A method and apparatus of resource selection for sidelink communication

[0028] The invention will now be discussed in detail with reference to the accompanying drawings briefly described above. In the following description, numerous specific details are set forth to explain applicant's best mode for practicing the invention and to enable others skilled in the art to make and use the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without many of these specific details. Furthermore, well known machines and method steps have not been described in particular detail in order to avoid unnecessarily obscuring the present invention. Unless otherwise indicated, identical parts and method steps will be designated by identical reference numerals.

[0029] The term "sidelink" as used in this invention is an adaptation of the core LTE standard that allows communication between two or more nearby devices using E-UTRAN technology (Evolved UMTS terrestrial radio access network). This technique can be used in out-of-network coverage situations.

[0030] Based on NR (New Radio) V2X business requirements, figure 1 The formation driving scenario shown in shows that the term "formation" used in the present invention may include a formation leader and a plurality of formation members, and formation members in a formation periodically receive data sent by the formation leader for use in Formation operations. Through information exchange between vehicles, the distance between vehicles can be very small, thereby reducing the fuel consumption of vehicles behind. Among them, the formation leader and multiple members can be regarded as user equipment (UE). Also, in other formation driving situations, formations are changed to groups for generality. Thus, a formation can be an instance of a group.

[0031] refer to figure 2 , an embodiment of a resource selection method for sidelink communication performed by group members includes:

[0032] Step 200, dividing the packet whose packet size is greater than a predetermined value into a basic part and an aperiodic part;

[0033] Step 210, sending the basic part through periodic traffic, and sending a resource request for the non-periodic part to the group leader;

[0034] Step 220, sending the aperiodic portion by the group leader based on the resources allocated by the joint resource selection.

[0035] In addition, at step 200, the predetermined value is firstly determined based on data traffic.

[0036] Taking the periodic traffic model 2 in NR V2X as an example, the periodic traffic model includes:

[0037] Arrival time between packets: 10ms

[0038] Other value(s) are not excluded, e.g. 100ms

[0039] Packet size: 1200 bytes with probability 0.2 and 800 bytes with probability 0.8

[0040] Latency requirement: 10ms

[0041] Therefore, the predetermined value of 800 bytes is determined based on the amount of data communication.

[0042] Subsequently, a packet having a packet size larger than the predetermined value is divided into a basic part and an aperiodic part. For example, the packet is divided into a first packet having said predetermined value and a second packet having a value equal to the difference between the size of the packet and said predetermined value, wherein the first packet is the base part, The second packet is the aperiodic part. The packet segmentation process can be performed at the RLC (Radio Link Control) layer or the MAC (Media Access Control) layer.

[0043] Taking NR's V2X periodic traffic model 2 as an example, a 1200-byte packet is divided into a basic part of 800 bytes and an aperiodic part of 400 bytes.

[0044] At step 210, the base portion may be treated as periodic traffic with a fixed traffic. The base part can be transmitted as periodic data, and during transmission, SPT (semi-permanent transmission) is an alternative. SPT makes it easy for other sensing UEs to avoid resources used by the base part, resulting in high resource efficiency. Group members can choose resources that are more suitable for their own surrounding radio environment.

[0045] At the same time, swarm members send aperiodic part resource requests to the swarm leader, which means swarm members request resources from the swarm leader. If aperiodic grouping has a low probability, the signaling overhead between the group leader and group members is also low.

[0046] Taking NR's V2X periodic traffic model 2 as an example, group members split 1200-byte packets into 800-byte basic parts using SPT, and send resource requests for non-periodic parts to the group leader for to arrange the remaining 400 bytes of resources.

[0047] At step 220, if the allocated resource by the group leader based on the joint resource selection is received within the predetermined delay limit, the group member transmits the aperiodic portion over the allocated resource. The group leader jointly reserves resources for aggregated data traffic for all members of the formation, which can easily avoid other sensing UEs, resulting in high resource efficiency similar to basic grouping.

[0048] The term "joint resource selection" as used in the present invention may include resources jointly selected by group leaders.

[0049] Alternatively, the group members send data traffic based on their own selected resources if the resources allocated by the group leader based on the joint resource selection are not received within a predetermined delay limit. This is similar to the one-shot transmission specified in LTE. The resource selection is one-time, and sensing for a one-time transmission cannot predict future resource usage.

[0050]Alternatively, the predetermined delay limit is generally less than 100ms.

[0051] Furthermore, an alternative is to use SPT (Semi-Permanent Transmission) to periodically transmit data traffic whose packet size is less than or equal to a predetermined value. That is, packet sizes smaller than or equal to a predetermined value of the base portion and packet sizes with a high probability are transmitted using periodic traffic, thereby forming continuity of periodic traffic transmission. Group members select periodic resources by themselves, and select resources that are more suitable for their own surrounding radio environment, resulting in high resource efficiency.

[0052] This embodiment of the resource selection method for sidelink communication divides packets with a small probability and a packet size larger than a predetermined value into a base part that is sent periodically and an aperiodic part that is sent aperiodically. In addition, resources are allocated for the aperiodic part of the aperiodic transmission by the group leader, thereby effectively avoiding conflicting transmissions with UEs outside the formation. Even without receiving resources allocated by the swarm leader, swarm members can transmit data at one time based on resources of their own choice without affecting future resource usage. In terms of resource allocation, SPT can be used for both periodic and aperiodic data transmission, in which the design of SPT is ensured through the PC5 interface, thereby avoiding resource conflicts in data transmission between vehicles within the coverage of traditional cellular in V2X services And the reliability of data transmission is improved.

[0053] refer to image 3 , an embodiment of a resource selection method for sidelink communication performed by a group leader includes:

[0054] Step 300, receiving the resource request of the aperiodic part sent by the group member;

[0055] Step 310, allocate resources to group members based on joint resource selection.

[0056] In addition, at step 300, the group leader, after receiving a resource request for the aperiodic part, looks for resources among the reserved joint resources, and allocates the found resources based on joint resource selection within a predetermined delay limit to Group members to send aperiodic parts. If no resource is found, the event is logged by the group leader to estimate joint data traffic statistics.

[0057] Alternatively, joint data traffic statistics are estimated by analyzing aperiodic portions of resource requests and/or resource assignment results for members, and/or by collecting traffic attribute information from group members. Wherein, the resource assignment result for group members may include resources allocated to group members after resources are found within a predetermined time delay limit, and after resources are not found within a predetermined time delay limit, the event is initiated by the group leader Record. For example, if there are 5 members in the formation and taking periodic traffic model 2 in NR's V2X as an example, the group leader needs to reserve the ability to support 5 group members for 400 bytes aperiodic transmission Resources.

[0058] Alternatively, the group leader can reserve joint resources semi-permanently, which facilitates sensing by UEs outside the formation, making it easier to avoid aperiodic parts from group members inside the formation and UEs outside the formation conflicts between sends.

[0059] Alternatively, the group leader can set priorities for retaining joint resources. Alternatively, the group leader can set the resource reservation priority to high and the reservation counter to a large value. Resources aggregated for all group members may then be reserved for a long time and considered semi-permanently reserved by UEs outside the formation.

[0060] This embodiment of the resource selection method for sidelink communication divides packets with a small probability and a packet size larger than a predetermined value into a base part that is sent periodically and an aperiodic part that is sent aperiodically. In addition, resources are allocated for the aperiodic part of the aperiodic transmission by the group leader, thereby effectively avoiding conflicting transmissions with UEs outside the formation. Even without receiving resources allocated by the swarm leader, swarm members can transmit data at one time based on resources of their own choice without affecting future resource usage. In terms of resource allocation, SPT can be used for both periodic and aperiodic data transmission, in which the design of SPT is ensured through the PC5 interface, thereby avoiding resource conflicts in data transmission between vehicles within the coverage of traditional cellular in V2X services And the reliability of data transmission is improved.

[0061] refer to Figure 4 , an embodiment of the resource selection method for sidelink communication performed jointly by the group leader and the group members includes:

[0062] Step 400, group members transmit packets with a packet size less than or equal to a predetermined value by periodic data transmission;

[0063] Step 410, the group member divides the group whose group size is greater than a predetermined value into a basic part and an aperiodic part;

[0064] Step 420, the group members periodically send the basic part;

[0065] Step 430, the group member sends a resource request for the aperiodic part to the group leader;

[0066] Step 440, the group leader searches for a resource among the reserved joint resources based on the resource request of the aperiodic portion, and if the resource is found within a predetermined delay limit based on the joint resource selection, then executes steps 450 to 460; otherwise, executes Step 470 to step 480 .

[0067] Step 450, the group leader allocates resources to the group members;

[0068] Step 460, the group members send the aperiodic part through the allocated resources;

[0069] Step 470, the group leader records the event;

[0070] Step 480, the group member sends the aperiodic part through the resource selected by itself;

[0071] At step 490, the group leader estimates joint data traffic statistics by analyzing aperiodic portions of resource requests and/or resource assignment results for group members, and/or by collecting traffic attribute information from group members.

[0072] In this example, the steps performed by group members are in Figure 5 The steps performed by the group leader are shown in Image 6 shown in .

[0073] This embodiment of the resource selection method for sidelink communication divides packets with a small probability and a packet size larger than a predetermined value into a base part that is sent periodically and an aperiodic part that is sent aperiodically. In addition, resources are allocated for the aperiodic part of the aperiodic transmission by the group leader, thereby effectively avoiding conflicting transmissions with UEs outside the formation. Even without receiving resources allocated by the swarm leader, swarm members can transmit data at one time based on resources of their own choice without affecting future resource usage. In terms of resource allocation, SPT can be used for both periodic and aperiodic data transmission, in which the design of SPT is ensured through the PC5 interface, thereby avoiding resource conflicts in data transmission between vehicles within the coverage of traditional cellular in V2X services And the reliability of data transmission is improved.

[0074] One embodiment of the means for resource selection performed by group members for sidelink communications includes means for performing the steps of:

[0075] splitting packets with a packet size greater than a predetermined value into a base part and an aperiodic part;

[0076] sending the base part through periodic traffic, and sending resource requests for the aperiodic part to the group leader; and

[0077] The aperiodic part is sent by the group leader based on the resources allocated by the joint resource selection.

[0078] Alternatively, in the device, the device is further configured to implement the following steps:

[0079] If the group member does not receive the resources allocated by the joint resource selection within a predetermined delay limit, the aperiodic part is transmitted by the resource selected by the group member.

[0080] Alternatively, in the device, the device is further configured to implement the following steps:

[0081] Packets having a packet size smaller than or equal to a predetermined value are sent by periodic traffic transmission.

[0082] Another embodiment of the means for resource selection performed by the group leader for sidelink communications includes means for performing the steps of:

[0083] receiving resource requests sent by group members for the aperiodic portion; and

[0084] Resources are allocated to group members based on joint resource selection.

[0085] Alternatively, in the device, the device is further configured to implement the following steps:

[0086] The reserved joint resources are searched for a resource based on the aperiodic portion of the resource request, and if a resource is found within a predetermined delay limit based on the joint resource selection, the resource is allocated to the group member.

[0087] Alternatively, in the device, the device is further configured to implement the following steps:

[0088] If no resource is found within a predetermined latency limit based on the joint resource selection, an event is logged to estimate joint data traffic statistics.

[0089] Alternatively, in the device, the device is further configured to implement the following steps:

[0090] Joint data traffic statistics are estimated by analyzing aperiodic portions of resource requests sent by group members and/or resource assignment results for group members, and/or by collecting traffic attribute information from group members.

[0091] In the previous method embodiments, the resource selection means performed by the group members for the sidelink communication and the resource selection means performed by the group leader for the sidelink communication are described. The specific implementation of each device function, and will not be repeated here.

[0092] It should be noted that the invention is not limited to the embodiments described in the foregoing, but extends to all embodiments consistent with its idea. The alternatives or options described in this section are directly derived from the descriptions of the preceding technical steps. They are valid for illustrative applications such as microbatteries, but can be transferred to other microelectronic assemblies. Unless mentioned otherwise, the steps describing the examples given in each section are based on the same principles mentioned before.