel prioritization (LCP) procedure to further transmit the data or further data to at least one further UE using at least a subset of resources not required to transmit the data to the second UE via direct inter-UE communication.

[0071] In one embodiment, first user equipment (UE) is provided, and the first user The equipment (UE) includes means for receiving information from a second protocol layer in a first protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across a plurality of consecutive time resources; means for sequentially performing each listen-before-talk (LBT) for each time resource of a plurality of consecutive time resources until the results of LBTs for corresponding time resources of the plurality of consecutive time resources indicate that data transmission can be initiated at the corresponding time resource, or until each LBT fails at any of the time resources of the plurality of consecutive time resources; and means for providing the second protocol layer to the first protocol layer to indicate at least one LBT failure if at least one LBT fails for a corresponding time resource among the plurality of consecutive time resources, wherein indicating at least one LBT failure includes indicating a single LBT failure provided when each LBT fails at any of the time resources of the plurality of consecutive time resources, indicating each LBT failure provided for each LBT that fails for a corresponding time resource among the plurality of consecutive time resources, or indicating an LBT failure that identifies at least one time resource in which an LBT among the plurality of consecutive time resources failed.

[0072] In one embodiment, a first user equipment (UE) is provided, the first user equipment (UE) comprising means for receiving from a second protocol layer in a first protocol layer information indicating a set of candidate resources for transmitting existing data using direct inter-UE communication in a plurality of consecutive time resources, and means for transmitting existing data to a second UE in a plurality of consecutive time resources via direct inter-UE communication in at least one transport block (TB) using at least a subset of the candidate resources, wherein if the existing data includes a plurality of different data each having a different priority level from a plurality of possible priority levels, the plurality of different data with different priority levels are included in a plurality of TBs in such a way that ensures that at least one TB contains a plurality of different data having different priority levels, or that each TB contains data having a common priority level, or that each TB contains only data having a priority level within a particular range of priority levels.

[0073] Herein, exemplary embodiments of the present disclosure will be described by reference to the accompanying drawings. [Brief explanation of the drawing]

[0074] [Figure 1] This is a schematic diagram illustrating a mobile ("cellular" or "wireless") telecommunications system. [Figure 2] This figure shows a typical frame structure that can be used in the telecommunications system shown in Figure 1. [Figure 3] Figure 1 shows a typical configuration of a sidelink resource pool that can be used in a telecommunications system. [Figure 4A] This figure shows various types of slot formats that can be used in telecommunications system 1. [Figure 4B]This figure shows various types of slot formats that can be used in telecommunications system 1. [Figure 5] Figure 1 is a simplified sequence diagram illustrating an exemplary dynamic grant procedure that can be implemented in the telecommunications system. [Figure 6] Figure 1 is a simplified sequence diagram showing an exemplary configured grant procedure that may be implemented in the telecommunications system. [Figure 7] This is a simplified diagram showing how different computer graphics (CGs) can be configured in the telecommunications system shown in Figure 1. [Figure 8] This is a simplified diagram illustrating how autonomous mode resource selection can operate in the telecommunications system shown in Figure 1. [Figure 9] Figure 1 is a simplified schematic block diagram showing the main components of the UE for the telecommunications system. [Figure 10] Figure 1 is a simplified schematic block diagram showing the main components of a base station for a telecommunications system. [Figure 11] Figure 1 is a simplified sequence diagram illustrating the procedure for autonomous MCSt resource selection that can be performed in the telecommunications system. [Figure 12] Figure 1 is a simplified sequence diagram illustrating the steps that may be performed following the autonomous selection of a candidate set of MCSt resources in the telecommunications system. [Figure 13] Figure 1 is a simplified sequence diagram illustrating the procedure for supporting autonomous MCSt resource selection in the context of HARQ operation, which can be performed in the telecommunications system shown. [Figure 14] Figure 1 is a simplified diagram illustrating several different ways in which HARQ process-based transmission with HARQ feedback disabled can be performed in the telecommunications system shown. [Figure 15] Figure 1 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in the telecommunications system shown. [Figure 16] Figure 1 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in the telecommunications system shown. [Figure 17] Figure 1 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in the telecommunications system shown. [Figure 18] Figure 1 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in the telecommunications system shown. [Figure 19] Figure 1 is a simplified sequence diagram showing several different LBT failure handling mechanisms that may be used in the telecommunications system. [Figure 20] Figure 1 shows an example of how TB(re)transmission is affected by one or more LBT failures within an MCSt slot group in the telecommunications system shown in Figure 1. [Figure 21] This figure shows another example of how TB(re)transmission is affected by one or more LBT failures within an MCSt slot group in the telecommunications system shown in Figure 1. [Modes for carrying out the invention]

[0075] overview Hereafter, an exemplary telecommunications system will be outlined as a simple example with reference to Figures 1 through 8.

[0076] Figure 1 is a schematic diagram of a mobile ("cellular" or "wireless") communication system 1, to which embodiments of the present disclosure can be applied.

[0077] In communication system 1, user equipment (UE) 3-1, 3-2, 3-3, 3-4 (such as mobile phones and / or other mobile devices) can communicate with each other via radio access network (RAN) nodes 5 operating according to one or more compatible radio access technologies (RATs). In the illustrated example, the RAN node 5 comprises a base station 5 or "gNB" 5 operating one or more associated cells 9. Communication via the base station 5 is typically routed via a core network 7 (such as a 5G / 6G core network or an evolved packet core network (EPC)).

[0078] As those skilled in the art will understand, Figure 1 shows four UEs 3 and one base station 5 for illustrative purposes, but the system typically includes other base stations and UEs in implementation.

[0079] Each base station 5 controls one or more associated cells, either directly or indirectly through one or more other nodes (such as home base stations, repeaters, remote radio heads, distributed units, and / or transmission reception points (TRPs)). It will be understood that base stations 5 may be configured to support 4G, 5G, and / or later generations, and / or any other 3GPP or non-3GPP communication protocols.

[0080] UE3 and its serving base station 5 are connected via an appropriate air interface (for example, a so-called "NG-Uu" interface). Neighboring base stations 5 may be connected to each other via appropriate inter-base station interfaces (for example, a so-called "X2" interface, an "Xn" interface, etc.).

[0081] The core network 7 includes several logical nodes (or "functions") to handle communications in the communication system 1. In this example, the core network 7 comprises a control plane function (CPF) 10 and one or more network node entities for the communications of user data 11 (e.g., a user plane function (UPF)). The CPF 10 includes one or more network node entities for the communications of control signaling 10-1 (e.g., an Access and Mobility Management Function (AMF)), one or more network node entities for session management 10-2 (e.g., a Session Management Function (SMF)), and several other functions 10-n.

[0082] Base station 5 is connected to the core network nodes via appropriate interfaces (or "reference points"), such as a reference point between base station 5 and AMF10-1 for control signaling communications (e.g., an N2 reference point), and a reference point between base station 5 and each UPF11 for user data communications (e.g., an N3 reference point). UE3 is connected to AMF10-1 via (logical) non-access stratum (NAS) connections through reference points (e.g., an N1 reference point, similar to the S1 reference point in LTE). It will be understood that N1 communications are routed transparently through base station 5.

[0083] One or more UPF11s are connected to an external data network (such as an IP network like the Internet) via a reference point (such as an N6 reference point) for communicating user data.

[0084] The AMF10-1 performs mobility management-related functions, maintains NAS connectivity with each UE3, and manages UE registration. The AMF10-1 also manages paging. The SMF10-2 connects to the AMF10-1 via a reference point (e.g., an N11 reference point). The SMF10-2 provides session management functions (which form part of the MME function in LTE) and also incorporates several control plane functions (provided by the serving gateway and packet data network gateway in LTE). The SMF10-2 also allocates IP addresses to each UE3.

[0085] Base station 5 is configured for transmitting control information and user data via several downlink (DL) physical channels, and for transmitting several physical signals, while UE3 is configured for receiving control information and user data via several downlink (DL) physical channels, and for transmitting several physical signals. DL physical channels correspond to resource elements (REs) that carry information emitted from higher layers, and DL physical signals correspond to REs used in the physical layer that do not carry information emitted from higher layers.

[0086] Physical channels can include, for example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). The PDSCH carries data that shares its capacity on a time and frequency basis. The PDSCH can carry various data items, including, for example, user data, UE-specific upper-layer control messages mapped down from higher channels, System Information Blocks (SIBs), and paging. The PDCCH carries downlink control information (DCI) to support several functions, including scheduling downlink transmissions on the PDSCH and uplink data transmissions on the physical uplink shared channel (PUSCH). The PBCH provides the Master Information Block (MIB) to the UE3. The PBCH also works in conjunction with the PDCCH to support time and frequency synchronization, which assists in cell acquisition, selection, and re-selection.

[0087] DL physical signals may include, for example, a reference signal (RS) and a synchronization signal (SS). The reference signal (sometimes known as a pilot signal) is a signal with a predetermined specific waveform that is known to both the UE3 and the base station 5. Reference signals may include, for example, a cell-specific reference signal, a UE-specific Reference Signal (UE-RS), a Positioning Reference Signal (PRS), and a Channel State Information Reference Signal (CSI-RS).

[0088] Similarly, UE3 is configured to transmit control information and user data via several uplink (UL) physical channels corresponding to REs that carry information transmitted from higher layers, as well as UL physical signals used in the physical layer that correspond to REs that do not carry information transmitted from higher layers, and base station 5 is configured to receive them. Physical channels may include, for example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and / or a physical random access channel (PRACH). UL physical signals may include, for example, a demodulation reference signal (DMRS) for UL control / data signals, and / or a sounding reference signal (SRS) used for UL channel measurement and / or UL positioning measurements.

[0089] Frame structure Referring to Figure 2, which shows a typical frame structure that may be used in communication system 1, the base station 5 and UE3 of communication system 1 communicate with each other in the time domain using resources organized into frames of length 10 ms. Each frame consists of 10 subframes of equal size, each with a length of 1 ms. Each subframe is divided into one or more slots, each containing 14 Orthogonal frequency-division multiplexing (OFDM) symbols of equal length.

[0090] As shown in Figure 2, communication system 1 corresponds to several different numerologies (subcarrier spacing (SCS), slot length, and consequently OFDM symbol length). Specifically, each numerology is identified by the parameter μ, where μ=0 represents 15kHz (corresponding to LTE SCS). Currently, SCS for other values ​​of μ can actually be derived from μ=0 by scaling up by a power of 2 (i.e., SCS = 15 × 2μkHz). The relationship between the parameter μ and SCS(Δf) is shown in Table 1. [Table 1]

[0091] Bandwidth portion In communication system 1, the cell bandwidth can be divided into multiple bandwidth parts (BWPs), each BWP beginning with its own starting resource block (RB), and each containing a set of consecutive RBs having a given numerology (sub-carrier spacing "SCS" and cyclic prefix "CP") on a given carrier. By setting a small BWP for UE3, the computational complexity and power consumption of that UE3 can be reduced. Since each BWP can have a different bandwidth and numerology, BWPs enable flexible and efficient use of resources by dividing the carrier bandwidth to multiplex transmissions with different configurations and requirements.

[0092] Therefore, the UE3 and base station 5 of communication system 1 are configured to operate using BWP. For each serving cell of UE3, base station 5 can configure at least one downlink (DL) BWP (e.g., the first DL BWP). Base station 5 can configure UE3 with up to (typically four) additional DL BWPs, with only one DL BWP active at a given time. UE3 is not expected to receive PDSCH, PDCCH, or CSI-RS outside the active bandwidth portion (except for radio resource management (RRM)). If the serving cell is configured using uplink (UL), base station 5 can configure at least one UL BWP (e.g., the first UL BWP). Base station 5 can configure UE3 with up to (typically four) additional UL BWPs, with only one UL BWP active at a given time. UE3 does not transmit PUSCH or PUCCH outside the active bandwidth portion. In the active cell, UE3 does not transmit SRS outside the active bandwidth portion.

[0093] The BWP identifier or index (BWP-ID) is used to refer to a BWP (independently in UL and DL). Therefore, various radio resource control (RRC) configuration procedures can use the BWP-ID to associate those procedures with a specific BWP.

[0094] General support for sidelink communication In telecommunications system 1, at least some of UE3-1, 3-2, and 3-4 are capable of performing direct (UE-to-UE) communication or "sidelink" communication with each other via a direct UE-to-UE interface (such as a "sidelink" or "PC5" interface) when they are within range. This direct communication may be an in-coverage sidelink communication involving a pair of UE3-1 and 3-2 that are both within the coverage of base station 5 (for example, as shown between UE3-2 and UE3-1), a partial coverage sidelink communication involving UE3-1 that is within the coverage of base station 5 and UE3-4 that is not within the coverage of base station 5 (for example, as shown between UE3-4 and UE3-1), or an out-of-coverage sidelink communication involving a pair of UE3-4 that are both outside the coverage of base station 5.

[0095] Sidelink-enabled UE3-1, 3-2, and 3-4 are configured to communicate via several dedicated sidelink physical channels and to transmit / receive several SL physical signals. The sidelink physical channels include the Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Feedback Channel (PSFCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Control Channel (PSCCH).

[0096] The PSBCH carries the sidelink broadcast transport channel (SL-BCH), which is used for the periodic transmission (e.g., every 160ms) of the Master Information Block (MIB) for sidelinks. The MIB carries system information for inter-UE communication. The information carried by the PSBCH is transmitted using the Sidelink Primary Synchronization Signal / Sidelink Secondary Synchronization Signal (S-PSS / SSS) as part of the sidelink-synchronization signal block (S-SSB).

[0097] PSFCH is used to transmit hybrid automatic repeat request (HARQ) feedback from receivers UE3-1, 3-2, and 3-4 to transmitters UE3-1, 3-2, and 3-4 on the SL, for example, unicast or groupcast communications. Blind retransmission is also supported by UE3-1, 3-2, and 3-4 for unicast, groupcast, or broadcast communications.

[0098] A PSSCH contains the transport block (i.e., user data traffic) of a sidelink shared transport channel (SL-SCH) and is typically associated with a PSCCH transmitted in the same slot.

[0099] Sidelink-enabled UE3-1, 3-2, and 3-4 can transmit two-stage sidelink control information (SCI) for general sidelink communication. The first stage is carried by the PSCCH, and the second stage is carried by the corresponding PSSCH associated with the PSCCH.

[0100] UE3-1, 3-2, and 3-4 can use the first-stage SCI to notify other UE3-1, 3-2, and 3-4 of resources allocated by the base station during a specific dynamic grant (DG) / configured grant (CG) period (e.g., in mode 1), or resources autonomously selected by the UE (e.g., in mode 2). UE3-1, 3-2, and 3-4 can use the second-stage SCI to notify other UE3-1, 3-2, and 3-4 of information used to decode PSSCH and information used to support HARQ feedback and CSI reporting.

[0101] The first-stage SCI may include, for example, information to enable detection work, information regarding resource allocation for the PSSCH, and, if necessary, instructions indicating that the UE can receive conflict information in inter-UE coordination. The first-stage SCI typically includes, for example, frequency resource (e.g., subchannel) allocation for the PSSCH, time resource allocation, resource reservation periods for up to two further transmissions of the associated TB, priority of the associated PSSCH, demodulation reference signal (DMRS) pattern, information identifying the second-stage SCI format and size, modulation and encoding scheme of the data payload carried on the associated PSSCH, one or more reserved bits, beta offset indicator, and / or DMRS port number.

[0102] The second stage SCI can carry information necessary to identify and decode the relevant SL-SCH, as well as controls for the HARQ procedure, triggers for channel state information (CSI) feedback, coordination requests and information between UEs, etc. The second stage SCI typically includes, for example, the HARQ process ID, new data indicators, redundant versions, source ID, destination ID, and / or CSI requests.

[0103] Resources for sidelink communication Referring to Figure 3, which shows a typical configuration of a sidelink resource pool that may be used in the telecommunications system of Figure 1, base station 5 can configure at least one dedicated sidelink BWP (SL-BWP) for each sidelink-enabled UE3-1, 3-2, 3-4. Each SL BWP occupies a contiguous portion of the bandwidth within the component carrier provided by cell 9. Sidelink transmission and reception of a given UE3-1, 3-2, 3-4 are contained within the SL BWP configured for that UE3-1, 3-2, 3-4, using the same numerology. Thus, all physical channels, reference signals, and synchronization signals in the sidelink are transmitted within the corresponding SL BWP. This also means that in the sidelink, UE3-1, 3-2, 3-4 are not expected to receive or transmit using one or more numerologies. The SL BWP is divided into a common RB, which consists of 12 contiguous subcarriers having the same SCS, given by the numerology of the SL BWP.

[0104] The communication resources available for sidelinks include time resources (e.g., sots) and frequency resources (e.g., common RBs) within the SL BWP. A subset of these available sidelink resources may be pre-configured / set up by one or more UE3-1, 3-2, 3-4 for use in their sidelink communications (transmit / receive). This subset of available resources may be referred to as a “resource pool”.

[0105] A given UE3-1, 3-2, or 3-4 can be pre-configured / set up with multiple resource pools, including one or more resource pools for transmission (TX resource pools), and one or more resource pools for reception (RX resource pools). Thus, UE3-1, 3-2, or 3-4 can receive data using the resource pools used for SL transmission by other UE3-1, 3-2, or 3-4, while UE3-1, 3-2, or 3-4 can further transmit over the sidelink using their own transmission resource pools. Resource pools can be used for all transmission types (e.g., unicast, groupcast, and / or broadcast).

[0106] Common resource blocks within a resource pool may also be called physical resource blocks (PRBs). As shown in Figure 3, the illustrated resource pool consists of contiguous PRBs and contiguous or discontinuous slots pre-configured / configured for sidelink communication. The resource pool is specified to reside within an SL BWP, and therefore a single numerology is used within the resource pool. If UE3-1, 3-2, and 3-4 are configured with an active UL BWP, the SL BWP will also use the same numerology as the UL BWP, provided both of these BWPs are on the same carrier.

[0107] The resource pool is divided in the frequency domain into a pre-configured / configured number ("L") consecutive subchannels (representing the smallest frequency unit for sidelink data transmission / reception), and each subchannel contains a group of consecutive PRBs within a slot. The size of the subchannel (in units of PRBs) is "M sub The PRBs are given by [the specified source] and can be pre-configured / set to any appropriate size (e.g., 10, 12, 15, 20, 25, 50, 75, or 100 PRBs). Each sidelink transmit may use one or more subchannels.

[0108] In the time domain, slots that are part of a resource pool are pre-configured / constituted and occur with a pre-configured periodicity corresponding to the resource pool period (the resource pool period is typically, for example, 10240ms). Slots that make up a resource pool can be pre-configured / constituted by bitmaps of any suitable length (e.g., 10, 11, 12, ..., 160 bits, etc.).

[0109] Figures 4A and 4B show different types of slot formats that may be used in communication system 1, respectively. As seen in Figures 4A and 4B, each slot may include PSSCH, PSCCH, PSFCH, automatic gain control (AGC), and a guard symbol. The AGC and guard symbols are transmitted as specific symbols. The AGC symbol may be used for level control in the sidelink receiver, while the guard symbol may be used as a guard period for switching between receiving and transmitting the sidelink. The guard symbol is placed directly after PSSCH, PSFCH, or S-SSB.

[0110] A PSSCH is transmitted in a sequence of symbols in a slot. The starting symbol and number of symbols for transmitting a PSSCH are configured by a higher layer (e.g., a media access control (MAC)). A PSSCH is never transmitted in the same symbols configured for transmitting a PSFCH, or in the last symbol of a slot configured as a placeholder for a guard symbol.

[0111] Network management resource allocation for sidelink communication Each of the sidelink UE3-1, 3-2, and 3-4 and base station 5 are configured to operate in network-managed resource allocation mode (e.g., mode 1 resource allocation) resource allocation (for example, when UE3-1, 3-2, and 3-4 are within the coverage of base station 5). Scheduling in network-managed resource allocation mode can include dynamic grant (DG) scheduling or configured grant (CG) scheduling.

[0112] Next, we will explain the network-managed resource allocation mode as a simple example, referring to Figures 5 to 7.

[0113] Figure 5 is a simplified sequence diagram showing an exemplary dynamic grant procedure that may be implemented in communication system 1.

[0114] As shown in Figure 5, in the illustrated example, dynamic grants are used to transmit two TBs (TB1 and TB2). When UE3-1, 3-2, and 3-4 generate a transport block (TB1) in S510-1, UE3-1, 3-2, and 3-4 send a scheduling request to base station 5 in S512-1 (e.g., on PUCCH) to request resources to transmit TB1. Base station 5 responds in S514-1 with downlink control information (DCI) indicating the resource 500-1 that UE3-1, 3-2, and 3-4 will use to transmit TB1 (and potentially up to two retransmissions). Subsequently, UE3-1, 3-2, and 3-4 can transmit TB1 in S516-1 (e.g., using PSSCH) using the scheduled resource 500-1. A similar process is followed when another transport block (TB2) is generated in S510-2. Specifically, UE3-1, 3-2, and 3-4 send another scheduling request to base station 5 in S512-2 (e.g., on PUCCH) to request resource 500-2 for transmitting TB2. Base station 5 responds in S514-2 with downlink control information indicating resource 500-2 that UE3-1, 3-2, and 3-4 will use to transmit TB2 (and potentially retransmit up to two times). Subsequently, UE3 can transmit TB2 in S516-2 (e.g., using PSSCH) using the scheduled resource 500-2.

[0115] Figure 6 is a simplified sequence diagram showing an exemplary configured grant procedure that may be implemented in communication system 1.

[0116] As shown in Figure 6, in the illustrated example, a configured grant is used to transmit two TBs (TB1 and TB2). When UE3-1, 3-2, and 3-4 generate a transport block (TB1) in S610-1, UE3-1, 3-2, and 3-4 do not request resources as in the case of a dynamic grant, but wait until base station 5 provides UE3-1, 3-2, and 3-4 with a configured grant (CG) to use for transmitting data in S612-1 (e.g., using radio resource control (RRC) signaling). The CG defines a set of resources 600-1 that are periodically allocated to UE3. The CG is configured using a set of parameters, including the CG index, time-frequency resource allocation, and the periodicity of the allocated sidelink resources 600-1.

[0117] There are two possible CG types, namely CG type 1 and CG type 2, for a CG that can be used by base station 5 and UE3-1, 3-2, and 3-4. (As shown in S612-1) Both can be configured using RRC signaling. In the case of CG type 1, the resource 600-1 of the CG can be used immediately by UE3-1, 3-2, and 3-4 until the CG is released by base station 5 (also using RRC signaling). In the case of CG type 2, the resource 600-1 of the CG can only be used by UE3-1, 3-2, and 3-4 after the CG has been activated by base station 5 (e.g., using DCI signaling), as shown in S614-1. An activated type 2 CG remains active until it is deactivated (e.g., using DCI signaling). In this case, the activation / deactivation DCI may also include the CG index and time-frequency allocation for CG type 2. When a CG is received (or activated in the case of CG type 2), UE3-1, 3-2, and 3-4 may use scheduled resource 600-1 in S616-1 to transmit TB1 (for example, using PSSCH).

[0118] In S610-2, when another transport block (TB2) is generated, UE3-1, 3-2, and 3-4 wait until the CG period is complete (i.e., when resource 600-1 of the configured grant is effectively reallocated), and then in S616-2, they send the TB2 using the scheduled resource 600-1 (e.g., using PSSCH). The period configured for the CG may be adjusted to be equal to (or approximately equal to) the expected time between TBs based on the information provided by UE3-1, 3-2, and 3-4 (e.g., in UE support information).

[0119] The CG method reduces the time required to transmit two TBs compared to DG. However, the DG method may be more resource-efficient, especially when handling aperiodic traffic, because resources are allocated only when specifically needed for TB transmission.

[0120] Referring to Figure 7, which is an exemplary example of how each CG can be configured in communication system 1, CG type 2 can be used to configure multiple different CGs for UE3-1, 3-2, and 3-4. In the case of CG type 2, a subset of the configured CGs can be activated for UE3-1, 3-2, and 3-4 based on their requirements (while the resources of other inactive CGs can be allocated to other UEs). Multiple CGs can also be configured using CG type 1, but in this case, each UE must activate each CG at the time of its configuration. Thus, CG type 1 reduces the signaling and time required to initiate transmission compared to CG type 2, but if any of the multiple CG type 1 CGs are not used by a UE, their resources are not utilized by other UEs.

[0121] To support scheduling in network-managed resource allocation mode (mode 1), UE3-1, 3-2, and 3-4 can provide UE support information to base station 5. UE support information may include, for example, sidelink-related information that allows base station 5 to infer expected sidelink traffic characteristics. Typically, UE support information includes, for example, the periodicity of TBs in the sidelink, the maximum TB size, and quality of service information. QoS information may include, for example, KPIs such as latency and reliability required by TBs, as well as their priorities. Base station 5 can then use the UE support information to identify appropriate CGs that meet the expected future sidelink traffic requirements.

[0122] Base station 5 can use UE-assisted information to identify the CG for uplink communication that best matches the characteristics and requirements of the traffic on the air interface. UE-assisted information may also be used to improve sidelink UE-to-network (e.g., vehicle-to-network) communication, where sidelink communication and communication with base station 5 via the air interface share the same radio resources. Base station 5 can use UE-assisted information regarding sidelink traffic characteristics to, for example, schedule uplink transmissions to base station 5 and identify a suitable CG for uplink communication that minimizes interference with sidelink communication. UE-assisted information reported to base station 5 may include information for network-managed mode (mode 1) or autonomous mode (mode 2) sidelink scheduling. For example, UE-assisted information may include information about sidelink traffic (e.g., sidelink channel busy rate in the sidelink resource pool) and UE-related location / mobility information (e.g., location, speed). Base station 5 may, for example, use location information to determine, in network-managed resource allocation mode, that the same resources can be allocated to UEs because they are sufficiently far apart from each other (or to avoid allocating the same resources to relatively close UEs). In autonomous mode, sidelink scheduling and location / mobility information can be used, for example, to allocate the same resource pool to sidelink UEs that are close to each other.

[0123] Autonomous resource allocation / selection for sidelink communication Each of the sidelink UE3-1, 3-2, and 3-4 is also configured to operate in an autonomous resource selection mode (e.g., mode 2 resource selection) where UE3-1, 3-2, and 3-4 can autonomously select sidelink resources (one or more subchannels) from the resource pool (for example, when UE3-1, 3-2, and 3-4 are not within the coverage of base station 5). The autonomous allocation mode is now explained as a simple example, with reference to Figure 8, a simplified diagram illustrating how autonomous mode resource selection can operate in the telecommunications system of Figure 1.

[0124] Specifically, UE3-1, 3-2, and 3-4, when operating in autonomous resource selection mode, can autonomously select sidelink resources (one or more subchannels) from a resource pool (which may be pre-configured and / or configured by the base station when UE3-1, 3-2, and 3-4 are within network coverage). NR autonomous mode (mode 2) resource allocation supports dynamic scheduling and semi-persistent scheduling. When using the dynamic method, UE3-1, 3-2, and 3-4 can select a new resource per TB and reserve the resource only for future retransmissions of that TB (by notifying range UEs). The semi-persistent method can be enabled or disabled within a given resource pool by (pre)configuration. When UE3-1, 3-2, and 3-4 reserve resources for future transmissions, they use a physical sidelink control channel (PSCCH) to notify nearby ("adjacent") UEs using a first-stage SCI transmitted directly from one UE to another. When using the semi-persistent scheduling method, UE3-1, 3-2, and 3-4 can select and reserve resources for sending (and retransmitting) several TBs.

[0125] In autonomous mode (mode 2), the UE selects a new sidelink resource when generating a new TB. In the semi-persistent scheme, selection can also be triggered if the new TB is too large to be sent using a previously reserved resource.

[0126] More specifically, the upper layer (MAC) can request / trigger the determination / selection of a subset of resources in Layer 1 (L1 / physical layer), thereby enabling the MAC layer to make the final selection of resources for PSSCH / PSCCH transmission. To trigger this procedure in a given slot, the MAC layer requests the following parameters from L1 for PSSCH / PSCCH transmission, namely: - Resource pools where resources are reported, - Layer 1 (L1) priority prio TX , - Remaining packet delay budget (PDB), - Slot L subCH The number of subchannels used for PSSCH / PSCCH transmission within, and / or -(Optional) Resource reservation interval P rsvp_TX We can provide this. To determine / select a subset of sidelink resources (either dynamic or semi-persistent), UE3-1, 3-2, 3-4 first define a time interval (corresponding to a range of slots) called a selection window, which contains resources (called candidate resources) from which new sidelink resources will be selected for TB transmission.

[0127] When not transmitting, the UE performs a detection operation to identify available candidate resources. This detection operation takes place during a time interval called a detection window, which corresponds to a set of slots. In the detection process, the UE decodes the first-stage SCIs received from other UE3-1, 3-2, and 3-4 on the detected sidelink resources. Each first-stage SCI received from each UE3-1, 3-2, and 3-4 indicates the sidelink resources reserved for the retransmission of the TB associated with the first-stage SCI, and the resources reserved for the initial transmission and retransmission of the next TB. UE3-1, 3-2, and 3-4 also measure the transmissions associated with each first-stage SCI received from the other UE3-1, 3-2, and 3-4 (e.g., reference signal received power (RSRP)). UE3-1, 3-2, and 3-4 store the detected information (decoded first-stage SCI and RSRP measurements) and, based on the detected information, determine which candidate resources should be excluded from the selection window (and therefore which candidate resources can be selected) when a new selection is triggered.

[0128] When selecting a resource to be used for transmission from a selection window, the UE can use a two-step procedure. In the first step, UE3-1, 3-2, and 3-4 restrict the selectable candidate resources by excluding from the selection window any candidate resources that are reserved or candidate resources for which UE3-1, 3-2, and 3-4 cannot determine whether a reservation has been made. For example, UE3-1, 3-2, and 3-4 exclude candidate resources in the selection window that may not have received a corresponding reservation (for example, because UE3-1, 3-2, and 3-4 were transmitting at a time when the corresponding reservation would have been announced by another UE3-1, 3-2, and 3-4). UE3-1, 3-2, and 3-4 also exclude candidate resources reserved by other UE3-1, 3-2, and 3-4 in the corresponding first-stage SCI that were detected and decoded during the detection window, provided that the measured RSRP associated with the reservation exceeds a threshold and the traffic priority in the measured resource is compared with the traffic priority of UE3-1, 3-2, and 3-4. Specifically, UE3-1, 3-2, and 3-4 exclude resources whose measured RSRP is higher than the threshold, and treat resources as occupied if their traffic priority is higher than the UE's own traffic priority. Nevertheless, the UE can still select occupied resources whose associated traffic priority is lower than the traffic priority of UE3-1, 3-2, and 3-4. Therefore, higher-priority traffic can still occupy resources even if they are reserved by other UE3-1, 3-2, and 3-4 instances.

[0129] In the second step, after excluding the reserved resources from the selection window, UE3-1, 3-2, and 3-4 randomly select sidelink resources from the list of available candidate resources (i.e., the resources remaining after the exclusion step). UE3-1, 3-2, and 3-4 can, for example, randomly select 20% of the best resources having a measured RSRP smaller than a threshold configured (in advance) based on a specific percentage of the resources from the best set of the remaining resources and based on traffic priority. If the remaining resources after the exclusion procedure are less than a specific percentage (e.g., 20%) of all the resources within the selection window, UE3-1, 3-2, and 3-4 can relax the RSRP threshold until at least a specific percentage (e.g., 20% or 35% or 50% etc. based on traffic priority) of all the resources within the selection window is identified for resource allocation. The set of identified "unoccupied" resources is passed from the physical (PHY) layer to the MAC layer. Thus, the final selection of resources can be performed at the MAC layer upon receiving the set of unoccupied resources from the physical layer. Then, the selection of resources within the MAC layer can be made based on a random selection procedure.

[0130] The start T1 of the selection window is defined by referring to the time resource (slot) n at which a new resource (re)selection is triggered (and the selection of resources starts) and the processing time (in slot units) T required by UE3-1, 3-2, and 3-4 to identify candidate resources and select a new sidelink resource for transmission. proc、1 The end T2 (and thus the size) of the selection window (for the (re)selection trigger) depends on the implementation of the UE but must be smaller than the packet delay budget (PDB) in slot units.

[0131] The end of the detection window is the time resource (slot) n at which the next new resource (re)selection is triggered and the time (in slot units) T required to complete the detection procedure. proc、0This is defined by referring to (typically equal to 1 slot for 15 or 30 kHz SCS, and 2 or 4 slots for 60 or 120 kHz SCS). The start of the detection window (and therefore its size) is defined by referring to an integer T0 defined by the number of slots (n before the trigger). T0 depends on the SCS configuration (for example, having a value equivalent to 1100 ms or 100 ms in number of slots). The selected value may be determined based on the (pre)configuration of the resource pool.

[0132] Sidelink Communication Over Unlicensed Spectrum (SL-U) support The sidelink-enabled UE3-1, 3-2, and 3-4 of communication system 1 are also configured to provide support for sidelink communication over unlicensed spectrum (SL-U) based on the “listen-before-talk” (LBT) channel access mechanism, and the transmitting UE3-1, 3-2, and 3-4 are expected to perform some form of clear channel assessment (CCA), which typically includes “sensing” the medium to detect any transmissions from other nodes before obtaining channel occupancy time (COT) to transmit, if the channel is clear / available. CCA may include, for example, energy detection (i.e., measuring the received RSRP of any signal transmitted from other devices) and determining whether the channel is idle or busy based on the detected energy.

[0133] Specifically, transmitting UE3-1, 3-2, and 3-4 can support operation on the unlicensed spectrum by accessing a channel on which one or more transmissions are to be performed, using an appropriate LBT channel access procedure according to one of the Type 1 or Type 2 categories. A Type 1 LBT channel access procedure requires transmitting UE3-1, 3-2, and 3-4 to perform periodic channel detection. For a Type 2A channel access procedure, transmitting UE3-1, 3-2, and 3-4 can transmit immediately after detecting that the channel is idle for at least a detection interval of 25 μs. For a Type 2B channel access procedure, transmitting UE3-1, 3-2, and 3-4 can transmit immediately after detecting that the channel is idle for at least a detection interval of 16 μs. For a Type 2C channel access procedure, UE3-1, 3-2, and 3-4 can transmit without detecting the channel before transmission.

[0134] Communication system 1 supports the existing side-link autonomous mode (mode 2) resource allocation scheme as a baseline for resource allocation for SL-U. In this regard, in communication system 1, detection-based resource selection is triggered before LBT is triggered (however, it will be understood that in modified versions of communication system 1, detection-based resource selection may be triggered after LBT is triggered).

[0135] Furthermore, in the case of SL-U, a similar procedure is used to determine the CAPC of the sidelink data radio bearer (SL-DRB) or sidelink signalling radio bearer (SL-SRB), as is used in NR-U. Specifically, as initially described for NR-U, the PC5 QoS identifier (PQI) can be used to determine the CAPC mapping. In the case of SL-DRB, the CAPC value is (pre-configured) per DRB. For all SL-SRBs, the CAPC value is fixed to the highest priority (i.e., the lowest CAPC value). Similarly, for all SL MAC CEs, the CAPC value is fixed to the highest priority (i.e., the lowest CAPC value). In the case of PQI-based CAPC mapping, at least the PDB (and possibly other parameters) can be used as a criterion for determining the CAPC. Furthermore, in the case of unstandardized PQIs, the CAPC of a standardized PQI that best matches the QoS characteristics of the unstandardized PQI may be used. UE3-1, 3-2, 3-4 can determine the CAPC of a sidelink TB if the CAPC is not indicated in the DCI. If only one or more SL MAC CEs are included in the sidelink TB, the highest priority sidelink CAPC is used. If a sidelink control channel (SCCH) service data unit (SDU) is included in the sidelink TB, the highest priority sidelink CAPC is used.

[0136] Support for Multiple Consecutive Slots Transmission (MCSt) Furthermore, the sidelink-compatible UE3-1, 3-2, and 3-4 of communication system 1 are configured to support sidelink communication with multiple consecutive slots transmission (MCSt).

[0137] As described in more detail below, to support MCSt, autonomous mode (mode 2) resource selection is used, and the MAC layer of the transmitting UE3-1, 3-2, and 3-4 provides a single set of parameters to trigger the physical layer (layer 1 / L1) to report a subset of candidate multi-slot resources that may be selected for transmission. For single-slot resources, these parameters are, for example, the Layer 1 (L1) priority. TX , remaining packet delay budget (PDB), number of subchannels used for PSSCH / PSCCH transmission within the slot, L subCH , and / or resource reservation interval P rsvp_TX Includes.

[0138] Next, at the MAC layer, a multi-slot resource is (randomly) selected from a set of candidate multi-slot resources for initial transmission and retransmission of single or multiple TBs.

[0139] In this example of communication system 1, L1 is the candidate multi-slot resource set S A It reports a set of candidate multi-slot resources, each candidate multi-slot resource consisting of a set of temporally consecutive single-slot resources (in this example, all are the same L subCH (It has, but is not necessarily required.)

[0140] Advantageously, when providing a set of parameters to trigger the physical layer to report a subset of candidate multi-slot resources, if the data intended to be transmitted (TB or multiple TBs) is from multiple sidelink logical channels (LCHs) and / or sidelink MAC CEs, the priority parameter (prio) of the parameter set provided to L1 TX) is based on the highest priority among the LCH and / or MAC CE (or based on the lowest CAPC value associated with the LCH or MAC CE). Furthermore, to the advantage of the fact that the data (of one or more TBs) is from multiple sidelink logical channels and / or sidelink MAC CEs, the remaining PDBs in the parameter set provided to L1 are based on the lowest remaining PDB among the LCH and / or MAC CE. Priority parameter (prio) is based on the highest priority among the LCH and / or MAC CE TX It will be understood that the determination of ) and the determination of the remaining PDB parameters based on the lowest remaining PDB among LCH and / or MAC CE are independent of each other, and that either parameter determination method may be implemented independently of the other.

[0141] Advantageously, when L1 provides a set of candidate multi-slot resources, if the data to be sent cannot be hosted by the indicated candidate multi-slot resources, the MAC layer can instruct the physical layer to perform a new resource selection for the (remaining) data (the data intended to be sent). This instruction may be before or after the actual transmission of the data. On the other hand, if the data to be sent using the candidate multi-slot resources is insufficient in the buffer (e.g., an RLC buffer), additional candidate multi-slot resources may be dropped. Alternatively (or additionally), the MAC layer may perform different SL logical channel prioritization (LCP) procedures to allow UE3-1, 3-2, 3-4 to use additional candidate multi-slot resources (at least some of them) to send data to one or more different peer UE3-1, 3-2, 3-4. In this regard, it will be understood that, advantageously, unlike the legacy SL LCP procedure, the sending UE3-1, 3-2, and 3-4 do not need to select the destination UE3-1, 3-2, and 3-4 with the highest priority for that data transmission from among all the destination UE3-1, 3-2, and 3-4 where the data to be transmitted is pending; in other words, there are no such destination restrictions.

[0142] HARQ operation for MCSt The sidelink-enabled UE3-1, 3-2, and 3-4 of communication system 1 are also configured to support sidelink HARQ operation for MCSt (including in the context of SL-U).

[0143] Specifically, the sidelink-enabled UE3-1, 3-2, and 3-4 of communication system 1 must have at least one of the following: - Transmission via consecutive slots of MCSt groups associated with a single sidelink HARQ process, - Transmission via consecutive slots of MCSt groups divided into multiple sidelink HARQ processes, - HARQ initial transmission and / or retransmission within one MCSt group, and / or - Configured to support at least one of the following within a single MCSt group: feedback-based HARQ retransmission and / or blind retransmission.

[0144] Advantageously, as will be explained in more detail below, the MAC layers of UE3-1, 3-2, and 3-4 may be configured to provide the physical layer with instructions for the intended transmission pattern to guide its resource selection. Information indicating the transmission pattern may include, for example, instructions for one or more TBs for transmission, instructions for the HARQ transmission mechanism (e.g., feedback-based / blind retransmission, the number of sidelink HARQ processes used for the intended HARQ transmission, the number of blind retransmissions of TBs, etc.), and the number of slots occupied for blind retransmissions. Alternatively or additionally, the MAC layer may provide the physical layer with the overall size of the data based on the calculation of (re)transmissions of TBs that are expected to be transmitted by MCSt.

[0145] LBT failure handling As will be described in more detail below, the sidelink-enabled UE3-1, 3-2, and 3-4 of communication system 1 are also configured to implement one or more extended LBT failure handling mechanisms in the context of MCSt for SL-U.

[0146] Advantageously, with a single LBT failure handling mechanism, instead of the physical layer reporting the LBT failure, resource (re)selection is triggered as soon as the LBT failure first occurs (e.g., in the first slot of an MCSt slot group), and the physical layer does not provide the MAC layer with any indication of the LBT failure until UE3-1, 3-2, and 3-4 experience (and do experience) LBT failures for all slots within that MCSt slot group.

[0147] Alternatively, in another LBT failure handling mechanism, the physical layer provides the MAC layer with the advantage of indicating each LBT failure sequentially until an LBT succeeds (i.e., indicating multiple LBT failures if two or more LBT failures occur in consecutive slots). However, upon receiving an indication of an LBT failure, the MAC layer can adjust the planned transmission / retransmission of one or more TBs, taking into account one or more slots in the MCSt slot group where the LBT failure occurred, rather than simply triggering resource (re)selection.

[0148] In an alternative LBT failure handling mechanism, advantageously, the physical layer provides the MAC layer with a single LBT failure if there is an LBT failure in one or more slots in an MCSt slot group. The physical layer also provides the MAC layer with the one or more slots in which the UE experienced the LBT failure. However, as in the example above, upon receiving a notification of an LBT failure rather than simply triggering a resource (re)selection, the MAC layer can adjust the planned transmission / retransmission of one or more TBs, taking into account the one or more slots in the MCSt slot group where the LBT failure occurred.

[0149] Logical channel prioritization (LCP) and CAPC As mentioned above, MCSt transmissions carry the risk of potentially blocking lower CAPC level (i.e., higher priority) data. To help mitigate this risk, the sidelink-enabled UE3-1, 3-2, and 3-4 of communication system 1 are also configured to implement one or more enhanced mechanisms for LCP in the context of MCSt, based on the CAPC associated with the data provided via the corresponding LCH.

[0150] In one LCP mechanism, data with different CAPC levels is multiplexed into one or more TBs (at the MAC layer of the UE) for transmission using MCSt slot groups. In this example, preemption is not permitted during MCSt-based transmission even if data with a lower CAPC level (higher priority) arrives in the MCSt slot group.

[0151] Advantageously, in another LCP mechanism, data with the same CAPC level is multiplexed (at the MAC layer of the UE) into one of the TBs for transmission using an MCSt slot group. In this example, preemption is permitted during MCSt-based transmission when, for example, data with a lower CAPC level (higher priority) arrives in the MCSt slot group. During preemption, transmissions of higher CAPC levels (lower priority) in the preempted TB may be deferred. For example, the MAC layer may request the physical layer to perform resource selection (MCSt or single-slot resource) for such transmissions.

[0152] Advantageously, in an alternative LCP mechanism, during LCP at the MAC layer, only data with a specific range of (lower) CAPC levels can be multiplexed into one or more TBs for transmission using MCSt slot groups. Therefore, in this example, only certain high-priority data (corresponding to a specific range of (lower) CAPC levels) can be transmitted in the MCSt slot group. In this mechanism, if newly arriving data has a higher priority than all the data multiplexed in one or more TBs to be transmitted via the MCSt slot group, preemption is only possible during MCSt-based transmission. For example, if the data multiplexed in one or more TBs to be transmitted has a range of CAPC levels from CAPC 2 and CAPC 3, only newly arriving data with CAPC 1 can preempt its transmission.

[0153] User equipment Figure 9 is a schematic block diagram showing the main components of UE3 for communication system 1 shown in Figure 1. In this example, UE3 is a UE capable of performing sidelink communication.

[0154] As shown in the figure, UE3 has a transceiver circuit 31 that can operate to transmit signals to and receive signals from base station 5 via one or more antennas 33. UE3 includes a subscriber identity module (SIM), which can be implemented in any suitable way, for example, physically (e.g., as a universal integrated circuit card (UICC)) or virtually (e.g., as an embedded SIM (eSIM)). UE3 also has a controller 37 for controlling the operation of UE3. The controller 37 is associated with memory 39 and coupled to the transceiver circuit 31.

[0155] While not strictly necessary for UE3 to function, UE3 can, of course, have all the standard features of conventional UE3 (e.g., user interfaces such as touchscreens / keypads / microphones / speakers 35 to enable direct user control and interaction), which can be provided, as appropriate, by hardware, software, and firmware, one or any combination thereof. The software may be pre-installed in memory 39 and / or downloaded, for example, via a communication network or from a removable data storage device (RMD).

[0156] The SIM can store subscriber information and security information (such as the UE's international mobile subscriber identity (IMSI) and encryption keys), as well as UE preconfiguration information for preconfiguring UE3.

[0157] In this example, the controller 37 is configured to control the overall operation of the UE3 by program instructions or software instructions stored in memory 39. As illustrated, these software instructions include, in particular, the operating system 41, the communication control module 43, and the direct communication module 45.

[0158] The communication control module 43 is capable of controlling overall communication between the UE3 and one or more serving base stations 5 (as well as other communication devices connected to the base station 5, such as further UEs and / or core network nodes). The communication control module 43 handles, for example, the generation / transmission / reception of signaling messages and sidelink / uplink / downlink data packets between the UE3 and other nodes and devices. Signaling may include control signaling (e.g., by system information or RRC) related to UE positioning. It will be understood that the communication control module 43 may include several submodules ("layers" or "entities") to support specific functions. For example, the communication control module 43 may include a PHY submodule, MAC submodule, RLC submodule, PDCP submodule, IP submodule, RRC submodule, etc. The communication control module 43 is also responsible for the overall processing of uplink communications over relevant uplink channels (e.g., physical uplink control channel (PUCCH) and / or physical uplink shared channel (PUSCH)), including both dynamic signaling and quasi-static signaling (e.g., SRS). The communication control module 43 is also configured for the overall processing of receiving downlink communications over relevant downlink channels (e.g., physical downlink control channel (PDCCH) and / or physical downlink shared channel (PDSCH)), including both dynamic signaling and quasi-static signaling. The communication control module 43 is responsible for determining the resources that should be used by the UE3 in order to determine how frequency resources and / or slots / symbols are configured (e.g., for UL communications or DL ​​communications, etc.) and which one or more bandwidth portions are configured for the UE3.

[0159] The direct communication module 45 operates under the overall control of the communication control module 43 and is responsible for direct inter-UE (i.e., sidelink) communication. For example, direct inter-UE communication may be based on control information / configuration information received (e.g., via the communication control module 43) from base station 5 (e.g., in downlink control information (DCI) provided via PDCCH, RRC, or MAC signaling) or from other UEs 3 (e.g., in sidelink control information (SCI) provided via PSCCH or PSSCH, or in RRC signaling transmitted / transmitted via the PC5 interface (e.g., using PC5-RRC signaling)). Nevertheless, it will be understood that direct inter-UE communication may be based entirely or partially on configuration information obtained from the SIM (e.g., stored as UE preconfiguration information). The direct communication module 45 also plays a role in determining (shared and / or dedicated) resource pools and the relevant resources within those pools used by the UEs 3 for direct inter-UE communication, based on the control information / configuration information.

[0160] base station Figure 10 is a schematic block diagram showing the main components of a base station 5 for the communication system 1 shown in Figure 1. As shown, the base station 5 has a transceiver circuit 51 for transmitting signals to and receiving signals from communication devices (such as UE3) via one or more antennas 53 (such as an antenna array / large antenna), and a core network interface 55 (including, for example, N2, N3, and other reference points / interfaces) for transmitting signals to and receiving signals from network nodes in the core network 7. Although not shown, the base station 5 may also be coupled to other base stations via appropriate interfaces (such as the so-called "Xn" interface in NR). The base station 5 has a controller 57 for controlling the operation of the base station 5. The controller 57 is associated with memory 59. Software may be pre-installed in memory 59 and / or downloaded, for example, via the communication network 1 or from a removable data storage device (RMD). In this example, the controller 57 is configured to control the overall operation of the base station 5 by program instructions or software instructions stored in memory 59.

[0161] As shown in the figure, these software instructions include, in particular, an operating system 61, a communication control module 63, a direct communication management module 65, and a positioning module 67.

[0162] The communication control module 63 is operable to control communication between the base station 5, the UE3, and other network entities connected to the base station 5. The communication control module 63 is configured for overall control of receiving uplink communications over the relevant uplink channels (e.g., over the physical uplink control channel (PUCCH) and / or the physical uplink shared channel (PUSCH)), including both dynamic and quasi-static signaling. The communication control module 63 is also configured for overall processing of transmitting downlink communications over the relevant downlink channels (e.g., over the physical downlink control channel (PDCCH) and / or the physical downlink shared channel (PDSCH)), including both dynamic and quasi-static signaling.

[0163] The direct communication management module 65 is responsible for managing aspects of network control for direct UE-to-UE (i.e., sidelink) communication (for example, for an in-coverage UE, or for an out-of-coverage UE communicating with an in-coverage UE in a partial-coverage sidelink scenario). For example, the direct communication module 65 is responsible for managing transmit control information / configuration information for direct UE-to-UE communication to UE3 (for example, in downlink control information (DCI) provided in PDCCH, RRC, or MAC signaling) for relaying by the receiving UE to the out-of-coverage UE (for example, via the PC5 interface (e.g., PC5-RRC signaling)). The control information / configuration information may include, for example, information for configuring (shared and / or dedicated) resource pools and / or allocating relevant resources used by UE3 for direct UE-to-UE communication within those pools.

[0164] MCSt Resource Selection Here, we will refer to Figures 11 and 12 as a simple example to illustrate in more detail how the UE's MAC and physical layers can cooperate during MCSt resource selection for sidelink communication.

[0165] Figure 11 is a simplified sequence diagram showing the procedure for autonomous MCSt resource selection in communication system 1.

[0166] As seen in S1110 of Figure 11, the MAC layer can predict the size of the data for transmission. The size may be provided as an estimated size predicted based on information about the data in the buffer (e.g., the number of slots required for transmission, channel state, modulation and coding scheme (MCS), data transmission requirements, and / or similar). Then, in S1112, the MAC layer determines that the MAC layer is selecting MCSt resources (e.g., prio TX , remaining PDB, L subCH and / or P rsvp_TX Before providing any parameters (such as those mentioned above), the physical layer can be given instructions for the predicted size.

[0167] Next, in S1114, the MAC layer has a single set of parameters for MCSt resource selection in the physical layer (prio TX , remaining PDB, L subCH and P rsvp_TX The parameters can be determined and, in S1116, provided to the physical layer.

[0168] When providing a set of parameters to trigger the physical layer to report a subset of candidate multi-slot resources, if the data intended to be sent (one or more TBs) originates from multiple sidelink logical channels (LCHs) and / or sidelink MAC CEs, the priority parameter (prio) of the parameter set provided to the physical layer will be changed. TX) is based on the highest priority among the LCH and / or MAC CE (or based on the lowest CAPC value associated with the LCH or MAC CE). Furthermore, if the data (of one or more TBs) is from multiple sidelink logical channels and / or sidelink MAC CEs, the remaining PDBs in the parameter set provided to the physical layer are based on the lowest remaining PDB among the LCH and / or MAC CE. Nevertheless, the priority parameter (prio) is based on the highest priority among the LCH and / or MAC CE. TX It will be understood that the determination of ) and the determination of the remaining PDB parameters based on the lowest remaining PDB in LCH and / or MAC CE are independent of each other, and that any parameter determination method can be implemented independently of each other.

[0169] On the other hand, if the data (of one or more TBs) is from a single sidelink logical channel and / or sidelink MAC CE, the parameters of the parameter set provided to the physical layer (prio TX ) and the remaining PDBs are mapped to their respective SL logical channels or MAC CEs.

[0170] Upon receiving a single parameter set in S1116, the physical layer of the UE can perform autonomous resource selection based on that single parameter set in S1118 (for example, in the same manner as described above with reference to Figure 8). Then, in S1120, the physical layer reports the selected set of candidate multi-slot resources to the MAC layer of the UE3.

[0171] In this example of communication system 1, the physical layer reports a set of candidate multislot resources as a candidate multislot resource set SA, and each candidate multislot resource consists of a set of temporally consecutive single-slot resources.

[0172] Next, at the MAC layer, a multi-slot resource may be (randomly) selected from a set of candidate multi-slot resources for initial transmission and retransmission of a single TB or multiple TBs.

[0173] Figure 12 is a simplified sequence diagram showing the steps that may be performed following the autonomous selection of a candidate set of MCSt resources in communication system 1.

[0174] As shown in Figure 12, at S1220, the physical layer reports the selected (or re-selected) set of candidate multi-slot resources to the MAC layer of UE3. These resources may be selected using a procedure similar to, or different from, the procedure described with reference to Figure 11, for example.

[0175] MAC then generates one or more MAC protocol data units (PDUs) to be transmitted as one or more TBs based on the candidate multi-slot resources in S1222, and then performs the associated (HARQ) transmission.

[0176] If the physical layer provides a set of candidate multi-slot resources, and the indicated candidate multi-slot resources are insufficient for the full transmission of the data to be sent, the MAC layer (in S1224) instructs the physical layer to perform a new resource selection for the (remaining) data (intended for transmission). This may or may not occur before the actual transmission of the data in S1222, or it may occur after the actual transmission of the data.

[0177] On the other hand, as seen in S1226, if the data in a buffer (e.g., an RLC buffer) that should be sent using a candidate multislot resource is insufficient, additional candidate multislot resources may be dropped. Alternatively (or additionally), the MAC layer may perform different SL logical channel prioritization (LCP) procedures to allow a UE to use at least some of the additional candidate multislot resources to send data to one or more different peer UEs. In this regard, it will be understood that, advantageously, unlike the legacy SL LCP procedure, the sending UE does not need to select the highest priority destination UE for sending that data from among all the destination UEs for which the data to be sent is pending; i.e., there are no such destination restrictions.

[0178] HARQ operation for MCSt The MAC and physical layers of the UE can cooperate during MCSt resource selection for sidelink communication to support MCSt sidelink HARQ operation (including in the context of SL-U), as can be seen in Figures 13-18, which will be described in more detail as just an example.

[0179] Figure 13 is a simplified sequence diagram illustrating the procedure for supporting autonomous MCSt resource selection in the context of HARQ operation, which may be performed in communication system 1.

[0180] As seen in S1310, the MAC layers of UE3-1, 3-2, and 3-4 can provide the physical layer with instructions for the intended transmission pattern. Information indicating the transmission pattern may include, for example, instructions for one or more TBs for transmission, instructions for the HARQ transmission mechanism (e.g., feedback-based / blind retransmission, the number of sidelink HARQ processes used for the intended HARQ transmission, the number of blind retransmissions of TBs, etc.), and slots to be occupied for blind retransmissions.

[0181] As seen in S1312, alternatively or additionally, the MAC layers of UE3-1, 3-2, and 3-4 can provide the physical layer with an indication of the estimated total size of data to be transmitted, calculated taking into account the retransmission of TB intended for transmission via the MCSt slots.

[0182] Upon receiving information from the MAC layer, the UE's physical layer can then perform autonomous resource selection based on the information in S1318. The physical layer then reports the selected set of candidate multi-slot resources to the UE3's MAC layer in S1320.

[0183] Although the information elements provided in S1310 and S1312 are shown as being provided separately for simplicity, it will be understood that (if both information elements are provided) the information may be provided together. It will also be understood that one or more information elements may be provided as part of a procedure similar to the one described with reference to Figure 11.

[0184] Figures 14 to 18 show several different ways in which HARQ process-based transmission can be performed in communication system 1 for a given set of MCSt slots.

[0185] Referring to Figure 14, this is a simplified diagram illustrating several different ways in which HARQ process-based transmission with HARQ feedback disabled may be performed in communication system 1.

[0186] As shown in Figure 14, in each of the illustrated examples, TB(re)transmission is performed on a selected SL-U resource in an MCSt slot group containing six consecutive slots (slots #2 through #7), using only a single HARQ process. This is purely illustrative, and it should be understood that any appropriate number of consecutive slots may be reported by the physical layer.

[0187] In the example (a) shown in Figure 14, multiple different TBs (6 in this example) are transmitted independently in the slot selected for MCSt, with different TBs (TB#1 to TB#6) being transmitted in each slot. This maximizes the number of individual TBs that can be transmitted to a given MCSt slot group.

[0188] In example (b) shown in Figure 14, as in example (a), multiple different TBs are transmitted independently in the slot selected for MCSt. However, in this example, the initial transmission and subsequent blind retransmission of each TB are performed in a combined slot set containing a subset of consecutive time resources from within the MCSt slot group. For illustrative purposes, in the illustrated example, TB#1 is transmitted in a combination of three consecutive slots (slots #2 to #4) in the MCSt slot group, and then blindly retransmitted. Subsequently, TB#2 is transmitted in a combination of three consecutive slots (slots #5 to #7) in the MCSt slot group set following the slot previously used for (re)transmission, and then blindly retransmitted.

[0189] Example (b) shows that one or more TBs are transmitted and blind retransmitted, and each (re)transmit of a TB has a different associated redundancy version (RV). The MAC layer can indicate to the physical layer the RVs and slots used for planned initial transmissions and blind retransmits within the SL HARQ process. Specifically, based on the configuration of the blind retransmit numbers, after the MAC PDU is generated, the MAC layer can provide the physical layer with instructions for the slots selected by the MAC layer within the MCSt slot group to command transmission.

[0190] In example (c) shown in Figure 14, as in example (a), multiple different TBs are transmitted independently in the slot selected for MCSt. However, in this example, the size of each TB is not limited to the size that can be transmitted within a single slot. Instead, relatively large TBs (e.g., too large to be transmitted in a single slot) can be transmitted using a combined slot set that includes a subset of consecutive slots from within the slot selected for MCSt. For example, in the illustrated example, TB#1 is a very large TB (requiring the resources of four slots for full transmission) transmitted using a combination of four consecutive slots (slots #2-#5) in the MCSt slot group. TB#2, on the other hand, is smaller than TB#1 but still relatively large and requires the resources of two consecutive slots (slots #6-#7) for full transmission. While this example has the advantage of enabling the transmission of very large TBs, it introduces complexity in the context of retransmission (e.g., blind retransmission).

[0191] Figure 15 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in communication system 1.

[0192] As shown in Figure 15, a single TB transmission is performed on a selected SL-U resource in an MCSt slot group containing six consecutive slots (slots #2 through #7), using only a single HARQ process. This is purely illustrative, and it should be understood that any appropriate number of consecutive slots may be reported by the physical layer.

[0193] Specifically, in the illustrated example, a single (very large) TB (TB#1) is transmitted through a combined slot set that includes all slots in the MCSt slot group (however, smaller TBs can only be transmitted through a portion of the MCSt slot group, i.e., a combined subset of consecutive slots from within the MCSt slot group). In this example, HARQ feedback can be either disabled or enabled.

[0194] Figure 16 is a simplified diagram illustrating another method in which HARQ process-based transmission may be performed in communication system 1.

[0195] As shown in Figure 16, a single TB transmission is performed on a selected SL-U resource in an MCSt slot group containing six consecutive slots (slots #2 through #7), using only a single HARQ process. This is purely illustrative, and it should be understood that any appropriate number of consecutive slots may be reported by the physical layer.

[0196] Specifically, in the illustrated example, a single (very large) TB (TB#1) is sent by the transmitting UE to the peer UE via a combined slot set that, in this example, includes a subset of five slots from the MCSt slot group.

[0197] In this example, HARQ feedback is enabled, and the last slot in the MCSt slot group is used for HARQ feedback on the peer UE. In the context of SL-U, this represents a portion of the channel occupancy time (COT) taken by the sending UE to send a TB shared with the peer UE, allowing the peer UE to send HARQ feedback (and / or other transmissions) without requiring the peer UE to perform LBT.

[0198] This example demonstrates support for sending a single TB across a portion of an MCSt slot group. During transmission, the sending UE sends appropriate COT sharing information (e.g., identifying shared slots) for HARQ feedback (HARQ NACK / ACK) from the peer UE and / or for one or more other transmissions from the peer UE to the sending UE.

[0199] Therefore, the peer UE can provide appropriate feedback (HARQ NACK / ACK) to the sending UE via the indicated slot. Alternatively (or additionally), the peer UE can use shared COT resources to perform data transmission to the sending UE.

[0200] Figure 17 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in communication system 1.

[0201] As shown in Figure 17, multiple TBs are transmitted interleaved using a selected SL-U resource in an MCSt slot group containing two contiguous slots (slot #2 and slot #3), each using a different HARQ process for each TB. This is purely illustrative, and it should be understood that any appropriate number of contiguous slots may be reported by the physical layer.

[0202] Specifically, in the illustrated example, one TB (TB#1) is sent using the first slot (slot#2) of the MCSt slot group as part of the first HARQ process, and another TB (TB#2) is sent using the second slot (slot#3) of the MCSt slot group as part of the second HARQ process.

[0203] More specifically, in this example, the MAC layer can trigger the physical layer to perform resource selection for MCSt using a single parameter set, and the physical layer reports all candidate consecutive slots to the MAC layer (for example, as mentioned above). The MAC layer can then generate multiple TBs for the same destination UE, for example, based on the data in (RLC) buffers having the same priority (ProSe Per-Packet Priority (PPPP)). The MAC layer can generate multiple TBs to send TBs in an interleaved manner using multiple HARQ processes during feedback-based HARQ retransmission, as illustrated. In the illustrated example, it will be understood that it is assumed that acknowledgments are received for all initial transmissions (meaning no retransmission is needed).

[0204] Figure 18 is a simplified diagram illustrating another possible method by which HARQ process-based transmission can be performed in communication system 1.

[0205] As shown in Figure 18, multiple TBs are transmitted and blindly retransmitted using a selected SL-U resource in an MCSt slot group containing six consecutive slots (slots #2 to #7), each using a different HARQ process for each TB. This is purely illustrative, and it should be understood that any appropriate number of consecutive slots may be reported by the physical layer.

[0206] Specifically, in the illustrated example, one TB (TB#1) is initially sent using the first slot (slot #2) of the MCSt slot group as part of the first HARQ process, and another TB (TB#2) is sent using the second slot (slot #3) of the MCSt candidate resource set as part of the second HARQ process. The blind retransmission of the first TB (TB#1) is then performed in subsequent slots (slots #4 and #6) of the MCSt slot group in a manner interleaved with the blind retransmission of the second TB (TB#2), and the second TB (TB#2) is performed in other subsequent slots (slots #5 and #7) of the MCSt slot group.

[0207] Nevertheless, in the illustrated example, the initial transmission and retransmission of the first TB are interleaved with the initial transmission and retransmission of the second TB, but it will be understood that this is not necessary. For example, the initial transmission and retransmission of the first TB may be performed in one subset of consecutive slots (e.g., slots #2 to #4), and the initial transmission and retransmission of the second TB may be performed in subsequent subsets of consecutive slots (e.g., slots #5 to #7) to mimic the repetition of the TB.

[0208] Therefore, in this example, we can see that the MAC layer can generate multiple different TBs and transmit them in a manner that is interleaved (or consecutive) during HARQ blind retransmission, using different HARQ processes.

[0209] LBT failure handling A method by which LBT failure handling can be implemented in communication system 1 for MCSt will be described in more detail below with reference to Figures 19-21, as merely an example.

[0210] Figure 19 is a simplified sequence diagram showing several different LBT failure handling mechanisms that may be used in communication system 1.

[0211] As shown in Figure 19, in one LBT failure handling mechanism, LBT is performed in each slot of the MCSt slot group until it succeeds, or until LBT fails in each slot of the MCSt slot group. If LBT fails in all slots of the MCSt slot group, the physical layer provides the MAC layer with an indication of LBT failure, except as shown in S1910.

[0212] As shown in Figure 19, in another LBT failure handling mechanism, the LBT is executed in each slot of the MCSt slot group until it succeeds or until the LBT fails in all slots of the MCSt slot group. However, this mechanism is advantageous in that the physical layer provides the MAC layer with sequential notification of each LBT failure (i.e., if two or more LBT failures occur in consecutive slots, it provides notification of multiple LBT failures) until the LBT succeeds or the LBT fails in all slots of the MCSt slot group. Upon receiving notification of an LBT failure, the MAC layer can adjust the planned transmission / retransmission of one or more TBs, taking into account one or more slots in the MCSt slot group where the LBT failure occurred in S1916, based on its knowledge of one or more remaining slots in the MCSt slot group. For example, the initial transmission of a TB may be delayed until a subsequent slot / consecutive slot in the MCSt slot group (where the LBT succeeded). Similarly, the number of planned blind retransmissions may be reduced by the LBT failure of one or more slots in the MCSt slot group.

[0213] As shown in Figure 19, in another LBT failure handling mechanism, LBT is performed in each slot of the MCSt slot group until it succeeds or until LBT fails in all slots of the MCSt slot group. However, in this mechanism, if there is an LBT failure in one or more slots of the MCSt slot group, advantageously, the physical layer provides the MAC layer with a single LBT failure. The physical layer also provides the one or more slots in which the UE experienced the LBT failure. As in the example above, upon receiving the indication of an LBT failure, the MAC layer can adjust the planned transmission / retransmission of one or more TBs, taking into account the one or more slots in the MCSt slot group where the LBT failure occurred in S1916, based on its knowledge of the one or more remaining slots in the MCSt slot group. For example, the initial transmission of a TB may be delayed until a subsequent slot / sequential slot in the MCSt slot group (where the LBT was successful). Similarly, the number of planned blind retransmissions may be reduced by the LBT failure in one or more slots in the MCSt slot group.

[0214] Figures 20 and 21 show, respectively, examples of how one or more LBT failures within an MCSt slot group can affect TB(re)transmissions.

[0215] In the example in Figure 20, the MAC layer planned to independently transmit multiple different TBs (6 TBs in this example) in each slot of the MCSt slot group (slots #2 to #7), each being a different TB (TB #1 to TB #6 in this example). However, LBT failures occur in the transmissions in slots #2 and #3. Therefore, the MAC layer transmission adjusts the planned transmission of one or more TBs, taking into account one or more slots in the MCSt slot group where the LBT failure occurred (as described, for example, in step S1916 in Figure 19), delaying the transmission of the previous TBs (TB #1 to TB #4 in this example) until the subsequent slots (slots #4 to #7) of the MCSt slot group. The subsequent TBs are dropped from the transmission within the current MCSt slot group (and may be delayed and transmitted on newly selected (MCSt) resources).

[0216] In the example in Figure 21, the MAC layer planned to transmit a single TB (TB#1) in the first slot (slot #2) of the MCSt slot group (slots #2 to #7), and then blind retransmit the same TB in each of the remaining slots in the MCSt slot group. However, LBT failures occur in the transmissions in slots #2 and #3. Therefore, the transmitting MAC layer adjusts the planned transmission / retransmission of the TB to account for one or more slots in the MCSt slot group where the LBT failure occurred (for example, as described in step S1916 in Figure 19), reducing the number of planned blind retransmissions, with subsequent blind retransmissions simply being dropped. Alternatively, some of the blind retransmissions may be delayed (for example, they may be delayed in the newly selected (MCSt) resource).

[0217] In the context of LBT, it will be understood that one of the advantages of MCSt transmission is that it reduces the occurrence (and therefore the duration) of Type 1 LBT durations, and thus improves transmission efficiency.

[0218] If LBT is successful for one or more slots (but not all) of an MCSt slot group, and therefore at least one or more associated TB(re)transmissions are dropped due to one or more LBT failures (for example, as a result of delaying one or more previous (re)transmissions), then resource(re)selection is triggered from the MAC layer to the physical layer to acquire resources for such dropped transmissions.

[0219] Furthermore, to further leverage the advantages of MCSt transmission, if the MAC layer receives an LBT failure report, the MAC layer can instruct the physical layer to reselect a contiguous resource (slot) within the MCSt slot group for such a drop (re)transmission resulting from the LBT failure.

[0220] Examples of changes and alternatives Detailed examples, along with several variations and alternatives, are provided above. As those skilled in the art will understand, several modifications and alternatives can be made to the above examples, but there are still benefits to the disclosures embodied therein.

[0221] For the sake of clarity, the above description assumes that the UE and base station have several separate functional components or modules. While such modules may be provided in a particular application, for example, in an application where an existing system is modified to implement the Disclosure, they may not be identified as separate entities because they can be incorporated into the overall operating system or code in other applications, for example, in a system designed from the outset with the features of the Invention in mind.

[0222] In the embodiments described above, several software modules have been explained. As those skilled in the art will understand, the software modules may be provided in compiled or uncompiled form and may be supplied to a base station, mobility management entity, or UE as a signal over a computer network or as a signal on a recording medium. Furthermore, some or all of the functions performed by this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred because it facilitates their updates for updating the functions of the base station or UE.

[0223] Each controller may include any suitable form of processing circuitry, including (but not limited to) one or more hardware-implemented computer processors, microprocessors, central processing units (CPUs), arithmetic logic units (ALUs), input / output (IO) circuits, internal memory / cache (programs and / or data), processing registers, communication buses (such as control buses, data buses, and / or address buses), direct memory access (DMA) functions, hardware or software-implemented counters, pointers, and / or timers. Various other modifications will be obvious to those skilled in the art and will not be described in further detail here.

[0224] A base station may comprise a “distributed” base station having a central unit (CU) and one or more individual distributed units (DU).

[0225] In this disclosure, User Equipment (or “UE,” “Mobile Station,” “Mobile Device,” or “Radio Device”) is an entity connected to a network via a radio interface.

[0226] Please note that this disclosure is not limited to dedicated communication devices, but can be applied to any device having communication functions as described in the following paragraphs.

[0227] The terms "User Equipment" or "UE," "Mobile Station," "Mobile Device," and "Radio Device" (terms used in 3GPP) are generally intended to be synonymous with each other and include standalone mobile stations such as terminals, cell phones, smartphones, tablets, cellular IoT devices, IoT devices, and machines. The terms "Mobile Station" and "Mobile Device" will also be understood to include devices that remain stationary for extended periods.

[0228] For example, UE can be items of equipment or machinery for production or manufacture (such as boilers, engines, turbines, solar panels, wind turbines, hydroelectric generators, thermal generators, nuclear generators, batteries, nuclear systems and / or related equipment, heavy electrical machinery, pumps including vacuum pumps, compressors, fans, blowers, hydraulic equipment, pneumatic equipment, metalworking machinery, manipulators, robots and / or their application systems, tools, molds or dies, rolls, conveying equipment, elevators, material handling equipment, textile machinery, sewing machinery, printing and / or related machinery, paper conversion machinery, chemical machinery, mining machinery and / or construction machinery and / or related equipment, machinery and / or equipment for agriculture, forestry and / or fisheries, safety and / or environmental protection equipment, tractors, precision bearings, chains, gears, power transmission equipment, lubrication equipment, valves, pipe fittings and / or application systems for any of the aforementioned equipment or machinery, etc.) and / or items of energy-related machinery.

[0229] For example, UE may be an item of transport equipment (such as transport equipment such as railway cars, automobiles, motorcycles, bicycles, trains, buses, carts, rickshaws, ships and other vessels, aircraft, rockets, satellites, drones, balloons, etc.).

[0230] For example, a UE may be an item of information and communication equipment (such as electronic computers and related equipment, communication and related equipment, electronic components, etc.).

[0231] For example, UE may be refrigerators, refrigerator applications, commercial and / or service industry equipment items, vending machines, automated service machines, office machines or equipment, and household appliances and electronic devices (such as audio equipment, video equipment, loudspeakers, radios, televisions, microwave ovens, rice cookers, coffee machines, dishwashers, washing machines, dryers, electronic fans or related equipment, vacuum cleaners, etc.).

[0232] For example, UE may be an electrical application system or device (such as an X-ray system, particle accelerator, radioisotope equipment, sound wave equipment, electromagnetic application equipment, power application equipment, etc.).

[0233] For example, UE may be electronic lamps, lighting fixtures, measuring instruments, analyzers, testers, or measuring or detection equipment (such as smoke detectors, human alarm sensors, motion sensors, wireless tags, etc.), watches or clocks, laboratory equipment, optical devices, medical devices and / or systems, weapons, cutlery items, hand tools, etc.

[0234] For example, the UE may be a wireless-equipped personal digital assistant or related device (such as a wireless card or module designed to be attached to or inserted into another electronic device, such as a personal computer or electrical measuring instrument).

[0235] The UE may be part of a device or system that uses various wired and / or wireless communication technologies to provide the following applications, services, and solutions related to the Internet of Things (IoT).

[0236] Internet of Things (IoT) devices (or "Things") can be equipped with appropriate electronics, software, sensors, network connectivity, etc., that enable them to collect and exchange data with each other and with other communication devices. IoT devices can include automated devices that follow software instructions stored in internal memory. IoT devices can operate without requiring human command or interaction with humans. IoT devices can also remain stationary and / or inactive for extended periods. IoT devices can be implemented as part of (generally) stationary devices. IoT devices can also be integrated into non-stationary devices (e.g., vehicles) or attached to animals or people being monitored / tracked.

[0237] IoT technology can be understood as being implemented on any communication device that can connect to a communication network to send / receive data, regardless of whether such communication devices are controlled by human input or by software instructions stored in memory.

[0238] It will be understood that IoT devices are sometimes called Machine-Type Communication (MTC) devices or Machine-to-Machine (M2M) communication devices. It will be understood that a UE can support one or more IoT or MTC applications. Several examples of MTC applications are listed in the table below. This list is not exhaustive and is intended to illustrate several examples of machine-type communication applications. [Table 2]

[0239] Applications, services, and solutions may include Mobile Virtual Network Operator (MVNO) services, emergency radio communication systems, Private Branch eXchange (PBX) systems, PHS / digital cordless telecommunications systems, Point of Sale (POS) systems, incoming advertising systems, Multimedia Broadcast and Multicast Service (MBMS), Vehicle to Everything (V2X) systems, train radio systems, location-related services, disaster / emergency radio communication services, community services, video streaming services, femtocell application services, Voice over LTE (VoLTE) services, billing services, wireless on-demand services, roaming services, activity monitoring services, telecommunications carrier / communication network selection services, function restriction services, Proof of Concept (PoC) services, personal information management services, ad hoc network / delay-tolerant networking (DTN) services, and others.

[0240] Furthermore, the aforementioned UE categories are merely examples of applications of the technical concepts and exemplary embodiments described in this document. Needless to say, these technical concepts and embodiments are not limited to the aforementioned UEs and are subject to various modifications.

[0241] Various other examples of modifications will be obvious to those skilled in the art and will not be described in further detail here.

[0242] For example, all or part of the exemplary embodiments disclosed above may be described, but are not limited to, as follows: (Note 1) A method performed by the first user equipment (UE), To provide information from the first protocol layer to the second protocol layer for use in selecting resources to transmit data using direct inter-UE communication across multiple consecutive time resources, The first protocol layer receives information from the second protocol layer indicating a set of candidate resources for direct inter-UE communication across multiple consecutive time resources, selected based on the information, This includes, in multiple consecutive time resources, using at least a subset of candidate resources to send data to a second UE via direct UE-to-UE communication, The information must be at least one of the following: At least one parameter associated with the autonomous mode of resource selection, where the data includes data from each of several different data sources, each parameter of the at least one parameter is based on a corresponding attribute associated with data from one of the several different data sources, Transmission pattern information identifying at least one intended transmission pattern for sending data via direct UE-to-UE communication, and / or A method comprising size information indicating the estimated total size of data to be transmitted, wherein the estimated total size is based on both the initial transmission of the data and any intended retransmission of the data, the size information comprising at least one of these. (Note 2) The method according to Appendix 1, wherein if the information includes at least one parameter, at least one parameter includes a priority parameter indicating a second protocol layer priority. (Note 3) If the data includes data from each of several different data sources, the priority parameter indicating the priority of the second protocol layer is based on the corresponding priority-associated attribute associated with the data from the data source with the highest associated priority among the several different data sources, as described in Appendix 2. (Note 4) The corresponding priority-related attribute associated with data from a data source is the channel access priority class (CAPC), and the priority parameter is based on the CAPC associated with the data source with the lowest associated CAPC among several different data sources, as described in Appendix 3. (Note 5) The method described in any one of the appendices 1 to 3, wherein if the information includes at least one parameter, at least one parameter includes a packet delay budget (PDB) parameter indicating the remaining PDBs. (Note 6) If the data includes data from each of several different data sources, the method described in Appendix 5, wherein the PDB parameter is based on the corresponding PDB-related attribute associated with the data from the data source, with the remaining PDBs among the several different data sources having the lowest value. (Note 7) If the data includes data from each of several different data sources, the method described in any one of the appendices 1 to 6 includes at least one direct inter-UE media access control (MAC) control element (CE). (Note 8) If the data includes data from each of several different data sources, the method described in any one of the appendices 1 to 7 includes at least one direct inter-UE logical channel (LCH) between the data sources. (Note 9) The method described in any one of the appendices 1 to 8, wherein the data contains more data than could be transmitted using a set of candidate resources, the first protocol layer includes triggering a second protocol layer to perform a further selection of resources for transmitting at least a portion of the data. (Note 10) The method according to any one of Appendices 1 to 9, comprising dropping at least a subset of the resources not required for data transmission when the set of candidate resources includes more resources than the resources required for data transmission. (Appendix 11) The method according to any one of Appendices 1 to 10, comprising performing logical channel prioritisation (LCP) procedures for further transmitting data or additional data to at least one additional UE via direct inter-UE communication, using at least a subset of the resources not required for data transmission to the second UE, when the set of candidate resources includes more resources than the resources required for data transmission. (Appendix 12) When the information includes transmission pattern information, the transmission pattern information includes at least one of the following, namely an indication of the number of transport blocks (TBs) for data transmission, an indication of the hybrid automatic repeat request (HARQ) transmission mechanism, and / or the number of slots to be occupied for blind retransmission, and is the method according to any one of Appendices 1 to 11. (Appendix 13) When the transmission pattern information includes an indication of the HARQ transmission mechanism, the indication of the HARQ transmission mechanism includes at least one of the following, namely whether the HARQ transmission mechanism is feedback-based or blind retransmission-based, the number of direct UE-to-UE HARQ processes to be used for the intended HARQ transmission, and / or the number of blind retransmissions for at least one TB, and is the method according to Appendix 12. (Appendix 14) Data is transmitted to a second UE in a plurality of different transport blocks (TBs) using a common hybrid automatic repeat request (HARQ) process, and each TB is transmitted using a different respective time resource of a plurality of consecutive time resources, according to the method described in any one of Appendices 1 to 13. (Appendix 15) Data is transmitted to a second UE in at least one transport block (TB) using a common hybrid automatic repeat request (HARQ) process, and at least one TB is transmitted using two or more time resources of a plurality of consecutive time resources, according to the method described in any one of Appendices 1 to 13. (Appendix 16) Data is transmitted to a second UE in at least one transport block (TB) using a common hybrid automatic repeat request (HARQ) process, and at least one TB is transmitted in a first time resource of a plurality of consecutive time resources and then retransmitted in at least one further time resource of a plurality of consecutive time resources, according to the method described in any one of Appendices 1 to 13. (Appendix 17) The method according to Appendix 16, including providing an indication of at least one of a redundant version and / or the time resources used for the transmission and / or each retransmission of the TB from a first protocol layer to a second protocol layer. (Appendix 18) Data is transmitted to a second UE in a single transport block (TB) using a hybrid automatic repeat request (HARQ) process, and the single TB is transmitted using at least one time resource of a plurality of consecutive time resources, according to the method described in any one of Appendices 1 to 13. (Appendix 19) The method according to Appendix 18, comprising receiving at least one of HARQ feedback and / or data transmission from a second UE in at least one other time resource among a plurality of consecutive time resources. (Note 20) The method described in Appendix 19, wherein at least one other time resource forms at least a portion of the shared channel occupancy time (COT). (Note 21) The method described in Appendix 20, which includes sending COT shared information indicating at least one other time resource to a second UE. (Note 22) The data is sent to the second UE in multiple transport blocks (TBs), each TB being sent using a different hybrid automatic repeat request (HARQ) process, as described in any one of the appendices 1 through 13. (Note 23) The method described in Appendix 22, wherein each TB is transmitted over a different time resource among a plurality of consecutive time resources. (Note 24) The method according to Appendix 22 or 23, wherein each TB carries data having the same priority. (Note 25) The data is transmitted using a feedback-based HARQ retransmission mechanism as described in Appendix 22, 23, or 24. (Note 26) The data is transmitted using a blind retransmission-based HARQ retransmission mechanism, and each TB is retransmitted on a different time resource among multiple consecutive time resources, as described in Appendix 22, 23, or 24. (Note 27) The method as described in Appendix 26, wherein a first TB of multiple TBs is transmitted and blind-retransmitted across multiple consecutive time resources in a manner interleaved with the transmission and blind-retransmission of a second TB of multiple TBs. (Note 28) The method as described in Appendix 26, wherein a first TB of multiple TBs is transmitted and blind-retransmitted in a contiguous time resource among multiple contiguous time resources, and a second TB of multiple TBs is transmitted and blind-retransmitted in a contiguous time resource among multiple contiguous time resources. (Note 29) The method described in any one of the appendices 1 to 28, wherein the first protocol layer is the media access control (MAC) layer. (Note 30) The method described in any one of the appendices 1 to 29, wherein the second protocol layer is the physical (PHY / L1) layer. (Note 31) A method performed by the first user equipment (UE), The first protocol layer receives information from the second protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across multiple consecutive time resources, This includes, in multiple consecutive time resources, using at least a subset of candidate resources to send data to a second UE via direct UE-to-UE communication, If the data contains more data than can be sent using the candidate resource set, the first protocol layer triggers the second protocol layer to perform further selection of resources for sending at least a portion of the data. If the set of candidate resources contains more resources than are needed to send the data, Drop at least a subset of resources that are not required for data transmission, and / or A method comprising performing a logical channel prioritization (LCP) procedure for the further transmission of data or further data to at least one further UE via direct inter-UE communication, using at least a subset of resources not required for the transmission of data to a second UE. (Note 32) The method according to Appendix 31, wherein at least one additional UE is selected as at least one destination UE for further transmission, regardless of whether the priority associated with at least one additional UE is higher than the priority associated with another potential destination UE. (Note 33) A method performed by the first user equipment (UE), The first protocol layer receives information from the second protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across multiple consecutive time resources, The process involves sequentially executing each listen-before-talk (LBT) for each time resource in a group of consecutive time resources until the LBT results for the corresponding time resources in the group indicate that data transmission can begin at the corresponding time resources, or until each LBT fails at all time resources in the group of consecutive time resources. The present invention provides that if at least one LBT fails for a corresponding time resource among a plurality of consecutive time resources, the second protocol layer indicates at least one LBT failure to the first protocol layer, Demonstrating at least one LBT failure is, Each LBT represents a single LBT failure provided when any of the time resources among multiple consecutive time resources fail. To indicate each LBT failure provided to each LBT that has failed for a corresponding time resource among multiple consecutive time resources, or A method comprising indicating an LBT failure, which identifies at least one time resource among a plurality of consecutive time resources in which an LBT failed. (Note 34) The method according to Appendix 33, wherein, upon receiving indication of at least one LBT failure from the second protocol layer, the first protocol layer adapts the planned transmission or retransmission of data based on the indication of at least one LBT failure from the second protocol layer. (Note 35) A method performed by the first user equipment (UE), The first protocol layer receives information from the second protocol layer indicating a set of candidate resources for transmitting existing data using direct inter-UE communication across multiple consecutive time resources, This includes, in multiple consecutive time resources, using at least a subset of candidate resources, transmitting existing data to a second UE via direct inter-UE communication in at least one transport block (TB), If existing data includes multiple different data, and each of these different data has a different priority level among multiple possible priority levels, Multiple different data with different priority levels are contained within at least one TB, regardless of whether the same TB contains different data with different priority levels. In a manner that ensures each TB contains data with a common priority level, or that multiple different data with different priority levels are contained within multiple TBs, A method to ensure that each TB contains only data having a priority level within a specific range of priority levels, such that multiple different data having different priority levels are contained in at least one TB. (Note 36) Regardless of whether the same transport block (TB) contains different data with different respective priority levels, when multiple different data with different priority levels are included in at least one TB and the UE has new data for transmission before the transmission of all existing data is completed, the UE waits for the transmission of the new data until the existing data is transmitted, regardless of whether the new data has a higher priority level than the existing data, in the method described in Supplementary Note 35. (Supplementary Note 37) In a method of ensuring that each TB contains data with a common priority level and the UE has new data for transmission before the transmission of all existing data is completed, when multiple different data with different priority levels are included in multiple TBs, the UE delays the transmission of at least one unsent TB that contains existing data with a lower priority level than the new data and transmits the new data prior to at least one unsent TB, in the method described in Supplementary Note 35. (Supplementary Note 38) In a method of ensuring that each TB contains only data with a priority level within a specific range of priority levels, when multiple different data with different priority levels are included in at least one TB and the UE has new data for transmission with a priority level higher than the range of the specific priority level before the transmission of all existing data is completed, the UE delays the transmission of at least one unsent TB that contains existing data with a priority level within the range of the specific priority level and transmits the new data prior to at least one unsent TB, in the method described in Supplementary Note 35. (Supplementary Note 39) The method according to any one of Supplementary Notes 35 to 38, wherein each priority level is associated with a different respective channel access priority class (CAPC), and a lower CAPC corresponds to a higher priority level. (Supplementary Note 40) A first user equipment (UE), A means for providing information from a first protocol layer to a second protocol layer for use in selecting a resource for transmitting data using direct inter-UE communication across multiple consecutive time resources, A means for receiving information from a second protocol layer in a first protocol layer that indicates a set of candidate resources for direct inter-UE communication in multiple consecutive time resources, selected based on the information, The system includes means for transmitting data to a second UE via direct inter-UE communication using at least a subset of candidate resources across multiple consecutive time resources, The information must be at least one of the following: At least one parameter associated with the autonomous mode of resource selection, where the data includes data from each of several different data sources, each parameter of the at least one parameter is based on a corresponding attribute associated with data from one of the several different data sources, Transmission pattern information identifying at least one intended transmission pattern for sending data via direct UE-to-UE communication, and / or A first user equipment (UE) comprising size information indicating the estimated total size of data to be transmitted, wherein the estimated total size is based on both the initial transmission of the data and any intended retransmission of the data, and at least one of the following: (Note 41) The first user equipment (UE), A means for receiving information from a second protocol layer in a first protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across multiple consecutive time resources, The system includes means for transmitting data to a second UE via direct inter-UE communication using at least a subset of candidate resources across multiple consecutive time resources, The first protocol layer is configured to trigger the second protocol layer to perform further selection of resources for transmitting at least a portion of the data if the data contains more data than can be transmitted using the set of candidate resources. If the set of candidate resources contains more resources than are needed to send the data, the UE will: Drop at least a subset of resources that are not required for data transmission, and / or A first user equipment (UE) is configured to perform a logical channel prioritization (LCP) procedure for the further transmission of data or further data to at least one further UE via direct inter-UE communication, using at least a subset of resources not required for the transmission of data to a second UE. (Note 42) The first user equipment (UE), A means for receiving information from a second protocol layer in a first protocol layer indicating a set of candidate resources for transmitting data using direct inter-UE communication across multiple consecutive time resources, A means for sequentially executing each listen-before-talk (LBT) for each time resource of multiple consecutive time resources until the results of the LBT for the corresponding time resources of multiple consecutive time resources indicate that data transmission can be started in the corresponding time resources, or until each LBT fails in all time resources of the multiple consecutive time resources, The system includes means for indicating at least one LBT failure from a second protocol layer to a first protocol layer when at least one LBT fails for a corresponding time resource among a plurality of consecutive time resources, Demonstrating at least one LBT failure is, Each LBT represents a single LBT failure provided when any time resource in multiple consecutive time resources fails. To indicate each LBT failure provided to each LBT that has failed for a corresponding time resource among multiple consecutive time resources, or A first user equipment (UE) that includes indicating an LBT failure, which identifies at least one time resource among multiple consecutive time resources in which an LBT has failed. (Note 43) The first user equipment (UE), A means for receiving information from a second protocol layer in a first protocol layer that indicates a set of candidate resources for transmitting existing data using direct inter-UE communication across multiple consecutive time resources, The system comprises means for transmitting existing data to a second UE via direct inter-UE communication in at least one transport block (TB) using at least a subset of candidate resources across multiple consecutive time resources, If existing data includes multiple different data, and each of these different data has a different priority level among multiple possible priority levels, Multiple different data with different priority levels are contained within at least one TB, regardless of whether the same TB contains different data with different priority levels. In a manner that ensures each TB contains data with a common priority level, or that multiple different data with different priority levels are contained within multiple TBs, A first user equipment (UE) that ensures each TB contains only data with a priority level within a specific range of priority levels, such that multiple different data with different priority levels are contained in at least one TB.

[0243] This application claims priority based on UK Patent Application No. 2307042.8, filed on 11 May 2023, the disclosure thereof being incorporated herein by reference in its entirety. [Explanation of symbols]

[0244] 1. Communication System 3. User equipment 5 base station 7 Core Network 9 cells 10 Control Plane Functions 11. User Plane Functions 20 External data network 31 Transmitter / Receiver Circuit 33 Antennas 35 User Interface 37 Controllers 39 memory 41 Operating Systems 43 Communication control module 45 Direct communication module 51 Transmitter / Receiver Circuit 53 Antenna 55 Core Network Interfaces 57 Controllers 59 memory 51 Operating Systems 53 Communication control module 55 Direct Communication Management Module

Claims

1. To determine whether a data unit is not transmitted in any of the resources for a data unit associated with the process of sidelink communication between a first user equipment (UE) and a second UE for multiple consecutive time resource transmissions due to listen-before-talk (LBT) failures, If the data unit is not transmitted in any of the resources for the data unit associated with the process of the sidelink communication between the first UE and the second UE for the transmission of a plurality of consecutive time resources, the process includes triggering a selection procedure for the resources for the data unit associated with the process of the sidelink communication for the transmission of a plurality of consecutive time resources. A method executed by the first user equipment (UE).

2. The selection procedure includes selecting resources based on the remaining packet delay budget (PDB). The method according to claim 1.

3. The selection procedure includes selecting a resource based on the channel access priority class (CAPC) level of the data unit. The method according to claim 1 or 2.

4. The selection procedure includes selecting a resource having at least one of the following: a Media Accesses Control (MAC) Control Element (CE) and a logical channel with the highest priority. The method according to any one of claims 1 to 3.

5. The selection procedure includes selecting a resource based on the autonomous mode of resource selection and associated parameters. The method according to any one of claims 1 to 4.

6. The selection procedure includes selecting a resource based on information identifying at least one transmission pattern for transmitting the data unit via the sidelink communication. The method according to any one of claims 1 to 5.

7. The selection procedure includes selecting a resource based on information indicating the size of the data unit. The method according to any one of claims 1 to 6.

8. The procedure includes performing a logical channel prioritization (LCP) procedure for transmitting the data unit or further data units to a third UE via sidelink communication using the resources for the plurality of consecutive time resource transmissions, wherein the resources are not required for transmitting the data unit to the second UE. The method according to any one of claims 1 to 7.

9. The above selection procedure is, Instructions for the number of transport blocks (TB) for transmission of the data unit, Instructions for the hybrid automatic repeat request (HARQ) transmission mechanism, or The number of slots that should be occupied for blind retransmission, Selecting resources based on at least one of the following: The method according to any one of claims 1 to 8.

10. The instruction of the HARQ transmission mechanism is, Whether the HARQ transmission mechanism is feedback-based or blind retransmission-based, The number of sidelink HARQ processes used for HARQ transmission, or Number of blind retransmissions for at least one TB, Showing at least one of the following: The method according to claim 9.

11. The aforementioned data unit is transmitted in multiple transport blocks (TBs) using a common hybrid automatic repeat request (HARQ) process. Each of the plurality of TBs is transmitted using the respective time resources of the resource for the plurality of consecutive time resource transmissions. The method according to any one of claims 1 to 10.

12. The data unit is transmitted in at least one transport block (TB) using a common hybrid automatic repeat request (HARQ) process. The at least one TB is transmitted using two or more time resources from the resources for the transmission of the plurality of consecutive time resources. The method according to any one of claims 1 to 11.

13. The data unit is transmitted in at least one transport block (TB) using a common hybrid automatic repeat request (HARQ) process. The at least one TB is transmitted in a first time resource among the resources for the plurality of consecutive time resource transmissions, and is retransmitted in at least one further time resource among the resources for the plurality of consecutive time resource transmissions. The method according to any one of claims 1 to 11.

14. The aforementioned at least one TB is For each transmission and / or retransmission of the at least one TB, Redundant version, or Resources used, Including being transmitted based on at least one of the following: The method according to claim 13.

15. The aforementioned data unit is transmitted in a single transport block (TB) using a hybrid automatic repeat request (HARQ) process. The single TB is transmitted using one of the resources for the transmission of the multiple consecutive time resources. The method according to any one of claims 1 to 14.

16. In at least one other resource for transmitting the plurality of consecutive time resources, HARQ feedback, or Data transmission, Includes receiving at least one of the above from the second UE, The method according to claim 14.

17. The aforementioned at least one other resource forms at least a portion of the shared channel occupancy time (COT). The method according to claim 16.

18. This includes transmitting COT sharing information indicating at least one other resource to the second UE, The method according to claim 17.

19. The aforementioned data unit is transmitted in multiple transport blocks (TBs), Each of the aforementioned plurality of TBs is sent using its respective hybrid automatic repeat request (HARQ) process. The method according to any one of claims 1 to 18.

20. Each of the plurality of TBs is transmitted using a different resource for the plurality of consecutive time resource transmissions. The method according to claim 19.

21. Each of the aforementioned plurality of TBs transports data units having the same priority. The method according to claim 19 or 20.

22. The data unit is transmitted using a feedback-based HARQ retransmission mechanism. The method according to any one of claims 19 to 21.

23. The data unit is transmitted using a blind retransmission-based HARQ retransmission mechanism. Each of the plurality of TBs is retransmitted on a different resource for the plurality of consecutive time resource transmissions. The method according to any one of claims 19 to 21.

24. The first of the plurality of TBs is transmitted and blind-retransmitted in the plurality of resources for continuous time resource transmission in a manner that is interleaved with the transmission and blind retransmission of the second of the plurality of TBs. The method according to claim 23.

25. The first of the plurality of TBs is transmitted and blindly retransmitted within a continuous resource for the plurality of continuous time resource transmissions. The second of the plurality of TBs is transmitted and blindly retransmitted within a continuous resource for the plurality of continuous time resource transmissions. The method according to claim 23.

26. For the process of sidelink communication between a first user equipment (UE) and a second UE for the transmission of multiple consecutive time resources, data having at least one channel access priority class (CAPC) level is multiplexed into at least one transport block (TB), This includes determining whether to preempt or block the transmission of data having a specific CAPC level over a plurality of consecutive time resource transmissions, A method executed by the first user equipment (UE).

27. The aforementioned multiplexing is performed by multiplexing the data having different CAPC levels onto at least one TB. The aforementioned decision is made by deciding not to preempt or block any transmission of the data having different CAPC levels over the plurality of consecutive time resource transmissions. The method according to claim 26.

28. The aforementioned multiplexing is performed by multiplexing the same CAPC level data onto a single TB. The aforementioned decision is made by deciding to preempt or block the transmission of the data having a lower CAPC level. The method according to claim 26.

29. This includes triggering a procedure for selecting a resource for the data having a lower CAPC level for the multiple consecutive time resource transmissions, The method according to claim 28.

30. The aforementioned multiplexing is performed by multiplexing the data having CAPC levels within a specific range of higher CAPC levels onto the at least one TB. The aforementioned decision is made by deciding not to multiplex the data having a lower CAPC level in order to preempt or block the transmission of the data having a lower CAPC level. The method according to claim 26.

31. Means for determining whether a data unit is not transmitted in any of the resources for the data unit associated with the process of sidelink communication between a first user equipment (UE) and a second UE for multiple consecutive time resource transmissions due to listen-before-talk (LBT) failures, If the data unit is not transmitted in any of the resources for the data unit associated with the process of sidelink communication between the first UE and the second UE for the transmission of a plurality of consecutive time resources, the system includes means for triggering a resource selection procedure for the resources for the data unit associated with the process of sidelink communication for the transmission of a plurality of consecutive time resources. The first user equipment (UE).

32. For the process of sidelink communication between a first user equipment (UE) and a second UE for the transmission of multiple consecutive time resources, means for multiplexing data having at least one channel access priority class (CAPC) level into at least one transport block (TB), The means includes determining whether to preempt or block the transmission of data having a specific CAPC level over a plurality of consecutive time resource transmissions, The first user equipment (UE).

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