WO2025209202A1 - Procédé et appareil de communication - Google Patents

Procédé et appareil de communication

Info

Publication number
WO2025209202A1
WO2025209202A1 PCT/CN2025/083909 CN2025083909W WO2025209202A1 WO 2025209202 A1 WO2025209202 A1 WO 2025209202A1 CN 2025083909 W CN2025083909 W CN 2025083909W WO 2025209202 A1 WO2025209202 A1 WO 2025209202A1
Authority
WO
WIPO (PCT)
Prior art keywords
data unit
information
data
sdu
timer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2025/083909
Other languages
English (en)
Chinese (zh)
Inventor
张彦清
张梦晨
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Publication of WO2025209202A1 publication Critical patent/WO2025209202A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/188—Time-out mechanisms
    • H04L1/1883—Time-out mechanisms using multiple timers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H04L1/1664—Details of the supervisory signal the supervisory signal being transmitted together with payload signals; piggybacking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/06—Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information

Definitions

  • the first device can determine whether to retransmit the first data unit based on the residual delay of the first data unit.
  • the first device retransmits the first data unit only when first feedback information indicating that the first data unit was not successfully received is received and the residual delay of the first data unit is greater than a first threshold. This can avoid retransmitting data units with smaller residual delays, thereby reducing or avoiding waste of transmission resources (e.g., air interface resources).
  • the first device may retransmit the first data unit, which may include: during the operation of a first timer corresponding to the first data unit, the first device may retransmit the first data unit. During the operation of the first timer, the remaining delay of the first data unit may be greater than the first threshold.
  • the first device will retransmit the first data unit only when it receives first feedback information indicating that the first data unit was not successfully received and the first timer has not timed out, thereby avoiding retransmission of the data unit whose corresponding timer has timed out, and further reducing or avoiding the waste of transmission resources (e.g., air interface resources).
  • transmission resources e.g., air interface resources
  • the importance of the first data unit may be lower than the second threshold.
  • the first device may determine whether to retransmit the data unit based on the residual delay of the data unit, thereby avoiding retransmitting unimportant data units with smaller residual delays, thereby reducing or avoiding waste of transmission resources (e.g., air interface resources) and reducing or avoiding impact on decoding of other data units.
  • transmission resources e.g., air interface resources
  • the remaining delay of the first data unit may be determined based on a first timer corresponding to the first data unit. In this way, the first device may quickly and accurately determine the remaining delay of the first data unit based on the first timer.
  • the method may further include: if the residual delay of the first data unit is less than or equal to a first threshold, the first device may not retransmit the first data unit.
  • the first device can avoid retransmitting data units with smaller residual delays, thereby reducing or avoiding waste of transmission resources (e.g., air interface resources).
  • inventions of the present application provide a communication method that can be applied to a first device.
  • the first device can be a terminal or a module in the terminal (e.g., a circuit, a chip (e.g., a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system, or a processor), or a logical node, logic module, or software that can implement all or part of the terminal's functions.
  • the first device can be an access network device, or a module applied to the access network device, such as a circuit, a chip (e.g., a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system, or a processor, or a logical node, logic module, or software that can implement all or part of the access network device's functions.
  • the method can include: after sending a first data unit, the first device receiving first feedback information, wherein the first feedback information can be used to indicate that the first data unit was not successfully received. If a first condition is met, the first device can trigger the first information.
  • the first information can be used to indicate that the first data unit is not to be retransmitted; the first condition can include: the remaining delay of the first data unit is less than or equal to a first threshold.
  • the first device can determine whether to trigger first information indicating that the first data unit should not be retransmitted based on the remaining latency of the first data unit.
  • the first device will only trigger the first information if it receives first feedback information indicating that the first data unit was not successfully received and the remaining latency of the first data unit is less than or equal to a first threshold, thereby promptly notifying the second device not to retransmit the first data unit.
  • the method may further include: after triggering the first information, if the third timer is not running, the first device may construct the first information when the first layer receives the first transmission opportunity indication from the second layer.
  • the second layer may be a lower layer of the first layer, and the third timer may be started when the information for indicating that the data unit is not to be retransmitted is delivered to the second layer.
  • the first device may start the third timer after constructing the information for indicating that the data unit is not to be retransmitted.
  • the remaining delay of the first data unit may be determined based on a first timer corresponding to the first data unit. In this way, the first device may quickly and accurately determine the remaining delay of the first data unit based on the first timer.
  • the first device may update the value of the first variable to the first SN.
  • the first variable may be the SN corresponding to the lower boundary of the sending window, and the first SN may be the smallest SN in a first set of SNs, where no data unit corresponding to any SN in the first set of SNs is indicated as not to be retransmitted.
  • the first device can promptly update the first variable, thereby promptly updating the SNs of the data units that the first device can send.
  • the sending window may include a first SN range
  • the data units corresponding to the SNs within the first SN range may be data units that can be sent by the first device.
  • the first information may be used to indicate a second SN, which may be determined based on the SN of the first data unit.
  • the first information may be used to update the value of a second variable to the second SN, which may be the SN corresponding to the lower boundary of the reassembly window in the second device.
  • the first information by indicating the second SN, may cause the second device to update the value of the second variable to the second SN.
  • the first information may not include SNs other than the second SN, resulting in reduced signaling overhead.
  • the reassembly window may include a second SN range, and the data units corresponding to the SNs within the second SN range may be data units that can be stored in the receiving buffer of the second device.
  • the first information may be used to indicate the SN of at least one data unit that is not retransmitted, and the at least one data unit may include the first data unit.
  • the first information can indicate the second SN, causing the second device to update the value of the second variable to the second SN.
  • the first information can accurately indicate the SN of the at least one data unit that is not retransmitted.
  • the first device may not determine whether to trigger information for indicating not to retransmit the data unit based on the remaining delay of the data unit, thereby not notifying the second device not to retransmit the data unit, thereby reducing or avoiding the waste of transmission resources (for example, air interface resources) and reducing or avoiding the impact on the decoding of other data units.
  • the first device may not determine whether to trigger information for indicating not to retransmit the data unit based on the remaining delay of the data unit, thereby not notifying the second device not to retransmit the data unit, thereby reducing or avoiding the waste of transmission resources (for example, air interface resources) and reducing or avoiding the impact on the decoding of other data units.
  • an embodiment of the present application provides a communication method, which can be applied to a second device.
  • the second device can be an access network device, or a module applied to the access network device, such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system or a processor, or a logical node, a logical module or software that can implement all or part of the functions of the access network device; or, the second device can be a terminal or a module in the terminal (such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system or a processor), or a logical node, a logical module or software that can implement all or part of the terminal functions.
  • the method may include: after receiving the first information, the second device may process the received data unit according to the first information.
  • the first information can be used to indicate that the first data unit is not
  • the second device can promptly learn, based on the first information, that the first data unit is a non-retransmitted data unit, and can process the received data unit accordingly.
  • the second device may update the value of the second variable to a second SN.
  • the second variable may be the SN corresponding to the lower boundary of the reassembly window, and the second SN may be determined based on the first information.
  • the second device may then process the received data unit based on the reassembly window.
  • the second device may promptly update the second variable based on the first information, thereby promptly updating the reassembly window and preventing the reassembly window from becoming stuck.
  • the second device may update the second variable so that the SN of the data unit that is not retransmitted is not within the reassembly window, thereby preventing the second device from affecting the reception of other data units due to waiting for the data unit that is not retransmitted.
  • the first information may be used to indicate the second SN.
  • the second device can quickly and accurately determine the second SN based on the first information.
  • the first information may not include SNs other than the second SN, resulting in low signaling overhead.
  • the first information may be used to indicate the SN of at least one data unit that is not to be retransmitted, where the at least one data unit may include the first data unit.
  • the second SN may be the smallest SN in a second set of SNs, and the data unit corresponding to any SN in the second set of SNs is not indicated as not to be retransmitted.
  • the second device can quickly and accurately determine the second SN based on the first information.
  • the first information can be used to indicate the SN of at least one data unit that is not to be retransmitted, and the at least one data unit can include the first data unit. If the SN corresponding to the at least one data unit includes the SN corresponding to the third variable, the second device can update the value of the third variable to the third SN and process the received data unit according to the third variable.
  • the third variable can be the highest SN in the second information, and the second information can be used to indicate whether one or more data units have been successfully received, and the data unit corresponding to the third SN has not been indicated as not to be retransmitted.
  • the second device can update the third variable in a timely manner according to the first information, and thus can send the second information according to the updated third variable.
  • the second information may not indicate whether the data unit indicated as not to be retransmitted has been received.
  • the second information does not indicate whether these data units have been received, which will not affect the transmission of these data units, and can reduce signaling overhead and save transmission resources.
  • the method further includes: when the reassembly timer times out, the second device may update the value of the third variable to the smallest SN in the third group of SNs.
  • the third variable may be the highest SN in the second information, and the second information may be used to indicate whether one or more data units have been successfully received, and the data unit corresponding to any SN in the third group of SNs has not been indicated as not to be retransmitted.
  • the second device may update the third variable based on the first information when the reassembly timer times out, and may thereby send the second information based on the updated third variable. In this way, the second information may not indicate whether the data units indicated as not to be retransmitted have been received.
  • the second information does not indicate whether these data units have been received, which will not affect the transmission of these data units, and may reduce signaling overhead and save transmission resources.
  • the second device may discard the first data unit.
  • a small residual delay e.g., a residual delay of 0
  • the second device may discard the data unit, thereby reducing processing complexity of the second device.
  • the method may further include: the second device may send second information.
  • the second information may be used to indicate whether one or more data units are successfully received, and any of the one or more data units is not indicated as not to be retransmitted.
  • the second information may not indicate whether data units indicated as not to be retransmitted are received.
  • the second information does not indicate whether these data units are received, which will not affect the transmission of these data units, and can reduce signaling overhead and save transmission resources.
  • the importance of the first data unit may be lower than the second threshold.
  • the first device may determine whether to trigger information for indicating not to retransmit the data unit based on the remaining delay of the data unit, thereby notifying the second device not to retransmit the data unit.
  • the first device may not determine whether to trigger information for indicating not to retransmit the data unit based on the remaining delay of the data unit, thereby not notifying the second device not to retransmit the data unit, thereby reducing or avoiding the waste of transmission resources (for example, air interface resources) and reducing or avoiding the impact on the decoding of other data units.
  • the first device may not determine whether to trigger information for indicating not to retransmit the data unit based on the remaining delay of the data unit, thereby not notifying the second device not to retransmit the data unit, thereby reducing or avoiding the waste of transmission resources (for example, air interface resources) and reducing or avoiding the impact on the decoding of other data units.
  • inventions of the present application provide a communication method that can be applied to a second device.
  • the second device can be an access network device, or a module applied to the access network device, such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system, or a processor. It can also be a logical node, logic module, or software that can implement all or part of the access network device functions.
  • the second device can be a terminal or a module in the terminal (such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system, or a processor).
  • the method may include: when the reassembly timer expires, the second device may determine that the first data unit was not successfully received. If the number of triggering and/or sending times of the first feedback information is less than a third threshold and the importance of the first data unit is less than a second threshold, the second device may trigger the first feedback information, and the first feedback information may be used to indicate that the first data unit was not successfully received.
  • the second device can determine whether to continue to send feedback information indicating that the data unit was not successfully received based on the triggering and/or transmission frequency of feedback information indicating that the data unit was not successfully received.
  • NACK negative acknowledgment
  • the method may further include: the second device may receive third information.
  • the third information may be used to indicate the importance of the first data unit. In this way, the second device may quickly and accurately determine the importance of the first data unit based on the third information.
  • the third information may also be used to indicate at least one of the following: a first data unit group, to which the first data unit may belong; and/or the number of data units contained in the first data unit group. If the third information indicates the first data unit group, the second device may accurately determine the importance of other data units in the first data unit group based on the importance of at least one data unit in the first data unit group. If the third information indicates the first data unit group and the number of data units contained in the first data unit group, then if the last K data units in the first data unit group are not successfully received, the second device may accurately determine the importance of the K data units based on the importance of at least one data unit in the first data unit group, where K is a positive integer.
  • the method may further include: when the number of times the first feedback information is triggered and/or sent is greater than or equal to a third threshold, and the importance of the first data unit is lower than a second threshold, the second device may trigger third feedback information.
  • the third feedback information may be used to indicate that the first data unit has been successfully received.
  • the method can include: the first device sending a first data unit.
  • the first device can receive the first feedback information.
  • the first feedback information can be used to indicate that the first data unit was not successfully received.
  • the third information may also be used to indicate at least one of the following: a first data unit group, to which the first data unit may belong; and/or the number of data units contained in the first data unit group.
  • the present application provides a communication device.
  • the communication device may be a terminal or a module in the terminal (such as a circuit, chip, chip system or processor), or a logical node, logic module or software that can implement all or part of the terminal functions; or the communication device may be an access network device, or a module (such as a circuit, chip, chip system or processor) applied to the access network device, or a logical node, logic module or software that can implement all or part of the access network device functions.
  • the communication device has the function of implementing at least one of the above aspects.
  • the communication device includes a module or unit or means corresponding to the operation involved in at least one aspect of the first, second or fifth aspects above.
  • the module or unit or means may be implemented by software, or by hardware, or the corresponding software implementation may be executed by hardware.
  • the communication device includes a module or unit or means corresponding to the operation involved in at least one aspect of the third or fourth aspects above.
  • the module or unit or means may be implemented by software, or by hardware, or the corresponding software implementation may be executed by hardware.
  • the communication device includes an interface unit and a processing unit.
  • the interface unit can be used to send and receive signals to enable communication between the communication device and other devices; the processing unit can be used to perform certain internal operations of the communication device.
  • the functions performed by the processing unit and the interface unit can correspond to the operations described in at least one of the above aspects.
  • the communication device includes a processor.
  • the processor can execute a computer program or instructions, and when the computer program or instructions are executed, the communication device implements the method in any possible design of at least one aspect above.
  • the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices through the interface circuit and execute the method in any possible design of at least one aspect above.
  • the present application provides a communication system, which may include at least one of a first device and a second device.
  • the first device may execute the communication method provided in at least one of the first, second, or fifth aspects
  • the second device may execute the communication method provided in at least one of the third or fourth aspects.
  • the communication system includes a terminal; wherein the terminal is configured to execute the communication method provided in the first aspect.
  • the communication system includes a terminal and an access network device.
  • the terminal is configured to execute the communication method provided in the second aspect, and the access network device is configured to execute the communication method provided in the third aspect; or, the terminal is configured to execute the communication method provided in the third aspect, and the access network device is configured to execute the communication method provided in the second aspect; or, the terminal is configured to execute the communication method provided in the fifth aspect, and the access network device is configured to execute the communication method provided in the fourth aspect; or, the terminal is configured to execute the communication method provided in the fourth aspect, and the access network device is configured to execute the communication method provided in the fifth aspect.
  • the present application provides a computer-readable storage medium, which stores a computer program or instruction.
  • the computer program or instruction When executed, the method in any possible design of any aspect from the first to the fifth aspects mentioned above is implemented.
  • the present application provides a computer program product, which includes a computer program code.
  • the computer program code When the computer program code is executed, the method in any possible design of any aspect from the first to the fifth aspects is implemented.
  • the present application provides a chip, which may include a processor, and the processor may be used to execute the method in any possible design of any aspect of the first to fifth aspects above.
  • FIG1 is an architecture diagram of a communication system provided in an embodiment of the present application.
  • FIG2 is a schematic diagram of a method for retransmitting a data unit provided in an embodiment of the present application
  • FIG3 is a flow chart of a communication method provided in an embodiment of the present application.
  • FIGS. 4A to 4C are schematic diagrams of several application scenarios provided by embodiments of the present application.
  • FIG5 is a flow chart of another communication method provided in an embodiment of the present application.
  • FIGS. 6A to 6C are schematic diagrams of several other application scenarios provided by embodiments of the present application.
  • FIG8 is a flow chart of another communication method provided in an embodiment of the present application.
  • FIGS. 9A and 9B are schematic diagrams of several data units provided in embodiments of the present application.
  • FIG10 is a structural diagram of a communication device provided in an embodiment of the present application.
  • FIG11 is a structural diagram of another communication device provided in an embodiment of the present application.
  • the technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.
  • the technical solutions in the embodiments of the present application can be applied to various communication systems, such as universal mobile telecommunications system (UMTS), wireless local area network (WLAN), wireless fidelity (Wi-Fi or WiFi) system, 4th generation (4G) mobile communication system such as long term evolution (LTE) system, 5th generation (5G) mobile communication system such as new radio (NR) system, and future evolved communication systems such as 6th generation (6G) mobile communication system.
  • UMTS universal mobile telecommunications system
  • WLAN wireless local area network
  • Wi-Fi or WiFi WiFi
  • 4th generation (4G) mobile communication system such as long term evolution (LTE) system
  • 5th generation (5G) mobile communication system such as new radio (NR) system
  • future evolved communication systems such as 6th generation (6G) mobile communication system.
  • FIG1 shows a possible, non-limiting system diagram.
  • a communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200.
  • the communication system 10 may also include the Internet 300.
  • the RAN 100 includes at least one RAN node (e.g., 110a and 110b in FIG. 1 , collectively referred to as 110) and at least one terminal (e.g., 120a-120j in FIG. 1 , collectively referred to as 120).
  • the RAN 100 may also include other RAN nodes, such as wireless relay equipment and/or wireless backhaul equipment (not shown in FIG. 1 ).
  • the terminal 120 is wirelessly connected to the RAN node 110.
  • the RAN node 110 is wirelessly or wiredly connected to the core network 200.
  • the core network equipment in the core network 200 and the RAN node 110 in the RAN 100 may be different physical devices, or they may be the same physical device that integrates core network logical functions and radio access network logical functions.
  • the RAN 100 can be a cellular system related to the Third Generation Partnership Project (3GPP), such as a 4G or 5G mobile communication system, or a future-oriented evolutionary system (such as a 6G mobile communication system).
  • the RAN 100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a WiFi system.
  • the RAN 100 can also be a communication system that integrates two or more of the above systems.
  • RAN node 110 forms part of the communication system and facilitates wireless access for terminals.
  • Multiple RAN nodes 110 in the communication system 10 can be of the same or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative.
  • network element 120i in Figure 1 can be a helicopter or drone, which can be configured as a mobile base station.
  • network element 120i is a base station; however, for base station 110a, network element 120i is a terminal.
  • RAN node 110 and terminal 120 are sometimes referred to as communication devices.
  • network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functionality, and network elements 120a-120j can be understood as communication devices with terminal functionality.
  • an access network device may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system.
  • the access network device may be a macro base station (such as 110a in FIG1 ), a micro base station or an indoor station (such as 110b in FIG1 ), a relay node or a donor node, or a wireless controller in a CRAN scenario.
  • the access network device may also be a server, a wearable device, a vehicle, or an onboard device.
  • an access network device can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU).
  • the CU and DU can be separate or included in the same network element, such as a baseband unit (BBU).
  • BBU baseband unit
  • the RU can be included in a radio frequency device or radio unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).
  • the data frame may be divided into multiple PDUs for transmission, and a PDU set may include the multiple PDUs.
  • a data burst can be understood as a group of PDUs generated and sent by an application (or application layer) within a period of time. This group of PDUs can come from one or more PDU sets, and the duration of the period can be less than the set value.
  • the broadband real-time broadband communication (RTBC) scenario under the new 5G vision is designed to support large bandwidth and low interaction latency.
  • the goal is to increase bandwidth tenfold within given latency and certain reliability requirements, thereby creating an immersive experience when people interact with the virtual world.
  • XR services which require ultra-large bandwidth and ultra-low latency, can be applied to RTBC scenarios.
  • XR services may include one or more types of data, such as video, audio, and control signals.
  • Video typically consists of several ultra-high-definition images, each of which can be compressed using encoding methods such as high-efficiency video coding (HEVC), resulting in a larger data block. The higher the video definition, the larger the data block.
  • HEVC high-efficiency video coding
  • XR data When XR services include video, the XR data is referred to as a data frame.
  • a data frame is typically transmitted by several Internet Protocol (IP) packets or PDUs.
  • IP Internet Protocol
  • data frames may be dependent on each other.
  • the second data frame may need to be decoded based on the first data frame. Therefore, if the transmission of the first data frame fails, even if the second data frame is received, the receiving device will not be able to decode it.
  • the concept of data importance is introduced. For example, data frames for services like XR are divided into important data frames and unimportant data frames.
  • the importance of data can be distinguished by an importance threshold. For example, if the importance of a certain data is higher than or equal to the importance threshold, the data can be considered important data, and the data frame corresponding to the data can be considered an important data frame. If the importance of a certain data is lower than the importance threshold, the data can be considered unimportant data or low-importance data, and the data frame corresponding to the data can be considered an unimportant data frame.
  • core network equipment can identify the importance of the data and notify the access network equipment of the data's importance so that the access network equipment can perform scheduling and management accordingly.
  • the terminal can identify the importance of the data.
  • the importance of the data is determined by the sending device, and the receiving device is usually unaware of the data's importance.
  • Entities corresponding to multiple layers in the transmitting device may process data sequentially.
  • an entity corresponding to the Service Data Adaptation Protocol (SDAP) layer in the transmitting device may map data in the form of a Quality of Service (QoS) stream to a corresponding Data Radio Bearer (DRB), generating a Packet Data Convergence Protocol (PDCP) SDU and submitting the PDCP SDU to the PDCP layer in the transmitting device.
  • An entity corresponding to the PDCP layer in the transmitting device (referred to as a first PDCP entity) may generate a PDCP PDU based on the PDCP SDU and submit the PDCP PDU to the RLC layer in the transmitting device.
  • the RLC layer in the transmitting device may also be referred to as the RLC transmit (TX) side.
  • TX data from a higher layer of the RLC layer
  • a PDCP PDU may be referred to as an RLC SDU.
  • the corresponding entity on the RLC TX side (which may be referred to as a first RLC entity) may generate an RLC PDU based on the RLC SDU and deliver the RLC PDU to a lower layer(s) of the RLC layer, so that the transmitting device transmits the RLC PDU.
  • the lower layer(s) of the RLC layer may be located in the transmitting device, for example, the lower layer(s) of the RLC layer may be a media access control (MAC) layer.
  • MAC media access control
  • the first RLC entity may support AM; in other words, the transmission mode of the first RLC entity may be AM.
  • the first RLC entity may also be referred to as a first AM RLC entity. The following describes some processing methods of the first RLC entity.
  • the first RLC SDU is any RLC SDU received by the first RLC entity.
  • the first RLC entity may assign an SN to the first RLC SDU through the following steps A1 and A2:
  • the first RLC entity may assign an SN equal to the variable TX_NEXT to the first RLC SDU.
  • the SN assigned by the first RLC entity to the first RLC SDU is equal to the current value of the variable TX_NEXT.
  • the bit width of the SN may be configured as 12 bits or 18 bits. In this application, the bit width of the SN may also be replaced by the length or number of bits of the SN.
  • the first RLC entity may also construct a first RLC PDU whose SN is the variable TX_NEXT, and the first RLC PDU may include the first RLC SDU or a segment of the first RLC SDU.
  • the sending device may send the RLC PDU; if the SN of an RLC PDU does not fall within SN range #1, the sending device may not send the RLC PDU, for example, the first RLC entity does not deliver the RLC PDU to a lower layer of the RLC layer.
  • the sending window can be determined based on the variable TX_Next_Ack and the constant #1.
  • the variable TX_Next_Ack may be the SN corresponding to the lower edge of the transmit window.
  • the variable TX_Next_Ack may be the largest SN corresponding to the first group of RLC SDUs + 1.
  • the SNs corresponding to the first group of RLC SDUs are consecutive, and the first RLC entity has received an ACK for each RLC SDU in the first group of RLC SDUs.
  • Constant #1 can be the size of the send window.
  • constant #1 can be half the value space of SN.
  • constant #1 can be 2048.
  • constant #1 can be 131072.
  • Constant #1 can also be replaced with other names, such as AM_Window_Size.
  • the first RLC entity may deliver the RLC PDU corresponding to the SN in the transmission window to the lower layer of the RLC layer.
  • the first RLC entity may also deliver the RLC PDU corresponding to the SN in the transmission window to the lower layer of the RLC layer based on the granted resources corresponding to the transmission opportunity indication.
  • the second RLC SDU is an RLC SDU to be transmitted in the first RLC entity.
  • the first RLC entity may include the second RLC SDU in an RLC PDU and deliver the RLC PDU to the lower layer of the RLC layer.
  • the second RLC SDU is an RLC SDU to be transmitted in the first RLC entity.
  • the first RLC entity may segment the second RLC SDU and deliver the segmented RLC PDU containing the second RLC SDU to a lower layer of the RLC layer.
  • This status report may be used to indicate whether one or more RLC SDUs have been successfully received.
  • Successful reception of an RLC SDU may be understood to mean that the RLC SDU has been completely received, i.e., all bytes of the RLC SDU have been successfully received, e.g., all segments of the RLC SDU have been successfully received.
  • unsuccessful reception of an RLC SDU may include: any data (e.g., any bit or any segment) in the RLC SDU has not been successfully received, or some bytes of the RLC SDU have been successfully received, e.g., some segments of the RLC SDU have been successfully received.
  • the status report may explicitly indicate whether one or more RLC SDUs were successfully received. For example, if the status report includes ACKs for RLC SDU#0 through RLC SDU#2 and a NACK for RLC SDU#3, this indicates that RLC SDU#0 through RLC SDU#2 were successfully received, but RLC SDU#3 was not successfully received.
  • the status report may include only indication information of unsuccessfully received RLC SDUs or RLC SDU segments (i.e., indication information of RLC SDUs or RLC SDU segments that require negative acknowledgment), and may not include indication information of successfully received RLC SDUs (i.e., indication information of RLC SDUs that require positive acknowledgment). For example, if RLC SDUs #0 to #2 are successfully received and RLC SDU #3 is unsuccessfully received, the status report may include only indication information of RLC SDU #3 (e.g., SN of RLC SDU #3) and/or indication information of unsuccessfully received segments of RLC SDU #3.
  • an ACK for receiving certain data may include: an ACK for the data being included in a received status report, or an indication that the data is not included in the received status report.
  • a NACK for receiving certain data may include: a NACK for the data being included in a received status report, or an indication that the data is included in the received status report.
  • an ACK for receiving certain data may be replaced by an ACK confirming the data, or a confirmation that the data is successfully received.
  • the status report may be received by the first RLC entity from an entity corresponding to the RLC layer in the receiving device (which may be referred to as a second RLC entity).
  • the RLC layer in the receiving device may also be referred to as the RLC receive (RX) side.
  • the status report may be included in an RLC control PDU.
  • the RLC control PDU may also be referred to as a status PDU.
  • the first RLC entity may retransmit the RLC SDU or the segment of the RLC SDU.
  • the following description uses the example of the first RLC entity retransmitting an RLC SDU. For example, if the first RLC entity has sent RLC SDU#1 to RLC SDU#3, the status report includes: ACKs for RLC SDU#0 to RLC SDU#2, and a NACK for RLC SDU#3, and the SN of RLC SDU#3 falls within the send window, the first RLC entity may retransmit RLC SDU#3.
  • the first RLC entity may retransmit the RLC SDU or the segment of the RLC SDU.
  • the number threshold may be pre-set, such as specified by a protocol; or it may be notified to the sending device by another device, such as an access network device sending a radio resource control (RRC) message to the sending device, and the RRC message is used to configure the number threshold.
  • RRC radio resource control
  • the first RLC entity has sent RLC SDU#0 to RLC SDU#3; the status report includes: ACKs for RLC SDU#0 to RLC SDU#2, and a NACK for RLC SDU#3. If the number of times the first RLC entity receives NACK for RLC SDU#3 is less than the number threshold, the first RLC entity may retransmit RLC SDU#3.
  • the first RLC entity may not retransmit the RLC SDU or RLC SDU segment. Furthermore, in some cases, if the number of times a NACK corresponding to the RLC SDU is received is greater than or equal to a number threshold, the first RLC entity may update a transmit window based on the RLC SDU, for example, by updating a variable TX_Next_Ack, thereby updating the transmit window.
  • the first RLC entity may update the variable TX_Next_Ack to the largest SN corresponding to a second group of RLC SDUs + 1.
  • the SNs corresponding to the second group of RLC SDUs are consecutive.
  • the second RLC SDU is any RLC SDU in the second group of RLC SDUs.
  • the first RLC entity has received an ACK for the second RLC SDU; or the number of times the first RLC entity has received a NACK for the second RLC SDU is greater than or equal to the number threshold.
  • the following example illustrates the situation where the first RLC entity does not retransmit an RLC SDU.
  • the first PDCP entity may configure and start a packet loss timer for a PDCP SDU. For example, upon receiving each PDCP SDU, the first PDCP entity may configure and start a packet loss timer for the PDCP SDU. Thus, each PDCP SDU may correspond to a packet loss timer. Because each PDCP PDU includes a PDCP SDU, and a PDCU PDU may be referred to as an RLC SDU, each RLC SDU may correspond to a packet loss timer.
  • the duration of the packet loss timer corresponding to different PDCP SDUs may be different.
  • packet loss timer #a the duration of the packet loss timer corresponding to important data
  • packet loss timer #b the duration of the packet loss timer corresponding to unimportant data
  • Packet loss timer #a may be the conventional packet loss timer described above
  • packet loss timer #b may be the timer configured by the high-layer signaling low importance packet loss timer (discardTimerForLowImportance).
  • the first RLC entity may receive information from the first PDCP entity indicating the packet loss timer expiration. If the RLC SDU corresponding to the PDCP SDU has not been transmitted at this time, for example, if the RLC SDU or any segment thereof has not been delivered to a lower layer, the transmitting device may discard the RLC SDU or the RLC PDU including the RLC SDU. For example, after receiving PDCP SDU#1, the first PDCP entity may start the associated packet loss timer #1 for PDCP SDU#1.
  • a transmitting device is configured for packet loss based on a granularity of a data unit group, such as a PDU set
  • a first RLC entity may discard the RLC SDU corresponding to the PDU set, or an RLC PDU including the RLC SDU, if the RLC SDU corresponding to the PDU set has not been transmitted.
  • the PDU set includes PDCP SDU#1 to PDCP SDU#4.
  • PDCP SDU#1 to PDCP SDU#4 correspond to RLC SDU#1 to RLC SDU#4, respectively.
  • the first device may discard PDCP SDU #1 to PDCP SDU #4.
  • packet loss at the data unit group granularity may be configured by the access network device for the first PDCP entity of the transmitting device (e.g., terminal) via an RRC message (e.g., PDU group discard (pdu-SetDiscard)).
  • Entities corresponding to multiple layers in the receiving device can process data in sequence.
  • the entity corresponding to the RLC layer in the receiving device (which may be referred to as the second RLC entity) may receive an RLC PDU from a lower layer (e.g., the MAC layer) of the RLC layer in the receiving device, and determine whether to store the received RLC PDU in a receive buffer based on the SN corresponding to the received RLC PDU. If the RLC SDU corresponding to the RLC PDU is completely received, in other words, the second RLC entity has received all bytes of the RLC SDU corresponding to the RLC PDU, the second RLC entity may deliver the RLC SDU to a higher layer of the RLC layer (deliver to upper layer(s)).
  • the higher layer may be located in the receiving device, such as the PDCP layer.
  • Step B1 The second RLC entity may update the variable RX_Highest_Status to the smallest SN in SN set #1.
  • Step B2 When condition d1 or condition d2 is satisfied, the second RLC entity may start a reassembly timer and set the variable RX_Next_Status_Trigger to the variable RX_Next_Highest.
  • variable RX_Next_Highest variable RX_Highest_Status + 1; the RLC SDU whose SN is the variable RX_Highest_Status is the sixth RLC SDU, and the second RLC entity receives at least one segment of the sixth RLC SDU, and there is at least one missing byte before the last byte in the at least one segment.
  • the variable RX_Next is 3 and the variable RX_Next_Highest is 5.
  • the second RLC entity may trigger a status report when the reassembly timer expires.
  • the second RLC entity may trigger the status report after updating the variable RX_Highest_Status; in other words, the content of the status report is determined based on the updated variable RX_Highest_Status.
  • the method for updating the variable RX_Highest_Status by the second RLC entity may be described in step B1 and will not be further described here.
  • the corresponding SNs are in ascending order within the RLC SDU in ascending order of segments, from the SN equal to the variable RX_Next to an SN such that the size of the status report is suitable for the size of the transmission resources indicated by the lower layers of the RLC layer.
  • Remaining delay refers to how long it will take for data to be transmitted.
  • the remaining delay can be understood as a duration.
  • the starting time of the remaining delay can be the current system time, and the ending time of the remaining delay can be the time when the transmission delay budget of the data to be transmitted is about to time out, or the time when the data to be transmitted is about to be discarded.
  • the transmission delay budget can be the packet delay budget (PDB) corresponding to the data to be transmitted.
  • the PDB can be understood as the delay requirement from the terminal to the access network device or the terminal to the UPF entity. For example, the maximum time from the arrival of a PDU at the terminal to the successful reception of the PDU by the access network device or the UPF entity.
  • QoS 5G Quality of Service
  • the transmission delay budget can be the PDU set delay budget (PSDB) corresponding to the data to be transmitted.
  • the moment when the data to be transmitted is about to be discarded can be understood as the moment when the packet loss timer corresponding to the data to be transmitted expires.
  • the remaining delay may also have other names, such as remaining time, remaining scheduling delay, remaining transmission delay, remaining scheduling time, remaining packet delay budget or remaining transmission time, etc., as long as they express the same meaning.
  • the device's operation on the message may include one or more of the following operations: triggering, constructing, and sending.
  • the following description uses the operation of a first device on a first message as an example. Triggering the first message by the first device may refer to the first device determining that it will send the first message. At this point, the first message may not exist in the first device. After the first device triggers the first message, the first device may construct the first message; after the first message is constructed, the first message exists in the first device. Sending the first message by the first device may refer to the first device sending the first message via air interface resources. It should be understood that constructing and/or sending may be optional.
  • the first device may not construct the first message and, therefore, may not send the first message. For example, if, after the first message is triggered and constructed, the first device is disconnected from the network, the first device may not send the first message.
  • the receiving device may send a status report to the transmitting device to indicate whether the data was successfully received. If the data was not successfully received, the transmitting device may retransmit the data.
  • data with high reliability may also have higher requirements for transmission delay.
  • the first RLC entity of the transmitting device does not consider transmission delay when retransmitting data, which may result in a waste of transmission resources. For example, as shown in Figure 2, at time T0, the transmitting device sends RLC SDU#0. The transmitting device receives a NACK for RLC SDU#0, and then at time T1, the transmitting device may retransmit RLC SDU#0.
  • FIG. 3 is a flow chart corresponding to the communication method provided by the present application.
  • the first device and the second device are used as the execution subjects of the interaction diagram to illustrate the method, but the present application does not limit the execution subjects of the interaction diagram.
  • the first device can be a terminal, or a module applied to the terminal, such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system or a processor, or a logical node, a logical module or software that can realize all or part of the terminal functions;
  • the second device can be an access network device, or a module applied to the access network device, such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system or a processor, or a logical node, a logical module or software that can realize all or part of the access network device functions.
  • the first device may be an access network device, or a module applied to the access network device, such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system, or a processor. It may also be a logical node, a logical module, or software that can implement all or part of the functions of the access network device.
  • the second device may be a terminal, or a module applied to the terminal, such as a circuit, a chip (such as a modem chip, or a SoC chip or SIP chip containing a modem core), a chip system, or a processor. It may also be a logical node, a logical module, or software that can implement all or part of the functions of the terminal.
  • the first device may be the sending device described above
  • the second device may be the receiving device described above.
  • the method includes:
  • a first device may send a first data unit.
  • the first data unit may be an SDU, a segment of an SDU, or a PDU.
  • the SDU may be, for example, an RLC SDU
  • the PDU may be, for example, an RLC PDU.
  • the importance of the first data unit may be lower than the second threshold.
  • the second threshold may be pre-set, for example, specified by the protocol, or saved in the factory settings or SIM card of the first device; or, the second threshold may be notified to the first device by other devices (for example, core network devices or second devices).
  • the second threshold may also have other names, for example, importance threshold, which is not limited in this application.
  • data below the second threshold may be understood as unimportant data. For example, if the importance of the first data unit is lower than the second threshold, the first data unit may be unimportant data, or belong to an unimportant data unit group.
  • S301 may include: the first device may initially transmit the first data unit, or the first device may retransmit the first data unit; in other words, the first data unit may be an initially transmitted data unit or a retransmitted data unit.
  • the first data unit may be an RLC SDU or a segment of an RLC SDU retransmitted by a first RLC entity in the first device.
  • the first data unit may be a data unit whose corresponding SN belongs to the sending window, or the first data unit may be a data unit whose corresponding SN does not belong to the sending window, for example, the SN corresponding to the first data unit is smaller than the SN corresponding to the variable TX_Next_Ack.
  • the second device may send first feedback information; correspondingly, the first device may receive the first feedback information, wherein the first feedback information may be used to indicate that the first data unit is not successfully received.
  • the first device may retransmit the first data unit.
  • the remaining delay of the first data unit may be determined based on a first timer corresponding to the first data unit. In this way, the first device may quickly and accurately determine the remaining delay of the first data unit based on the first timer.
  • the packet loss timer corresponding to the first data unit may be a conventional packet loss timer, such as the packet loss timer #a in the explanation of the term, or the packet loss timer corresponding to the first data unit may also be a timer configured by the high-layer signaling discardTimerForLowImportance, such as the packet loss timer #b in the explanation of the term.
  • the first device can determine the remaining delay of the first data unit based on the packet loss timer without adding a new timer, thereby reducing the complexity of the first device.
  • the first threshold may be pre-set, for example, specified by a protocol, or stored in the factory settings of the first device or in a SIM card; alternatively, the first threshold may be notified to the first device by another device (e.g., a core network device or a second device).
  • the first threshold may be greater than or equal to 0.
  • the first threshold may be 0.
  • the remaining delay of the first data unit may be greater than the first threshold; in other words, before the first timer expires, the remaining delay of the first data unit may be greater than the first threshold. For example, if the remaining delay of the first data unit is the remaining duration of the first timer and the first threshold is 0, then during the operation of the first timer, the remaining delay of the first data unit may be greater than the first threshold.
  • the first device retransmits the first data unit only upon receiving first feedback information indicating that the first data unit was not successfully received and upon receiving the first timer before expiration. This avoids retransmitting data units whose corresponding timers have timed out, thereby reducing or avoiding waste of transmission resources (e.g., air interface resources). Furthermore, if the first timer is the packet loss timer corresponding to the first data unit, the first device can reuse the packet loss timer, eliminating the need to add a new timer and reducing the complexity of the first device. Optionally, in this manner, the importance of the first data unit may be lower than the second threshold.
  • the method shown in FIG3 may further include S304:
  • the specific contents of the remaining delay of the first data unit and the first threshold value can be referred to the description of the remaining delay of the first data unit and the first threshold value in S303, and will not be repeated here.
  • the first device can determine the remaining delay of the first data unit and the first threshold value, and thus determine whether the remaining delay of the first data unit is less than or equal to the first threshold value. For example, if the remaining delay of the first data unit is 0ms and the first threshold value is 0, the first device can determine that the remaining delay of the first data unit is less than or equal to the first threshold value, and thus may not retransmit the first data unit.
  • S302 and S304 may be combined as follows: if first feedback information indicating that the first data unit is not successfully received is received, and the remaining delay of the first data unit is less than or equal to a first threshold, the first device may not retransmit the first data unit.
  • S304 may include (or S304 may be replaced by): if the first timer corresponding to the first data unit expires, the first device does not retransmit the first data unit.
  • S302 and S304 may be combined to: if first feedback information indicating that the first data unit was not successfully received is received and the first timer expires, the first device may not retransmit the first data unit.
  • the time when the first timer times out may be the same as or different from the first time when the first device receives the first feedback information. In the case where the time when the first timer times out is different from the first time, the time when the first timer times out may be earlier or later than the first time.
  • the PDCP entity of the first device may start the packet loss timer corresponding to SDU#1. If the first device receives a NACK for SDU#1 after sending SDU#1 and after the packet loss timer corresponding to SDU#1 expires, the first device does not retransmit SDU#1.
  • the SDU#1 in "sending SDU#1," "not retransmitting SDU#1,” and "NACK for SDU#1" may be replaced with a segment of SDU#1.
  • the PDCP entity of the first device may start the packet loss timer corresponding to SDU#1.
  • the first device may receive a NACK for SDU#1. If, after receiving the NACK for SDU#1 and before the packet loss timer corresponding to SDU#1 expires, the first device does not deliver SDU#1 to a lower layer of the RLC layer (e.g., the MAC layer), then after the packet loss timer corresponding to SDU#1 expires, the first device does not retransmit SDU#1.
  • SDU#1 in "sending SDU#1," "delivering SDU#1,” “not retransmitting SDU#1,” and "NACK for SDU#1” may be replaced with a segment of SDU#1.
  • the first device upon receiving first feedback information indicating that a first data unit was not successfully received and a first timer has expired, the first device does not retransmit the first data unit, thereby avoiding retransmission of the corresponding data unit whose timer has expired, thereby reducing or avoiding waste of transmission resources (e.g., air interface resources). Furthermore, if the first timer is a packet loss timer corresponding to the first data unit, the first device can reuse the packet loss timer, eliminating the need to add a new timer and reducing the complexity of the first device. Optionally, in this manner, the importance of the first data unit may be lower than the second threshold.
  • the first device upon receiving first feedback information indicating that the first data unit was not successfully received and a first timer has expired, the first device does not retransmit the first data unit, thereby avoiding retransmission of the unimportant data unit whose timer has expired, thereby reducing or avoiding waste of transmission resources (e.g., air interface resources) and reducing or avoiding impact on the decoding of other data units.
  • transmission resources e.g., air interface resources
  • the method shown in FIG. 3 may not include S303 ; in other words, the method shown in FIG. 3 may include S301 , S302 , and S304 .
  • the operations performed by the first device may be performed by a first entity (eg, an RLC entity) in the first device.
  • a first entity eg, an RLC entity
  • the first device can determine whether to retransmit the first data unit based on the residual delay of the first data unit.
  • the first device may not retransmit the first data unit, thereby reducing or avoiding the waste of transmission resources (e.g., air interface resources).
  • the importance of the first data unit may be lower than a second threshold.
  • the first device can determine whether to retransmit the data unit based on the residual delay of the data unit.
  • the first device may not retransmit the unimportant data unit, thereby reducing or avoiding the waste of transmission resources (e.g., air interface resources) and reducing or avoiding the impact on the decoding of other data units.
  • transmission resources e.g., air interface resources
  • FIG. 5 is a flow chart corresponding to the communication method provided by the present application.
  • Figure 5 illustrates the method by taking the first device and the second device as the execution subjects of the interaction diagram as an example, but the present application does not limit the execution subjects of the interaction diagram.
  • the specific contents of the first device and the second device can be referred to the description of the first device and the second device in the method shown in Figure 3, respectively, and will not be repeated here.
  • the method includes:
  • a first device may send a first data unit.
  • the importance of the first data unit may be lower than the second threshold.
  • the second device may send first feedback information; correspondingly, the first device may receive the first feedback information, wherein the first feedback information may be used to indicate that the first data unit is not successfully received.
  • S501 to S502 can be referred to S301 to S302 and will not be repeated here.
  • the first device may trigger the first information.
  • the first device may trigger the first information.
  • the conditions for triggering the first information may include: the first device receiving the first feedback information and the first condition being met.
  • the first information may be used to indicate that the first data unit is not to be retransmitted.
  • the first information may be included in an RLC control PDU. The specific content of the first information will be described in the following method c1 or method c2 and will not be expanded here.
  • the first condition may include condition e1: the remaining delay of the first data unit is less than or equal to a first threshold.
  • condition e1 can be replaced by: the first timer corresponding to the first data unit has expired.
  • the first timer corresponding to the first data unit's expiration refer to the description of the first timer corresponding to the first data unit in S304 and are not further described here.
  • the first device can quickly determine whether condition e1 is satisfied based on the first timer.
  • the first timer is a packet loss timer corresponding to the first data unit, the first device can reuse the packet loss timer, eliminating the need to add a new timer and reducing the complexity of the first device.
  • the following example illustrates how steps S501 to S503 are implemented when the first condition is implemented in method a1.
  • the PDCP entity of the first device may start the packet loss timer corresponding to SDU#1. If the first device receives a NACK for SDU#1 after sending SDU#1 and after the packet loss timer corresponding to SDU#1 expires, the first device may trigger information indicating that SDU#1 will not be retransmitted after receiving the NACK for SDU#1.
  • the SDU#1 in "sending SDU#1" and "NACK for SDU#1" may be replaced with a segment of SDU#1.
  • the PDCP entity of the first device may start the packet loss timer corresponding to SDU#1.
  • the first device may receive a NACK for SDU#1. If, after receiving the NACK for SDU#1 and before the packet loss timer corresponding to SDU#1 expires, the first device does not deliver SDU#1 to a lower layer of the RLC layer (e.g., the MAC layer), then when the packet loss timer corresponding to SDU#1 expires or after the packet loss timer corresponding to SDU#1 expires, the first device may trigger information indicating that SDU#1 will not be retransmitted.
  • SDU#1 in "sending SDU#1," "delivering SDU#1,” and "NACK for SDU#1” may be replaced by a segment of SDU#1.
  • the first device may determine whether to trigger first information indicating not to retransmit the first data unit based on the remaining latency of the first data unit.
  • the first device triggers the first information only if it receives first feedback indicating that the first data unit was not successfully received and the remaining latency of the first data unit is less than or equal to a first threshold, thereby promptly notifying the second device not to retransmit the first data unit.
  • the first condition may include condition e1 and condition e2.
  • Condition e1 may include: the remaining delay of the first data unit is less than or equal to the first threshold.
  • the specific content of condition e1 can refer to the description of condition e1 in method a1, and will not be repeated here.
  • Condition e2 may include: the first time at which the first feedback information is received is later than or equal to a second time.
  • the second time may be the time at which the remaining latency of the first data unit equals the first threshold. For example, if the first device receives the first feedback information at 11 ms, and the time at which the remaining latency of the first data unit equals the first threshold is 10 ms, then condition e2 is satisfied.
  • the second moment may be the moment when the remaining delay of the first data unit is equal to the first threshold
  • condition e2 can be replaced with: the second moment may be the moment when the first timer corresponding to the first data unit times out.
  • the remaining delay of the first data unit may be equal to the first threshold.
  • the first device can quickly determine whether condition e2 is met based on the first timer.
  • the first timer is the packet loss timer corresponding to the first data unit
  • the first device can reuse the packet loss timer, thereby eliminating the need to add a new timer and reducing the complexity of the first device.
  • the following example illustrates how steps S501 to S503 are implemented when the first condition is implemented as method a2.
  • the PDCP entity of the first device may start the packet loss timer corresponding to SDU#1.
  • the first device receives the first NACK of SDU#1.
  • the first device retransmits SDU#1.
  • the first device receives the second NACK of SDU#1.
  • the first device may trigger the first information.
  • SDU#1 in "sending SDU#1", "retransmitting SDU#1" and "NACK of SDU#1" may be replaced by a segment of SDU#1.
  • the first device takes into account the chronological relationship between the first moment of receiving the first feedback information and the second moment when the remaining delay of the first data unit is equal to the first threshold.
  • the first device triggers the first information only when the first moment is later than or equal to the second moment. If the first moment is earlier than the second moment, the first device may have retransmitted the first data unit, and the retransmitted first data unit may have been successfully received by the second device. In this case, if the first information is triggered, transmission resources will be unnecessarily occupied and the second device will be misled.
  • the waste of transmission resources for example, air interface resources
  • misleading the second device can be avoided.
  • the SN of the first data unit may be less than a first variable.
  • the first variable may be the SN corresponding to the lower boundary of the transmit window.
  • the first variable is the variable TX_Next_Ack.
  • the specific content of the variable TX_Next_Ack can be found in the explanation of the variable TX_Next_Ack in the above terminology section and will not be repeated here.
  • the first device may trigger the first information, thereby notifying the second device not to retransmit the first data unit.
  • the first condition may further include condition e3 and/or condition e4:
  • the first data unit is not indicated as not to be retransmitted. In this way, for each data unit, the first device may indicate not to retransmit the data unit only once, thereby avoiding repeated instructions not to retransmit a data unit and reducing signaling overhead.
  • Condition e4 The importance of the first data unit is lower than the second threshold.
  • the specific content of condition e4 can be referred to the description of "the importance of the first data unit may be lower than the second threshold" in S301, and will not be repeated here.
  • the first condition includes condition e1 and condition e3. For example, if the remaining delay of SDU#1 is less than or equal to a first threshold when the first device receives a NACK for SDU#1, and the first device has not sent information indicating that SDU#1 should not be retransmitted before receiving the NACK for SDU#1, then after receiving the NACK for SDU#1, the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • the start time of time period #1 is the time when the NACK for SDU#1 is received
  • the end time of time period #1 is the time when the remaining delay of SDU#1 equals the first threshold.
  • the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • SDU#1 in “send SDU#1”, “deliver SDU#1” and “NACK of SDU#1” may be replaced by a segment of SDU#1.
  • the first condition includes condition e1 and condition e4. For example, if, when the first device receives a NACK for SDU#1, the remaining latency of SDU#1 is less than or equal to a first threshold, and the importance of SDU#1 is less than a second threshold, then, after receiving the NACK for SDU#1, the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • the start time of time period #1 is the time when the NACK for SDU#1 is received, and the end time of time period #1 is the time when the remaining latency of SDU#1 equals the first threshold.
  • the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • “SDU#1" in “sending SDU#1,” "delivering SDU#1,” and “NACK for SDU#1” may be replaced with a segment of SDU#1.
  • the first condition includes condition e1, condition e3, and condition e4. For example, if, when the first device receives a NACK for SDU#1, the remaining latency of SDU#1 is less than or equal to a first threshold, and before receiving the NACK for SDU#1, the first device has not sent information indicating that SDU#1 should not be retransmitted, and the importance of SDU#1 is less than a second threshold, then, after receiving the NACK for SDU#1, the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • the start time of time period #1 is the time when the NACK for SDU#1 is received
  • the end time of time period #1 is the time when the remaining latency of SDU#1 equals the first threshold. If, within time period #1, the first device does not deliver SDU#1 to a lower layer of the RLC layer (e.g., the MAC layer), and before the remaining latency of SDU#1 equals a first threshold, the first device does not send information indicating that SDU#1 should not be retransmitted, and the importance of SDU#1 is lower than a second threshold, then after the remaining latency of SDU#1 equals the first threshold, the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • SDU#1 in "sending SDU#1," "delivering SDU#1,” and "NACK for SDU#1” may be replaced with a segment of SDU#1.
  • the first condition includes condition e1, condition e2, and condition e3.
  • the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • the SDU#1 in "sending SDU#1" and "NACK for SDU#1" may be replaced with a segment of SDU#1.
  • the first condition includes condition e1, condition e2, and condition e4.
  • condition e1 condition e2
  • condition e4 condition e4.
  • the first device may trigger information indicating that SDU#1 will not be retransmitted.
  • the SDU#1 in "sending SDU#1" and "NACK for SDU#1" may be replaced with a segment of SDU#1.
  • the first condition includes conditions e1 to e4. For example, if, when the first device receives a NACK for SDU#1, the remaining latency of SDU#1 is less than or equal to a first threshold, and before receiving the NACK for SDU#1, the first device has not sent information indicating that SDU#1 should not be retransmitted, and the importance of SDU#1 is less than a second threshold, then, after receiving the NACK for SDU#1, the first device may trigger information indicating that SDU#1 should not be retransmitted.
  • the SDU#1 in "sending SDU#1" and "NACK for SDU#1" may be replaced with a segment of SDU#1.
  • the first device may further determine whether to retransmit the first data unit based on condition e1, or based on condition e1 and condition e2. For example, if the first feedback information is received and condition e1 is satisfied, the first device may not retransmit the first data unit. For another example, if the first feedback information is received and both condition e1 and condition e2 are satisfied, the first device may not retransmit the first data unit.
  • the specific content of condition e1 can be found in the description of condition e1 in method a1, and the specific content of condition e2 can be found in the description of condition e2 in method a2, and will not be further described here.
  • condition e1 may be replaced by: determining not to retransmit the first data unit. For example, in method a1, if the first device determines not to retransmit the first data unit, the first device may trigger the first information. For another example, in method a2, if the first device determines not to retransmit the first data unit at a first moment and receives first feedback information at a second moment that is later than or equal to the first moment, the first device may trigger the first information.
  • first data unit as an example for description, and the first device and the second device may also process other data units in a similar manner.
  • S503 may include: when the first condition is met, if the second timer is not running, the first device may trigger the first information; in other words, when the first condition is met, if the second timer is running, the first device may not trigger the first information; or, the condition for triggering the first information may include: the first device receives the first feedback information, the first condition is met, and the second timer is not running.
  • the second timer can be started when the information for indicating not to retransmit the data unit is triggered.
  • the first device can start the second timer.
  • the specific content of the condition for triggering the information for indicating not to retransmit the data unit can refer to the description of the condition for triggering the first information in S503, except that the first data unit is replaced by the data unit, and the information for indicating not to retransmit the data unit is replaced by the first information, which will not be repeated here.
  • the duration of the second timer can be pre-set, for example, specified by the protocol, or saved in the factory settings or SIM card of the first device; or, the duration of the second timer can be notified to the first device by other devices (for example, the second device or the core network device), and this application does not limit this.
  • the second timer may also have other names, such as a prohibition timer (for example, a status prohibition timer (t-StatusProhibit)), and this application does not limit this.
  • the first condition includes the expiration of the packet loss timer corresponding to the first data unit.
  • the first device may trigger information indicating that SDU#1 should not be retransmitted and start the second timer. If the first device receives a NACK for SDU#2 while the second timer is running and the packet loss timer corresponding to SDU#2 expires, the first device will not trigger information indicating that SDU#2 should not be retransmitted while the second timer is running.
  • the first device may trigger information indicating that SDU#3 should not be retransmitted and start the second timer. This process can be repeated and so on.
  • the first device may start a second timer. While the second timer is running, the first device no longer triggers information indicating that a data unit is not to be retransmitted. Only after the second timer expires does the first device trigger the next information indicating that a data unit is not to be retransmitted.
  • This manner can avoid frequent triggering of information indicating that a data unit is not to be retransmitted, and thereby avoid frequent transmission of information indicating that a data unit is not to be retransmitted.
  • the method shown in FIG5 may further include step C1:
  • Step C1 After triggering the first information, if the third timer is not running, the first device may construct the first information when the first layer receives the first transmission opportunity indication from the second layer; in other words, after triggering the first information, the first device may not construct the first information during the running of the third timer.
  • the second layer may be a lower layer than the first layer.
  • the first layer is the RLC layer and the second layer is the MAC layer.
  • the third timer may be started when the information indicating that the data unit is not to be retransmitted is delivered to the second layer, or the third timer may be started when the information indicating that the data unit is not to be retransmitted is triggered, constructed, or sent.
  • the first device may start the third timer when the first information is delivered to the second layer, or when the first information is triggered, constructed, or sent.
  • the specific content of the information indicating that the data unit is not to be retransmitted can refer to the first information in S503, except that the first data unit is replaced by the data unit, which will not be repeated here.
  • the duration of the third timer may be pre-set, for example, specified by the protocol, or saved in the factory settings or SIM card of the first device; or the duration of the third timer may be notified to the first device by other devices (for example, the second device or the core network device), which is not limited in this application.
  • the third timer may also have other names, such as a prohibition timer (for example, t-StatusProhibit), which is not limited in this application.
  • the first device may construct information #1 and start the third timer.
  • Information #1 may be used to indicate that SDU#1 should not be retransmitted. If, while the third timer is running, the first device triggers information indicating that SDU#2 should not be retransmitted, the first device may not construct information indicating that SDU#2 should not be retransmitted while the third timer is running. After the third timer expires, the first device may construct the next information indicating that the data unit should not be retransmitted.
  • step C1 may be implemented in multiple ways, for example, way b1 or way b2.
  • Mode b1 When the first message is triggered, if the third timer is not running, then after the first message is triggered, when the first layer receives the first transmission opportunity indication from the second layer, the first device may construct the first message.
  • the first device may construct information #1 and start the third timer.
  • Information #1 may be used to indicate not to retransmit SDU#1.
  • the first device may start a third timer. While the third timer is running, the first device no longer constructs information indicating that a data unit is not to be retransmitted. Only after the third timer expires can the first device construct the next information indicating that a data unit is not to be retransmitted. This manner can avoid frequent construction of information indicating that a data unit is not to be retransmitted, and thus avoid frequent transmission of information indicating that a data unit is not to be retransmitted.
  • the first information when constructing the first information in step C1, the first information may indicate that at least one data unit is not to be retransmitted, and the at least one data unit may include the first data unit.
  • the first device when the information indicating that SDU#1 is not to be retransmitted is triggered, if the third timer is not running, then after the information indicating that SDU#1 is not to be retransmitted is triggered, upon receiving the first transmission opportunity indication from the second layer, the first device may construct information #1 and start the third timer. Information #1 may be used to indicate that SDU#1 is not to be retransmitted.
  • the method shown in FIG5 may further include step D1:
  • Step D1 The first device may update the sending window according to the data unit determined not to be retransmitted, such as the first data unit in S501-S502.
  • Case 1 The first condition is satisfied.
  • the specific content of the first condition can be found in the above method a1 or method a2, and will not be repeated here.
  • Case 2 The first information is triggered; in other words, the first device triggers the first information.
  • the first device triggers the first information.
  • the first information is triggered; please refer to the description of how the first device can trigger the first information in S503, which will not be repeated here.
  • Case 3 The first message is constructed; in other words, the first device constructs the first message.
  • the first device may construct the first message when the first layer receives the first transmission opportunity indication from the second layer.
  • the first device may construct the first message according to step C1.
  • Case 4 The first information is sent; in other words, the first device sends the first information. This application does not limit the specific content of the first information being sent.
  • the first device may timely update the sending window according to the first data unit, thereby timely updating the SN of the data unit that the first device can send.
  • Case 5 The second device sends the second feedback information; accordingly, the first device receives the second feedback information.
  • the second feedback information can be used to indicate that the first information has been successfully received.
  • the second feedback information can be an ACK for the first information.
  • the second feedback information can be included in a status report.
  • the specific content of the status report can refer to the description of the status report in the above explanation of terms, which will not be repeated here.
  • the first device updates the sending window according to the first data unit. In this way, the first device and the second device have the same understanding of the first data unit, and the sending window in the first device and the reassembly window in the second device can correspond.
  • the sending window may include a first SN range, and the data units corresponding to the SNs within the first SN range may be data units that the first device can send.
  • the data units that the first device can send may include at least one of the following: data units that the first device has not yet sent, or data units that the first device has sent but has not received an ACK.
  • the specific contents of the sending window and the first SN range can be referred to the descriptions of the sending window and SN range #1 in the above explanation of terms, and will not be repeated here.
  • the first device may update the sending window in the following manner: if the current value of the first variable is equal to the SN corresponding to the first data unit, the first device may update the value of the first variable to the first SN.
  • the first variable may be the SN corresponding to the lower boundary of the transmit window.
  • the first variable is the variable TX_Next_Ack.
  • the specific content of the variable TX_Next_Ack can be referred to the description of the variable TX_Next_Ack in the above explanation of terms, and will not be repeated here.
  • the first SN may be the smallest SN in the first group of SNs.
  • the data unit corresponding to any SN in the first group of SNs is not indicated as not to be retransmitted; or, the data unit corresponding to any SN in the first group of SNs does not meet the conditions for triggering the information for indicating not to retransmit the data unit.
  • the specific content of the conditions for triggering the information for indicating not to retransmit the data unit please refer to the description of the conditions for triggering the first information in S503, except that the first data unit is replaced by the data unit corresponding to any SN in the first group of SNs, which will not be repeated here.
  • the SN corresponding to the first data unit is 5, and the data units that are not instructed not to be retransmitted include data units whose SN is greater than or equal to 7, then the smallest SN in the first group of SNs may be 7, and the first device may update the value of the first variable to 7.
  • any SN in the first set of SNs is not instructed not to be retransmitted, and condition f1 is satisfied. For example, if the current value of the first variable is 5 and the SN corresponding to the first data unit is 5, the first device may update the value of the first variable. If the current value of the fifth variable is 10, and the data units not instructed not to be retransmitted include data units with SNs greater than or equal to 7, the first set of SNs may include: 7 to 10, and the first device may update the value of the first variable to 7.
  • any SN in the first set of SNs is not instructed not to be retransmitted, and condition f2 is satisfied. For example, if the current value of the first variable is 5 and the SN corresponding to the first data unit is 5, the first device may update the value of the first variable. If the data units that are not instructed not to be retransmitted include data units with SNs greater than or equal to 7, and the SNs of the data units for which the first device receives an ACK include 1 to 4, 6, and 7, then the smallest SN in the first set of SNs is 8, and the first device may update the value of the first variable to 8.
  • the importance of the data unit corresponding to any SN in the first group of SNs is greater than or equal to the second threshold.
  • the data unit corresponding to any SN in the first group of SNs may be an important data unit or a data unit of high importance.
  • the first device can timely update the sending window according to the first data unit, thereby timely updating the SN of the data unit that the first device can send.
  • the first information can indicate the second SN, so that the second device updates the value of the second variable to the second SN.
  • the first information may not include other SNs except the second SN, and the signaling overhead is relatively small.
  • the first information may be used to indicate the SN of at least one data unit that is not to be retransmitted, and the at least one data unit may include the first data unit.
  • Any data unit in the at least one data unit may satisfy a condition for triggering information indicating not to retransmit the data unit.
  • a condition for triggering information indicating not to retransmit the data unit refer to the description of the condition for triggering the first information in S503, except that the first data unit is replaced by any data unit in the at least one data unit, and no further description is given here.
  • any data unit in the at least one data unit may further satisfy at least one of the following conditions g1 to g2:
  • the SN corresponding to any data unit in the at least one data unit may be greater than or equal to the first variable.
  • the specific content of the first variable can refer to the description of the first variable in step D1 and will not be repeated here.
  • the at least one data unit may include data units with corresponding SNs of 6 and 7.
  • the data unit whose SN is less than the first variable may be a data unit successfully received by the second device. Therefore, in this way, for the data unit successfully received by the second device, the first device may not indicate through the first information not to retransmit the data unit, thereby avoiding the transmission of unnecessary information and saving transmission resources.
  • the at least one data unit may be different from the data unit corresponding to information #3.
  • the at least one data unit may include: a data unit that meets the conditions of the information for indicating that the data unit is not to be retransmitted after constructing or sending information #3. For example, information #3 indicates that SDU #1 is not to be retransmitted. If, after constructing or sending information #3, SDU #2 and SDU #4 meet the conditions for triggering the information for indicating that the data unit is not to be retransmitted, then the at least one data unit may include SDU #2 and SDU #4. In this way, the first device may not repeatedly indicate that a certain data unit is not to be retransmitted, thereby avoiding the transmission of unnecessary information and saving transmission resources.
  • the first information can indicate the SN of at least one data unit that is not retransmitted, for example, one of ways d1 to d8.
  • the SN of at least one data unit can be represented as M SNs, where M is a positive integer.
  • the first information includes M SNs.
  • the first information is shown in FIG7C .
  • the M SNs may be indicated by SN#1 to SN#M in FIG7C , respectively.
  • the length of each SN in SN#1 to SN#M is, for example, 12 bits.
  • the M SNs in the first information may be arranged in a set order, and the set order is, for example, an ascending or descending order of the M SNs.
  • the first information may include SN#1 to SN#3, wherein the SN indicated by SN#1 is 2, the SN indicated by SN#2 is 5, and the SN indicated by SN#3 is 7.
  • the value range of Field #1 may be related to the bit width x occupied by Field #1, where x may be expressed in bits.
  • Field #1 may have a value of [0, 2 x -1].
  • M may be at most 2 x or 2 x +1.
  • Field #1 may indicate that a maximum of 16 or 17 data units are not to be retransmitted.
  • Field #1 may be named in various ways, such as by the number of data units not to be retransmitted, and this application does not impose any restrictions thereon.
  • the first information when M is greater than or equal to 2, the first information may indicate M; in other words, when M is equal to 1, the first information may not indicate M.
  • the first information can accurately indicate the SN of at least one data unit that is not retransmitted.
  • the first information may include a first bitmap, and the first bitmap may be used to indicate the M SNs.
  • the first bitmap may include at least one bit. Any bit in the at least one bit may correspond to an SN. If the value of a bit in the first bitmap is a first value (e.g., 1 or 0), it means that the SN corresponding to the bit belongs to M SNs; if the value of a bit in the first bitmap is a second value (e.g., 0 or 1), it means that the SN corresponding to the bit does not belong to M SNs. The first value and the second value are different.
  • a first value e.g., 1 or 0
  • a second value e.g., 0 or 1
  • the at least one bit may correspond to at least one SN in ascending order of SN.
  • the SN corresponding to the first bit of the multiple bits may be implemented in multiple ways, for example, way e1 or way e2.
  • Mode e1 The SN corresponding to the first bit in the multiple bits is determined according to the first SN in the M SNs.
  • the first SN among the M SNs may be indicated by the first information.
  • the first information may include the first SN among the M SNs.
  • the first information may include information corresponding to the first SN among the M SNs, for example, the first information may include the first SN+1 among the M SNs.
  • the first bit in the first bitmap may correspond to the first SN of the M SNs.
  • the first SN of the M SNs is 2, and the first bitmap is 1000101.
  • the first bit in the first bitmap corresponds to SN 2
  • the remaining six bits in the first bitmap correspond to SNs 3 to 8, respectively. If the first value is 1, the M SNs may include 2, 6, and 8.
  • the first information may be as shown in FIG. 7D or FIG. 7E .
  • the first SN of the M SNs may be indicated by the first SN (FSN) in FIG. 7D or FIG. 7E .
  • the length of the FSN is 12 bits; in FIG. 7E , the length of the FSN may be 18 bits.
  • the first bitmap may include bitmap #1 to bitmap #L in FIG. 7D or FIG. 7E , which may be used to indicate whether L*8 SNs belong to the M SNs, where L is a positive integer.
  • the number of bits included in the first bitmap may be related to at least one of the following information #a1 to information #a4, wherein the number of bits included in the first bitmap may be replaced by the size of the first bitmap:
  • the size of the resources indicated by the lower layer of the first layer in the first device wherein the first layer is, for example, the RLC layer, and the lower layer of the first layer is, for example, the MAC layer.
  • the number of bits included in the first bitmap may be proportional to the size of the resources indicated by the lower layer of the first layer in the first device. The larger the size of the resources indicated by the lower layer of the first layer in the first device, the larger the number of bits included in the first bitmap; the smaller the size of the resources indicated by the lower layer of the first layer in the first device, the smaller the number of bits included in the first bitmap.
  • the number of bits included in the first bitmap may correspond to the 8 data units, for example, the number of bits included in the first bitmap may be 8.
  • the 8 data units may include the 8 data units with the smallest SNs among the 10 data units.
  • the number of data units delivered by the first layer in the first device to a lower layer of the first layer can also be understood as the number of data units sent by the lower layer of the first layer in the first device.
  • the number of bits included in the first bitmap may be proportional to the number of data units sent by the lower layer of the first layer in the first device.
  • the number of bits included in the first bitmap may be greater than or equal to 10.
  • the bit corresponding to the maximum SN in the first bitmap may correspond to a data unit with the largest SN among data units of the first layer delivered to a lower layer in the first device.
  • the SN of the data unit (e.g., RLC SDU) most recently sent by the lower layer of the first layer in the first device: wherein the first layer is, for example, the RLC layer, and the lower layer of the first layer is, for example, the MAC layer.
  • the number of bits included in the first bitmap may be proportional to the SN of the data unit most recently sent by the lower layer of the first layer in the first device.
  • the bit corresponding to the maximum SN in the first bitmap may correspond to the data unit with the largest SN among the data units delivered from the first layer to the lower layer in the first device.
  • the number of bits contained in the first bitmap may be proportional to the first difference.
  • the first difference may be the difference between the SN of the data unit most recently sent by the first device and the SN corresponding to the first variable, or the first difference may be the difference between the SN of the data unit most recently sent by the first device and the SN of the data unit that triggers the first information.
  • the larger the first difference the larger the number of bits contained in the first bitmap; the smaller the first difference, the smaller the number of bits contained in the first bitmap.
  • the bit corresponding to the maximum SN in the first bitmap may correspond to the data unit with the largest SN among the data units delivered from the first layer in the first device to the lower layer of the first layer.
  • the number of data units (e.g., RLC SDUs) for which the first device receives ACKs and/or NACKs may be inversely proportional to the number of data units for which the first device receives ACKs; and/or the number of bits included in the first bitmap may be directly proportional to the number of data units for which the first device receives NACKs. The larger the number of data units for which the first device receives ACKs, and/or the smaller the number of data units for which the first device receives NACKs, the smaller the number of bits included in the first bitmap.
  • the bit corresponding to the maximum SN in the first bitmap may correspond to a data unit with the largest SN among the data units delivered from the first layer in the first device to the lower layer of the first layer and which has not received ACK; or, the bit corresponding to the maximum SN in the first bitmap may correspond to a data unit with the largest SN among the data units delivered from the first layer in the first device to the lower layer of the first layer and which has received NACK.
  • the number of bits included in the first bitmap may be an integer multiple of 8. If, based on at least one of the above information #a1 to information #a4, a bitmap having a bit number that is not an integer multiple of 8 is determined, the first apparatus may perform a rounding operation on the bitmap to obtain the first bitmap.
  • the rounding operation may be, for example, rounding up, rounding up, or rounding down.
  • the number of bits included in bitmap #a1 is determined based on at least one of the above-mentioned information #a1 to information #a4.
  • the number of bits included in bitmap #a1 is not an integer multiple of 8. In other words, bitmap #a1 includes incomplete bytes, or bitmap #a1 does not constitute a complete byte. If the number of bytes that the resources indicated by the lower layer of the first layer can carry is greater than the number of bytes corresponding to bitmap #a1, the number of bytes corresponding to bitmap #a1 can be rounded up to the minimum number of bytes that can represent the first bitmap.
  • bitmap #a1 includes 10 bits and the number of bytes that the resources indicated by the lower layer of the first layer can carry is greater than or equal to 2, the number of bytes corresponding to bitmap #a1 can be rounded up to 2 bytes (or 16 bits), thereby obtaining a 2-byte first bitmap. If the number of bytes that the resources indicated by the lower layer of the first layer can carry is not greater than the number of bytes of bitmap #a1, the number of bytes corresponding to bitmap #a1 can be rounded down, thereby obtaining the first bitmap.
  • bitmap #a1 includes 10 bits, and the number of bytes that the resource can carry indicated by the lower layer of the first layer is 1, then the number of bytes corresponding to the bitmap #a1 can be rounded down to 1 byte (or 8 bits), thereby obtaining a first bitmap of 1 byte.
  • Mode e2 The SN corresponding to the first bit in the multiple bits is determined according to the previous information before the first information for indicating not to retransmit the data unit (hereinafter referred to as information #3).
  • the first bit in the first bitmap may correspond to the last SN corresponding to information #3.
  • the SNs corresponding to information #3 range from 1 to 5.
  • the first bitmap is 1000101.
  • the SN corresponding to the first bit in the first bitmap is 5, and the SNs corresponding to the last six bits in the first bitmap are 6 to 11, respectively. If the first value is 1, the M SNs may include 5, 9, and 11.
  • the first bit in the first bitmap corresponds to the next adjacent SN of the last SN corresponding to information #3.
  • the SNs corresponding to information #3 include 1 to 5.
  • the first bitmap is 1000101.
  • the SNs corresponding to bits 1 to 7 in the first bitmap are 6 to 12, respectively. If the first value is 1, the M SNs may include 5, 10, and 12.
  • the specific content of the first bitmap can be found in the description of the first bitmap shown in FIG. 7D in method e1, and will not be repeated here.
  • the first information when M is greater than or equal to 2, the first information may indicate the first bitmap; in other words, when M is equal to 1, the first information may not indicate the first bitmap.
  • the first information may indicate the first and last SNs of the M SNs, which can be used to determine the M SNs.
  • the first information may include the first and last SNs of the M SNs; alternatively, the first information may include information that corresponds to the first and last SNs of the M SNs.
  • the first information may be as shown in FIG7F .
  • the first SN among the M SNs may be indicated by the FSN in FIG7F , where the length of the FSN is, for example, 12 bits.
  • the last SN among the M SNs may be indicated by the last SN (LSN) in FIG7F , where the length of the LSN is, for example, 12 bits. If the SN indicated by the FSN is 1 and the SN indicated by the LSN is 6, then the M SNs may include 1 to 6.
  • the first information may indicate the first SN and the last SN among the M SNs.
  • the first information may include the first SN and the last SN of the M SNs, and does not need to include other SNs of the M SNs, thereby saving signaling overhead and transmission resources.
  • the first information may indicate the first SN and M among the M SNs, and the first SN and M among the M SNs are used to determine the M SNs.
  • the first information may include the first SN and M among the M SNs.
  • the first information may include information corresponding to the first SN and M among the M SNs.
  • the first information may include the first SN and M-1 among the M SNs.
  • the first information may include the first SN-1 and M among the M SNs.
  • the first information may include the first SN in each segment of the P segment SNs and the number of SNs in each segment.
  • the first information may include information that corresponds to the first SN in each segment of the P segment SNs and the number of SNs in each segment.
  • the first information may include the first SN in the i-th segment of the SNs and the number of SNs in the i-th segment.
  • the first information may include the first SN in the i-th segment of the SNs and the number of SNs in the i-th segment of the SNs - 1, where i may be an integer from 1 to P.
  • the method shown in FIG5 further includes S504 to S505:
  • the first information is used to indicate the SN of at least one data unit that is not to be retransmitted, and the at least one data unit includes the first data unit.
  • the first information indicates the SN of at least one data unit that is not to be retransmitted, please refer to mode c2 and will not be repeated here.
  • the second SN may be the smallest SN in the second group of SNs, and the data unit corresponding to any SN in the second group of SNs is not indicated as not to be retransmitted; or, the data unit corresponding to any SN in the second group of SNs does not meet the conditions for triggering the information for indicating that the data unit is not to be retransmitted.
  • the smallest SN in the second group of SNs may be 7, and the second device may update the value of the second variable to 7.
  • Condition h1 greater than the current value of the second variable. For example, if the current value of the second variable is 5, then an SN greater than 5 satisfies condition h1.
  • any SN in the second set of SNs is not instructed not to be retransmitted, and conditions h1 and h2 are satisfied. For example, if the current value of the second variable is 5, the SNs of the at least one data unit include 5 to 6, the data unit with an SN of 7 is completely received, and the data unit with an SN greater than or equal to 8 is not completely received, then the smallest SN in the second set of SNs may be 8, and the second device may update the value of the second variable to 8.
  • any SN in the second set of SNs is not instructed not to be retransmitted, and condition h1 is satisfied. For example, if the current value of the second variable is 5, and the SNs of the at least one data unit range from 5 to 6, then the smallest SN in the second set of SNs may be 7, and the second device may update the value of the second variable to 7.
  • any SN in the second set of SNs is not instructed not to be retransmitted, and condition h2 is satisfied. For example, if the SNs of the at least one data unit include 0 to 6, a data unit with an SN of 7 is completely received, and a data unit with an SN greater than or equal to 8 is not completely received, then the smallest SN in the second set of SNs may be 8, and the second device may update the value of the second variable to 8.
  • the second device may perform step E1.
  • Step E2 The second device may process the received data unit according to the reassembly window.
  • step E2 does not limit the specific content of step E2.
  • the specific content of step E2 can be referred to the explanation of the terms above, which is related to the description of the reorganization window in the processing of data by the receiving device, and will not be repeated here.
  • the second device can promptly update the second variable based on the first information, thereby promptly updating the reassembly window and preventing the reassembly window from being stuck.
  • the second device can update the second variable so that the SN of the non-retransmitted data unit is not within the reassembly window. This prevents the second device from waiting for the non-retransmitted data unit from affecting the reception of other data units.
  • the first information may be used to indicate the SN of at least one data unit that is not retransmitted, and the at least one data unit may include the first data unit.
  • the specific content of the first information indicating the SN of at least one data unit that is not retransmitted refer to mode c2 and are not further described here.
  • Method f2 may include steps F1 to F2:
  • Step F1 If the SN corresponding to at least one data unit includes the SN corresponding to the third variable, the second device may update the value of the third variable to the third SN, wherein the SN corresponding to the third variable may be replaced by the current value of the third variable.
  • the third variable may be the highest (or largest) SN in the second information, and the second information may be used to indicate whether one or more data units have been successfully received.
  • the third variable may be the variable RX_Highest_Status, and/or the second information may be a status report.
  • the specific contents of the variable RX_Highest_Status and the status report please refer to the description of the variable RX_Highest_Status and the status report in the above explanation of terms, and will not be repeated here.
  • the data unit corresponding to the third SN is not instructed not to be retransmitted; or the data unit corresponding to the third SN does not meet the condition for triggering the information for instructing not to retransmit the data unit.
  • the specific content of the condition for triggering the information for instructing not to retransmit the data unit can be found in the description of the condition for triggering the first information in S503, except that the first data unit is replaced by the data unit corresponding to the third SN, and is not further described here.
  • the second device may update the value of the third variable to 7.
  • the third SN may be the smallest SN in the fourth group of SNs, any SN in the fourth group of SNs may not be instructed not to retransmit, and any SN in the fourth group of SNs may further satisfy at least one of the following conditions i1 to i2:
  • Condition i1 greater than the current value of the third variable. For example, if the current value of the third variable is 5, then an SN greater than 5 satisfies condition i1.
  • Condition i2 The corresponding data unit is not completely received by the (second device).
  • the specific content of condition i2 can be referred to condition h2 and will not be repeated here.
  • any SN in the fourth set of SNs is not instructed not to be retransmitted, and conditions i1 and i2 are satisfied. For example, if the current value of the third variable is 5, the SNs of the at least one data unit include 5 to 6, the data unit with an SN of 7 is completely received, and the data unit with an SN greater than or equal to 8 is not completely received, then the smallest SN in the fourth set of SNs may be 8, and the second device may update the value of the third variable to 8.
  • any SN in the fourth set of SNs is not instructed not to be retransmitted, and condition i1 is satisfied. For example, if the current value of the third variable is 5, and the SNs of the at least one data unit range from 5 to 6, then the smallest SN in the fourth set of SNs may be 7, and the second device may update the value of the third variable to 7.
  • any SN in the fourth set of SNs is not instructed not to be retransmitted, and condition i2 is satisfied. For example, if the SNs of the at least one data unit include 0 to 6, a data unit with an SN of 7 is completely received, and a data unit with an SN greater than or equal to 8 is not completely received, then the smallest SN in the fourth set of SNs may be 8, and the second device may update the value of the third variable to 8.
  • the second device may execute step F1.
  • Step F2 The second device may process the received data unit according to the third variable.
  • Condition j2 The corresponding data unit is not completely received by the (second device).
  • the specific content of condition j2 can be referred to condition h2 and will not be repeated here.
  • none of the SNs in the third set of SNs is instructed not to be retransmitted, and condition j1 is satisfied. For example, if the current value of the fourth variable is 5 when the reassembly timer expires, and the SNs of the at least one data unit range from 5 to 6, then the smallest SN in the third set of SNs may be 7. When the reassembly timer expires, the second device may update the value of the third variable to 7.
  • the second device may execute step G1.
  • Step G2 The second device may process the received data unit according to the third variable.
  • step G2 For the specific content of step G2, please refer to step F2 and will not be repeated here.
  • the second device can update the third variable based on the first information when the reassembly timer expires, thereby transmitting the second information based on the updated third variable.
  • the second information does not indicate whether the data units indicated as not to be retransmitted have been received.
  • the third variable can be updated when the reassembly timer expires, thereby transmitting the second information based on the updated third variable. The second information can then confirm the receipt of the data units indicated as not to be retransmitted.
  • the method shown in FIG5 may further include step H1:
  • Step H1 The second device sends the second information; correspondingly, the first device can receive the second information.
  • the second information may be used to indicate whether one or more data units have been successfully received.
  • the second information may be a status report.
  • the second information may be triggered after the second device receives the first information.
  • the specific content of triggering the second information please refer to the description of triggering the status report in the above explanation of terms and will not be repeated here.
  • Any data unit in the one or more data units is not instructed not to be retransmitted; in other words, the second information may not indicate whether a data unit indicated not to be retransmitted has been received. Any data unit in the one or more data units may not satisfy the condition for triggering the information for instructing not to retransmit the data unit.
  • the condition for triggering the information for instructing not to retransmit the data unit refer to the description of the condition for triggering the first information in S503, except that the first data unit is replaced by any data unit in the one or more data units, and will not be repeated here.
  • the second information may indicate that SDU#1, SDU#4 and SDU#5 are not successfully received, but does not indicate that SDU#2 to SDU#3 are not successfully received.
  • the second information may not indicate whether a data unit indicated as not to be retransmitted is received.
  • the second information may not include ACKs and/or NACKs for data units indicated as not to be retransmitted.
  • the second information may include NACKs for SDU#1, SDU#4, and SDU#5, but not NACKs for SDU#2 to SDU#3.
  • the second information may not include indication information for data units indicated as not to be retransmitted.
  • the second information may include SNs for SDU#1, SDU#4, and SDU#5, but not SNs for SDU#2 to SDU#3.
  • any data unit among the one or more data units may further satisfy at least one of conditions k1 to k3:
  • Condition k1 The corresponding SN is greater than or equal to the second variable and less than the third variable. For example, if the second variable is RX_Next, which is 3, and the third variable is RX_Highest_Status, which is 6, then data units with SNs of 3, 4, and 5 meet condition k1.
  • Condition k2 Not fully received. The specific content of condition k2 can be found in condition h2 and will not be repeated here.
  • Condition k3 The corresponding SNs are in ascending order, in ascending order of the segments within the RLC SDU, from SN equal to the variable RX_Next, to a SN such that the size of the status report is less than or equal to the size of the transmission resources indicated by the lower layers of the RLC layer; in other words, the corresponding SNs are in ascending order, in ascending order of the segments within the RLC SDU, from SN equal to the variable RX_Next, to a SN such that the size of the status report is suitable for the size of the transmission resources indicated by the lower layers of the RLC layer.
  • any data unit in the one or more data units is not indicated as not to be retransmitted, and conditions k1 to k3 are satisfied.
  • the second variable is the variable RX_Next
  • the variable RX_Next is 3
  • the third variable is the variable RX_Highest_Status
  • the variable RX_Highest_Status is 6
  • the data units with SNs 4 and 5 are not indicated as not to be retransmitted
  • the data units with SNs 4 and 5 are not completely received
  • the lower layer of the RLC layer indicates a size of transmission resources that can transmit information indicating whether the data units with SNs 4 and 5 are successfully received
  • the one or more data units may include data units with SNs 4 and 5.
  • any data unit in the one or more data units is not instructed not to be retransmitted, and conditions k1 and k3 are satisfied.
  • the second variable is the variable RX_Next
  • the variable RX_Next is 3
  • the third variable is the variable RX_Highest_Status
  • the variable RX_Highest_Status is 6
  • the data units with SNs 4 and 5 are not instructed not to be retransmitted
  • the size of the transmission resource indicated by the lower layer of the RLC layer can transmit information indicating whether the data units with SNs 4 and 5 are successfully received
  • the one or more data units may include data units with SNs 4 and 5.
  • the second information may not indicate whether data units indicated as not to be retransmitted have been received. For data units indicated as not to be retransmitted, since the first device has already determined not to retransmit these data units, the second information not indicating whether these data units have been received does not affect the transmission of these data units, reduces signaling overhead, and conserves transmission resources.
  • the operation performed by the second device may be performed by a second entity (eg, an RLC entity) in the second device.
  • a second entity eg, an RLC entity
  • the method shown in FIG5 may be combined with the method shown in FIG3 .
  • the first device can determine, based on the remaining latency of the first data unit, whether to trigger first information indicating that the first data unit should not be retransmitted.
  • the first device triggers the first information only when it receives first feedback information indicating that the first data unit was not successfully received and the remaining latency of the first data unit is less than or equal to a first threshold, thereby promptly notifying the second device not to retransmit the first data unit.
  • the importance of the first data unit may be lower than the second threshold.
  • the first device may determine whether to trigger information for indicating not to retransmit the data unit based on the remaining delay of the data unit, thereby notifying the second device not to retransmit the data unit.
  • Figure 8 is a flow chart corresponding to the communication method provided by the present application.
  • Figure 8 uses the first device and the second device as examples to illustrate the method, but the present application does not limit the execution subjects of the interaction diagram.
  • the specific contents of the first device and the second device can be referred to the description of the first device and the second device in the method shown in Figure 3, and will not be repeated here.
  • the method includes:
  • a first device may send a first data unit.
  • the first feedback information may be used to indicate that the first data unit has not been successfully received.
  • For the specific content of the first feedback information reference may be made to the specific description of the first feedback information in S302, which will not be repeated here.
  • the third threshold may be pre-set, for example, specified by a protocol, or stored in the factory settings of the second device; alternatively, the third threshold may be notified to the second device by another device (e.g., a core network device).
  • the third threshold may be, for example, a number threshold. For details on the number threshold, please refer to the explanation of the number threshold in the above terminology section and will not be repeated here.
  • the specific contents of the first feedback information and the third threshold please refer to the description of the first feedback information and the third threshold in S803, respectively, and will not be repeated here.
  • the specific contents of the importance of the first data unit being lower than the second threshold please refer to the description of "the importance of the first data unit may be lower than the second threshold" in S301, and will not be repeated here.
  • the specific contents of the first feedback information and the third threshold please refer to the description of the first feedback information and the third threshold in S803, respectively, and will not be repeated here.
  • the specific contents of the importance of the first data unit being lower than the second threshold please refer to the description of "the importance of the first data unit may be lower than the second threshold" in S301, and will not be repeated here.
  • the third feedback information may be used to indicate that the first data unit was successfully received.
  • the third feedback information may be a status report including an ACK for the first data unit, or the third feedback information may be a status report not including an SN for the first data unit.
  • the status report please refer to the description of the status report in the above explanation of terms and will not be repeated here.
  • the second device determines that SDU#1 is not successfully received, then the second device can trigger the ACK of SDU#1.
  • the second device determines that SDU#1 is not successfully received, then the second device can trigger the ACK of SDU#1.
  • the second device may send an ACK for the data unit.
  • the first device may not retransmit the unimportant data unit, thereby saving transmission resources and reducing or avoiding waste of transmission resources.
  • the method shown in Figure 8 may not include S803; in other words, the method shown in Figure 8 may include S801, S802 and S805, or the method shown in Figure 8 may include S801, S802 and S806.
  • the method shown in FIG8 further includes:
  • the second device sends third feedback information; correspondingly, the first device receives the third feedback information.
  • This application does not limit the specific process of the second device sending the third feedback information.
  • S806 and S807 can be combined as follows: when the triggering and/or sending times of the first feedback information is greater than or equal to a third threshold, and the importance of the first data unit is lower than the second threshold, the second device sends third feedback information; accordingly, the first device receives the third feedback information.
  • the method shown in FIG8 further includes steps I1 and/or I2:
  • Step I1 When the number of times the first device receives the first feedback information is less than a third threshold and the importance of the first data unit is lower than a second threshold, the first device may retransmit the first data unit; and/or, when the number of times the first device receives the first feedback information is greater than or equal to the third threshold and the importance of the first data unit is lower than the second threshold, the first device may not retransmit the first data unit.
  • Step I2 When the number of times the first device sends the first data unit is less than a third threshold and the importance of the first data unit is lower than a second threshold, the first device may retransmit the first data unit; and/or, when the number of times the first device sends the first data unit is greater than or equal to the third threshold and the importance of the first data unit is lower than the second threshold, the first device may not retransmit the first data unit.
  • the specific content of the first feedback information and the third threshold please refer to the description of the first feedback information and the third threshold in S803, respectively, and will not be repeated here.
  • the specific content of the importance of the first data unit being lower than the second threshold please refer to the description of "the importance of the first data unit may be lower than the second threshold" in S301, and the repeated parts will not be repeated here.
  • the third threshold may be related to the fourth threshold, and the fourth threshold may be a threshold related to radio link failure (RLF).
  • the third threshold may be less than the fourth threshold.
  • the first device may send information to a higher layer (e.g., PDCP layer) of the first layer (e.g., RLC layer) to indicate that RLF exists between the first device and the second device. Based on the information, the higher layer of the first layer may instruct the first device to enter a random access procedure to reconnect with the second device.
  • the third threshold may be equal to the fourth threshold.
  • the first device may not send information to a higher layer (e.g., PDCP layer) of the first layer (e.g., RLC layer) to indicate that RLF exists between the first device and the second device.
  • a higher layer e.g., PDCP layer
  • RLC layer the first layer
  • the first device can determine whether to retransmit the data unit based on the number of NACKs received for the data unit or the number of times the data unit was sent. In this way, the number of times the first device retransmits the unimportant data unit is limited, thereby reducing the transmission resources occupied by retransmitting unimportant data and reducing or avoiding waste of transmission resources.
  • unimportant data units e.g., data units whose importance is less than a second threshold
  • the first device may determine whether to retransmit the data unit regardless of the number of times a NACK is received for the data unit or the number of times the data unit is sent. For example, if a NACK is received for an important data unit, the first device may retransmit the data unit, thereby reducing or avoiding the impact on the decoding of other data units.
  • important data units e.g., data units with an importance greater than or equal to a second threshold
  • the method shown in FIG8 further includes steps J1 to J2:
  • Step J1 When the number of triggering and/or sending times of the first feedback information is greater than or equal to the third threshold and the importance of the first data unit is lower than the second threshold, the second device may determine not to retransmit the first data unit.
  • Step J2 The second device may perform at least one of the following operations 1 to 3 based on the first data unit:
  • the fourth SN can be determined based on the SN of the first data unit.
  • the fourth SN can be the smallest SN in the fifth set of SNs.
  • the specific contents of the fifth set of SNs can refer to the description of the first set of SNs in step D1, except that "not indicated not to retransmit" is replaced with "not determined not to retransmit.”
  • the method for determining not to retransmit a data unit can refer to the description of determining not to retransmit the first data unit in step J1, except that the first data unit is replaced with the data unit.
  • the second device can promptly update the second variable, thereby promptly updating the reassembly window and preventing the reassembly window from being stuck.
  • the second device can update the second variable so that the SN of data units that do not trigger a NACK are not within the reassembly window. This prevents the second device from waiting for data units that do not trigger a NACK from affecting the reception of other data units.
  • the specific content of the fifth SN can refer to the description of the third SN in method f2, except that "not instructed not to retransmit” is replaced by "not determined not to retransmit", which will not be repeated here.
  • the timeout of the reassembly timer can be triggered by the first data unit, or by a data unit other than the first data unit.
  • the second device can reuse the reassembly timer, thereby eliminating the need to add a new timer and reducing the complexity of the second device.
  • the second device may determine whether to continue sending feedback information indicating that the data unit was not successfully received, regardless of the triggering and/or transmission count of the feedback information indicating that the data unit was not successfully received. For example, for an important data unit, if the second device determines that the data unit was not successfully received when the reassembly timer expires, the second device may trigger a NACK for the data unit. In this way, the first device can retransmit the important data unit, thereby reducing or avoiding the impact on the decoding of other data units.
  • important data units e.g., data units whose importance is greater than or equal to a second threshold
  • the embodiment of the present application provides a corresponding communication device, which can be used to perform the functions of the relevant steps in the above-mentioned method embodiment.
  • This function can be implemented by hardware, can be implemented by software, or can be implemented by hardware executing the corresponding software.
  • the hardware or software includes one or more modules corresponding to the above-mentioned functions.
  • the communication device can be a terminal, or can be a module in a terminal (such as a circuit or a chip), or can be a logical node, logical module or software that can implement all or part of the functions of a terminal or access network device; or the communication device can be an access network device or a module in an access network device (such as a circuit or a chip), or can be a logical node, logical module or software that can implement all or part of the functions of an access network device.
  • the structure of the communication device provided in the embodiment of the present application is shown in FIG10 , and includes a processing unit 1002.
  • the communication device further includes an interface unit 1001. The functions of each unit in the communication device 1000 are described below.
  • the processing unit 1002 can be used to support the communication device 1000 in performing the processing actions in the above-mentioned method embodiment.
  • the processing unit 1002 can be implemented by one or more processors.
  • the processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof.
  • the general-purpose processor can be a microprocessor or any conventional processor.
  • the processing unit 1002 is specifically used to: retransmit the first data unit through the interface unit 1001 during the operation of the first timer corresponding to the first data unit; wherein, during the operation of the first timer, the remaining delay of the first data unit is greater than the first threshold.
  • the processing unit 1002 is further configured to: not retransmit the first data unit when the remaining delay of the first data unit is less than or equal to a first threshold.
  • the communication device 1000 is applied to the second device in the embodiment of the present application shown in Figure 5.
  • the specific functions of the processing unit 1002 in this embodiment are introduced below.
  • the processing unit 1002 is configured to: receive first information through the interface unit 1001, where the first information is used to indicate not to retransmit the first data unit; and process the received data unit according to the first information.
  • the processing unit 1002 when the first information is used to indicate the SN of at least one data unit that is not retransmitted, and at least one data unit includes the first data unit, the processing unit 1002 is specifically used to: if the SN corresponding to at least one data unit includes the SN corresponding to the third variable, then the value of the third variable is updated to the third SN, and the received data unit is processed according to the third variable; wherein the third variable is the highest SN in the second information, the second information is used to indicate whether one or more data units are successfully received, and the data unit corresponding to the third SN is not indicated as not to be retransmitted.
  • the processing unit 1002 is specifically used to: when the reassembly timer times out, update the value of the third variable to the smallest SN in the third group of SNs, the third variable is the highest SN in the second information, the second information is used to indicate whether one or more data units are successfully received, and the data unit corresponding to any SN in the third group of SNs is not indicated not to be retransmitted.
  • the processing unit 1002 is specifically configured to discard the first data unit if the first data unit is received.
  • the processing unit 1002 is further used to: send second information through the interface unit 1001, where the second information is used to indicate whether one or more data units are successfully received, and any data unit in the one or more data units is not instructed not to be retransmitted.
  • the communication device 1000 is applied to the second device in the embodiment of the present application shown in Figure 8.
  • the specific functions of the processing unit 1002 in this embodiment are introduced below.
  • Processing unit 1002 is used to: when the reassembly timer times out, determine that the first data unit has not been successfully received; when the number of triggering and/or sending times of the first feedback information is less than the third threshold and the importance of the first data unit is lower than the second threshold, trigger the first feedback information, and the first feedback information is used to indicate that the first data unit has not been successfully received.
  • the processing unit 1002 is further used to: receive third information through the interface unit 1001, where the third information is used to indicate the importance of the first data unit.
  • the communication device 1000 is applied to the first device in the embodiment of the present application shown in Figure 8.
  • the specific functions of the processing unit 1002 in this embodiment are introduced below.
  • processing unit 1002 is further used to: send third information through the interface unit 1001, where the third information is used to indicate the importance of the first data unit.
  • the processing unit 1002 is also used to: when the number of triggering and/or sending of the first feedback information is greater than or equal to a third threshold and the importance of the first data unit is lower than a second threshold, receive third feedback information through the interface unit 1001, and the third feedback information is used to indicate that the first data unit is successfully received.
  • processing unit 1002 and the interface unit 1001 can be directly obtained by referring to the relevant description in the method embodiment shown in Figure 3, Figure 5 or Figure 8, and will not be repeated here.
  • the division of modules in the above embodiments of the present application is illustrative and is only a logical functional division. In actual implementation, there may be other division methods.
  • the functional units in the various embodiments of the present application may be integrated into a processing unit, or may exist separately physically, or two or more units may be integrated into a single unit.
  • the above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units.
  • the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.
  • the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application.
  • the aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, and other media that can store program code.
  • the communication device 1100 includes a processor 1102.
  • the communication device 1100 further includes an interface circuit 1101 and a memory 1103.
  • the interface circuit 1101, the processor 1102, and the memory 1103 are coupled to each other.
  • Bus 1104 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified as address buses, data buses, control buses, and the like. For ease of illustration, FIG11 uses only one thick line, but this does not imply that there is only one bus or only one type of bus.
  • PCI Peripheral Component Interconnect
  • EISA Extended Industry Standard Architecture
  • the communication device 1100 is applied to the first device in the embodiment of the present application shown in Figure 3.
  • the specific functions of the processor 1102 in this embodiment are described below.
  • Processor 1102 is used to: send a first data unit through interface circuit 1101; receive first feedback information through interface circuit 1101, the first feedback information is used to indicate that the first data unit was not successfully received; when the remaining delay of the first data unit is greater than a first threshold, retransmit the first data unit through interface circuit 1101.
  • the communication device 1100 is applied to the first device in the embodiment of the present application shown in Figure 5.
  • the specific functions of the processor 1102 in this embodiment are introduced below.
  • Processor 1102 is used to: send a first data unit through interface circuit 1101; receive first feedback information through interface circuit 1101, the first feedback information is used to indicate that the first data unit was not successfully received; when a first condition is met, trigger first information, the first information is used to indicate that the first data unit is not retransmitted, the first condition including: a remaining delay of the first data unit is less than or equal to a first threshold.
  • the communication device 1100 is applied to the second device in the embodiment of the present application shown in Figure 8.
  • the specific functions of the processor 1102 in this embodiment are described below.
  • Processor 1102 is configured to: determine, when the reassembly timer times out, that the first data unit has not been successfully received; and trigger first feedback information when the number of times the first feedback information is triggered and/or sent is less than a third threshold and the importance of the first data unit is lower than a second threshold, wherein the first feedback information is used to indicate that the first data unit has not been successfully received.
  • the communication device 1100 is applied to the first device in the embodiment of the present application shown in Figure 8.
  • the specific functions of the processor 1102 in this embodiment are described below.
  • Processor 1102 is used to: send a first data unit through interface circuit 1101; when the triggering and/or sending times of the first feedback information are less than a third threshold and the importance of the first data unit is lower than a second threshold, receive first feedback information through interface circuit 1101, the first feedback information being used to indicate that the first data unit was not successfully received.
  • processor 1102 can refer to the description of the communication method provided in the above embodiments and examples of the present application, as well as the specific functional description of the communication device 1000 in the embodiment of the present application shown in Figure 10, and will not be repeated here.
  • the memory 1103 is used to store program instructions and/or data, etc.
  • the program instructions may include program code, which includes computer operation instructions.
  • the memory 1103 may include RAM, and may also include non-volatile memory (non-volatile memory), such as at least one disk storage.
  • the processor 1102 executes the program instructions stored in the memory 1103 and uses the data stored in the memory 1103 to implement the above functions, thereby realizing the communication method provided in the above embodiment of the present application.
  • the memory 1103 can be integrated with the processor 1102, or it can be a memory outside the communication device.
  • the memory 1103 in FIG. 11 of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories.
  • the non-volatile memory can be ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory.
  • the volatile memory can be RAM, which is used as an external cache.
  • RAM random access memory
  • SRAM static RAM
  • DRAM dynamic RAM
  • SDRAM synchronous DRAM
  • DDR SDRAM double data rate SDRAM
  • ESDRAM enhanced SDRAM
  • SLDRAM synchlink DRAM
  • DR RAM direct RAM
  • an embodiment of the present application further provides a computer program product including computer-executable instructions.
  • the computer program product is run, the method provided in the above embodiments is executed.
  • an embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored.
  • the computer program is executed by a computer, the computer executes the method provided in the above embodiments.
  • the storage medium may be any available medium that can be accessed by a computer.
  • computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.
  • an embodiment of the present application further provides a chip, which is used to read a computer program stored in a memory to implement the method provided in the above embodiments.
  • embodiments of the present application provide a chip system, which includes a processor for supporting a computer device to implement the functions involved in each device in the above embodiments.
  • the chip system also includes a memory for storing the necessary programs and data for the computer device.
  • the chip system can be composed of a chip or can include a chip and other discrete devices.
  • each flow and/or box in the flow chart and/or block diagram, as well as the combination of the flow chart and/or box in the flow chart and/or block diagram can be implemented by computer program instructions.
  • These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and/or one or more boxes in the block diagram.
  • These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.
  • These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.
  • “at least one” means one or more, and “more than one” means two or more.
  • “And/or” describes the relationship between related objects, indicating that three possible relationships exist. For example, “A and/or B” can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character “/” generally indicates that the related objects are in an "or” relationship.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente demande se rapporte à un procédé et à un appareil de communication. Le procédé comprend les étapes suivantes : un premier appareil peut envoyer une première unité de données. Si des premières informations de rétroaction, utilisées pour indiquer que la première unité de données n'a pas été reçue avec succès, sont reçues, et si le retard restant de la première unité de données est supérieur à un premier seuil, le premier appareil peut retransmettre la première unité de données. Au moyen du procédé, le premier appareil peut déterminer, sur la base du retard restant de la première unité de données, s'il faut retransmettre la première unité de données. De cette manière, si le retard restant de la première unité de données est faible, par exemple, le retard restant de la première unité de données est 0, le premier appareil peut ne pas retransmettre la première unité de données, ce qui permet de réduire ou d'éviter le gaspillage de ressources de transmission (telles que des ressources d'interface radio).
PCT/CN2025/083909 2024-04-03 2025-03-20 Procédé et appareil de communication Pending WO2025209202A1 (fr)

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