Sidelink channel access processing method, apparatus, and network-side equipment

Abstract

The present disclosure provides a channel access processing method, an apparatus and a network side device for sidelink, which relate to the field of communication technology. The channel access processing method for sidelink applied to a first terminal includes the steps of: the first terminal performing resource selection to determine a first target resource; and performing a first type channel access procedure for at least a part of the first target resource to determine whether a channel is idle and a channel occupation time (COT).

Description

[Technical Field]

[0001] [Cross-reference of related applications] This disclosure claims priority to Chinese Patent Application No. 202210470995.2, filed in China on 28 April 2022, all of which are incorporated herein by reference. This disclosure relates to the telecommunications technology field, and more particularly to channel access processing methods, apparatus, and network-side equipment for sidelinks. [Background technology]

[0002] 3GPP® (3rd Generation Partnership Project) has introduced SL-U (Sidelink Operation on Unlicensed Spectrum) as a related technology. Compared to communication mechanisms in licensed bands, devices operating in unlicensed bands can use those bands without a license, so it is necessary to introduce an LBT (Listen Before Talk) mechanism to avoid mutual interference between different systems.

[0003] The SL-U in related technologies remains unclear regarding resource selection, resource transmission, its relationship with LBT, and processing steps. While some designs from NR-U (New Radio Unlicensed), which operates in unlicensed bands, can be reused, the impact of the distributed resource allocation mechanism employed in Sidelink on LBT must be considered. For example, poor integrated scheduling at base stations can lead to discontinuous transmissions between different terminals, interrupting continuous channel occupancy. Therefore, new LBT processing steps and methods need to be designed considering the relevant characteristics of Sidelink. In short, the LBT mechanism for SL-U is still unclear, and the relevant processing steps need to be normalized and defined during the standardization process. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The purpose of this disclosure is to provide a channel access processing method, apparatus, and network-side equipment for sidelinks, thereby avoiding the problem of discontinuous transmission between terminals and interruption of continuous channel occupancy, and to clarify the LBT processing mechanism of SL-U. [Means for solving the problem]

[0005] To achieve the above objectives, embodiments of the present disclosure provide a channel access processing method for sidelinks applicable to a first terminal. The method includes the steps of the first terminal performing resource selection to determine first target resources, and performing a Class I channel access procedure on at least some of the first target resources to determine whether the channel is idle and the channel occupancy time (COT).

[0006] To achieve the above objective, embodiments of the present disclosure further provide a channel access processing method for a sidelink that is applicable to a second terminal. The method includes the steps of the second terminal receiving first control information transmitted by a first terminal, the first control information including information relating to a channel occupancy time (COT) determined by the first terminal, and transmitting information based on the first control information.

[0007] To achieve the above objectives, embodiments of the present disclosure further provide a channel access processing device for sidelinks, the device comprising: a first processing module configured for a first terminal to perform resource selection and determine a first target resource; and a second processing module configured to perform a Class I channel access procedure on at least some of the first target resources and to determine whether the channel is idle and the channel occupancy time (COT).

[0008] To achieve the above object, an embodiment of the present disclosure further provides a sidelink channel access processing apparatus. The apparatus includes a third processing module configured to receive first control information transmitted by a first terminal by a second terminal, and a fourth processing module configured to perform information transmission based on the first control information, where the first control information includes information related to a channel occupancy time (COT) determined by the first terminal.

[0009] To achieve the above object, an embodiment of the present disclosure provides a network-side device. The device includes a transceiver, a processor, a memory, and a program or instruction stored in the memory and executable by the processor. When the processor executes the program or instruction, the sidelink channel access process method according to any one of the above embodiments is realized.

[0010] To achieve the above object, an embodiment of the present disclosure provides a readable storage medium. The storage medium stores a program or instruction that, when executed by a processor, realizes the sidelink channel access process method according to any one of the above embodiments.

Advantages of the Invention

[0011] The technical effects of the above technical solutions of the present disclosure are as follows.

[0012] In an embodiment of the present disclosure, the first terminal performs resource selection to determine a first target resource, executes a first type of channel access procedure for at least a part of the first target resources, and determines whether the channel is idle and a channel occupancy time (COT). The present disclosure complements the sidelink channel access processing process, clarifies the specific operations for the terminal to perform channel access, further guarantees the maintenance of continuous occupancy of the sidelink during channel access, and reduces the probability of transmission failure caused by access to other systems.

Brief Description of the Drawings

[0013] [Figure 1] This is a flowchart of the processing method applied to the first terminal according to the embodiment of this disclosure. [Figure 2] This is a schematic diagram of the first specific embodiment according to the embodiments of the present disclosure. [Figure 3] This is a schematic diagram of a second specific embodiment relating to the embodiments of this disclosure. [Figure 4] This is a schematic diagram of a third specific embodiment according to the embodiments of this disclosure. [Figure 5] This is a schematic diagram of the fourth specific embodiment according to the embodiments of this disclosure. [Figure 6] This is a schematic diagram of the fifth specific embodiment according to the embodiments of this disclosure. [Figure 7] This is a flowchart of the processing method applied to the second terminal according to the embodiment of this disclosure. [Figure 8] This is a schematic diagram of the sixth specific embodiment according to the embodiments of this disclosure. [Figure 9] This is a schematic diagram of the seventh specific embodiment according to the embodiments of this disclosure. [Figure 10] This is a schematic diagram (1) of a module of the processing apparatus according to an embodiment of the present disclosure. [Figure 11] This is a schematic diagram (part 2) of a module of the processing apparatus according to an embodiment of the present disclosure. [Figure 12] This is a structural diagram of a mobile terminal according to an embodiment of the present disclosure. [Figure 13] This is a structural diagram of the network-side equipment according to an embodiment of the present disclosure. [Figure 14] This is a schematic diagram illustrating the transmission of a placeholder message according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0014] To further clarify the technical problems, technical solutions, and advantages that this disclosure aims to solve, they will be described in detail below with reference to the drawings and examples.

[0015] In the various embodiments of this disclosure, the numbering of each process below does not indicate the order of execution. The execution order of each process should be determined by its function and internal logic, and is not limited in any way to the execution process of the embodiments of this disclosure.

[0016] In this specification, the terms "system" and "network" are often interchangeable.

[0017] The terms “first,” “second,” etc., in the specification and claims of this disclosure are for distinguishing similar subjects and not to describe a specific order or sequence. The data used in this manner may be replaced where appropriate so that the embodiments of this application may be carried out in an order other than those illustrated or described herein. Furthermore, subjects distinguished by “first,” “second,” etc., are generally of the same kind and do not limit the number of subjects; for example, there may be one or more first subjects. Also, “and / or” in the specification and claims indicates at least one of the preceding or following subjects, and the letter “ / ” generally indicates that the preceding and following related subjects are in an “or” relationship.

[0018] Before describing the embodiments of this disclosure, we will first explain some of the concepts used in the following description.

[0019] 1. Unlicensed band Unlicensed spectrum can be used free of charge without application and can be used by any organization or individual. For example, commonly used technologies such as Wi-Fi (Wireless Network Communication Technology) and Bluetooth (Registered Trademark) all use unlicensed bands. To avoid interference between different systems, it is necessary to avoid interfering with other systems as much as possible when using unlicensed bands. Therefore, LBT (Low-Level Band Testing) technology is implemented, which monitors the channel before accessing it and does not access the channel until it is confirmed that the system is idle.

[0020] 2. LBT (Listen Before Talk) Mechanism Terminals operating in the unlicensed band must perform channel discovery before accessing a channel. Only if they detect that the channel is idle can they access the channel and transmit services that are waiting to be transmitted. The channel discovery method includes the following steps:

[0021] (1) Type 1 channel access method As shown in the table below, the terminal first determines the priority of channel access, and then determines the relevant parameters for channel access. This process is as follows (Steps 1-6).

[0022] In Step 1, the counter N is set to Nint, where Nint is a random number uniformly distributed between 0 and CWp. Next, Step 4 is executed.

[0023] In Step 2, if N > 0, the terminal subtracts 1 from the counter, i.e., N = N - 1.

[0024] In Step 3, a monitoring slot with a time duration of Tsl (Tsl indicates an LBT monitoring slot, with a length of 9 μs) is detected for the channel. If the monitoring slot is idle, Step 4 is executed; otherwise, Step 5 is executed.

[0025] In Step 4, if N=0, terminate channel access; otherwise, execute Step 2.

[0026] In Step 5, detection is performed on the channel at time intervals of length Td (where Td = 16 + mp × 9 μs), and the detection result for that time interval is either that at least one monitoring slot is occupied or that all monitoring slots are idle.

[0027] In Step 6, if the channel monitoring result shows that all monitoring slots are idle during Td time, execute Step 4; otherwise, execute Step 5.

[0028] After the channel access procedure is completed, the terminal will have a corresponding maximum channel occupancy time T mcot,p After determining this, the transmission of the waiting service is performed using that channel. The terminal's Channel Occupancy Time (COT) is the maximum channel occupancy time corresponding to its channel access priority. mcot,p This must not be exceeded. Furthermore, to ensure that different users of the same system have continuous access to the system and to prevent other systems from intercepting and hijacking the channel, a terminal may share the COT with other terminals after acquiring it; this is called COT sharing. The channel access priority classes are shown in the table below.

[0029] JPEG0007880982000001.jpg45170

[0030] Here, CW min,p This is the minimum contention window size, CW max,p This is the maximum contention window size, T mcot,p This is the maximum channel occupancy time, CW p This may also be called the set of allowed contention window sizes.

[0031] (2) Type 2 channel access method A terminal may evaluate the channel using a Type 2 method after obtaining the COT shared by another terminal before transmission. The Type 2 channel access method is a channel access method based on a certain channel monitoring length and includes the following three methods:

[0032] 1) Type 2A channel access The terminal performs channel monitoring for at least 25 μs before starting transmission, and transmits only after the channel monitoring is successful.

[0033] 2) Type 2B channel access The terminal performs a 16μs channel monitoring before starting transmission, and transmission begins only after the channel monitoring is successful.

[0034] 3) Type 2C channel access The terminal transmits directly without channel monitoring. Here, the gap between the start of the current transmission and the end of the previous transmission is 16 μs or less, and the transmission length does not exceed 584 μs.

[0035] Note that "Category 1 channel access" as described below refers to the Type 1 channel access method, and is indicated by Type 1 LBT. "Category 2 channel access" refers to the Type 2 channel access method, and is indicated by Type 2 LBT.

[0036] As shown in Figure 1, a selective embodiment of the present disclosure provides a channel access processing method for a side link applied to a first terminal, the method comprising steps 100 and 200.

[0037] In step 100, the first terminal performs resource selection to determine the first target resource.

[0038] The resource selection performed by the first terminal includes, but is not limited to, processing processes for contiguous resources, determining the number of resources to select, and processing processes for non-contiguous resources. The resource selection by the first terminal determines the first target resource with enhanced resource selection capabilities.

[0039] In step 200, a Class 1 channel access procedure is performed on at least some of the aforementioned first target resources to determine whether the channel is idle and the channel occupancy time (COT).

[0040] Here, the Class 1 channel access refers to a channel access method that performs random backoff using a variable-size contention window (CW) and determines the size of the CW based on the channel access priority class.

[0041] In this embodiment, the COT determined in step 200 is not necessarily that of the first terminal, but may be shared with the second terminal, and the COT here simply indicates that it is determined by the first terminal. The purpose of determining whether the channel is idle or not in step 200 is to avoid as much as possible the problem of mutual interference caused by different systems transmitting simultaneously. This disclosure complements the flow of sidelink channel access processing.

[0042] Selectively, step 100 may include steps 110 to 130.

[0043] In step 110, determine the time to trigger resource selection.

[0044] In step 120, the resource selection window is determined based on the time that triggers resource selection.

[0045] In step 130, the first target resource is determined based on the resource selection window.

[0046] Here, the first time interval T1 between the start time of the resource selection window and the time that triggers resource selection is determined by the transmission processing delay, the resource selection processing delay of the first terminal, and the minimum time length for executing the first type channel access procedure.

[0047] In this embodiment, before determining the first target resource, the front edge of the resource selection window determined by the first terminal (start time of the resource selection window) ofThe range is restricted. When the first terminal executes resource selection, it determines the time n that triggers the resource selection, and determines the time range [n + T1, n + T2] of the resource selection window. (n + T1) indicates the front edge of the resource selection window, and (n + T2) indicates the back edge of the resource selection window. That is, the first terminal determines the first target resource within the range of [n + T1, n + T2] based on the sensing result.

[0048] Here, the first time interval T1 is determined based on the start time of the resource selection window and the time when the resource selection is triggered. To determine the first time interval T1, the transmission processing delay T proc,1 , the resource selection processing delay T proc,1-A , and at least one element of the minimum time length T minLBT for executing the first type of channel access procedure needs to be considered. The minimum time length for executing the first type of channel access procedure is the minimum time length of the type1 LBT to be executed this time (from now on). The resource selection processing delay T proc,1-A is a parameter newly defined in this disclosure. That is, the first terminal completes the resource selection at (n + T proc,1-A ), and determines the time-frequency position of the resource at this time.

[0049] Note that the transmission processing delay T proc,1 is the parameter information determined in the Sidelink resource selection process, which is the same as the determination method in the related technology protocol, and the description is omitted here.

[0050] Specifically, the first time interval T1 satisfies at least one of the following conditions: the first time interval T1 is greater than or equal to zero, the first time interval T1 is less than or equal to the transmission processing delay, the first time interval T1 is greater than the minimum time length, and the first time interval T1 is greater than the sum of the minimum time length and the resource selection processing delay.

[0051] In this embodiment, the first time interval T1 is expressed as a formula such as 0 ≤ T1 or T1 ≤ T proc,1 , or T1>T minLBT , or T1>T minLBT +T proc,1-A It is represented as follows.

[0052] Furthermore, the first time interval T1 is defined as T1 ≥ T minLBT , or T1≧T minLBT +T proc,1-A It satisfies at least one of the following conditions.

[0053] Specifically, in this case, the end time of the resource selection window is, The end time of the resource selection window is within a range smaller than the data packet delay budget (PDB), The end time of the resource selection window is within a first predetermined time range after the resource selection is triggered, and at least one of these conditions is met.

[0054] Furthermore, this first predetermined time is the time limit during which the terminal can select one resource.

[0055] Furthermore, embodiments of this disclosure may further include determining the back edge (n+T2) parameter of the resource selection window, where the value and definition of T2 is the minimum acceptable value T2. min This relates to the remaining packet transmission delay (Remaining PDB).

[0056] This disclosure is advantageous in achieving enhanced resource selection in Sidelink resource selection by determining the first time interval T1.

[0057] Selectively, the first target resource satisfies the condition that the number of first target resources is N+M resources.

[0058] Here, N is the number of transmission resources required for the transmission of transmission block TB, and M is the number of additional candidate transmission resources. N and M are integers greater than or equal to 1.

[0059] Furthermore, by adding M candidate transmission resources, the transmission resources of the first terminal are prevented from being discarded.

[0060] Specifically, the value of M is, A value set by the higher layer, or The protocol predefined, pre-configured, or set values, or Includes a value determined based on the first parameter information.

[0061] Specifically, the first parameter information described above is: Channel access priority and Data priority and Channel Busy Ratio (CBR) and The value of N and, The past duration of the first terminal during which it performed the first type channel access procedure, i.e., the duration of the first terminal's history Type 1 LBT, Channel Occupancy Ratio (CR) and Maximum Channel Occupancy (CR) limit ) and include at least one of the following.

[0062] In this embodiment, considering that the LBT time is constant, when the channel is busy, the duration of the Type 1 LBT increases, causing the LBT completion time to be later than the time of some transmission resources, resulting in expired transmission resources being discarded after the LBT ends. If extra candidate resources are not added, there is a risk that the number of available transmissions will decrease due to LBT. In view of this, the number of resources selected when the first terminal performs resource selection is set to N+M, where N is the number of transmission resources required for the transmission of a transmission block (TB), and M is the number of additional candidate transmission resources. Here, M is a value set or pre-configured by the upper layer, or determined by the first parameter information.

[0063] Note that N is the number of transmission resources set by the current resource selection or pre-configured. For example, if one TB requires 32 transmissions, and the current resource selection corresponds to only 4 of them, then N=4, not 32.

[0064] As shown in Figure 2, in the first embodiment, assuming that the number of transmissions corresponding to one TB of the first terminal is 4, some resources may become unavailable due to the uncertainty of the Type 1 LBT duration. Therefore, the terminal needs to select M additional candidate resources when making resource selection. If M=2, the terminal needs to select a total of 6 possible resources to be used for transmission. After resource selection, the terminal performs a Type 1 LBT. Since the LBT completion time falls after the initially selected second candidate resource, the previous two initially selected resources are invalidated and unavailable for transmission. Subsequently, the terminal infers that the initially selected third resource is the actual initial transmission resource, and the initially selected fourth resource is the actual first retransmission resource.

[0065] Selectively, the first target resource determined in step 100 is: Among the available resources, resources that are consecutive in the time domain, In the available resources, resources that are consecutive in the time domain with resources reserved by other devices, Among the available resources, resources that are within one maximum channel occupancy time, and The available resources include at least one resource that is within the same single maximum channel occupancy time as a resource reserved by another terminal.

[0066] In this embodiment, when the first terminal selects a resource, it determines the corresponding channel access priority based on data priority, and further determines the corresponding maximum channel occupancy time (COT). To ensure that the COT determined by Type 1 LBT is utilized to the maximum extent and to ensure continuous channel occupancy by Sidelink, enhancements based on random resource selection may include at least one of the following embodiments.

[0067] In Embodiment 1-1, the terminal preferentially selects resources that are consecutive in the time domain from the available resources (primarily for blind retransmissions, and does not require consideration of Hybrid Automatic Repeat reQuest (HARQ) feedback time).

[0068] In embodiment 1-2, the terminal prioritizes selecting from available resources resources that are contiguous with resources reserved by other terminals in the time domain.

[0069] In embodiment 1-3, the transmission resource selected by the terminal from the available resources is within one maximum channel occupancy time.

[0070] In embodiment 1-4, the transmission resource selected by the terminal from the available resources is within the same single maximum channel occupancy time as the resources reserved by other terminals.

[0071] As shown in Figure 3, in the second embodiment, assuming that the transmission of the first terminal needs to occupy one subchannel, four transmissions are required, and their numbers are indices of the available resources. According to the resource selection method described above, the terminal performs random resource selection, which may be {1,6,17,21}, or {1,5,10,14}, etc.

[0072] In embodiment 1-1, consecutive resources in the time domain are selected, and in this case {1,6,17,21} does not satisfy the requirements, so the first terminal can select consecutive resources in the time domain such as {1,5,10,14} or {4,9,13,18}.

[0073] In embodiment 1-2, a resource is selected that is consecutive in sequence with a resource reserved by another terminal. Between candidate resources {5, 14, 19, 23} and candidate resources {5, 19, 23, 28}, the terminal preferentially selects {5, 14, 19, 23}. This is to ensure that the terminal's transmission is consecutive in the time domain with the transmission of other terminals, and to guarantee continuous channel occupancy by the Sidelink system.

[0074] In embodiment 1-3, we assume that the COT time is divided into four slots. In this case, the terminal preferentially selects {5,10,14,19} over resources {5,14,23,33}. This is because the corresponding resources fall within a single COT time. For transmissions within a single COT, the terminal only needs to perform the Type 2 channel access procedure, which is relatively simpler and faster.

[0075] In aspect 1-4, similarly, we assume that the COT time is divided into five slots. In this case, the terminal preferentially selects resource {10, 14, 28, 33} over resource {10, 14, 23, 28}. This is to ensure that, overall, the system occupation by Sidelink for the latter is temporally continuous and within a single COT time.

[0076] Based on the above, this disclosure ensures that the COT determined by Type 1 LBT is utilized to the fullest extent, that enhancements are made based on random resource selection, and that continuous channel occupancy by Sidelink is guaranteed.

[0077] Selectively, the first target resource determined in step 100 further includes resources from the available resources that satisfy the second condition and are discontinuous in the time domain.

[0078] Here, the second condition is that the second time interval between two adjacent transmissions is greater than the first predetermined threshold, and the first predetermined threshold is a value set by the upper layer, or a value predefined, pre-set, or set by the protocol.

[0079] Here, the first predetermined threshold is preferably the minimum time length of the first channel access procedure.

[0080] In this embodiment, if the available resources are discontinuous in the time domain, and one transmission lies within the shared COT, but a subsequent transmission does not lie within the COT time, i.e., a Type 1 LBT still needs to be performed before the subsequent transmission, the embodiment for this case is to ensure that the interval between the two transmissions is greater than a first predetermined threshold, thereby ensuring that the terminal has time to perform a Type 1 LBT. Here, the first predetermined threshold is the minimum time required to perform a Type 1 LBT, i.e., N init ×T sl It's fine. sl This represents the LBT monitoring slot, which has a length of 9 μs.init 0 to CW p This is a random number that is uniformly distributed between [times]. This disclosure allows for sufficient LBT time to be reserved in advance when continuity cannot be achieved with available resources, thereby enabling the enhancement of the first target resource.

[0081] The available resources mentioned above refer to the remaining resources after unavailable resources have been removed from the resource selection window based on the detection results.

[0082] Selectively performing a Class I channel access procedure for at least some of the first target resources in step 200 may include the following steps:

[0083] In step 210, a first candidate time for the commencement of the Class 1 channel access procedure and / or a second candidate time for the commencement of the Class 1 channel access procedure are determined.

[0084] In step 220, the LBT start time for executing the Class 1 channel access procedure is determined based on the first candidate time and / or the second candidate time.

[0085] In step 230, a Class 1 channel access procedure is performed for at least some of the first target resources based on the LBT start time.

[0086] In this embodiment, by determining the first candidate time and / or the second candidate time, the time when the first terminal starts LBT, i.e., the LBT start time, can be determined. This allows different users of the same system to determine the time when the first terminal starts LBT. channel This ensures continuous occupancy and prevents other systems from intercepting and hijacking the channel.

[0087] Specifically, step 220 may include step 221, step 222, or step 223.

[0088] In step 221, if the second candidate time is equal to or later than the first candidate time, it is determined that the LBT start time is equal to or later than the first candidate time and equal to or earlier than the second candidate time.

[0089] In this embodiment, based on the determined first candidate time and second candidate time, the time at which the first terminal actually starts LBT (i.e., the LBT start time) is further determined. In step 221, it is determined that the LBT start time lies between the first candidate time and the second candidate time, i.e., first candidate time ≤ LBT start time ≤ second candidate time. Specifically, the LBT start time may be the earliest time for LBT, the latest time for LBT, or a time somewhere between the two, and can be realized by the first terminal.

[0090] In step 222, if the second candidate time is earlier than the first candidate time, it is determined that the LBT start time is equal to or later than the first candidate time.

[0091] In this embodiment, if the second candidate time is earlier than the first candidate time, only the first candidate time is valid. The first candidate time is the time when the determination of the resource's time-frequency position is completed; that is, the first terminal can perform LBT only after determining the resource's time-frequency position.

[0092] Alternatively, step 220 includes step 223.

[0093] In step 223, it is determined that the LBT start time is equal to or later than the first candidate time.

[0094] In this embodiment, only the first candidate time is determined, and it is ensured that the LBT start time is later than or equal to the first candidate time. The first candidate time is the time when the determination of the resource's time-frequency position is completed, that is, the first terminal can perform LBT only after the resource's time-frequency position has been determined.

[0095] Determining the first candidate time is The steps include determining a first start time that triggers the first terminal to perform resource selection, and a processing delay for the first terminal to perform resource selection, The step may include determining the first candidate time using the formula A1=B1+C1.

[0096] Here, A1 indicates the first candidate time, B1 indicates the first start time, and C1 indicates the processing delay for the first terminal to perform resource selection.

[0097] Note that C1 may indicate the transmission processing delay of the first terminal.

[0098] In this embodiment, the first terminal determines the sensing result and starts the transmission process at a first start time for performing resource selection, i.e., time n, which is the time that triggers resource selection, determined based on the first target resource. The disclosure further includes a processing delay T for the first terminal to perform resource selection. proc,1-A (In related technologies, the transmission processing delay T proc,1 Only is defined, and here the above T proc,1-A Determine the first candidate time (which represents the total time for resource selection and transmission-related operations such as the transmission process), and the first candidate time = n + T proc,1-A The completion time for resource selection is determined by equation 1, which is expressed as follows, and at this time the time-frequency position of the resource is determined.

[0099] Here, the first candidate time is preferably the earliest time of the LBT, and is similar to the time used to determine the resource time frequency position.

[0100] Selectively determining the second candidate time is The steps include determining, based on the first target resource, the time at which the resource corresponding to the Class 1 channel access procedure is located among the first target resources, and the first time length for executing the Class 1 channel access procedure, This includes the step of determining the second candidate time using the formula A2 = B2 - C2. Here, the first time length represents the minimum time for Type 1 LBT. Here, A2 indicates the second candidate time, B2 indicates the time when the resource is located, and C2 indicates the first time length.

[0101] In Equation 2, the second candidate time = TLBT waiting resource - minimum value of Type1 LBT duration. Here, the TLBT waiting resource is the time at which the resource is located, i.e., the time domain position of the resource when Type1 LBT is performed, and the minimum value of Type1 LBT duration is Ninit × Tsl. Here, Ninit and Tsl are the same as those described above.

[0102] Alternatively, determining the second candidate time is A step of determining the time length required for the transmission block TB of the first target resource, the latest time in the resource selection window of the first target resource, and the first time length. The step may also include determining the second candidate time using the formula A2=B3-C2-D1 (Formula 3).

[0103] Here, A2 indicates the second candidate time, B2 indicates the time the resource is located, C2 indicates the first time length, B3 indicates the latest time in the resource selection window, and D1 indicates the time length required for the transmission block TB. Note that B3 may also be the latest time allowed for service transmission, i.e., packet arrival time + packet transmission delay.

[0104] In formula 3, the second candidate time is equal to the back edge of the resource selection window (or the latest time allowed for service transmission) - the time required for TB - the minimum Type 1 LBT time.

[0105] The second candidate time may also be understood as the latest time at which LBT (Low-Based Testing) begins.

[0106] Furthermore, the second candidate time may be before the first candidate time, i.e., (T LBT待ちリソース - (Minimum value of Type 1 LBT time length) < (n+T proc,1-A) is a possibility. In this case, only the earliest time is valid, i.e., (n+T proc,1-A This is valid because the first terminal can only perform LBT after determining the time-frequency position of the resource.

[0107] As shown in Figure 4, in the third embodiment, the first terminal starts resource selection and other transmission processes at time n. proc,1-A Assuming that resource selection is completed and the location of the selected resources is determined at time ), this is the earliest time that the first terminal can perform LBT. The latest time that LBT can be started is (T 初期送信 -N init ×T sl ) In this case, the time period for which each Tsl still needs to be monitored, even if all Tsls are idle, is N. init ×T sl Therefore, the latest time LBT will start is (T 初期送信 -N init ×T sl ) Initial transmission resources delayed beyond this time are, of course, unusable. In practice, the time when the first terminal initiates LBT may fall between the earliest and latest time points.

[0108] Selectively, after performing the Class 1 channel access procedure in step 200, the method further includes steps 240 and 250.

[0109] In step 240, the end time at which the execution of the Class 1 channel access procedure is completed and the first time of the transmission waiting resource closest to the end time are determined.

[0110] In step 250, the resources waiting to be transmitted are transmitted based on the end time and the first time.

[0111] This disclosure determines whether or not placeholder information was transmitted between the end time and the first time by determining the end time and the first time, thereby avoiding a situation where channel resources are always reserved due to the terminal being unable to receive the second terminal scheduling, and improving the efficiency of channel usage.

[0112] Selectively, step 250 includes step 251, or includes steps 252 and 253.

[0113] In step 251, if the end time is equal to the first time or the interval between the end time and the first time is less than or equal to the second predetermined threshold, the resource waiting to be transmitted is transmitted directly.

[0114] In step 252, if the end time is before the first time, a first target interval is determined between the end time and the first time.

[0115] In step 253, it is decided to transmit the resources waiting to be transmitted based on the first target interval.

[0116] In this embodiment, after the LBT (which may be a Type 1 LBT or a Type 2 LBT) of the first terminal has finished, the end time of the execution of the first channel access procedure is determined, that is, the time X1 during which the channel becomes idle is determined. Furthermore, the first time M1 of the nearest waiting resource for transmission from the end of the LBT is determined. In this case, the behavior of the first terminal before transmitting at M1 may include at least one of the following:

[0117] In step 251, if the position where the LBT ends is exactly at the first time M1 of the resource waiting to be transmitted, or if the interval with M1 is less than or equal to a second predetermined threshold, the first terminal transmits the resource waiting to be transmitted directly. The role of the second predetermined threshold is to determine whether or not placeholder information needs to be transmitted in the interval between M1 and the position where the LBT ends. For example, if the interval between M1 and the position where the LBT ends is less than 16 μs, it can be transmitted directly. Here, the second predetermined threshold is a value set by the upper layer, or a value predefined, pre-set, or configured by the protocol.

[0118] In steps 252 to 253, if there is a first target interval between the time M1 and the time LBT ends, it is decided to transmit the resource waiting to be transmitted based on the first target interval.

[0119] Specifically, the step before step 253 may include a step of transmitting the first placeholder information using one of the following three methods.

[0120] In the first method, if the first target interval is greater than or equal to the first time threshold, it is decided to transmit the first placeholder information before the first time.

[0121] In the first method, placeholder information is transmitted only when the interval is sufficiently large, and placeholder information is not transmitted when the interval is small. If the first target interval is greater than (or equal to) the first time threshold, it is decided to transmit the first placeholder information and occupy the channel before the first time, and if the first target interval is less than or equal to the first time threshold, placeholder information is not transmitted.

[0122] In the second method, if the first target interval is less than or equal to the second time threshold, it is decided to transmit the first placeholder information before the first time.

[0123] In the second method, to avoid unfairness to other systems, it is ensured that the time taken to transmit placeholder information is not too long. If the interval between the two is less than (or less than or equal to) the second time threshold, it is decided to transmit the first placeholder information before the first time and occupy the channel. If the interval between the two is greater than (or equal to) the second time threshold, placeholder information is not transmitted, and Type 2 channel access is performed before transmission.

[0124] In the third method, if the first target interval is between the second time threshold and the first time threshold, it is decided to transmit the first placeholder information before the first time.

[0125] The third method is a combination of the second method and the first method, in which case the second time threshold is smaller than the first time threshold.

[0126] Here, the time duration for transmitting the first placeholder information is less than or equal to the third predetermined threshold. The first time threshold, the second time threshold, and the third predetermined threshold are all values ​​set by the upper layer, or values ​​predefined, pre-set, or configured by the protocol.

[0127] The duration for transmitting the first placeholder information may be set by a higher layer or pre-configured. The first time threshold may also be related to the time required for Type 2 LBT. The duration for transmitting the first placeholder information may also be related to the location of the waiting resource at the first terminal and / or the time required for Type 2 LBT and / or the service priority and / or the channel access priority.

[0128] The first and second thresholds mentioned above are merely illustrative examples of several different situations; in practice, we do not define first and second thresholds, but simply indicate that the transmission of placeholder information is permitted before transmission and that the transmission time of the placeholder information must be less than or equal to a (pre-configured) threshold. Here, the (pre-configured) threshold corresponding to the transmission time of the placeholder information may be related to service priority or channel access priority.

[0129] As shown in Figure 5, in the fourth embodiment, the first terminal performs Physical Sidelink Control Channel (PSCCH) / Physical Sidelink Shared Channel (PSSCH) transmission after completing Type 1 LBT. If the interval between subsequent transmissions is smaller than a set delay threshold and longer than the Type 2 LBT time, the terminal sends placeholder information for a predetermined duration to ensure that the interval between transmissions satisfies the Type 2 LBT duration, thereby preventing access by other systems during this period. The reason for defining a delay threshold is to avoid unfairness to other systems due to excessively long durations of placeholder information transmitted by the terminal. In other words, placeholder information can only be transmitted under predetermined conditions, and the duration of the placeholder information is never excessively long.

[0130] Selectively, the method further includes step 300.

[0131] In step 300, the first terminal transmits the first control information to the second terminal.

[0132] The first control information includes information related to the COT determined by the first terminal.

[0133] Steps 100 to 200 are processes in which the first terminal performs a Type 1 LBT based on the first target resource to determine the Cost of the Investment (COT), and this process is relevant only to the first terminal. Steps 100 to 300 are processes in which the first terminal performs a Type 1 LBT based on the first target resource to determine the COT, and further shares the relevant information of the COT determined by the first terminal with the second terminal.

[0134] Sharing of the COT is not a mandatory feature; it does not need to be shared with other user terminals (User Equipment, UE), meaning the COT may be used only by the first terminal (steps 100 to 200). The aforementioned sharing of the COT can also realize the process of "LBT of the first terminal + the first terminal shares the determined COT + the second terminal receives the COT" (steps 100 to 300).

[0135] In step 300, after performing the Type 1 LBT, the first terminal may transmit the information regarding the COT determined by the first terminal to the second terminal. Here, the first control information includes at least one of the following: Remaining COT (remaining COT time), time-frequency position of the transmission waiting resource of the first terminal, LBT subband information, ID of the first terminal, ID of the terminal scheduled to receive shared COT information, priority of the transmission waiting service of the first terminal, COT placeholder information determined by the first terminal, Channel Busy Ratio (CBR) information measured by the first terminal, time-frequency range of transmission resources to recommend to other terminals (similar to inter-UE cooperative processing), time-frequency range of transmission resources not to recommend to other terminals, and channel access priority.

[0136] The scene in step 300 may include at least one of unicast, connected multicast, unconnected multicast, and broadcast.

[0137] Selectively, step 300 includes the step of the first terminal transmitting the first control information to the second terminal if the first condition is met.

[0138] The first condition is, The remaining time of the aforementioned COT is equal to or greater than a pre-set first threshold. The duration for executing the aforementioned Class 1 channel access procedure is less than or equal to a pre-configured second threshold. The remaining number of transmissions for the first terminal is less than or equal to a pre-set third threshold. The first terminal receives the billing information transmitted to the first terminal by the second terminal (the billing information is used to indicate that it expects to receive the first control information transmitted by the first terminal), The first terminal has a service to transmit to the second terminal, The higher-level settings or pre-configurations support COT sharing. The first terminal supports the execution of COT sharing. The service priority value of the first terminal is less than (or less than) a predetermined service priority threshold. The channel access priority value of the first terminal is less than (or less than) the channel access priority threshold, and The first terminal satisfies at least one of the following conditions: the time-frequency resource occupancy rate of the first terminal is less than (or less than) the value of the COT time-frequency resource ratio set or pre-configured by the upper layer.

[0139] The pre-configured first threshold, pre-configured second threshold, pre-configured third threshold, predetermined service priority threshold, and COT time-frequency resource ratio are all values ​​that have been set by a higher layer or pre-configured by a protocol. The first and second thresholds may be 3 to 5 ms. The number of the third threshold may be 1, 2, 3, 4, etc., and is not limited thereto. The predetermined service priority threshold may be 1 to 8. The COT time-frequency resource ratio may be 20%, etc.

[0140] Prior to step 300, the method may further include step 310.

[0141] In step 310, the maximum decoding delay is determined.

[0142] In this embodiment, prior to step 300, the first terminal determines the maximum decoding delay from a predetermined protocol. The maximum decoding delay is greater than or equal to the decoding delay of the second terminal, ensuring continuous occupancy of the channel and avoiding access from other systems.

[0143] Selectively, the first terminal, within the maximum decoding processing delay, The first terminal can perform at least one of the following: transmit a service to the second terminal, and transmit second placeholder information to the second terminal. Here, the delay of the second placeholder information is less than or equal to a fourth predetermined threshold.

[0144] The fourth predetermined threshold is related to service priority or channel access priority.

[0145] The first terminal occupies the channel by performing continuous transmissions within the maximum decoding processing delay. The continuous transmissions include at least one of PSCCH (Physical Sidelink Control Channel) / PSSCH (Physical Sidelink Shared Channel) transmissions and the transmission of the second placeholder information.

[0146] Here, the time duration for transmitting the second placeholder information is T. proc,0 -T PSCCH / PSSCH And here, T proc,0 is the maximum decoding delay, and T PSCCH / PSSCH This is the time when the first terminal transmits PSCCH / PSSCH, and T PSCCH / PSSCH It may be 0.

[0147] Furthermore, after the first terminal determines the COT, it shares the COT with the second terminal. However, considering the decoding processing time of the second terminal, it is necessary to perform additional processing to ensure continuous occupancy of the channel and avoid access from other systems. In addition, the first terminal may transmit PSCCH / PSSCH continuously, and since the channel is already occupied during this time, TPSCCH / PSSCH is further subtracted.

[0148] After determining the COT in step 200, the method may further include steps 410 to 430.

[0149] In step 410, the retransmission time of the first terminal is determined.

[0150] In step 420, if the retransmission time falls within the COT range, a Class II channel access procedure is performed for the retransmission of at least some of the first target resources.

[0151] In step 430, if the retransmission time is outside the range of the COT, a Class 1 channel access procedure is performed for the retransmission of at least some of the first target resources.

[0152] Here, the aforementioned Class 2 channel access refers to channel access that performs only LBT based on a determined interval.

[0153] In this embodiment, if the subsequent transmission of the first terminal, i.e., the retransmission time of the first terminal, falls within the valid range of the COT, the type of Type 2 LBT is determined based on the transmission location and required time, and the transmission process is executed after determining that the channel is idle. Here, the COT described above may be a COT determined by the first terminal itself, or a COT shared by the second terminal that has been received, but the COT here refers only to a COT determined by the first terminal. If the retransmission time of the first terminal does not fall within the valid range of the COT, the channel is monitored again according to the Type 1 LBT before the subsequent transmission, i.e., a Type 1 channel access procedure is performed for the retransmission of at least some of the first target resources.

[0154] If, in step 200, when performing a Class I channel access procedure for at least some of the first target resources, the method receives second control information transmitted to the first terminal by the second terminal, the method may further include step 500.

[0155] In step 500, 3 If the conditions are met, it is decided to terminate the Class 1 channel access procedure and to execute the Class 2 channel access procedure for at least some of the Class 1 target resources based on the second control information. Here, the second control information includes information about the COT determined by the second terminal, and the second type of channel access indicates that channel access is performed based only on the LBT of the determined interval.

[0156] The information regarding COT determined by the aforementioned second terminal is similar to the information regarding COT determined by the first terminal described above, and therefore will not be explained in detail here.

[0157] Needless to say, the method further includes the step of directly deciding to terminate the Class 1 channel access procedure and performing a Class 2 channel access procedure for at least some of the Class 1 target resources.

[0158] In this embodiment, if the first terminal receives relevant information about the COT shared by the second terminal while executing a Type 1 LBT, the first terminal may terminate the Type 1 LBT and, based on the second control information, transmit using a Type 2 LBT during the remaining time of the COT shared by the second terminal, that is, it may preferentially use the COT shared by the other terminal. In other words, it is the process defined in step 500 as "deciding to terminate the first channel access procedure and executing a second channel access procedure for at least some of the first target resources."

[0159] Needless to say, the priority of the COT determined by the first terminal itself is higher than the priority of the COT shared by the second terminal that it receives; in other words, the COT determined by the first terminal is used preferentially.

[0160] Specifically, the aforementioned 3 The conditions are, The service priority of the first terminal is less than or equal to the service priority of the second terminal. The channel access priority of the first terminal is lower than (or less than) the channel access priority of the second terminal. This includes at least one of the following: the remaining COT time of the second terminal is greater than (or greater than) the third time threshold.

[0161] Here, the third time threshold is a value set by the upper layer, or a value predefined, pre-configured, or set by the protocol.

[0162] The aforementioned Class 2 channel access represents performing channel access based solely on LBT at a determined interval.

[0163] In this embodiment, the first terminal determines the second based on its own relevant information (service priority, channel access priority, etc.) and / or the received second control information (information related to COT determined by the second terminal, i.e., service priority, channel access priority, remaining COT, etc.). 3 The conditions are, If the service priority of the first terminal is higher than (or greater than) the service priority of the terminal sharing the COT, the first terminal will continue with its Type1 LBT; otherwise, it will terminate its Type1 LBT and perform Type2 LBT using the COT shared by the second terminal for transmission. If the channel access priority of the first terminal is higher than (or greater than) the channel access priority of the terminal sharing the COT, the first terminal will proceed with its Type1 LBT; otherwise, it will terminate its Type1 LBT and perform Type2 LBT using the COT shared by the second terminal for transmission. The procedure includes at least one of the following: if the remaining COT of a terminal sharing COT is less than (or less than) the third time threshold, the first terminal continues its Type1 LBT; otherwise, the terminal terminates its Type1 LBT and performs a Type2 LBT using the COT shared by the second terminal for transmission. Here, the third time threshold is a value set by the upper layer, or a value predefined, pre-configured, or set by the protocol.

[0164] Steps 500 and 500 of this disclosure 3 The conditions define the process by which the first terminal should handle the COT (Control Point) when it receives a COT shared by another terminal (second terminal) during Type 1 LBT (Low-Level Testing), thereby complementing the processing mechanism of the first terminal.

[0165] As shown in Figure 6, Figure 6 shows the priority relationship between Type 1 LBT and Type 2 LBT. In the fifth embodiment, the first terminal executes Type 1 LBT for initial transmission, with a start time of m1. During execution, if the terminal receives a COT shared by the second terminal at time m2 shown in Figure 6, and the resources for the initial transmission and retransmission of subsequent transmissions are located within the COT time period shared by the second terminal, the terminal can terminate Type 1 LBT. Since the resources for initial transmission and retransmission belong to the second terminal's shared COT, the first terminal can execute Type 2 LBT before transmission, thereby enabling faster access to the channel.

[0166] Based on the above, the first terminal of this disclosure can perform resource selection, execution of Type 1 LBT, determination of COT, enhancement processing before initial transmission, initial transmission, COT sharing, enhancement processing after COT sharing, LBT for retransmission, and retransmission. This disclosure complements the sidelink channel access processing procedure, clarifies the specific behavior of the terminal when accessing the channel, and further ensures continuous occupancy of the sidelink during channel access, thereby reducing the risk of transmission failure due to access by other systems.

[0167] As shown in Figure 7, embodiments of the present disclosure further provide a channel access processing method for a side link applied to a second terminal, the method comprising steps 400 and 500.

[0168] In step 400, the second terminal receives first control information transmitted by the first terminal. The first control information includes information about the COT determined by the first terminal.

[0169] Here, the information regarding the COT determined by the aforementioned first terminal is consistent with the information introduced above and will not be explained in detail here.

[0170] In step 500, information transmission is performed based on the first control information.

[0171] In this embodiment, after the second terminal receives information regarding the COT determined by the first terminal, its own resource selection process or transmission process may be affected to some extent. Therefore, steps 400 to 500 further complement the processing process of the second terminal and maintain continuous channel occupancy by the Sidelink system as much as possible.

[0172] Specifically, the following two methods may be included for complementing the resource selection processing process of the second terminal. In Method 1, the terminal determines a resource selection window based on the received COT. The specific determination method may be to use the intersection of the COT and the resource selection window determined by the terminal as the final resource selection window. In Method 2, the terminal determines (or updates) the final set of available resources based on the received COT. In the specific method, all available resources within the COT time period from the set of available resources determined by the terminal are designated as the first set of available resources, and the second terminal first selects a resource from the first set of available resources. If the resources in the first set of available resources do not satisfy the transmission request, the second terminal returns to the complete set of available resources determined by the terminal and selects a resource.

[0173] Selectively, after step 400 and if the second terminal has already determined the second target resource, step 500 includes steps 510 and 520.

[0174] In step 510, the remaining time of the COT is determined based on the first control information.

[0175] In step 520, if the transmission time of the second target resource determined by the second terminal at the first terminal falls within the remaining time of the COT, the second terminal performs a Class 2 channel access procedure to transmit information.

[0176] In this embodiment, if the second terminal has already determined the second target resource, only the impact of the received COT on the transmission is considered. If the transmission by the second terminal is within the remaining COT (Remaining COT), the Type 2 channel access procedure performed by the second terminal is relatively simpler and the access process is faster.

[0177] Specifically, the start time when the second terminal executes the second channel access procedure is the time unit immediately preceding the time unit in which the second target resource is located.

[0178] Note that LBT is performed in the previous time unit, and the transmit / receive switching time is guaranteed after LBT. Placeholder information may be sent after the transmit / receive switching time. However, sending placeholder information is not mandatory; for example, if the transmit / receive switching (TX / RX switching) is completed exactly one unit prior. Time unit If located on the back edge, the second terminal may perform a transmission directly in the current time unit. The time unit may be a slot, a set of consecutive symbols, and the like. In particular, the start time when the second terminal performs the second-class channel access procedure may be located at the last symbol of the previous time unit.

[0179] Refer to Figure 8. In Figure 8, CPE is an extension of the cyclic prefix (CP) and can be understood as a method for transmitting placeholder information. In the sixth embodiment, taking the time unit as a slot as an example, each slot contains 14 symbols. If the current subcarrier interval is 15 kHz, the length of one symbol is approximately 71.4 μs. A terminal can perform PSCCH / PSSCH transmission in slot n and execute Type 2-A LBT, and the terminal starts LBT at some point in symbol #13 of the previous slot. Here, the selection of the start time must take into account the LBT duration and the transmit / receive switching (TX / RX switching) time, and ensure that the LBT and transmit / receive switching are completed before the transmit slot n.

[0180] In Method 1, after the transmission / reception switchover is complete, the terminal can send placeholder information to occupy the channel, thereby ensuring that the placeholder information and the actual transmission are temporally consecutive.

[0181] In method 2, after the transmission / reception switchover is complete, if the interval between the next slot is greater than a certain threshold, the terminal can transmit placeholder information to occupy the channel, thereby ensuring that the placeholder information and the actual transmission are temporally continuous.

[0182] Here, the last symbol of the previous slot is determined as the start time of the Type 2 LBT, i.e., the start time when the second terminal performs the Type 2 channel access procedure.

[0183] Alternatively, the start time at which the second terminal performs the second channel access procedure is the time unit in which the second target resource is located.

[0184] In this embodiment, the start time for the second terminal to perform the second channel access procedure is the time unit in which the second target resource is located. That is, the terminal performs LBT in the time unit (which can be understood as a slot) in which the LBT waiting resource is located, and provides a transmit / receive switching time before transmitting, and then maps all or part of the contents of the second symbol to the remaining part of the symbol in which the LBT is located. In particular, the start time of the LBT may be located in the first symbol occupied by the current PSCCH / PSSCH transmission.

[0185] As shown in Figure 9, in the seventh embodiment, the terminal can perform PSCCH / PSSCH transmission in slot n and execute Type2-A LBT. The terminal must start Type2 LBT from the starting position of the first symbol in slot n, pre-hold the transmit / receive switching time after the LBT is completed, and then map a portion of the content of the second symbol onto the remaining part of the first symbol.

[0186] Here, the first symbol of the current slot is determined as the start time of the Type 2 LBT, that is, the start time when the second terminal performs the Type 2 channel access procedure.

[0187] In this disclosure, the granularity of resources in the frequency domain may be subchannels, IRBs, discontinuous physical resources, etc.

[0188] If, after step 400, the second terminal has not determined the second target resource, then step 500 proceeds as follows: The remaining time of COT is determined based on the first control information, Based on the remaining time of the aforementioned COT, the second terminal performs resource selection to determine the second target resource, This includes transmitting information based on the second target resource and the first control information.

[0189] In this embodiment, if the second terminal has not determined a second target resource, only the impact of the received COT on the enhancement of resource selection is considered. Specifically, the enhancement method is almost the same as in steps 110-130 on the first terminal side, but the difference is that the first terminal side enhances resource selection based on the COT it itself determined based on access priority, whereas here resource selection is enhanced based on the received COT. Similarly, this includes selecting consecutive resources and being located within the COT time.

[0190] Needless to say, the method for determining contiguous and discontinuous resources among available resources is also applied to the second terminal.

[0191] As shown in Figure 14, regarding the transmission of placeholder information, the first and second terminals can transmit placeholder information both before and after transmission, and may also be CPEs. The length of the transmitted placeholder information must be less than or equal to the second pre-configured threshold, and the second pre-configured threshold is related to channel access priority or service priority.

[0192] As shown in Figure 10, embodiments of the present disclosure further provide a channel access processing device for side links. The device is A first processing module 10 is used by the first terminal to perform resource selection and determine the first target resource, The system includes a second processing module 20 used to perform a Class I channel access procedure on at least some of the aforementioned first target resources and to determine whether the channel is idle and the channel occupancy time (COT).

[0193] Selectively, the apparatus may further include a first transmission module used by the first terminal to transmit first control information to a second terminal, wherein the first control information includes information related to the COT determined by the first terminal.

[0194] Selectively, the first processing module 10, A first decision submodule used to determine the time to trigger resource selection, A second decision submodule used to determine the resource selection window based on the time that triggers resource selection, It may also include a third decision submodule used to determine a first target resource based on the resource selection window, Here, the first time interval T1 between the start time of the resource selection window and the time that triggers resource selection is determined by the transmission processing delay, the resource selection processing delay of the first terminal, and the minimum time length for executing the first type channel access procedure.

[0195] The first time interval T1 is, The first time interval T1 is greater than or equal to zero. The first time interval T1 is less than or equal to the transmission processing delay. The first time interval T1 is longer than the minimum time length, and The first time interval T1 is greater than the sum of the minimum time length and the resource selection processing delay, and includes at least one of these conditions.

[0196] Furthermore, the first target resource satisfies the condition that the number of first target resources is N+M resources.

[0197] Here, N is the number of transmission resources required for the transmission of transmission block TB, and M is the number of additional candidate transmission resources. N and M are integers greater than or equal to 1.

[0198] The value of M is A value set by the higher layer, or The protocol predefined, pre-configured, or set values, or Includes a value determined based on the first parameter information.

[0199] Furthermore, the first parameter information is Channel access priority and Data priority and Channel busy rate and The value of N and, The past duration of the first terminal's execution of the first type channel access procedure, Channel occupancy and Includes at least one of the following: maximum channel occupancy.

[0200] The first target resource that was decided upon is: Among the available resources, resources that are consecutive in the time domain, In the available resources, resources that are consecutive in the time domain with resources reserved by other devices, Among the available resources, resources that are within one maximum channel occupancy time, and The available resources include at least one resource that is within the same single maximum channel occupancy time as a resource reserved by another terminal.

[0201] Furthermore, the determined first target resource includes resources from the available resources that satisfy the second condition and are discontinuous in the time domain.

[0202] The second condition is that the second time interval between two adjacent transmissions is greater than a first predetermined threshold, the first predetermined threshold being a value set by a higher layer, or a value predefined, pre-set, or configured by the protocol.

[0203] The second processing module 20 is: A fourth decision submodule used to determine a first candidate time for the commencement of the Class 1 channel access procedure, and / or a second candidate time for the commencement of the Class 1 channel access procedure, A fifth decision submodule used to determine the LBT start time for executing the Class 1 channel access procedure based on the first candidate time and / or the second candidate time, The system may also include a sixth decision submodule used to perform a Class I channel access procedure on at least some of the first target resources based on the LBT start time.

[0204] Selectively, the fifth decision submodule includes a first decision unit, the first decision unit is If the second candidate time is equal to or later than the first candidate time, then it is determined that the LBT start time is equal to or later than the first candidate time and equal to or earlier than the second candidate time, or If the second candidate time is earlier than the first candidate time, this is used to determine whether the LBT start time is equal to or later than the first candidate time.

[0205] Selectively, the fourth decision submodule includes the second decision unit, and the second decision unit is, Determine a first start time that triggers the first terminal to perform resource selection, and a processing delay for the first terminal to perform resource selection. Formula 1, A1 = B1 + C1, is used to determine the first candidate time.

[0206] Here, A1 indicates the first candidate time, B1 indicates the first start time, and C1 indicates the processing delay for the first terminal to perform resource selection.

[0207] Selectively, the fourth decision submodule further includes a third decision unit, and the third decision unit is Based on the first target resource, the time at which the resource corresponding to the first channel access procedure is located among the first target resources and the first time duration for executing the first channel access procedure are determined, and the second candidate time is determined using formula 2, A2 = B2 - C2, or, The time length required for the transmission block TB of the first target resource, the latest time in the resource selection window of the first target resource, and the first time length are determined and used to determine the second candidate time using formula 3, A2=B3-C2-D1.

[0208] Here, A2 indicates the second candidate time, B2 indicates the time the resource is located, C2 indicates the first time length, B3 indicates the latest time in the resource selection window, and D1 indicates the time length required for the transmission block TB.

[0209] Selectively, the apparatus, A first determination module used to determine the retransmission time of the first terminal, If the retransmission time falls within the COT range, a first execution module is used to perform a Class II channel access procedure for the retransmission of at least some of the first target resources, If the retransmission time falls outside the range of the COT, the system may further include a second executable module used to perform a Class I channel access procedure for the retransmission of at least some of the first target resources.

[0210] Selectively, the apparatus, A second determination module used to determine the end time at which the execution of the Class 1 channel access procedure described above is completed, and the first time of the nearest waiting resource for transmission from the end time, The system may further include a second transmission module used to transmit the waiting resources based on the aforementioned end time and the aforementioned first time.

[0211] The second transmission module includes either a first transmission unit or a fourth decision unit and a second transmission unit. The first transmission unit is used to directly transmit the resources waiting to be transmitted if the end time is equal to the first time or the interval between the end time and the first time is less than or equal to a second predetermined threshold. The fourth decision unit is used to determine a first target interval between the end time and the first time, if the end time is before the first time. The second transmission unit is used to determine whether to transmit the pending resources based on the first target interval.

[0212] Selectively, the second transmission module further includes a third transmission unit, or a fourth transmission unit, or a fifth transmission unit. The third transmission unit is used to determine whether to transmit the first placeholder information before the first time if the first target interval is greater than or equal to the first time threshold. The fourth transmission unit is used to determine whether to transmit the first placeholder information before the first time if the first target interval is less than or equal to the second time threshold. The fifth transmission unit is used to determine whether to transmit the first placeholder information before the first time if the first target interval is between the second time threshold and the first time threshold.

[0213] Here, the time duration for transmitting the first placeholder information is less than or equal to the third predetermined threshold. The first time threshold, the second time threshold, and the third predetermined threshold are all values ​​set by the upper layer, or values ​​predefined, pre-set, or configured by the protocol.

[0214] Selectively, the above First transmission The module, when the first condition is met, transmits the first control information to the second terminal. send Submodules may be included.

[0215] The first condition is, The remaining time of the aforementioned COT is equal to or greater than a pre-set first threshold. The duration for executing the aforementioned Class 1 channel access procedure is less than or equal to a pre-configured second threshold. The remaining number of transmissions for the first terminal is less than or equal to a pre-set third threshold. The first terminal receives billing information transmitted to the first terminal by the second terminal (the billing information is used to indicate that it expects to receive the first control information transmitted by the first terminal), The first terminal has a service to transmit to the second terminal, The higher-level settings or pre-configurations support COT sharing. The first terminal supports the execution of COT sharing. The service priority value of the first terminal is less than a predetermined service priority threshold. The channel access priority value of the first terminal is less than the channel access priority threshold, and The first terminal satisfies at least one of the following conditions: the time-frequency resource occupancy rate of the first terminal is less than the value of the COT time-frequency resource ratio set or pre-configured by the upper layer.

[0216] Selectively, the apparatus further includes a third execution module, the third execution module being 3 If the conditions are met, it is decided to terminate the Class 1 channel access procedure and the second control information is used to execute a Class 2 channel access procedure for at least some of the Class 1 target resources.

[0217] Here, the second control information includes information about the COT determined by the second terminal.

[0218] Furthermore, the above 3 The conditions are, The service priority of the first terminal is less than or equal to the service priority of the second terminal. The channel access priority of the first terminal is lower than the channel access priority of the second terminal. This includes at least one of the following: the remaining COT time of the second terminal is greater than the third time threshold.

[0219] Here, the third time threshold value is a value set by a higher layer or a value pre-defined, pre-set, or set by a protocol.

[0220] Optionally, the device may further include a third determination module used to determine the maximum decoding processing delay.

[0221] Note that within the maximum decoding processing delay, the first terminal can perform at least one of the following: transmitting service to the second terminal; transmitting second placeholder information to the second terminal. Here, the delay of the second placeholder information is not more than a fourth predetermined threshold value.

[0222] As shown in FIG. 11, a selectable embodiment of the present disclosure further provides a sidelink channel access processing device. The device includes a third processing module 30 and a fourth processing module 40. The third processing module 30 is used to receive first control information transmitted by the first terminal to the second terminal, and the first control information includes information related to the COT determined by the first terminal. The fourth processing module 40 is used to perform information transmission based on the first control information.

[0223] Optionally, the fourth processing module 40 includes a fifth determination unit and a first processing unit. The fifth determination unit is used to determine the remaining time of the COT based on the first control information. The first processing unit enables the second terminal to perform a second type of channel access procedure for information transmission when the transmission time of the second target resource determined by the second terminal at the first terminal is within the remaining time of the COT.

[0224] Note that the start time for the second terminal to execute the second type of channel access procedure is the time unit before the time unit where the second target resource is located, or the start time for the second terminal to execute the second type of channel access procedure is the time unit where the second target resource is located.

[0225] Optionally, the fourth processing module 40 may further include a sixth determination unit used to determine the remaining time of the COT based on the first control information, a seventh determination unit used to determine the second target resource by the second terminal performing resource selection based on the remaining time of the COT, and a second processing unit used to perform information transmission based on the second target resource and the first control information.

[0226] As shown in FIG. 12, a mobile terminal according to another embodiment of the present disclosure includes a transceiver 1210, a processor 1200, a memory 1220, and a program or instruction stored in the memory 1220 and executable by the processor 1200. When the processor 120 executes the program or instruction, the above-described sidelink channel access processing method is realized.

[0227] The transceiver 1210 is used to transmit and receive data under the control of the processor 1200.

[0228] In Figure 12, the bus architecture may include any number of interconnected buses and bridges, specifically connecting various circuits between one or more processors, represented by processor 1200, and memory, represented by memory 1220. The bus architecture may further connect various other circuits, such as peripherals, regulators, and power management circuits, all of which are well known in the art and will not be described further here. The bus interface provides an interface. The transmitter / receiver 1210 may be a set of elements including a transmitter and a receiver, providing a unit for communicating with various other devices over a transmission medium. For different user devices, the user interface may be an interface for connecting necessary devices externally or internally, and the connected devices may include, but are not limited to, keypads, displays, speakers, microphones, joysticks, etc.

[0229] The processor 1200 manages the bus architecture and normal processing, and the memory 1220 can store data that the processor 1200 uses when performing operations.

[0230] Network-side equipment according to other embodiments of the present disclosure, as shown in Figure 13, includes a transmitter / receiver 1310, a processor 1300, a memory 1320, and a program or instruction stored in the memory 1320 that can be executed by the processor 1300. When the processor 1300 executes the program or instruction, the above-described side-link channel access processing method is realized.

[0231] The transmitter / receiver 1310 is used to send and receive data under the control of the processor 1300.

[0232] In Figure 13, the bus architecture may include any number of interconnected buses and bridges, specifically connecting various circuits between one or more processors, represented by processor 1300, and memory, represented by memory 1320. The bus architecture may further connect various other circuits, such as peripherals, regulators, and power management circuits, all of which are well known in the art and will not be described further here. The bus interface provides an interface. The transmitter / receiver 1310 may be a set of elements including a transmitter and a receiver, providing a unit for communicating with various other devices over a transmission medium. Processor 1300 manages the bus architecture and normal operations, and memory 1320 can store data used by processor 1300 when performing operations.

[0233] Embodiments of this disclosure further provide network-side equipment. The network-side equipment includes memory, a processor, and a computer program stored in memory and executable on the processor, and when the computer program is executed by the processor, it can realize each process in the embodiment of the side-link channel access processing method described above and achieve the same technical effects, which will not be described in detail here to avoid duplication.

[0234] The readable storage medium according to the embodiments of this disclosure stores a program or instruction, and when the program or instruction is executed by the processor, it can realize the steps in the side-link channel access processing method described above and achieve the same technical effect, which will be omitted here to avoid duplication.

[0235] Here, the processor is the processor in the side-link channel access processing method described in the above embodiment. The readable storage medium includes computer-readable storage media such as read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0236] The devices described herein include, but are not limited to, smartphones and tablet computers. Furthermore, many of the functional components described are referred to as modules, further emphasizing the independence of their implementation methods.

[0237] In embodiments of this disclosure, modules may be implemented in software to be executed by various types of processors. For example, an identified executable code module may include one or more physical or logical blocks of computer instructions, which may be constructed as, for example, an object, process, or function. Nevertheless, the executable code of an identified module does not need to be physically located in the same place, and may include different instructions stored in different locations, which, when logically combined, constitute a module and achieve a predetermined purpose of that module.

[0238] In practice, an executable code module may be a single instruction or a number of instructions, distributed across multiple different code segments, distributed across different programs, or distributed across multiple memory devices. Similarly, operational data may be recognized within a module, or it may be implemented in any suitable form and embedded in any suitable type of data structure. Such operational data may be collected as a single dataset, or distributed in different locations (including different storage devices), or it may exist in a system or network at least partially as electronic signals.

[0239] If a module can be implemented by software, and considering the level of hardware processes in the related technology, a person skilled in the art can construct a corresponding hardware circuit to implement the corresponding function for a software-implementable module, disregarding cost. The hardware circuit may be a conventional very large-scale integrated circuit (VLSI) or gate array, and semiconductors or other independent elements in the related technology, such as logic chips or transistors. The module may also be implemented by programmable hardware devices such as field-programmable gate arrays, programmable array logic, or programmable logic devices.

[0240] The above describes preferred embodiments of the present disclosure. Those skilled in the art can make several improvements and modifications without departing from the principles described in the present disclosure, and these improvements and modifications should also be considered within the scope of the present disclosure.

Claims

1. A channel access processing method for side links applied to a first terminal, The first terminal performs resource selection and determines the first target resource, A step of performing a Class I channel access procedure on at least some of the aforementioned first target resources to determine whether the channel is idle and the channel occupancy time (COT), The first terminal transmits first control information to the second terminal, The first control information includes information related to the COT determined by the first terminal, The first control information includes the remaining time of the COT and the channel access priority, and further includes at least one of the ID of the first terminal and the ID of a terminal that is scheduled to receive the shared COT information. The first target resource determined includes resources from the available resources that satisfy the second condition and are discontinuous in the time domain. The second condition is that the second time interval between two adjacent transmissions is greater than the first predetermined threshold. A method for processing channel access for side links.

2. The first terminal performs resource selection and determines the first target resource, The steps include determining the time to trigger resource selection, The steps include determining a resource selection window based on the time that triggers the resource selection, The step of determining the first target resource based on the resource selection window, Here, the first time interval (T1) between the start time of the resource selection window and the time that triggers the resource selection is determined by the transmission processing delay, the resource selection processing delay of the first terminal, and the minimum time length for executing the first channel access procedure. The first time interval (T1) is The first time interval (T1) is greater than or equal to zero. The first time interval (T1) is less than or equal to the transmission processing delay. The first time interval (T1) is longer than the minimum time length, and At least one of the following is satisfied: the first time interval (T1) is greater than the sum of the minimum time length and the resource selection processing delay. The channel access processing method for side links according to claim 1.

3. The first target resource that was decided was: Among the available resources, resources that are consecutive in the time domain, In the available resources, resources that are consecutive in the time domain with resources reserved by other devices, Among the available resources, resources that are within one maximum channel occupancy time, and Among the available resources, at least one of the resources that are within the same maximum channel occupancy time as a resource reserved by another terminal, The channel access processing method for side links according to claim 1.

4. The step of performing a Class I channel access procedure for at least some of the aforementioned first target resources is: The steps include determining a first candidate time for initiating the Class 1 channel access procedure and / or a second candidate time for initiating the Class 1 channel access procedure, A step of determining the LBT start time for executing the Class 1 channel access procedure based on the first candidate time and / or the second candidate time, The steps include: performing a Class 1 channel access procedure for at least some of the first target resources based on the LBT start time; The channel access processing method for side links according to claim 1.

5. The step of determining the LBT start time for executing the Class 1 channel access procedure is: If the second candidate time is later than or equal to the first candidate time, the step of determining that the LBT start time is later than or equal to the first candidate time, and earlier than or equal to the second candidate time, or The process includes the step of determining, if the second candidate time is earlier than the first candidate time, that the LBT start time is later than the first candidate time or equal to the first candidate time. The channel access processing method for side links according to claim 4.

6. The step of determining the first candidate time is: The steps include determining a first start time at which the first terminal is triggered to perform resource selection, and a processing delay for the first terminal to perform resource selection. The step includes determining the first candidate time using the formula A1 = B1 + C1, Here, A1 indicates the first candidate time, B1 indicates the first start time, and C1 indicates the processing delay for the first terminal to perform resource selection. The channel access processing method for side links according to claim 4.

7. The step of determining the second candidate time is: The steps include determining, based on the first target resource, the time at which the resource corresponding to the first channel access procedure is located among the first target resources, and the first time length for executing the first channel access procedure, The step of determining the second candidate time using the formula A2 = B2 - C2, or includes, or The steps include determining the time length required for the transmission block TB of the first target resource, the latest time in the resource selection window of the first target resource, and the first time length, This includes the step of determining the second candidate time using the formula A2 = B3 - C2 - D1, Here, A2 indicates the second candidate time, B2 indicates the time the resource is located, C2 indicates the first time length, B3 indicates the latest time in the resource selection window, and D1 indicates the time length required for the transmission block TB. The channel access processing method for side links according to claim 4.

8. After determining the aforementioned COT, The steps include determining the retransmission time of the first terminal, If the retransmission time falls within the range of the COT, the steps include performing a Class II channel access procedure for the retransmission of at least some of the first target resources, If the retransmission time falls outside the range of the COT, the further step includes performing a Class I channel access procedure for the retransmission of at least some of the first target resources. The channel access processing method for side links according to claim 1.

9. The step of the first terminal transmitting the first control information to the second terminal is: If the first condition is met, the first terminal transmits the first control information to the second terminal, The first condition is, The remaining time of the COT is greater than or equal to a pre-set first threshold. The first terminal has a service to transmit to the second terminal, The higher layer's configuration or pre-configuration supports COT sharing, and The first terminal supports the execution of COT sharing. Satisfying at least one of the following: The channel access processing method for side links according to claim 1.

10. When performing a Class 1 channel access procedure for at least some of the first target resources, and receiving second control information transmitted to the first terminal by the second terminal, the side link channel access processing method: If the third condition is met, the procedure further includes deciding to terminate the Class 1 channel access procedure and, based on the second control information, performing a Class 2 channel access procedure for at least some of the Class 1 target resources. Here, the second control information includes information about the COT determined by the second terminal, The third condition mentioned above is, The service priority of the first terminal is less than or equal to the service priority of the second terminal. The channel access priority of the first terminal is lower than the channel access priority of the second terminal, and The condition includes at least one of the following: the remaining COT time of the second terminal is greater than the third time threshold, The channel access processing method for side links according to claim 1.

11. Before the first terminal transmits the first control information to the second terminal, The step further includes determining the maximum decoding delay. The channel access processing method for side links according to claim 1.

12. The first terminal, within the maximum decoding processing delay, To transmit a service to the second terminal, The system can perform at least one of the following: transmitting second placeholder information to the second terminal, wherein the time length of the second placeholder information is less than or equal to a fourth predetermined threshold. The channel access processing method for side links according to claim 11.

13. Terminal device, It includes a transmitter / receiver, a processor, memory, and a program or instructions stored in the memory that can be executed by the processor, When the processor executes the program or instruction, it implements the side-link channel access processing method described in any one of claims 1 to 12. Terminal equipment.

14. A program or instruction is stored, and when the program or instruction is executed by the processor, the side-link channel access processing method described in any one of claims 1 to 12 is realized. A readable storage medium.

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