A message transmission method, apparatus, device, and storage medium

Abstract

The present disclosure provides a message transmission method, device, equipment and storage medium. The method comprises: sending a sidelink positioning protocol (SLPP) message and / or a ranging and sidelink positioning protocol (RSPP) message, wherein the SLPP message and / or the RSPP message comprises indication information for indicating that acknowledgement (ACK) feedback is required for the SLPP message and / or the RSPP message. The method of the present disclosure ensures the successful transmission of the SLPP message and / or the RSPP message for the second UE, guarantees the transmission stability of the SLPP message and / or the RSPP message, and further guarantees the stability of SL positioning and / or SL ranging.

Description

Technical Field

[0001] This disclosure relates to the field of communication technology, and in particular to message transmission methods, apparatus, devices and storage media. Background Technology

[0002] In communication systems, sidelink (SL) communication is introduced to enable direct communication between user equipment (UE). For UEs connected via SL, SL positioning and / or SL ranging are typically required. During SL positioning and / or SL ranging, UEs utilize the Sidelink Positioning Protocol (SLPP) and / or the Range and Sidelink Positioning Protocol (RSPP) to transmit SLPP and / or RSPP messages for positioning. Summary of the Invention

[0003] The message transmission method, apparatus, device, and storage medium disclosed herein are for reliable transmission of SLPP and / or RSPP messages.

[0004] In a first aspect, embodiments of this disclosure provide a message transmission method, which is executed by a first UE, including:

[0005] Send a Side Link Positioning Protocol (SLPP) message and / or a Ranging and Side Link Positioning Protocol (RSPP) message, wherein the SLPP message and / or RSPP message includes an indication information for indicating that an acknowledgment (ACK) feedback is required for the SLPP message and / or RSPP message.

[0006] In this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UEs receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0007] Secondly, embodiments of this disclosure provide a message transmission method, which is executed by a second UE, including:

[0008] Receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information for indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0009] Thirdly, embodiments of this disclosure provide a communication device configured in a first UE, comprising:

[0010] The transceiver module is used to send SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0011] Fourthly, embodiments of this disclosure provide a communication device configured in a second UE, comprising:

[0012] The transceiver module is used to receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0013] Fifthly, embodiments of this disclosure provide a communication device including a processor that, when the processor invokes a computer program in memory, executes the method described in the first aspect.

[0014] In a sixth aspect, embodiments of this disclosure provide a communication device including a processor that, when the processor invokes a computer program in memory, executes the method described in the second aspect above.

[0015] In a seventh aspect, embodiments of this disclosure provide a communication device including a processor and a memory, the memory storing a computer program; the processor executes the computer program stored in the memory to cause the communication device to perform the method described in the first aspect above.

[0016] Eighthly, embodiments of this disclosure provide a communication device including a processor and a memory storing a computer program; the processor executes the computer program stored in the memory to cause the communication device to perform the method described in the second aspect above.

[0017] Ninthly, embodiments of this disclosure provide a communication device including a processor and an interface circuit. The interface circuit is configured to receive code instructions and transmit them to the processor, which is configured to execute the code instructions to cause the device to perform the method described in the first aspect above.

[0018] In a tenth aspect, embodiments of this disclosure provide a communication device including a processor and an interface circuit. The interface circuit is configured to receive code instructions and transmit them to the processor, which is configured to execute the code instructions to cause the device to perform the method described in the second aspect above.

[0019] Eleventhly, embodiments of this disclosure provide a communication system, which includes the communication devices described in the third aspect to the fourth aspect, or the communication devices described in the fifth aspect to the sixth aspect, or the communication devices described in the seventh aspect to the eighth aspect, or the communication devices described in the ninth aspect to the tenth aspect.

[0020] In a twelfth aspect, embodiments of the present invention provide a computer-readable storage medium for storing instructions for use by the network device described above, which, when executed, cause the terminal device to perform the method described in any one of the first to second aspects.

[0021] In a thirteenth aspect, this disclosure also provides a computer program product including a computer program that, when run on a computer, causes the computer to perform the methods described in any one of the first to second aspects.

[0022] In a fourteenth aspect, this disclosure provides a chip system including at least one processor and an interface for supporting network devices in implementing the functions involved in the methods described in any one of the first to second aspects, such as determining or processing at least one of the data and information involved in the aforementioned methods. In one possible design, the chip system further includes a memory for storing computer programs and data necessary for source and slave nodes. The chip system may be composed of chips or may include chips and other discrete devices.

[0023] In a fifteenth aspect, this disclosure provides a computer program that, when run on a computer, causes the computer to perform the methods described in any one of the first to second aspects. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of the present disclosure;

[0026] Figure 2 A flowchart illustrating a message transmission method provided in another embodiment of this disclosure;

[0027] Figure 3 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0028] Figure 4 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0029] Figure 5 A flowchart illustrating a message transmission method provided in another embodiment of this disclosure;

[0030] Figures 6a-6d A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0031] Figure 7 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0032] Figure 8 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0033] Figure 9 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0034] Figure 10A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0035] Figure 11 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0036] Figure 12 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0037] Figures 13a-13c A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0038] Figure 14 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0039] Figure 15 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0040] Figure 16 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0041] Figure 17 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0042] Figure 18 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0043] Figure 19 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0044] Figure 20 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0045] Figure 21 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0046] Figure 22 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0047] Figure 23 A flowchart illustrating a message transmission method provided in yet another embodiment of this disclosure;

[0048] Figure 24 An interactive schematic diagram of a message transmission method provided in yet another embodiment of this disclosure;

[0049] Figure 25An interactive schematic diagram of a message transmission method provided in yet another embodiment of this disclosure;

[0050] Figure 26 This is a schematic diagram of the structure of a communication device provided in one embodiment of the present disclosure;

[0051] Figure 27 This is a schematic diagram of the structure of a communication device provided in another embodiment of the present disclosure;

[0052] Figure 28 This is a block diagram of a user equipment provided in one embodiment of the present disclosure;

[0053] Figure 29 This is a block diagram of a network-side device provided in one embodiment of the present disclosure. Detailed Implementation

[0054] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this disclosure as detailed in the appended claims.

[0055] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. The singular forms “a” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0056] It should be understood that although the terms first, second, third, etc., may be used to describe various information in embodiments of this disclosure, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of embodiments of this disclosure, and similarly, second information may also be referred to as first information. Depending on the context, the words “if” and “suppose” as used herein may be interpreted as “when”, “when”, or “in response to a determination”.

[0057] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0058] To facilitate understanding, the terminology used in this application will be introduced first.

[0059] 1. Fifth-generation mobile networks (5G)

[0060] 5G is a new generation of broadband mobile communication technology with high speed and low latency, and it is the network infrastructure for realizing the interconnection of people, machines and things.

[0061] 2. Sidelink (SL)

[0062] Links for direct communication between terminal devices.

[0063] To better understand the message transmission method disclosed in this embodiment, the communication system to which this embodiment applies is first described below.

[0064] Please see Figure 1 , Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of the present disclosure. The communication system may include, but is not limited to, two UEs. Figure 1 The number and form of devices shown are for illustrative purposes only and do not constitute a limitation on the embodiments of this disclosure. In actual applications, two or more UEs may be included. Figure 1 The communication system shown is an example including a first UE11 and a second UE12.

[0065] It should be noted that the technical solutions of this disclosure can be applied to various communication systems. For example, long term evolution (LTE) systems, 5th generation (5G) mobile communication systems, 5G new radio (NR) systems, or other future new mobile communication systems.

[0066] In the embodiments of this disclosure, the first UE11 and the second UE12 can be entities on the user side used to receive or transmit signals, such as mobile phones. UE can also be referred to as terminal equipment, user equipment (UE), mobile station (MS), mobile terminal equipment (MT), etc. UE can be a car with communication capabilities, a smart car, a mobile phone, a wearable device, a tablet computer, a computer with wireless transceiver capabilities, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, a wireless terminal device in a smart home, etc. The embodiments of this disclosure do not limit the specific technology or device form used by the UE.

[0067] It is understood that the communication system described in the embodiments of this disclosure is for the purpose of more clearly illustrating the technical solutions of the embodiments of this disclosure, and does not constitute a limitation on the technical solutions provided in the embodiments of this disclosure. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this disclosure are also applicable to similar technical problems.

[0068] The message transmission method, apparatus, device, and storage medium provided in the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0069] It should be noted that in this disclosure, any message transmission method provided in any embodiment can be executed alone, any implementation method in the embodiment can be executed alone, or it can be combined with other embodiments, or possible implementation methods in other embodiments, or it can be combined with any technical solution in the related technology.

[0070] Figure 2 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 2 As shown, the message transmission method may include the following steps:

[0071] Step 201: Send an SLPP message and / or an RSPP message, which includes an indication that an acknowledgment (ACK) response is required for the SLPP message and / or RSPP message.

[0072] In one embodiment of this disclosure, the aforementioned SLPP message and / or RSPP message can be messages required for transmission when UEs perform SL positioning and / or SL ranging. Specifically, the SLPP message and / or RSPP message can be transmitted from a first UE to a second UE, where the second UE is a UE connected to the first UE via SL.

[0073] Furthermore, in one embodiment of this disclosure, the aforementioned "need to provide ACK feedback for SLPP messages and / or RSPP messages" can be understood as follows: when the second UE receives SLPP messages and / or RSPP messages transmitted by the first UE, it needs to provide ACK feedback to the first UE; when the second UE does not receive SLPP messages and / or RSPP messages transmitted by the first UE, it does not provide ACK feedback to the first UE.

[0074] Based on this, in one embodiment of this disclosure, by including the aforementioned indication information in the SLPP message and / or RSPP message, the second UE is instructed to send an ACK feedback to the first UE after receiving the SLPP message and / or RSPP message. Thus, based on the received ACK feedback, the first UE can determine whether it successfully sent the SLPP message and / or RSPP message to the second UE, and can determine which second UEs received the SLPP message and / or RSPP message successfully, and which second UEs did not receive the message successfully. In this case, the first UE can retransmit the SLPP message and / or RSPP message to the second UE that did not successfully receive the message, ensuring successful transmission of the SLPP message and / or RSPP message to the second UE. This guarantees the transmission stability of the SLPP message and / or RSPP message, thereby ensuring the stability of SL positioning and / or SL ranging.

[0075] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0076] Figure 3 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 3 As shown, the message transmission method may include the following steps:

[0077] Step 301: Unicast SLPP message and / or RSPP message to the second UE. The SLPP message and / or RSPP message includes: indication information for indicating that an ACK feedback is required for the SLPP message and / or RSPP message.

[0078] As can be seen from the foregoing, the SLPP message and / or RSPP message are messages required to be transmitted when UEs perform SL positioning and / or SL ranging. Based on this, in one embodiment of this disclosure, when the first UE unicasts the SLPP message and / or RSPP message to the second UE, it indicates that the first UE only requests SL ranging service and / or SL positioning service with the second UE.

[0079] Furthermore, for a detailed description of step 301, please refer to the above embodiments.

[0080] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0081] Figure 4 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 4 As shown, the message transmission method may include the following steps:

[0082] Step 401: Multicast SLPP messages and / or RSPP messages to a UE group consisting of at least one second UE. The SLPP messages and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0083] As can be seen from the foregoing, the SLPP message and / or RSPP message are messages required to be transmitted when UEs perform SL positioning and / or SL ranging. Based on this, in one embodiment of this disclosure, when a first UE multicasts SLPP messages and / or RSPP messages to a UE group, it indicates that the first UE requests group ranging service and / or group positioning service with at least one second UE in the UE group.

[0084] Furthermore, for a detailed description of step 401, please refer to the above embodiments.

[0085] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0086] Figure 5 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 5 As shown, the message transmission method may include the following steps:

[0087] Step 501: Broadcast SLPP message and / or RSPP message, which includes indication information indicating that an ACK response is required for the SLPP message and / or RSPP message.

[0088] For a detailed description of step 501, please refer to the above embodiment.

[0089] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0090] Figure 6a This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 6a As shown, the message transmission method may include the following steps:

[0091] Step 601a: Send an SLPP message and / or an RSPP message, which also includes a sequence number.

[0092] Since the first UE may transmit multiple different SLPP messages and / or RSPP messages to the same second UE, when the first UE receives an ACK feedback from the second UE, the first UE may not be able to determine which SLPP message and / or RSPP message the ACK feedback is for. Therefore, in one embodiment of this disclosure, the SLPP message and / or RSPP message may also include a sequence number, which may correspond to the SLPP message and / or RSPP message. Furthermore, when the second UE receives an SLPP message and / or RSPP message, it parses the SLPP message and / or RSPP message to obtain the corresponding sequence number. Then, when the second UE sends an ACK feedback to the first UE, it can send an ACK feedback to the SLPP message and / or RSPP message based on the sequence number included in the SLPP message and / or RSPP message. This allows the first UE to determine, based on the sequence number, which SLPP message and / or RSPP message the ACK feedback is for, and thus determine which SLPP messages and / or RSPP messages the second UE has successfully received and which it has not successfully received. The first UE can then retransmit the SLPP messages and / or RSPP messages that the second UE has not successfully received, ensuring the successful transmission of the SLPP messages and / or RSPP messages for the second UE and guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, thereby ensuring the stability of SL positioning and / or SL ranging.

[0093] Optionally, in one embodiment of this disclosure, the above-mentioned "acknowledging the SLPP message and / or RSPP message according to the sequence number included in the SLPP message and / or RSPP message" may include: carrying the sequence number corresponding to the SLPP message and / or RSPP message in the ACK feedback, so that the first UE can determine which SLPP message and / or RSPP message the ACK feedback is for based on the sequence number carried in the ACK feedback.

[0094] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0095] Figure 6b This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 6b As shown, the message transmission method may include the following steps:

[0096] Step 601b: Unicast SLPP and / or RSPP messages to the second UE, the SLPP and / or RSPP messages also including a sequence number.

[0097] For a detailed description of step 601b, please refer to the above embodiment.

[0098] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0099] Figure 6c This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 6c As shown, the message transmission method may include the following steps:

[0100] Step 601c: Multicast SLPP messages and / or RSPP messages to a UE group consisting of at least one second UE, the SLPP messages and / or RSPP messages also including a sequence number.

[0101] For a detailed description of step 601c, please refer to the above embodiment description.

[0102] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0103] Figure 6d This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 6d As shown, the message transmission method may include the following steps:

[0104] Step 601d: Broadcast SLPP and / or RSPP messages, which also include a sequence number.

[0105] For a detailed description of step 601d, please refer to the above embodiment.

[0106] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0107] Figure 7 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 7 As shown, the message transmission method may include the following steps:

[0108] Step 701: In response to receiving an ACK message containing the sequence number corresponding to the SLPP message and / or RSPP message, determine that the second UE has received the ACK feedback for the SLPP message and / or RSPP message.

[0109] For a detailed description of step 701, please refer to the above embodiment.

[0110] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0111] Figure 8 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 8 As shown, the message transmission method may include the following steps:

[0112] Step 801: In response to not receiving an ACK message containing the sequence number corresponding to the SLPP message and / or RSPP message within a preset time period, determine that no ACK feedback has been received from the second UE for the SLPP message and / or RSPP message.

[0113] In one embodiment of this disclosure, the preset time period may be agreed upon by a protocol, configured by a network device, configured by pre-configured information, or determined autonomously by the first UE based on the implementation.

[0114] Furthermore, for a detailed description of step 801, please refer to the above embodiment description.

[0115] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0116] Figure 9 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 9 As shown, the message transmission method may include the following steps:

[0117] Step 901: If no ACK feedback is received for the SLPP message and / or RSPP message, retransmit the SLPP message and / or RSPP message.

[0118] For a detailed description of step 901, please refer to the above embodiment.

[0119] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0120] Figure 10 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 10 As shown, the message transmission method may include the following steps:

[0121] Step 1001: In response to the first UE sending SLPP messages and / or RSPP messages in unicast form, unicast retransmission of SLPP messages and / or RSPP messages.

[0122] For a detailed description of step 1001, please refer to the above embodiment.

[0123] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0124] Figure 11 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 11 As shown, the message transmission method may include the following steps:

[0125] Step 1101: In response to the first UE sending SLPP messages and / or RSPP messages in multicast form, if the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is less than the first threshold value, the SLPP messages and / or RSPP messages are retransmitted via multicast.

[0126] In one embodiment of this disclosure, the "number of ACK feedbacks received by the first UE" can be the number of ACK feedbacks received by the first UE during this multicast transmission.

[0127] Furthermore, in one embodiment of this disclosure, the expected threshold can be determined by the first UE based on the capabilities (such as ranging and / or positioning capabilities) of each second UE in the UE group. Specifically, as described above, when the first UE multicasts SLPP and / or RSPP messages to the UE group, it indicates that the first UE requests group ranging and / or group positioning services with at least one second UE in the UE group. However, since different second UEs have different capabilities, they may support different positioning and ranging algorithms. Therefore, if the positioning and / or ranging algorithms supported by some second UEs in the UE group are different from the positioning and / or ranging algorithms corresponding to the ranging and / or positioning services requested by the first UE, then those second UEs cannot participate in the ranging and / or positioning services requested by the first UE. That is, only some second UEs in the UE group may be able to perform ranging and / or positioning services with the first UE. Based on this, the expected threshold can be the number of second UEs in the UE group that can perform ranging and / or positioning services with the first UE.

[0128] Alternatively, in one embodiment of this disclosure, the expected threshold can also be determined by the first UE based on the number of second UEs in the UE group that can normally interact and communicate with the first UE. Specifically, in one embodiment of this disclosure, when the first UE requests group ranging service and / or group positioning service with at least one second UE in the UE group, the first UE will establish a session with the second UE to interact normally with the second UE through the session. If a second UE does not respond to the messages in the session with the first UE, it indicates that the session between the second UE and the first UE has been terminated or suspended, and the two cannot perform normal interaction related to ranging service and / or positioning service. At this time, the first UE will mark the second UE as inactive or unreachable. Based on this, the expected threshold can be the number of second UEs in the UE group that are not marked as inactive or unreachable, that is, the expected threshold can be the number of second UEs in the UE group that can normally interact with the first UE related to ranging service and / or positioning service.

[0129] Furthermore, in one embodiment of this disclosure, when the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is less than the first threshold, it indicates that there are many second UEs in the current UE group that have not received SLPP messages and / or RSPP messages. At this time, the first UE can multicast and retransmit the SLPP message and / or RSPP message to ensure the successful transmission of the SLPP message and / or RSPP message.

[0130] Furthermore, for a detailed description of step 1101, please refer to the above embodiment description.

[0131] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0132] Figure 12 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 12 As shown, the message transmission method may include the following steps:

[0133] Step 1201: In response to the first UE sending SLPP messages and / or RSPP messages in multicast form, if the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the first threshold and less than the second threshold, the SLPP messages and / or RSPP messages are retransmitted unicast to the second UE in the UE group that needs ACK feedback but has not sent ACK feedback.

[0134] The "number of ACK feedbacks received by the first UE" here can be: the number of ACK feedbacks received by the first UE in this multicast transmission.

[0135] In one embodiment of this disclosure, when the difference or ratio between the number of ACK responses received by the first UE and a predetermined threshold is greater than or equal to a first threshold and less than a second threshold, it indicates that there are second UEs in the current UE group that have not received SLPP and / or RSPP messages, but their number is small. In this case, the first UE can unicast and retransmit the SLPP and / or RSPP messages only to the second UEs in the UE group that require ACK responses but have not yet responded. The second UE requiring ACK responses can be a second UE capable of participating in the ranging service and / or positioning service requested by the first UE, or it can be a second UE that has not been marked as inactive or unreachable.

[0136] It should be noted that the aforementioned first threshold value can be configured by the network device to the first UE, determined by the first UE itself, or pre-configured. Similarly, the second threshold value, third threshold value, first threshold, second threshold, and third threshold value mentioned in subsequent embodiments can also be configured by the network device to the first UE, determined by the first UE itself, or pre-configured. These different values ​​can be the same or different.

[0137] Furthermore, for a detailed description of step 1201, please refer to the above embodiment description.

[0138] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0139] Figure 13a This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 13a As shown, the message transmission method may include the following steps:

[0140] Step 1301a: In response to the first UE sending SLPP messages and / or RSPP messages in multicast form, if the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the second threshold, the SLPP messages and / or RSPP messages are not retransmitted.

[0141] The "number of ACK feedbacks received by the first UE" here can be: the number of ACK feedbacks received by the first UE in this multicast transmission.

[0142] In one embodiment of this disclosure, when the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the second threshold, it indicates that the number of second UEs in the current UE group that have not received SLPP messages and / or RSPP messages is small, and therefore will not affect the positioning service and / or ranging service requested by the first UE, and can be ignored. In this case, SLPP messages and / or RSPP messages do not need to be retransmitted.

[0143] Furthermore, for a detailed description of step 1301a, please refer to the above embodiment description.

[0144] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0145] Figure 13b This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 13b As shown, the message transmission method may include the following steps:

[0146] Step 1301b: In response to the first UE sending SLPP messages and / or RSPP messages in multicast form, if the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold, the SLPP messages and / or RSPP messages are unicast retransmitted to the second UE in the UE group that needs ACK feedback but has not sent ACK feedback.

[0147] The "number of ACK feedbacks received by the first UE" here can be: the number of ACK feedbacks received by the first UE in this multicast transmission.

[0148] In one embodiment of this disclosure, when the difference or ratio between the number of ACK responses received by the first UE and the expected threshold is greater than a first threshold, it indicates that the number of second UEs in the current UE group that have not received SLPP and / or RSPP messages is relatively small. In this case, the first UE can unicast and retransmit the SLPP and / or RSPP messages only to the second UEs in the UE group that require ACK responses but have not yet responded. The second UE requiring ACK responses can be a second UE capable of participating in the ranging service and / or positioning service requested by the first UE, or it can be a second UE that has not been marked as inactive or unreachable.

[0149] Furthermore, for a detailed description of step 1301b, please refer to the above embodiment description.

[0150] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0151] Figure 13c This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 13c As shown, the message transmission method may include the following steps:

[0152] Step 1301c: In response to the first UE sending SLPP messages and / or RSPP messages in multicast form, if the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold value, the SLPP messages and / or RSPP messages are not retransmitted.

[0153] The "number of ACK feedbacks received by the first UE" here can be: the number of ACK feedbacks received by the first UE in this multicast transmission.

[0154] In one embodiment of this disclosure, when the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold, it indicates that there are a large number of second UEs in the current UE group that have received SLPP messages and / or RSPP messages, and therefore the SLPP messages and / or RSPP messages do not need to be retransmitted.

[0155] Furthermore, for a detailed description of step 1301c, please refer to the above embodiment description.

[0156] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0157] Figure 14 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 14 As shown, the message transmission method may include the following steps:

[0158] Step 1401: Determine the expected threshold based on the number of second UEs in a UE group consisting of at least one second UE that can participate in the execution of ranging and / or positioning services indicated by SLPP messages and / or RSPP messages.

[0159] For a detailed description of step 1401, please refer to the above embodiment.

[0160] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0161] Figure 15 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 15 As shown, the message transmission method may include the following steps:

[0162] Step 1501: In response to the first UE sending SLPP messages and / or RSPP messages in broadcast form, if the number of ACK feedback received by the first UE is less than the third threshold value, broadcast retransmission of SLPP messages and / or RSPP messages.

[0163] The "number of ACK feedback received by the first UE" here can be: the number of ACK feedback received by the first UE during this broadcast transmission.

[0164] In one embodiment of this disclosure, when the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is less than the third threshold, it indicates that there are many second UEs that have not received SLPP messages and / or RSPP messages. At this time, the first UE can broadcast and retransmit the SLPP message and / or RSPP message to ensure the successful transmission of the SLPP message and / or RSPP message.

[0165] Furthermore, for a detailed description of step 1501, please refer to the above embodiment description.

[0166] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0167] Figure 16 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 16 As shown, the message transmission method may include the following steps:

[0168] Step 1601: In response to the first UE's unicast retransmission count reaching the first threshold and still not receiving ACK feedback, stop retransmission and terminate the service with the second UE.

[0169] Optionally, in one embodiment of this disclosure, the service may be: a ranging and / or positioning service process corresponding to the SLPP message and / or RSPP message, or a session associated with the SLPP message and / or RSPP message.

[0170] In one embodiment of this disclosure, when the number of retransmissions reaches a first threshold, it indicates that the number of retransmissions is too high. If no ACK feedback is received at this time, it indicates that the link or session between the first UE and the second UE is abnormal, or that the second UE is in an inactive or unreachable state. If retransmissions continue, the probability of successful transmission is low. Therefore, it is necessary to stop retransmissions and terminate the service with the second UE to avoid additional resource consumption.

[0171] It should be noted that, in one embodiment of this disclosure, the aforementioned termination of service with the second UE can be understood as: terminating the session related to the RSPP and / or SLPP messages established with the second UE; or, in another embodiment of this disclosure, for the session-less case, the aforementioned termination of service with the second UE can be understood as: terminating the location service and / or ranging service process with the second UE that utilizes the RSPP and / or SLPP messages to request the corresponding location service and / or ranging service process.

[0172] Furthermore, for a detailed description of step 1601, please refer to the above embodiment description.

[0173] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0174] Figure 17 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 17 As shown, the message transmission method may include the following steps:

[0175] Step 1701: In response to the first UE's multicast retransmission count reaching the second threshold, and the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold being less than the first threshold, retransmission is stopped, and service with all second UEs is terminated.

[0176] It should be noted that, in one embodiment of this disclosure, the "number of ACK feedbacks received by the first UE" can be: the number of second UEs corresponding to the ACK feedbacks received by the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE. In other words, the "number of ACK feedbacks received by the first UE" is: the number of second UEs that have provided ACK feedback to the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE.

[0177] Furthermore, in one embodiment of this disclosure, the aforementioned "all second UEs" can be: all second UEs in the UE group participating in the service indicated by the SLPP message and / or RSPP message. The UE group may include some or all UEs participating in the service indicated by the SLPP message and / or RSPP message.

[0178] Furthermore, in one embodiment of this disclosure, the service may be: a ranging and / or positioning service process corresponding to the SLPP message and / or RSPP message, or a session associated with the SLPP message and / or RSPP message.

[0179] It should be noted that, in one embodiment of this disclosure, the aforementioned termination of service with the second UE can be understood as: terminating the session related to the RSPP and / or SLPP messages established with the second UE; or, in another embodiment of this disclosure, for the session-less case, the aforementioned termination of service with the second UE can be understood as: terminating the location service and / or ranging service process with the second UE that utilizes the RSPP and / or SLPP messages to request the corresponding location service and / or ranging service process.

[0180] For a detailed description of step 1701, please refer to the above embodiment.

[0181] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0182] Figure 18 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 18 As shown, the message transmission method may include the following steps:

[0183] Step 1801: In response to the first UE's multicast retransmission count reaching the second threshold, and the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is still less than the first threshold, retransmission is stopped, and it is determined that the service between the first UE and the second UE in the UE group that did not provide ACK feedback is abnormally terminated, inactive, or suspended.

[0184] It should be noted that, in one embodiment of this disclosure, the "number of ACK feedbacks received by the first UE" can be: the number of second UEs corresponding to the ACK feedbacks received by the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE. In other words, the "number of ACK feedbacks received by the first UE" is: the number of second UEs that have provided ACK feedback to the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE.

[0185] Optionally, in one embodiment of this disclosure, the above-mentioned "the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is still less than the first threshold value" can be understood as: the first UE still has not received ACK feedbacks from some or all of the second UEs in the UE group.

[0186] Furthermore, in one embodiment of this disclosure, the service may be: a ranging and / or positioning service process corresponding to the SLPP message and / or RSPP message, or a session associated with the SLPP message and / or RSPP message.

[0187] It should be noted that, in one embodiment of this disclosure, the above-mentioned abnormal termination, inactivity, or suspension of service with the second UE can be understood as: the session related to the RSPP and / or SLPP messages established with the second UE is abnormally terminated, inactive, or suspended; or, in another embodiment of this disclosure, for the session-less case, the above-mentioned termination of service with the second UE can be understood as: the location service and / or ranging service process corresponding to the request using RSPP and / or SLPP messages with the second UE is abnormally terminated, inactive, or suspended.

[0188] It should also be noted that the termination, suspension, or inactivation of services by some UEs within a UE group does not affect the services performed by other UEs in the UE group. Therefore, in one embodiment of this disclosure, when the service between a second UE in the UE group that has not responded with an ACK is terminated, suspended, or inactivated, the ranging and / or positioning services performed between the other second UEs in the UE group and the first UE will not be affected.

[0189] For a detailed description of step 1801, please refer to the above embodiment.

[0190] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0191] Figure 19This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 19 As shown, the message transmission method may include the following steps:

[0192] Step 1901: In response to the first UE's unicast retransmission count to the second UE in the UE group that requires ACK feedback but does not reach the second threshold, and the difference or ratio between the number of ACK feedback received by the first UE and the expected threshold is still less than the first threshold, retransmission is stopped, and it is determined that the service between the first UE and the second UE that requires ACK feedback but does not reach the second threshold is abnormally terminated, inactive, or suspended.

[0193] It should be noted that, in one embodiment of this disclosure, the "number of ACK feedbacks received by the first UE" can be: the number of second UEs corresponding to the ACK feedbacks received by the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE. In other words, the "number of ACK feedbacks received by the first UE" is: the number of second UEs that have provided ACK feedback to the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE.

[0194] It should also be noted that the termination, suspension, or inactivation of services by some UEs within a UE group does not affect the services performed by other UEs in the UE group. Therefore, in one embodiment of this disclosure, when the service between a second UE in the UE group that has not responded with an ACK is terminated, suspended, or inactivated, the ranging and / or positioning services performed between the other second UEs in the UE group and the first UE will not be affected.

[0195] For a detailed description of step 1901, please refer to the above embodiment.

[0196] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0197] Figure 20 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a first UE, such as... Figure 20 As shown, the message transmission method may include the following steps:

[0198] Step 2001: In response to the first UE's broadcast retransmission count reaching the third threshold and the number of ACK feedback received by the first UE still being less than the third threshold, retransmission is stopped and the service is terminated.

[0199] It should be noted that, in one embodiment of this disclosure, the "number of ACK feedbacks received by the first UE" can be: the number of second UEs corresponding to the ACK feedbacks received by the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE. In other words, the "number of ACK feedbacks received by the first UE" is: the number of second UEs that have provided ACK feedback to the first UE in the historical transmission count of SLPP messages and / or RSPP messages related to the service currently requested by the first UE.

[0200] For a detailed description of step 2001, please refer to the above embodiment.

[0201] In summary, in the message transmission method provided in this disclosure, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs' SLPP messages and / or RSPP messages were not successfully received. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not successfully receive them, thereby ensuring successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guaranteeing the transmission stability of the SLPP messages and / or RSPP messages, and thus ensuring the stability of SL positioning and / or SL ranging.

[0202] Figure 21 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a second UE, such as... Figure 21 As shown, the message transmission method may include the following steps:

[0203] Step 2101: Receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information for indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0204] For a detailed description of step 2101, please refer to the above embodiment.

[0205] In summary, in the message transmission method provided in this disclosure, the second UE receives SLPP messages and / or RSPP messages. These SLPP and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP and / or RSPP messages, this disclosure instructs the second UE receiving the SLPP and / or RSPP messages to send an ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs received its SLPP and / or RSPP messages. In this case, the first UE can retransmit the SLPP and / or RSPP messages to the second UEs that did not successfully receive them. This ensures the successful transmission of the SLPP and / or RSPP messages to the second UEs, guarantees the transmission stability of the SLPP and / or RSPP messages, and thus ensures the stability of SL positioning and / or SL ranging.

[0206] Figure 22 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a second UE, such as... Figure 22 As shown, the message transmission method may include the following steps:

[0207] Step 2201: Receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include a sequence number.

[0208] For a detailed description of step 2201, please refer to the above embodiment.

[0209] In summary, in the message transmission method provided in this disclosure, the second UE receives SLPP messages and / or RSPP messages. These SLPP and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP and / or RSPP messages, this disclosure instructs the second UE receiving the SLPP and / or RSPP messages to send an ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs received its SLPP and / or RSPP messages. In this case, the first UE can retransmit the SLPP and / or RSPP messages to the second UEs that did not successfully receive them. This ensures the successful transmission of the SLPP and / or RSPP messages to the second UEs, guarantees the transmission stability of the SLPP and / or RSPP messages, and thus ensures the stability of SL positioning and / or SL ranging.

[0210] Figure 23 This is a flowchart illustrating a message transmission method provided in an embodiment of the present disclosure. The method is executed by a second UE, such as... Figure 23 As shown, the message transmission method may include the following steps:

[0211] Step 2301: In response to receiving the SLPP message and / or RSPP message, send an ACK feedback, the ACK feedback containing the sequence number corresponding to the SLPP message and / or RSPP message.

[0212] For a detailed description of step 2301, please refer to the above embodiment.

[0213] In summary, in the message transmission method provided in this disclosure, the second UE receives SLPP messages and / or RSPP messages. These SLPP and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP and / or RSPP messages, this disclosure instructs the second UE receiving the SLPP and / or RSPP messages to send an ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs received its SLPP and / or RSPP messages. In this case, the first UE can retransmit the SLPP and / or RSPP messages to the second UEs that did not successfully receive them. This ensures the successful transmission of the SLPP and / or RSPP messages to the second UEs, guarantees the transmission stability of the SLPP and / or RSPP messages, and thus ensures the stability of SL positioning and / or SL ranging.

[0214] It should be noted that, in this disclosure, the terms "greater than" and "greater than or equal to" mentioned above can be substituted for each other unless contradictory. Similarly, "the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is less than" and "the difference or ratio between the number of ACK feedbacks not received by the first UE and the expected threshold is greater than" have the same meaning and can be substituted for each other.

[0215] Figure 24 This is a schematic diagram of the interaction flow of a message transmission method provided in an embodiment of the present disclosure, as shown below. Figure 24 As shown, the message transmission method may include the following steps:

[0216] Step 2401: The first UE transmits SLPP messages and / or RSPP messages to the second UE.

[0217] The SLPP message and / or RSPP message includes: indication information for indicating that an ACK response is required for the SLPP message and / or RSPP message.

[0218] The SLPP and / or RSPP messages also include a sequence number.

[0219] Step 2402: The second UE sends an ACK message to the first UE.

[0220] For a detailed description of steps 2401-2402, please refer to the above embodiments.

[0221] Figure 25 This is a schematic diagram of the interaction flow of a message transmission method provided in an embodiment of the present disclosure, as shown below. Figure 25 As shown, the message transmission method may include the following steps:

[0222] Step 2501: The first UE transmits SLPP messages and / or RSPP messages to the second UE.

[0223] The SLPP message and / or RSPP message includes: indication information for indicating that an ACK response is required for the SLPP message and / or RSPP message.

[0224] The SLPP and / or RSPP messages also include a sequence number.

[0225] Step 2502: The first UE retransmits SLPP messages and / or RSPP messages to the second UE.

[0226] For a detailed description of steps 2501-2502, please refer to the above embodiments.

[0227] The following is a specific example of the message transmission method disclosed herein.

[0228] UE A (i.e., the first UE mentioned above) includes a sequence number in its SLPP / RSPP message and further indicates that ACK feedback is required. UE B (i.e., the second UE mentioned above) sends ACK feedback when it receives the SLPP / RSPP message containing the indication for ACK feedback.

[0229] Example: The multicast or unicast message sent by the UE carries a sequence number X and indicates in the message that an ACK feedback is required. After a group member UE or unicast receiving UE receives the message, it needs to send an ACK feedback for the multicast or unicast message with sequence number X.

[0230] Example 1: Support for ACK feedback only for unicast transmission

[0231] Example 2: For multicast transmission, whether or not ACK feedback is supported.

[0232] Example 3: Broadcast transmission, with or without ACK feedback.

[0233] Example 4: If UE A does not receive an ACK response within a certain period of time after sending an SLPP / RSPP message, UE A will retransmit the message.

[0234] Example: This time period can be agreed upon by the protocol, configured by the network or pre-configured information, or determined by the UE.

[0235] Example 4.1: For multicast messages requiring ACK feedback, if UE A does not receive any ACK feedback or only receives ACK feedback from some group member UEs, the following methods are possible:

[0236] Method 1: If the difference or proportion between the number of unreceived ACKs and the expected number is greater than a certain threshold (or the difference or proportion between the number of received ACKs and the expected number is less than a certain threshold), UE A can multicast and retransmit the message.

[0237] Example: The expected number can be determined in advance by the sending UE. When the UE expects which UEs in a group can respond, it can consider whether the UE needs to receive the message (e.g., the UE is not able to respond to the relevant message), or whether the UE is currently in an active state in the session (e.g., the UE has been unable to respond to the message in the session, so the UE marks the UE as inactive or unreachable, or the session of the UE has been terminated or suspended).

[0238] Method 2: If the difference or proportion between the number of unreceived ACK feedbacks and the expected number is less than a certain threshold (or the difference or proportion between the number of received ACK feedbacks and the expected number is greater than a certain threshold), UE A can unicast the message to UEs that are expected to provide feedback but have not done so.

[0239] Method 3: If the difference or proportion between the number of unreceived ACKs and the expected number is less than a certain threshold (or the difference or proportion between the number of received ACKs and the expected number is greater than a certain threshold), UE A may not retransmit the message.

[0240] If a UE does not receive a certain number of ACK responses, it can decide whether to unicast or multicast retransmission based on the number of ACKs received. For example, if no ACKs are received, multicast retransmission is performed; if only one ACK is not received, it is unicast only to the UE that did not respond with an ACK. A threshold can be set for the number of ACK responses received; if the number is less than the threshold, multicast is performed, and if the number is greater than the threshold, unicast is performed.

[0241] Example 4.2: For a unicast session, if UE A sends a message and still does not receive an ACK response after retransmitting it a certain number of times, UE A terminates all activities of that session.

[0242] Example 4.3: For a multicast session, if a multicast message sent by UE A is retransmitted a certain number of times, and the number of unacknowledged responses is less than a certain threshold compared to the expected number, UE A terminates all activities of that session.

[0243] Example 4.3.1: For a multicast session, if UE A retransmits a multicast message a certain number of times and still does not receive ACK feedback from some or all UEs, UE A considers that the session of these UEs that did not provide ACK feedback has been abnormally terminated or is in an inactive / suspended state.

[0244] Example: The termination / suspend or inactivity of a session for some UEs within a group does not affect the activity of other UEs within that session.

[0245] Example 4.4: For a multicast session, if a unicast message sent by UE A is retransmitted a certain number of times, and the number of ACK responses not received is less than a certain threshold compared to the expected number, UE A considers that the session of that UE has been abnormally terminated or is in an inactive / suspended state.

[0246] Example 4.5: For a message broadcast, if the number of ACK responses received by UE A is less than a certain threshold, the UE will retransmit the message.

[0247] Example 4.5.1: For a message broadcast, if the number of retransmissions by UE A reaches a certain threshold, the UE stops retransmitting and terminates the broadcast session.

[0248] Figure 26 This is a schematic diagram of the structure of a communication device provided in an embodiment of the present disclosure, as shown below. Figure 26 As shown, the device may include:

[0249] The transceiver module is used to send SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0250] In summary, in the communication device provided in this embodiment, the first UE sends SLPP messages and / or RSPP messages, which include indication information indicating that ACK feedback is required for the SLPP messages and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP messages and / or RSPP messages sent by the first UE, this disclosure instructs the second UE receiving the SLPP messages and / or RSPP messages to provide ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs received the SLPP messages and / or RSPP messages. In this case, the first UE can retransmit the SLPP messages and / or RSPP messages to the second UEs that did not receive them successfully. This ensures the successful transmission of the SLPP messages and / or RSPP messages to the second UEs, guarantees the transmission stability of the SLPP messages and / or RSPP messages, and thus ensures the stability of SL positioning and / or SL ranging.

[0251] Optionally, in one embodiment of this disclosure, the transceiver module is further used for at least one of the following:

[0252] unicast the SLPP message and / or RSPP message to the second UE;

[0253] Multicast the SLPP message and / or RSPP message to a UE group consisting of at least one second UE;

[0254] Broadcast the SLPP message and / or RSPP message.

[0255] Optionally, in one embodiment of this disclosure, the SLPP message and / or RSPP message may further include a sequence number;

[0256] The device is also used for:

[0257] In response to receiving an ACK message containing the sequence number corresponding to the SLPP message and / or RSPP message, it is determined that the second UE has received the ACK feedback for the SLPP message and / or RSPP message;

[0258] If no ACK message containing the sequence number corresponding to the SLPP message and / or RSPP message is received within a preset time period, it is determined that no ACK feedback from the second UE for the SLPP message and / or RSPP message has been received.

[0259] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0260] If no ACK feedback is received for the SLPP message and / or RSPP message, the SLPP message and / or RSPP message will be retransmitted.

[0261] Optionally, in one embodiment of this disclosure, in response to the first UE sending the SLPP message and / or RSPP message in unicast form, the apparatus is further configured to:

[0262] Unicast retransmission of the SLPP and / or RSPP messages.

[0263] Optionally, in one embodiment of this disclosure, in response to the first UE sending the SLPP message and / or RSPP message in multicast form, the apparatus is further configured to include at least one of the following:

[0264] If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is less than the first threshold, the SLPP message and / or RSPP message will be retransmitted via multicast.

[0265] If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the first threshold and less than the second threshold, the SLPP message and / or RSPP message shall be retransmitted unicast to the second UE in the UE group that needs ACK feedback but has not ACK feedback.

[0266] If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold, the SLPP message and / or RSPP message are unicast and retransmitted to the second UE in the UE group that needs ACK feedback but has not yet provided ACK feedback.

[0267] Optionally, in one embodiment of this disclosure, in response to the first UE sending the SLPP message and / or RSPP message in multicast form, the apparatus is further configured to:

[0268] If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the second threshold, the SLPP message and / or RSPP message will not be retransmitted.

[0269] If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold, the SLPP message and / or RSPP message will not be retransmitted.

[0270] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0271] The expected threshold is determined based on the number of second UEs in the UE group consisting of at least one second UE that can participate in executing the ranging and / or positioning services indicated by the SLPP message and / or RSPP message.

[0272] Optionally, in one embodiment of this disclosure, in response to the first UE broadcasting the SLPP message and / or RSPP message, the apparatus is further configured to:

[0273] If the number of ACK feedbacks received by the first UE is less than the third threshold, the SLPP message and / or RSPP message are broadcast and retransmitted.

[0274] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0275] If the number of unicast retransmissions by the first UE reaches a first threshold and no ACK feedback is received, retransmission is stopped and the service with the second UE is terminated.

[0276] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0277] In response to the first UE's multicast retransmission count reaching the second threshold, and the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold still being less than the first threshold, retransmission is stopped, and service with all second UEs is terminated.

[0278] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0279] In response to the first UE's multicast retransmission count reaching the second threshold, and the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is still less than the first threshold, retransmission is stopped, and it is determined that the service between the first UE and the second UE in the UE group that did not provide ACK feedback has been abnormally terminated, is inactive, or is in a suspended state.

[0280] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0281] In response to the first UE's unicast retransmission count to the second UE in the UE group that requires ACK feedback but does not reach the second threshold, and the difference or ratio between the number of ACK feedback received by the first UE and the expected threshold is still less than the first threshold, retransmission is stopped, and it is determined that the service between the first UE and the second UE that requires ACK feedback but does not reach the second threshold is abnormally terminated, inactive, or suspended.

[0282] Optionally, in one embodiment of this disclosure, the apparatus is further configured to:

[0283] If the number of broadcast retransmissions by the first UE reaches the third threshold and the number of ACK feedbacks received by the first UE is still less than the third threshold, retransmissions will stop and the service will be terminated.

[0284] Optionally, in one embodiment of this disclosure, the service is: a ranging and / or positioning service process corresponding to the SLPP message and / or RSPP message, or a session associated with the SLPP message and / or RSPP message.

[0285] Figure 27 This is a schematic diagram of the structure of a communication device provided in an embodiment of the present disclosure, as shown below. Figure 27 As shown, the device may include:

[0286] The transceiver module is used to receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages.

[0287] In summary, in the communication device provided in this embodiment, the second UE receives SLPP messages and / or RSPP messages. These SLPP and / or RSPP messages include indication information indicating that an ACK feedback is required for the SLPP and / or RSPP messages. Therefore, by including the aforementioned indication information in the SLPP and / or RSPP messages, this disclosure instructs the second UE receiving the SLPP and / or RSPP messages to send an ACK feedback to the first UE. Based on the received ACK feedback, the first UE can determine which second UEs received its SLPP and / or RSPP messages. In this case, the first UE can retransmit the SLPP and / or RSPP messages to the second UEs that did not receive them successfully. This ensures the successful transmission of the SLPP and / or RSPP messages to the second UEs, guarantees the transmission stability of the SLPP and / or RSPP messages, and thus ensures the stability of SL positioning and / or SL ranging.

[0288] The SLPP message and / or RSPP message also include a sequence number;

[0289] The device is also used for:

[0290] In response to receiving the SLPP message and / or RSPP message, an ACK feedback is sent, the ACK feedback containing the sequence number corresponding to the SLPP message and / or RSPP message.

[0291] Please see Figure 28 , Figure 28 This is a schematic diagram of the structure of a communication device 2800 provided in an embodiment of this application. The communication device 2800 can be a network device, a terminal device, a chip, chip system, or processor that supports the implementation of the above methods in a network device, or a chip, chip system, or processor that supports the implementation of the above methods in a terminal device. This device can be used to implement the methods described in the above method embodiments; for details, please refer to the descriptions in the above method embodiments.

[0292] The communication device 2800 may include one or more processors 2801. The processor 2801 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit (CPU). The baseband processor can be used to process communication protocols and communication data, while the CPU can be used to control the communication device (e.g., base station, baseband chip, terminal equipment, terminal equipment chip, DU or CU, etc.), execute computer programs, and process data from the computer programs.

[0293] Optionally, the communication device 2800 may further include one or more memories 2802, which may store a computer program 2804. The processor 2801 executes the computer program 2804 to cause the communication device 2800 to perform the method described in the above method embodiments. Optionally, the memory 2802 may also store data. The communication device 2800 and the memory 2802 may be provided separately or integrated together.

[0294] Optionally, the communication device 2800 may also include a transceiver 2805 and an antenna 2806. The transceiver 2805 may be referred to as a transceiver unit, transceiver, or transceiver circuit, etc., and is used to implement the transmission and reception functions. The transceiver 2805 may include a receiver and a transmitter. The receiver may be referred to as a receiver or receiving circuit, etc., and is used to implement the receiving function; the transmitter may be referred to as a transmitter or transmitting circuit, etc., and is used to implement the transmitting function.

[0295] Optionally, the communication device 2800 may further include one or more interface circuits 2807. The interface circuits 2807 are used to receive code instructions and transmit them to the processor 2801. The processor 2801 executes the code instructions to cause the communication device 2800 to perform the methods described in the above method embodiments.

[0296] In one implementation, the processor 2801 may include a transceiver for implementing receive and transmit functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receive and transmit functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit can be used for reading and writing code / data, or it can be used for transmitting or relaying signals.

[0297] In one implementation, processor 2801 may store computer program 2803, which runs on processor 2801 and causes communication device 2800 to perform the methods described in the above method embodiments. Computer program 2803 may be embedded in processor 2801; in this case, processor 2801 may be implemented in hardware.

[0298] In one implementation, the communication device 2800 may include circuitry capable of performing the functions of transmitting, receiving, or communicating as described in the foregoing method embodiments. The processor and transceiver described in this application can be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductors (CMOS), n-metal-oxide-semiconductor (NMOS), positive-channel metal oxide semiconductors (PMOS), bipolar junction transistors (BJTs), bipolar CMOS (BiCMOS), silicon-germanium (SiGe), gallium arsenide (GaAs), etc.

[0299] The communication device described in the above embodiments may be a network device or a terminal device, but the scope of the communication device described in this application is not limited thereto, and the structure of the communication device may vary. Figure 28 The communication device may be a standalone device or part of a larger device. For example, the communication device may be:

[0300] (1) Independent integrated circuit IC, or chip, or chip system or subsystem;

[0301] (2) A collection of one or more ICs, optionally including storage components for storing data and computer programs;

[0302] (3) ASIC, such as modem;

[0303] (4) Modules that can be embedded in other devices;

[0304] (5) Receivers, terminal equipment, smart terminal equipment, cellular phones, wireless equipment, handheld devices, mobile units, vehicle-mounted equipment, network equipment, cloud equipment, artificial intelligence equipment, etc.

[0305] (6) Others, etc.

[0306] For cases where the communication device can be a chip or a chip system, please refer to [link / reference]. Figure 29 The diagram shows the structure of the chip. Figure 29 The chip shown includes a processor 2901 and an interface 2902. There can be one or more processors 2901, and multiple interfaces 2902.

[0307] Optionally, the chip also includes a memory 2903, which is used to store necessary computer programs and data.

[0308] Those skilled in the art will also understand that the various illustrative logical blocks and steps listed in the embodiments of this application can be implemented by electronic hardware, computer software, or a combination of both. Whether such functionality is implemented through hardware or software depends on the specific application and the overall system design requirements. Those skilled in the art can implement the described functionality using various methods for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of this application.

[0309] This application also provides a readable storage medium having instructions stored thereon that, when executed by a computer, implement the functions of any of the above method embodiments.

[0310] This application also provides a computer program product that, when executed by a computer, implements the functions of any of the above method embodiments.

[0311] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer programs. When the computer program is loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program can be transferred from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., high-density digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0312] Those skilled in the art will understand that the various numerical designations such as "first," "second," etc., involved in this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application, nor do they indicate the order of sequence.

[0313] At least one in this application can also be described as one or more, and multiple can be two, three, four or more, and this application does not impose any limitation. In the embodiments of this application, for a technical feature, the technical features in that technical feature are distinguished by "first", "second", "third", "A", "B", "C" and "D", and there is no order or size among the technical features described by "first", "second", "third", "A", "B", "C" and "D".

[0314] The correspondences shown in the tables of this application can be configured or predefined. The values ​​of the information in each table are merely examples and can be configured to other values; this application is not limited to these values. When configuring the correspondences between information and parameters, it is not necessarily required to configure all the correspondences shown in each table. For example, the correspondences shown in some rows of the tables in this application may not be configured. Furthermore, appropriate modifications and adjustments can be made based on the above tables, such as splitting, merging, etc. The names of the parameters shown in the headings of the above tables can also use other names that the communication device can understand, and the values ​​or representations of the parameters can also be other values ​​or representations that the communication device can understand. In the implementation of the above tables, other data structures can also be used, such as arrays, queues, containers, stacks, linear lists, pointers, linked lists, trees, graphs, structures, classes, heaps, hash tables, or hash tables, etc.

[0315] The term "predefined" in this application can be understood as definition, pre-defined, stored, pre-stored, pre-negotiated, pre-configured, solidified, or pre-burned.

[0316] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0317] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0318] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A message transmission method, characterized in that, The method is executed by a first user equipment (UE), including: Send a Side Link Positioning Protocol (SLPP) message and / or a Ranging and Side Link Positioning Protocol (RSPP) message, wherein the SLPP message and / or RSPP message includes: indication information for indicating that an acknowledgment (ACK) feedback is required for the SLPP message and / or RSPP message; The sending of SLPP messages and / or RSPP messages includes at least one of the following: unicast the SLPP message and / or RSPP message to the second UE; Multicast the SLPP message and / or RSPP message to a UE group consisting of at least one second UE; Broadcast the SLPP message and / or RSPP message; Wherein, the first UE sends the SLPP message and / or RSPP message in unicast form, and the method further includes: If no ACK feedback is received for the SLPP message and / or RSPP message, the SLPP message and / or RSPP message will be retransmitted via unicast.

2. The method as described in claim 1, characterized in that, The SLPP message and / or RSPP message also include a sequence number; The method further includes: In response to receiving an ACK message containing the sequence number corresponding to the SLPP message and / or RSPP message, it is determined that the second UE has received the ACK feedback for the SLPP message and / or RSPP message; If no ACK message containing the sequence number corresponding to the SLPP message and / or RSPP message is received within a preset time period, it is determined that no ACK feedback from the second UE for the SLPP message and / or RSPP message has been received.

3. The method as described in claim 2, characterized in that, The method further includes: If no ACK feedback is received for the SLPP message and / or RSPP message, the SLPP message and / or RSPP message will be retransmitted.

4. The method as described in claim 3, characterized in that, In response to the first UE sending the SLPP message and / or RSPP message in multicast form, the retransmission of the SLPP message and / or RSPP message includes at least one of the following: If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is less than the first threshold, the SLPP message and / or RSPP message will be retransmitted via multicast. If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the first threshold and less than the second threshold, the SLPP message and / or RSPP message shall be retransmitted unicast to the second UE in the UE group that needs ACK feedback but has not ACK feedback. If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold, the SLPP message and / or RSPP message are unicast and retransmitted to the second UE in the UE group that needs ACK feedback but has not yet provided ACK feedback.

5. The method as described in claim 4, characterized in that, In response to the first UE sending the SLPP message and / or RSPP message in multicast form, the method further includes at least one of the following: If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than or equal to the second threshold, the SLPP message and / or RSPP message will not be retransmitted. If the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is greater than the first threshold, the SLPP message and / or RSPP message will not be retransmitted.

6. The method as described in claim 5, characterized in that, The method further includes: The expected threshold is determined based on the number of second UEs in the UE group consisting of at least one second UE that can participate in executing the service indicated by the SLPP message and / or RSPP message.

7. The method as described in claim 3, characterized in that, In response to the first UE broadcasting the SLPP message and / or RSPP message, the retransmission of the SLPP message and / or RSPP message includes: If the number of ACK feedbacks received by the first UE is less than the third threshold, the SLPP message and / or RSPP message are broadcast and retransmitted.

8. The method as described in claim 1, characterized in that, The method further includes: If the number of unicast retransmissions by the first UE reaches a first threshold and no ACK feedback is received, retransmission is stopped and the service with the second UE is terminated.

9. The method as described in claim 4, characterized in that, The method further includes: In response to the first UE's multicast retransmission count reaching the second threshold, and the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold still being less than the first threshold, retransmission is stopped, and service with all second UEs is terminated.

10. The method as described in claim 4, characterized in that, The method further includes: In response to the first UE's multicast retransmission count reaching the second threshold, and the difference or ratio between the number of ACK feedbacks received by the first UE and the expected threshold is still less than the first threshold, retransmission is stopped, and it is determined that the service between the first UE and the second UE in the UE group that did not provide ACK feedback has been abnormally terminated, is inactive, or is in a suspended state.

11. The method as described in claim 4, characterized in that, The method further includes: In response to the first UE's unicast retransmission count to the second UE in the UE group that requires ACK feedback but does not reach the second threshold, and the difference or ratio between the number of ACK feedback received by the first UE and the expected threshold is still less than the first threshold, retransmission is stopped, and it is determined that the service between the first UE and the second UE that requires ACK feedback but does not reach the second threshold is abnormally terminated, inactive, or suspended.

12. The method as described in claim 7, characterized in that, The method further includes: If the number of broadcast retransmissions by the first UE reaches the third threshold and the number of ACK feedbacks received by the first UE is still less than the third threshold, retransmissions will stop and the service will be terminated.

13. The method as described in claim 6 or any one of 8-12, characterized in that, The service is: the ranging and / or positioning service process corresponding to the SLPP message and / or RSPP message, or the session associated with the SLPP message and / or RSPP message.

14. A message transmission method, characterized in that, The method is executed by the second UE, including: Receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information for indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages; The SLPP message and / or RSPP message are sent in at least one of the following ways: unicast, multicast, or broadcast. The method further includes: The first UE sends the SLPP message and / or RSPP message in unicast format. If the first UE does not receive the ACK feedback of the SLPP message and / or RSPP message, it receives the SLPP message and / or RSPP message retransmitted by the first UE unicast.

15. The method as described in claim 14, characterized in that, The SLPP message and / or RSPP message also include a sequence number; The method further includes: In response to receiving the SLPP message and / or RSPP message, an ACK feedback is sent, the ACK feedback containing the sequence number corresponding to the SLPP message and / or RSPP message.

16. A communication device, characterized in that, Configured in the first UE, including: The transceiver module is used to send SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include: indication information indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages; The transceiver module is further configured to include at least one of the following: unicast the SLPP message and / or RSPP message to the second UE; Multicast the SLPP message and / or RSPP message to a UE group consisting of at least one second UE; Broadcast the SLPP message and / or RSPP message; Wherein, the first UE sends the SLPP message and / or RSPP message in unicast form, and the device is further configured to: If no ACK feedback is received for the SLPP message and / or RSPP message, the SLPP message and / or RSPP message will be retransmitted via unicast.

17. A communication device, characterized in that, Configured in the second UE, including: A transceiver module is used to receive SLPP messages and / or RSPP messages, wherein the SLPP messages and / or RSPP messages include indication information for indicating that an ACK feedback is required for the SLPP messages and / or RSPP messages; The SLPP message and / or RSPP message are sent in at least one of the following ways: unicast, multicast, or broadcast. Wherein, the first UE sends the SLPP message and / or RSPP message in unicast form, and the device is further configured to: If the first UE does not receive the ACK feedback of the SLPP message and / or RSPP message, it receives the SLPP message and / or RSPP message retransmitted by the first UE unicast.

18. A communication device, characterized in that, The device includes a processor and a memory, wherein the memory stores a computer program, and the processor executes the computer program stored in the memory to cause the device to perform the method as claimed in any one of claims 1 to 13, or the processor executes the computer program stored in the memory to cause the device to perform the method as claimed in claims 14 to 15.

19. A communication device, characterized in that, include: Processor and interface circuitry, among which The interface circuit is used to receive code instructions and transmit them to the processor; The processor is configured to execute the code instructions to perform the method as claimed in any one of claims 1 to 13, or to execute the code instructions to perform the method as claimed in claims 14 to 15.

20. A computer-readable storage medium for storing instructions that, when executed, cause the method of any one of claims 1 to 13 to be implemented, or, when executed, cause the method of claims 14 to 15 to be implemented.

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