Communication method and application apparatus

Abstract

The present application discloses a communication method and an application apparatus. The method comprises: adding a first probe indication to a first data packet, the first probe indication being used for requesting a first state report, the first data packet being a second data packet having the largest sequence number, and the remaining time of the second data packet being less than or equal to a remaining time threshold. By implementing embodiments of the present application, a probe indication can be reported for a data packet having the largest sequence number among data packets (e.g., delay critical data) having a remaining time less than or equal to a remaining time threshold, so that signaling overhead can be reduced, the retransmission efficiency of such a data packet can be improved, and the effectiveness of data transmission can be improved.

Description

Communication method and application device

[0001] The present application claims priority to Chinese Patent Application No. 202411603535.8, filed on November 8, 2024, entitled "Communication method and application device" and Chinese Patent Application No. 202411342877.9, filed on September 25, 2024, entitled "Communication method, communication device and storage medium", both of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method and an application device. BACKGROUND

[0003] With the continuous development of communication systems, the data transmission delay is continuously reduced, and the transmission capacity is increasingly large. The 5th generation (5G) communication system has gradually emerged some multimedia services with stronger real-time performance, such as video transmission, cloud gaming, extended reality (XR), and tactile Internet. In order to realize the immersive experience of human interaction with the virtual world, the XR service with ultra-high bandwidth and ultra-low latency requirements has attracted much attention.

[0004] Since the retransmission delay of the RLC layer is high due to the high latency requirement of the XR service, the RLC retransmission is considered to be enhanced for timely retransmission. In Rel-18 XR enhancement, the RLC layer can know the delay-critical data, so it is expected that the RLC will perform fast retransmission for these data packets. The delay-critical data refers to the data packets with a remaining time less than a threshold. Currently, the conference does not discuss the timely triggering of RLC retransmission. SUMMARY

[0005] Embodiments of the present application disclose a communication method and an application device, which can report a seeking (or polling) indication for the data packet with the largest sequence number among the data packets (e.g., delay-critical data, etc.) with a remaining time less than or equal to a remaining time threshold, thereby saving signaling, improving the retransmission efficiency of such data packets, and improving the effectiveness of data transmission.

[0006] In a first aspect, the embodiments of the present application disclose a communication method, which is applied to a first device. The first device can be a terminal device or a network device, or can be a device (for example, a chip, or a chip system, or a circuit, or a means, etc.) in a terminal device or a network device. The first device can be understood as a sending end of a data packet. In addition to sending the data packet, the first device can also send a first inquiry indication, and can receive a first status report to indicate a receiving status of the data packet. The method comprises the following steps: determining first data, the first data packet being a second data packet with a maximum sequence number, and a remaining time of the second data packet being less than or equal to a remaining time threshold; adding the first inquiry indication in the first data packet, the first inquiry indication being used to request the first status report; and sending the first data packet with the first inquiry indication added. In this way, the inquiry indication can be reported for the data packet (for example, delay critical data, etc.) with the maximum sequence number and the remaining time less than or equal to the remaining time threshold, signaling can be saved, retransmission efficiency of the data packet can be improved, and the effectiveness of data transmission can be improved.

[0007] In some possible examples, the method further comprises: starting a first timer based on sending the first data packet with the first inquiry indication added. That is, the first timer starts timing when the first data packet with the first inquiry indication added is sent.

[0008] The first timer is used to determine whether the first inquiry indication is retransmitted. It can be understood that, in the case that the first timer expires, if the first status report is not received, or the receiving status of the SN number of the first data packet is not included in the received first status report, the first inquiry indication can be retransmitted. The retransmitted first inquiry indication can be carried in a data packet with a remaining time less than or equal to a remaining time threshold, and the data packet can be a data packet with a maximum SN number among all data packets with a remaining time less than or equal to a remaining time threshold. The first timer is a timer for the data packet with the remaining time less than or equal to the remaining time threshold, that is, the first timer is used to indicate whether the data packet with the remaining time less than or equal to the remaining time threshold is retransmitted. The first timer is started only when the data packet with the remaining time less than or equal to the remaining time threshold carries the first inquiry indication, or the first timer is started after the data packet with the remaining time less than or equal to the remaining time threshold is retransmitted and the first inquiry indication is added in the data packet.

[0009] In some possible examples, the method further includes: determining a third data packet, the sequence number of the third data packet being greater than the sequence number of the first data packet, and the remaining time of the third data packet being less than or equal to the remaining time threshold; adding the first seeking indication in the third data packet; sending the third data packet with the first seeking indication added; and restarting the first timer based on sending the third data packet with the first seeking indication added. As described previously, the first timer is used to indicate whether a data packet with a remaining time less than or equal to the remaining time threshold is retransmitted. It can be understood that, after the first timer is started based on sending the first data packet with the first seeking indication added, if it is determined that the sequence number of the third data packet is greater than the sequence number of the first data packet, and the remaining time of the third data packet is less than or equal to the remaining time threshold, the first seeking indication can be added in the third data packet, and the first timer can be restarted based on sending the third data packet with the first seeking indication added. In this way, the receiving status of the second data packet before the third data packet, i.e., the receiving status of the second data packet before the first data packet, or even the data packet with a remaining time less than the remaining time threshold before the third data packet can be sought, and the accuracy of data retransmission can be improved.

[0010] In some possible examples, the method further includes: in a case where the first timer expires or the first status report is received, retransmitting a data packet with an unreceived receiving status and / or an undropped remaining time less than or equal to the remaining time threshold. In this way, the data packet with an unreceived receiving status and / or an undropped remaining time less than or equal to the remaining time threshold can be retransmitted in time, and the effectiveness of data transmission can be improved.

[0011] In some possible examples, the method further includes: based on a first condition, stopping the first timer.

[0012] In some possible examples, the first condition includes at least one of the following: the first data packet or the third data packet is dropped; the second data packet is dropped; a data packet with a remaining time less than or equal to the remaining time threshold is dropped; a second timer expires; a receiving status of a data packet with a remaining time less than or equal to the remaining time threshold is obtained; the first status report is received, and the first status report includes the receiving status of the first data packet or the third data packet or the second data packet; and the second timer is a timer started based on a second seeking indication sent based on a second condition, and the second seeking indication is used to request a second status report, and the second condition includes at least one of the following: a number of newly sent data packets or a number of bytes is greater than or equal to a threshold; there is no data packet in a buffer that needs to be newly transmitted or retransmitted.

[0013] It can be understood that, in the case that the first data packet or the third data packet is discarded, the first data packet or the third data packet in the second data in the data packet indicating the remaining time less than or equal to the remaining time threshold is discarded, the first data packet or the third data packet does not need to be retransmitted, and the first timer can be stopped. In the case that the second data packet is discarded, the second data in the data packet indicating the remaining time less than or equal to the remaining time threshold is discarded, the second data packet does not need to be retransmitted, and the first timer can be stopped. In the case that the data packet indicating the remaining time less than or equal to the remaining time threshold is discarded, the data packet indicating the remaining time less than or equal to the remaining time threshold is discarded, the data packet does not need to be retransmitted, and the first timer can be stopped, so that the data packet indicating the remaining time less than or equal to the remaining time threshold is not retransmitted.

[0014] In the embodiment of the present application, the second timer can be a timer started based on the second condition sending of the second probe indication, which can be understood as a reassembly timer, that is, a trigger condition for receiving a status report in the prior art. The second probe indication is used to request a second status report, which can be understood as a status report in the prior art. The second timer is not for the data packet indicating the remaining time less than or equal to the remaining time threshold, and the data packet in the second status report includes the data packet indicating the remaining time less than or equal to the remaining time threshold, and can also include the data packet indicating the remaining time greater than the remaining time threshold. It can be understood that, in the case that the second timer times out, the status report of the data packet indicating the remaining time less than or equal to the remaining time threshold and the data packet indicating the remaining time greater than the remaining time threshold is not sent, the first timer can be stopped, and the second timer can also be restarted, or the data packet that is not discarded or not received can be retransmitted, or even the data packet that is not discarded and the data packet that is not received in the data packet that is not discarded can be retransmitted.

[0015] It should be noted that the first timer and the second timer in the present application can also be executed separately. That is, the first timer and the second timer can be decoupled, so that the running of the first timer is not affected by the timeout of the second timer. Or the first timer and the second timer can be associated, for example, when the first condition is the timeout of the second timer, the first timer is stopped, so that the running of the first timer is affected by the second timer.

[0016] It can be understood that, in the case that the receiving status of the data packet indicating the remaining time less than or equal to the remaining time threshold is obtained, it can be determined that the first probe indication triggers the second device to send the receiving status of the data packet, and the first timer can be stopped. In the case that the first status report is received and the first status report includes the receiving status of the first data packet or the third data packet or the second data packet, it can be determined that the first probe indication triggers the second device to send the first status report, and the receiving status of the data packet indicating the remaining time less than or equal to the remaining time threshold is indicated in the first status report, and the first timer can be stopped.

[0017] It should be noted that the above first condition is only an example. In fact, other first conditions or a combination of at least two of the above first conditions, or a combination of one or more of the above six first conditions and other first conditions can be included. For example, the second timer expires, and the retransmission of the data packet with a remaining time less than the remaining time threshold, etc.

[0018] In some possible examples, the method further includes determining the first data packet based on a discard configuration of a protocol data unit (PDU) set. The discard configuration of the PDU set is used to indicate discard based on the PDU set. That is, in the case of discard of one data packet in the PDU set, all data packets in the PDU set are discarded. It can be understood that based on the discard configuration of the PDU set, if there is a data packet in the PDU set with a remaining time less than or equal to the remaining time threshold, the remaining time of all data packets in the PDU set is less than or equal to the remaining time, that is, in the case of one second data packet in the PDU set, all data packets in the PDU set are second data packets.

[0019] In some possible examples, the first data packet belongs to the PDU set, and the first probe indication is used to request the reception status of the data packet of the PDU set. In this way, the first probe indication can be added in one data packet based on the granularity of the PDU set, and the first probe indication can be added in each data packet in the PDU set, thereby saving signaling.

[0020] In some possible examples, the method further includes obtaining indication information of the first protocol layer based on the discard configuration of the PDU set. The indication information is used to indicate that in the case of the data packet of the PDU set being the second data packet, the data packet in the PDU set sent to the second protocol layer latest is the first data packet.

[0021] In some possible examples, the method further includes that when the protocol layer of the first device can receive different data packets at the same time, the remaining times of the data packets can be the same, in which case the remaining times of the data packets are less than or equal to the remaining time threshold at the same time, and the second data packet includes a plurality of data packets, in which the first data packet is the data packet with the largest sequence number in the second data packet.

[0022] In some possible examples, the method further includes that when the remaining time of the data packet is less than or equal to the remaining time threshold, the data packet is retransmitted, in which case the data packet in the second data packet is also transmitted, but only the first data packet adds the first probe indication for retransmission.

[0023] The first protocol layer can be a PDCP layer, and the second protocol layer can be an RLC layer. It can be understood that, based on the discard configuration of the PDU set, if there is one second packet in the PDU set, all the packets in the PDU set are second packets. According to the indication information of the first protocol layer, it can be determined that the first packet is the second packet that is sent to the second protocol layer latest, so that the first packet in the PDU set can be determined, and the first packet is the packet with the largest sequence number sent to the second protocol layer. In this way, the second protocol layer can know that all the packets in the PDU set are second packets, and can determine the first packet in the second packet, and the first seeking indication can be added in the first packet, so that the efficiency of timely retransmission can be improved.

[0024] In some possible examples, the first seeking indication is located in a second protocol layer subheader, and the second protocol layer subheader includes a first field, and the first field is used to indicate one of the following: a normal seeking, an enhanced seeking for a single packet, and an enhanced seeking for the PDU set.

[0025] In some possible examples, the second protocol layer subheader further includes a second field, and the second field is used to indicate whether to send a seeking indication.

[0026] In some possible examples, when the first field is a first value, the first field is used to indicate the enhanced seeking for the PDU set, and the second protocol layer subheader further includes a third field; or when the first field is not the first value, the first field is used to indicate one of the following: the normal seeking, the enhanced seeking for a single packet, and the enhanced seeking for the PDU set, and the second protocol layer subheader does not include the third field; wherein the third field is used to indicate the sequence number of the PDU set. In this way, the sequence number of the PDU set in the enhanced seeking for the PDU set can be determined through the third field.

[0027] In some possible examples, the second protocol layer subheader further includes a fourth field, and the fourth field is used to indicate the sequence number of the packet that is sent to the second protocol layer latest in the PDU set, and the third field is located after the fourth field. In this way, the sequence number of the packet that is sent to the second protocol layer latest in the PDU set, i.e., the sequence number of the first packet, can be determined through the fourth field.

[0028] In some possible examples, the first seeking indication is an enhanced seeking, and the triggering time of the first status report is less than the triggering time of a third status report, and the third status report is triggered by a normal seeking. In this way, compared with the case where the seeking indication of the normal seeking is sent, the status report can be received more timely after the seeking indication of the enhanced seeking is sent.

[0029] In a second aspect, embodiments of the present disclosure disclose another communication method, which is applied to a second device. The second device can be a terminal device or a network device, or can be a device (e.g., a chip, or a chip system, or a circuit, or a means, etc.) in a terminal device or a network device to perform. The second device can be understood as a receiving end of a data packet, and the second device can also be understood as a sending end of a status report. The method comprises: receiving a first data packet with a first probe indication added; and sending a first status report, wherein the first status report is used to indicate a receiving status of the data packet, and the receiving status comprises an unreceived receiving status, and the unreceived receiving status comprises an unacknowledged receiving status and an unreceived status.

[0030] In some possible examples, the receiving status comprises an acknowledged receiving status.

[0031] In some possible examples, the unacknowledged receiving status is determined by a reassembly timer timeout, or is determined based on a sequence number of a probe, or is determined based on a data packet that has been received and discarded; and the unreceived status is determined by the reassembly timer.

[0032] In some possible examples, the method further comprises: receiving a data packet that is unreceived and / or has a remaining time less than or equal to the remaining time threshold.

[0033] In some possible examples, the first data packet belongs to a protocol data unit (PDU) set, and the first probe indication is used to request a receiving status of the data packet in the PDU set.

[0034] In some possible examples, the first probe indication is located in a second protocol layer subheader, and the second protocol layer subheader comprises a first field, and the first field is used to indicate one of the following: a normal probe, an enhanced probe for a single data packet, and an enhanced probe for the PDU set.

[0035] In some possible examples, the second protocol layer subheader further comprises a second field, and the second field is used to indicate whether to send a probe indication.

[0036] In some possible examples, when the first field is a first value, the first field is used to indicate an enhanced probe type of the PDU set, and the second protocol layer subheader further includes a third field; or when the first field is not the first value, the first field is used to indicate one of the following: a normal probe type, an enhanced probe type for a single data packet, and an enhanced probe type for the PDU set, and the second protocol layer subheader does not include the third field; and the third field is used to indicate a sequence number of the PDU set.

[0037] In some possible examples, the second protocol layer subheader further includes a fourth field, the fourth field is used to indicate a sequence number of a data packet that is sent to the second protocol layer latest in the PDU set, and the third field is located after the fourth field.

[0038] In some possible examples, the first probe indication is an enhanced probe, a triggering time of the first status report is less than a triggering time of a third status report, and the third status report is triggered by a normal probe.

[0039] It should be understood that the execution subject of the second aspect is the second device, and the specific content of the second aspect corresponds to the content of the first aspect. The corresponding features of the second aspect and the beneficial effects achieved can refer to the description of the first aspect, and the detailed description is appropriately omitted here to avoid repetition.

[0040] In a third aspect, an embodiment of the present application provides a communication device, including units or modules or means for performing each step of the above-mentioned first aspect or second aspect or any aspect.

[0041] In a fourth aspect, an embodiment of the present application provides another communication device, which can be the first device or the second device, or can include a device in these devices, for example, a chip, or a chip system, or a circuit, or a device capable of realizing related functions. The communication device includes a processor configured to execute instructions stored in a memory, when the instructions are executed, the communication method in the above-mentioned first aspect or second aspect or any possible example of any aspect is implemented.

[0042] In some possible examples, the communication device further includes one or more of the memory and a transceiver, and the transceiver is configured to transceive data and / or signaling.

[0043] In a fifth aspect, an embodiment of the present application discloses a computer readable storage medium, configured to store instructions or a computer program, when the instructions or the computer program are executed by a processor, the communication method in the above-mentioned first aspect or second aspect or any possible example of any aspect is executed.

[0044] In a sixth aspect, an embodiment of the present application discloses a computer program product, comprising instructions or computer programs, when the instructions or computer programs are executed by a processor, the communication method in the first aspect or the second aspect or any possible implementation of the first aspect or the second aspect is executed.

[0045] In a seventh aspect, an embodiment of the present application discloses a first chip, comprising a processor, the processor is configured to call and execute instructions stored in a memory, so that a device installed with the chip executes the communication method in the first aspect or the second aspect or any possible implementation of the first aspect or the second aspect.

[0046] In an eighth aspect, an embodiment of the present application discloses a second chip, comprising an input interface, an output interface and a processing circuit, the input interface, the output interface and the processing circuit are connected through an internal connection path, and the processing circuit is configured to execute the communication method in the first aspect or the second aspect or any possible implementation of the first aspect or the second aspect.

[0047] In a ninth aspect, an embodiment of the present application discloses a third chip, comprising an input interface, an output interface, a processor and optionally a memory, the input interface, the output interface, the processor and the memory are connected through an internal connection path, and the processor is configured to execute a code in the memory, when the code is executed, the processor is configured to execute the communication method in the first aspect or the second aspect or any possible implementation of the first aspect or the second aspect.

[0048] In a tenth aspect, an embodiment of the present application discloses a chip system, comprising at least one processor, a memory and an interface circuit, the memory, a transceiver and the at least one processor are connected through a line, and the at least one memory stores a computer program; the computer program is executed by the processor to execute the communication method in the first aspect or the second aspect or any possible implementation of the first aspect or the second aspect.

[0049] In an eleventh aspect, an embodiment of the present application provides a communication system, the communication system comprises a communication device corresponding to a sending end and a communication device corresponding to a receiving end, when the communication device is running in the communication system, the communication device is configured to execute the method in the first aspect or the second aspect or any possible implementation.

[0050] It should be understood that the implementation and beneficial effects of the above aspects of the present application can be mutually referred to. BRIEF DESCRIPTION OF DRAWINGS

[0051] The following describes the drawings used in the embodiments of the present application.

[0052] FIG. 1 is a schematic diagram of an architecture of a communication system provided by an embodiment of the present application;

[0053] FIG. 2 is a schematic diagram of a structure of a user plane protocol stack provided by an embodiment of the present application;

[0054] Figure 3 is a schematic diagram of a sending window of an RLC according to an embodiment of the present application;

[0055] Figure 4 is a schematic diagram of a receiving window of an RLC according to an embodiment of the present application;

[0056] Figure 5A is a schematic diagram of a structure of a status report of a PDU with a 12-bit SN according to an embodiment of the present application;

[0057] Figure 5B is a schematic diagram of a structure of a status report of a PDU with an 18-bit SN according to an embodiment of the present application;

[0058] Figure 6A is a schematic diagram of a structure of a 12-bit SN non-segmented data packet according to an embodiment of the present application;

[0059] Figure 6B is a schematic diagram of a structure of an 18-bit SN non-segmented data packet according to an embodiment of the present application;

[0060] Figure 6C is a schematic diagram of a structure of a 12-bit SN segmented data packet according to an embodiment of the present application;

[0061] Figure 6D is a schematic diagram of a structure of an 18-bit SN segmented data packet according to an embodiment of the present application;

[0062] Figure 7 is a schematic diagram of a flow of a communication method according to an embodiment of the present application;

[0063] Figure 8A is a schematic diagram of reporting of seeking information according to an embodiment of the present application;

[0064] Figure 8B is a schematic diagram of reporting of seeking information according to another embodiment of the present application;

[0065] Figure 9A is a schematic diagram of a structure of a first seeking indication according to an embodiment of the present application;

[0066] Figure 9B is a schematic diagram of a structure of another first seeking indication according to an embodiment of the present application;

[0067] Figure 10A is a schematic diagram of data transmission according to an embodiment of the present application;

[0068] Figure 10B is a schematic diagram of another data transmission according to an embodiment of the present application;

[0069] Figure 11 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0070] Figure 12 is a schematic diagram of a structure of another communication apparatus according to an embodiment of the present application;

[0071] Figure 13 is a schematic diagram of a structure of a terminal device according to an embodiment of the present application. DETAILED DESCRIPTION

[0072] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: a long term evolution (LTE) system, a new radio (NR) system, a public land mobile network (PLMN) system, a long term evolution advanced (LTE-A) system, a device-to-device (D2D) communication system, a machine to machine (M2M) communication system, an internet of things (IoT), a narrow band internet of thing (NB-IoT), a cognitive communication integrated system, a frequency division duplex (FDD) system, a time division duplex (TDD) system, a non-terrestrial communication (NTN) system, a wireless projection communication system, an integrated access and backhaul (IAB) communication system, and a communication system evolved after a 5G communication system (for example, a 6G communication system), or a non-3rd generation partnership project (3GPP) communication system, and the like, and the present application is not limited thereto.

[0073] Please refer to FIG. 1, which is an architecture schematic diagram of a communication system provided by an embodiment of the present application. As shown in FIG. 1, the communication system can include at least one terminal device 101 and at least one network device 102. Wherein, the terminal device 101 can be connected with the network device 102 in a wireless manner. The terminal device 101 and the network device 102 can perform uplink communication or downlink communication, and the terminal devices 101 can perform sidelink communication.

[0074] The terminal device 101 can be fixed in position, and can also be movable. The terminal device 101 and the network device 102 can be deployed on land, for example, indoors or outdoors, handheld or vehicle-mounted, and the like. The terminal device 101 and the network device 102 can also be deployed on the water surface, airplanes, balloons and satellites in the air, and the like, and the present application is not limited thereto.

[0075] In the embodiments of the present application, the terminal device 101 can be an entity for receiving or transmitting signals on the user side. The terminal device 101 can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a VR terminal device, an AR terminal device, a customer premise equipment (CPE), an IoT terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical treatment, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a terminal in communication and perception integration, a vehicle-mounted terminal, a vehicle with vehicle-to-vehicle (V2X) communication capability, a smart connected vehicle, a UAV with UAV to UAV (U2U) communication capability, a personal digital assistance (PDA), a smart factory or a smart grid, and the like, without limitation.

[0076] The terminal device 101 can be referred to as a user equipment (UE), a terminal, an access terminal, a UE unit, a UE station, a mobile device, a mobile station, a mobile station, a mobile terminal, a mobile client, a mobile unit, a remote station, a remote terminal device, a remote unit, a wireless unit, a wireless communication device, a user agent, or a user apparatus, etc. Among them, the access terminal can be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a PDA, a handheld device with wireless communication function, a computing device, or other processing devices connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a PLMN evolved after the 5G communication system, or a terminal device in a non-public network (NPN) evolved after the 5G communication system, etc. In the 5G communication system, the terminal device 101 will adopt the new radio technology to establish signal connection and data connection with the network device 102, so as to transmit control signals and service data to the data network.

[0077] The network device 102 can be an entity for transmitting or receiving signals, and is mainly used to implement functions such as wireless physical control, resource scheduling and wireless resource management, wireless access control and mobility management, and provide reliable wireless transmission protocols and data encryption protocols. The network device 102 can support wired access and can also support wireless access, which can be referred to as an access network device hereinafter.

[0078] Optionally, the access network device can be an access network (AN) / radio access network (RAN) device, which is composed of multiple AN / RAN nodes. The AN / RAN node can include but is not limited to an access point (AP), an enhanced nodeB (eNB), a home base station (for example, a home evolved NodeB or a home NodeB, HNB), a baseband unit (BBU), a next-generation base station (NR nodeB, gNB), a transmission reception point (TRP), a transmission point (TP), or some other access node, such as a wireless relay node, a wireless backhaul node, and the like. The AN / RAN node can also be one or more constituent antenna panels, or can be a network node constituting a gNB or a transmission point, such as a BBU or a distributed unit (DU), or can be a device that undertakes a base station function in a D2D, V2X, M2M, U2U, or the like communication system, and the like. The AN / RAN node can also be a wireless controller in a cloud radio access network (CRAN) scenario, or can be an open access network (O-RAN or ORAN), or can be a base station in a communication system evolved after the 5G communication system, such as an xNodeB in a 6G communication system, or can be an access network device in a PLMN network evolved after the 5G communication system, and the like, without limitation.

[0079] The main functions of the access network device include: managing radio resources, compressing internet protocol (IP) headers and encrypting user data streams, selecting a mobile management entity (MME) when a user equipment is attached, routing user plane data to a service gateway (SGW), organizing and sending paging messages, organizing and sending broadcast messages, configuring measurements and measurement reports for mobility or scheduling purposes, and the like.

[0080] Optionally, the network device 102 can also include a core network device for maintaining subscription data of a mobile network, managing network elements of the mobile network, and providing session management, mobility management, policy management, security authentication, and the like for the terminal device 101.

[0081] The NR wireless protocol stack is divided into two planes: a user plane (UP) and a control plane (CP). The control plane protocol stack is a protocol cluster used for transmission of control signaling of the system, and the user plane protocol stack is a protocol cluster used for transmission of user data. The NR user plane protocol stack has an additional service data adaptation protocol (SDAP) layer compared to the LTE protocol stack. Taking a terminal device as UE and an access network device as gNB as examples. As shown in FIG. 2, the user plane protocol stack includes, from top to bottom, an SDAP layer, a packet data convergence protocol (PDCP) layer, an RLC layer, a medium access control (MAC) layer, and a physical layer (Physical, PHY) layer. The SDAP layer includes a service data application protocol, and the main function is to mark quality of service (Qos) flow identifiers in uplink and downlink data packets and to map the Qos flow to a data radio bearer (DRB). Transmission of data packets on the user plane is mainly completed through the DRB. According to different Qos flows, data between the UE and the gNB can be carried on multiple DRBs.

[0082] The PDCP layer is mainly responsible for compressing and decompressing the internet protocol (IP) header, transmitting user data, and maintaining the sequence number (SN) of the radio bearer (RB) (used to indicate the sending order of the data packet), and processing the RRC message on the control plane and the IP packet on the user plane. On the user plane, the PDCP sublayer can perform header compression and encryption on the IP data packet after receiving the IP data packet from the upper layer, and then deliver it to the RLC sublayer. The PDCP sublayer can also provide in-sequence delivery and duplicate packet detection functions to the upper layer according to the SN of the PDCP data packet.

[0083] The RLC layer communicates with the PDCP layer through an RLC channel, and communicates with the MAC layer through a logic channel (LCH). The main functions include segmentation and reassembly of RLC service data units (SDUs), automatic repeat-request (ARQ) error correction and duplicate detection, etc.

[0084] The MAC layer is mainly responsible for processing the mapping between the logic channel and the transmission channel and the scheduling of the radio resource, and the main functions include the mapping between the logic channel and the transmission channel, the multiplexing and demultiplexing of the logic channel, and the scheduling, etc. The PHY layer is located at the bottom of the air interface protocol stack, and is mainly responsible for coding, modulation, multi-antenna processing, and time-frequency resource mapping, etc.

[0085] The SDAP layer, the PDCP layer, the RLC layer, the MAC layer, and the PHY layer can also be referred to as SDAP entities, PDCP entities, RLC entities, MAC entities, and PHY entities, or can be referred to as SDAP network elements, PDCP network elements, RLC network elements, MAC network elements, and PHY network elements, or simply referred to as SDAP, PDCP, RLC, MAC, and PHY. It should be understood that the above network elements are only a schematic. In practice, the network elements can be network elements implemented on dedicated hardware, software instances running on dedicated hardware, or instances of virtualized functions on appropriate platforms, for example, a cloud platform. In future communication systems, the above network elements can have other names, which are not limited in the present application.

[0086] The access network device can configure whether the PDCP layer of the RB of the terminal device is to copy the data of the PDCP entity and then transmit the copied data through two or more different paths (such as two different RLC entities) respectively. The function of PDCP data duplication can be indicated by MAC-control element (MAC-CE) signaling to start (i.e., activate) or stop (i.e., deactivate). When configuring the PDCP data duplication function of the RB, the access network device can configure whether the PDCP data duplication function is to start immediately after the configuration is completed. When the RLC entity is in an activated state, the PDCP entity can send data to the RLC entity.

[0087] In the NR user plane protocol stack, the RLC layer communicates with the PDCP layer (or the RRC layer) through an RLC channel and communicates with the MAC layer through an LCH. RLC configuration is an LCH-level configuration, and one RLC entity corresponds to only one LCH of a terminal device. The data received by the RLC entity from the PDCP layer or sent to the PDCP layer is referred to as an RLC service data unit (SDU) (or a PDCP protocol data unit (PDU)). The data received by the RLC entity from the MAC layer or sent to the MAC layer is referred to as an RLC PDU (or a MAC SDU). The RLC PDU is divided into an RLC (data) data PDU and an RLC (control) control PDU.

[0088] The RLC layer includes a transparent mode (TM), an acknowledged mode (AM), and an unacknowledged mode (UM). The RLC layer is mainly responsible for segmenting / reassembling, reassembling, and reassembling and discarding processing of RLC SDUs in the AM and UM modes; error correction through ARQ, duplicate detection, re-segmentation of RLC SDU segmentation, and protocol error detection in the AM mode. In addition, the RLC layer can also be used to implement transmission of upper layer PDU and RLC layer reestablishment.

[0089] The present application mainly considers AM mode, the RLC data PDU sent and received by the AM RLC entity is called acknowledgement mode data (AMD) PDU. Each AMD PDU contains a complete RLC SDU or a RLC SDU segment. The RLC control PDU sent and received by the AM RLC entity is called status PDU.

[0090] The sending end of the AM RLC entity should give priority to transmitting the RLC control PDU through the AMD PDU, and the sending end of the AM RLC entity should give priority to transmitting the AMD PDU containing the previously sent RLC SDU or RLC SDU segment.

[0091] The sending end of the AM RLC entity should maintain a sending window according to the TX_Next_Ack state variable. The sending window of the RLC can refer to Fig. 3. As shown in Fig. 3, the state variables of the sending window of the RLC include the TX_Next_Ack state variable and the TX_Next state variable. The TX_Next_Ack state variable is an acknowledgement state variable, indicating the SN of the next data packet of the acknowledged data packet received in sequence, and is the lower boundary of the sending window. Once the SN of a data packet is received as TX_Next_Ack, the TX_Next_Ack needs to be updated.

[0092] The TX_Next state variable is a send state variable, indicating the SN of the next newly generated AMD PDU. Once the AM RLC entity generates an AMD PDU with the SN of TX_Next, the update of TX_Next, or the update of the sending window, is realized, and the AMD PDU contains a RLC SDU or a RLC SDU segment.

[0093] The AM_Windows_Size is the size of the AM window, which depends on the number of bits of the RLC SN and the comprehensive consideration of the speed of data transmission and the system, and is determined by the protocol. For example, when a 12-bit SN is used, AM_Windows_Size = 2024; when an 18-bit SN is used, AM_Windows_Size = 131072.

[0094] As shown in Fig. 3, if TX_Next_Ack <= SN < TX_Next_Ack + AM_Window_Size, the SN will fall in the sending window, otherwise the SN will fall out of the sending window. The transmitting end of the AM RLC entity will not transmit any AMD PDU whose SN falls out of the sending window to the underlying layer.

[0095] For each RLC SDU received from the upper layer, the AM RLC entity will: associate the SN of one RLC SDU = TX_Next, and construct an AMD PDU by setting the SN of the AMD PDU = TX_Next, and then increase TX_Next by 1.

[0096] When transmitting an AMD PDU containing RLC SDU segments to the underlying layer, the transmitting end of the AM RLC entity should: set the SN of the AMD PDU to the SN of the corresponding RLC SDU.

[0097] The transmitting end of the AM RLC receives a positive acknowledgement (the AM RLC entity at the opposite end confirms that the RLC SDU has been successfully received) of one RLC SDU from the STATUS PDU of the AM RLC entity at the opposite end. When receiving a positive acknowledgement of the SN = x of one RLC SDU, the AM RLC entity at the opposite end will: send an indication to inform the upper layer that the RLC SDU has been successfully sent out; set TX_Next_Ack equal to the smallest SN of the RLC SDU, SN is in the range TX_Next_Ack <= SN <= TX_Next, and no positive acknowledgement has been received.

[0098] The receiving end of the AM RLC entity will maintain a receiving window through the state variable RX_Next. The receiving window of the RLC can refer to Fig. 4. As shown in Fig. 4, the state variables of the receiving window of the RLC include the RX_Next state variable, the RX_Next_Status_Trigger state variable, the RX_Next_Status_Trigger state variable and the RX_Next_Highest state variable. Among them, AM_Window_Size can refer to the description of the sending window, which will not be described here.

[0099] RX_Next state variable is a receive state variable indicating the SN number of the latest in-sequence complete received RLC SDU, and is the lower bound of the receive window. It is updated as soon as an AMD PDU with SN = RX_Next is received. RX_Next_Status_Trigger is a t-Reassembly state variable, and is the next SN of the RLC SDU that triggers the t-Reassembly timer. RX_Highest_Status state variable indicates the highest possible SN number when a status PDU needs to be built, and this SN number can be indicated as "ACK_SN". RX_Next_Highest state variable is a highest received state variable, and indicates the next SN number of the highest SN number of the received RLC SDUs.

[0100] As shown in Figure 4, if RX_Next <= SN < RX_Next + AM_Window_Size, the SN falls within the receive window, otherwise the SN falls outside the receive window. When an AMD PDU is received from the lower layer, the AM RLC receiving entity will: either discard the AMD PDU, or put it in the receive buffer; if the received AMD PDU is already in the receive buffer: update the status variables, reassemble and send the RLC SDU to the upper layer, and start or stop t-Reassembly as necessary.

[0101] When t-Reassembly expires, the AM RLC receiving entity will: update the status variables, and start t-Reassembly as necessary. When an AMD PDU has been received from the lower layer, wherein the AMD PDU contains byte segments number y to z of the RLC SDU with SN = x, the AM RLC receiving entity will: if x falls outside the receive window; if byte segment number y to z of the RLC SDU with SN = x has already been received; discard the received AMD PDU. Or put the received AMD PDU in the receive buffer. If some of the byte segments of the RLC SDU contained in the AMD PDU have already been received; discard the duplicated byte segments.

[0102] When an AMD PDU with SN = x has been placed in the receive buffer, the AM RLC entity receiving side will: if x >= RX_Next_Highest, update RX_Next_Highest = x + 1; if all bytes of the RLC SDU with SN = x have been received, reassemble the RLC SDU from the AMD PDUs with SN = x, remove the RLC header fields, and send the reassembled RLC SDU to upper layers. If x = RX_Highest_Status, update RX_Highest_Status to the SN of the first RLC SDU with SN > current RX_Highest_Status for which all bytes have not yet been received. If x = RX_Next, update RX_Next to the SN of the first RLC SDU with SN > current RX_Next for which all bytes have not yet been received.

[0103] If t-Reassembly is running, and in the case that RX_Next_Status_Trigger = RX_Next; or RX_Next_Status_Trigger = RX_Next + 1, and there is no missing byte segment of an SDU associated with SN = RX_Next before the last byte of all received segments of that SDU; or RX_Next_Status_Trigger falls outside the receive window, and RX_Next_Status_Trigger is not equal to RX_Next + AM_Window_Size, stop and reset t-Reassembly.

[0104] If t-Reassembly is not running, and in the case that RX_Next_Highest > RX_Next + 1; or RX_Next_Highest = RX_Next + 1, and there is at least one missing byte segment of an SDU associated with SN = RX_Next before the last byte of all received segments of that SDU, start t-Reassembly and set RX_Next_Status_Trigger = RX_Next_Highest.

[0105] When t-Reassembly expires, the AM RLC entity receiving side will: update RX_Highest_Status of SN >= RX_Next_Status_Trigger to the SN of the first RLC SDU whose all bytes have not been received; in case of RX_Next_Highest > RX_Highest_Status + 1, or in case of RX_Next_Highest = RX_Highest_Status + 1 and at least one SDU associated with SN = RX_Highest_Status has missing byte segment before the last byte of all received segments of this SDU, start t-Reassembly and set RX_Next_Status_Trigger = RX_Next_Highest.

[0106] In the embodiments of the present application, the terminal device 101 and the network device 102, the network device 102 and the network device 102, and the terminal device 101 and the terminal device 101 can communicate through a licensed spectrum or a granted spectrum, or can communicate through an unlicensed spectrum or a grant-free spectrum, or can communicate through both the licensed spectrum and the unlicensed spectrum. The present application does not limit the spectrum resources used by the terminal device 101 and the network device 102. The terminal device 101 and the network device 102 can communicate through a user equipment-user equipment (uu) interface for uplink (UL) communication or downlink (DL) communication, and the terminal device 101 and the terminal device 101 can communicate through a sidelink interface (PC5 interface) for sidelink (SL) communication.

[0107] The two terminal devices 101 can be respectively within the coverage of different network devices 102, or the two terminal devices 101 can be within the coverage of the same network device 102. If a single terminal device 101 is within the same coverage of two network devices 102, multi-station cooperative transmission can be performed through the two network devices 102. It should be understood that when the two network devices 102 transmit the same data and / or information to the terminal device 101, the reliability of communication can be improved.

[0108] In the embodiments of the present application, the terminal device or the network device includes a hardware layer, an operating system layer running above the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also referred to as a main memory). The operating system can be any one or more computer operating systems that implement business processing through a process, for example, a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes applications such as a browser, an address book, word processing software, and instant messaging software. Moreover, the embodiments of the present application do not particularly limit the specific structure of the execution subject of the method provided by the embodiments of the present application, as long as the execution subject can communicate according to the method provided by the embodiments of the present application by running a program in which the code of the method provided by the embodiments of the present application is recorded. For example, the execution subject of the method provided by the embodiments of the present application can be a terminal device or a network device, or a functional module capable of calling and executing a program in a terminal device or a network device.

[0109] In addition, various aspects or features of the disclosure can be realized as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used in the application is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, or magnetic strips), optical disks (e.g., compact disk (CD), digital versatile disk (DVD), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROM), card, stick, or key drive, etc.). The various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" can include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0110] It should be noted that the number and type of network devices and terminal devices included in the network architecture shown in FIG. 1 are merely examples, and the embodiments of the present application are not limited thereto. For example, more or fewer terminal devices can be included that communicate with the network devices. For another example, more or fewer core network devices can be included that communicate with the network devices. For the sake of simplicity, they are not described one by one in the drawings.

[0111] In the diagram as shown in FIG. 1 or FIG. 2, although the network device and the terminal device are shown, the application scenario can not be limited to including the network device and the terminal device, for example, can also include a device for carrying a virtualized network function, and the like, which is obvious to those skilled in the art, and will not be described one by one here.

[0112] In order to facilitate understanding of the embodiments of the present application, the definitions of the technical terms that can appear in the embodiments of the present application are given below. The terms used in the implementation part of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0113] (1) Extended Reality (XR) can be a term for different types of reality. For example, XR can refer to all real and virtual combined environments and human-machine interactions generated by computer technology and wearable devices. XR services can include, but are not limited to, the following: Augmented Reality (AR), Mixed Reality (MR), Virtual Reality (VR).

[0114] In order to improve the experience of human interaction with the virtual world, XR services have strict requirements for bandwidth and latency. In the embodiments of the present application, XR data can refer to data related to XR services. The transmission delay requirement of XR data / XR services is high, for example, the delay requirement of uplink XR data can be 30 ms.

[0115] (2) Delay-critical data refers to the minimum value of the remaining time less than a threshold (such as a remaining time threshold (remainingTimeThreshold)). The remaining time can be obtained by counting down the remaining time threshold by the PDCP entity applying (starting or enabling) the discard timer of each data packet, that is, the minimum remaining time is the minimum remaining value of the cached data packet in the discard timer.

[0116] In the embodiments of the present application, the remaining time can also be referred to as the remaining duration or the remaining delay. Accordingly, the remaining time threshold can also be referred to as the remaining duration threshold or the remaining delay threshold. The data packet with a remaining time less than the remaining time threshold can be understood as a data packet with insufficient remaining time (delay). The existing XR standard introduces the reporting of delay information based on data packets, such as reporting the delay-critical data volume of the data packet with a remaining time less than the remaining time threshold through a delay status report (DSR). The delay-critical data volume can also be referred to as delay-sensitive data volume, or can be referred to as delay-critical data volume.

[0117] Optionally, the delay critical data amount can include a delay critical PDCP data amount, a delay critical RLC data amount, etc. The delay critical PDCP data refers to PDCP data whose remaining time of a discard timer is less than a remaining time threshold, if a PDU set discard configuration is not configured. If the PDU set discard configuration is configured, and the PDCP data belongs to a PDU set, and there is data in the PDU set whose remaining time of a discard timer is less than a remaining time threshold before the timer expires, the data of the PDU set is delay critical PDCP data.

[0118] If a certain PDCP SDU is delay critical PDCP SDU, and the corresponding PDCP data PDU has been submitted to the lower layer, the delay critical indication of the PDCP data PDU is provided to the lower layer (such as an RLC entity, etc.).

[0119] Optionally, for reporting the DSR, the terminal device (MAC) can transmit a delay critical PDCP data amount, which includes at least one of the following: delay critical data that has not been constructed into a PDCP data PDU; a PDCP data PDU containing delay critical data that has not been submitted to the lower layer (for example, an RLC layer); a PDCP control PDU; a PDCP SDU to be retransmitted for an AM DRB; or a PDCP data PDU to be retransmitted for an AM DRB.

[0120] In the embodiments of the present application, the delay critical RLC data amount is the data amount of the RLC layer. Optionally, for reporting the DSR, the terminal device (or the MAC in the terminal device) can transmit a delay critical RLC data amount. The delay critical RLC data amount includes at least one of the following: delay critical RLC SDUs and / or delay critical RLC SDU segments that are not contained in an RLC data PDU; an RLC data PDU waiting for initial transmission, and the RLC data PDU contains a delay critical RLC SDU and / or a delay critical RLC SDU segment; an RLC data PDU (RLC AM) waiting for retransmission; an RLC control PDU.

[0121] (3) Status report, used to indicate the reception status of the data packet sent by the sending end at the receiving end. The status report includes acknowledge (ACK) information used to indicate that the reception status is an acknowledge reception, and can also include negative acknowledge (NACK) information used to indicate that the reception status is a negative acknowledge reception.

[0122] According to the ACK information, the received data packets at the receiving end can be determined. According to the NACK information, the unreceived data packets at the receiving end can be determined. In the embodiments of the present application, the receiving state of the unreceived data packets can be referred to as state 1, or unconfirmed receiving state. The receiving state of the received data packets cannot be determined according to the NACK information and the ACK information, and the receiving state of the unreceived data packets cannot be determined, which can be referred to as state 2, or unreceived state. The state 1 and the state 2 can be collectively referred to as unreceived receiving state.

[0123] Optionally, the data packets in the state 1 are the unreceived data packets (e.g., considered as lost) determined by the reassembly timer timeout, or the unreceived data packets determined by the poll (e.g., the SN of the received data packet triggered by the poll is less than RX_Highest_Status, or greater than RX_Next+AM_Window_Size), or the data packets discarded based on the received data packets (e.g., the data packet has been received). The data packets in the state 2 are the unreceived data packets which are not determined as unreceived by the reassembly timer. That is, the state 1 is for the data packets which are confirmed as lost. The state 2 is for the data packets which are not received and not determined as unreceived.

[0124] The premise of the sending of the status report by the receiving end can include the reassembly timer timeout, and / or the poll indication from the opposite end (i.e., the sending end) and the satisfaction of certain sending conditions (e.g., the SN of the polled data packet is less than RX_Highest_Status, or greater than RX_Next+AM_Window_Size). That is, in the case of the reassembly timer timeout, the sending of the status report by the receiving end can be triggered. Alternatively, after the sending end sends the poll indication to the receiving end, if the receiving end satisfies the sending conditions, the sending of the status report by the receiving end can be triggered.

[0125] (4) Poll indication, sent by the sending end to the receiving end, used for requesting the status report, to indicate whether the data packets sent by the sending end are correctly received. The poll indication in the prior art can be referred to as legacy poll, and the condition for triggering the status report can include that the number of newly sent bytes or the number of data packets is greater than or equal to a threshold; there is no data packet in the buffer which needs to be newly transmitted or retransmitted.

[0126] After receiving the probe indication, the receiving end will not immediately send a status report to the sending end, but needs to see whether the SN of the probe data packet meets the condition. For example, in the case of SN x, a status report can be sent in the case of x < RX_Highest_Status, or x >= RX_Next + AM_Window_Size. That is, the receiving end can send a status report for a data packet with an SN less than RX_Highest_Status, or when the window has overflowed, a status report can be sent to feedback the status information of the currently received data packet.

[0127] The RLC status report sent by the receiving end to the sending end can include a status report payload and an RLC control PDU header. The RLC control PDU header includes a data or control (D / C) and a control PDU type (CPT) field. Among them, the SN of the PDU is 12 bits of the status report can refer to FIG. 5A, and the SN of the PDU is 18 bits of the status report can refer to FIG. 5B.

[0128] In the status report shown in FIG. 5A or FIG. 5B, the D / C field occupies 1 bit, which is used to indicate whether it is a control PDU or a data PDU. The CPT field occupies 3 bits, which is used to indicate the type of RLC control PDU. The ACK_SN field can occupy 4 bits, which is used to indicate the SN of the next RLC SDU that has not been received. This RLC SDU is not reported as missing in the status report. When the sending end receives the status report, in addition to the following indications in the status report: (1) NACK_SN RLC SDUs; (2) NACK_SN and sequence number start (SOstart) and sequence number end (SOend) RLC SDUs; (3) NACK_SN and denial range (NACK_range) RLC SDUs; (4) NACK_SN, NACK range, SOstart and SOend RLC SDUs. These RLC SDUs and all RLC SDUs not including ACK_SN have been received. That is, other RLC SDUs less than ACK_SN except the above 4 kinds of RLC SDUs have been correctly received.

[0129] The NACK_SN field occupies 12 bits in FIG. 5A and 18 bits in FIG. 5B, which is used to indicate that the RLC SDU (or RLC SDU segment) with this SN is detected to be discarded at the receiving side.

[0130] In the status report shown in FIG. 5A or FIG. 5B, the E1 field, occupying 1 bit, is used to indicate whether there is a NACK_SN, E1, E2 and E3 following. E1 is 0 indicates that there is no NACK_SN, E1, E2 and E3 following. The E2 field, occupying 1 bit, is used to indicate whether there is a SOstart and SOend following, i.e. whether it is an RLC SDU segment. The interpretation of the E1 field can refer to Table 1 below, and the interpretation of the E2 field can refer to Table 2.

[0131] Table 1

[0132] Table 2

[0133] The SOstart field, occupying 16 bits. The SOstart field (together with the SOend field) is used to indicate that the part (segment) of the RLC SDU with SN as NACK_SN is detected to be discarded. The SOstart field indicates the position of the first byte of the RLC SDU part in the original RLC SDU. That is, the first byte of the original RLC SDU is 0000000000000000, i.e. starts with 0.

[0134] The SOend field, occupying 16 bits. When E3 is 0, the SOend field (together with the SOstart field) indicates that the part (segment) of the RLC SDU with SN as NACK_SN (SOend related SOend) is detected to be discarded. The SOend field indicates the position of the last byte of the RLC SDU part in the original RLC SDU. When E3 is 1, the SOend field indicates that the part of the RLC SDU with SN as NACK_SN+NACK range-1 is detected to be missing.

[0135] The E3 field, occupying 1 bit, is used to indicate whether there is a continuous RLC SDU sequence that has not been received. The interpretation of the E3 field can refer to Table 3, wherein the NACK range field, occupying 8 bits, is used to indicate the number of consecutive RLC SDUs missing from NACK_SN.

[0136] Table 3

[0137] In the prior art, after sending the probe indication, a probe retransmission timer is started. If a status report is received and the status report includes the reception status of the SN of the data packet in the probe indication, the probe retransmission timer is stopped; if the probe retransmission timer expires and the transmission buffer and the retransmission buffer are empty or there is no new data to be sent, the data packet corresponding to the maximum SN and the data packet for which no acknowledgement is received are retransmitted to the underlying layer, and a transmission probe indication is sent.

[0138] The data packet in the probe indication can include a 12-bit SN non-segmented data packet, an 18-bit SN non-segmented data packet, a 12-bit SN segmented data packet, and an 18-bit SN segmented data packet. The schematic diagram of the 12-bit SN non-segmented data packet can refer to FIG. 6A, the schematic diagram of the 18-bit SN non-segmented data packet can refer to FIG. 6B, the schematic diagram of the 12-bit SN segmented data packet can refer to FIG. 6C, and the schematic diagram of the 18-bit SN segmented data packet can refer to FIG. 6D. The SO field occupies 16 bits, and can refer to the description of the SO start field described above, and will not be described here.

[0139] In FIGS. 6A to 6D, the probe (P) field occupies 1 bit, and is used to indicate whether the sending end of the AM RLC entity requests a status report from the opposite AM RLC entity. The interpretation of the P field can refer to Table 4.

[0140] Table 4

[0141] The sequence information (SI) field occupies 2 bits, and is used to indicate whether there is a segmented RLC SDU in the RLC PDU. The interpretation of the SI field can refer to Table 5.

[0142] Table 5

[0143] When the PDU set is discarded, as long as one data packet in the PDU set is a delay-critical data packet, all data packets in the PDU set are delay-critical data packets. The status report with a 12-bit SN has no spare bit to send the probe indication, resulting in that each delay-critical data packet in the PDU set needs to use a new format to send the probe indication, which occupies a large amount of signaling.

[0144] When the delay trigger state report, that is, the SN is greater than the RX_Highest_Status data packet, the receiving end also needs to wait for the reassembly timer to time out to determine the receiving state of the data packet. Therefore, after the sending end sends the probe indication, there may be a delay for the receiving end to determine the receiving state, so the state report cannot be triggered in time. Even if the probe indication is frequently triggered or the state report is triggered in time, the receiving state of the probe data packet cannot be determined.

[0145] In addition, one of the reasons for introducing timely retransmission is that the delay requirement of XR services is relatively high. Since the retransmission delay of the current RLC layer is high, the RLC retransmission is considered to be enhanced for timely retransmission.

[0146] In order to improve the retransmission efficiency of the data packet and improve the effectiveness of data transmission, a communication method is provided. The communication device involved in the communication method can refer to the description of FIG. 1 and FIG. 2. The first device and the second device in the present application can be terminal equipment or network equipment, or can be a device (for example, a chip, or a chip system, or a circuit, or a means, etc.) in the terminal equipment or the network equipment to execute. Specifically, it can be executed by a PDCP entity or an RLC entity in the terminal equipment or the network equipment. The first device can be understood as the sending end of the data packet. In addition to sending the data packet, the first device can also send the probe indication, etc., and can receive the state report to indicate the receiving state of the data packet. The second device can be understood as the receiving end of the data packet, and can also be understood as the sending end of the state report.

[0147] Please refer to FIG. 7, which is a flowchart of a communication method provided by an embodiment of the present application. The communication method includes the following steps:

[0148] S701, the first device determines a first data packet, the first data packet is a second data packet with the largest sequence number, and the remaining time of the second data packet is less than or equal to a remaining time threshold.

[0149] Among them, the second data packet can be the delay critical data described above, or can be other data packets with a remaining time less than or equal to a remaining time threshold. It should be noted that the data packet with a remaining time less than or equal to a remaining time threshold includes the second data packet. That is, the data packet with a remaining time less than or equal to a remaining time threshold can include other data packets in addition to the second data packet. That is, the range of the data packet with a remaining time less than or equal to a remaining time threshold is greater than the range of the second data packet.

[0150] The first data packet is the second data packet with the largest sequence number, i.e., the second data packet includes the first data packet, the remaining time of the first data packet is also less than or equal to the remaining time threshold, and the first data packet is the second data packet sent to the lower layer last. For example, the first device is the PDCP layer, and the first data packet is the second data packet sent to the RLC layer last.

[0151] In some possible examples, the method further includes that the first device determines the first data packet based on a discard configuration of the PDU set. The discard configuration of the PDU set is used to indicate discard based on the PDU set. That is, in the case that one data packet in the PDU set is discarded, all data packets in the PDU set are discarded. For other descriptions of the discard configuration of the PDU set, reference can be made to the description herein, and details are not described herein again. It can be understood that based on the discard configuration of the PDU set, if there is a case that the remaining time of one data packet in the PDU set is less than or equal to the remaining time threshold, the remaining time of all data packets in the PDU set is less than or equal to the remaining time, i.e., in the case that there is one second data packet in the PDU set, all data packets in the PDU set are second data packets.

[0152] In some possible examples, the method further includes that the first device obtains the indication information of the first protocol layer based on the discard configuration of the PDU set. The indication information is used to indicate that, in the case that the data packet of the PDU set is a second data packet, the data packet sent to the second protocol layer last in the PDU set is a first data packet.

[0153] In some possible examples, the method further includes that the protocol layer of the first device can receive different data packets at the same time, and the remaining time of the data packets can be the same. In this case, the remaining time of the data packets is less than or equal to the remaining time threshold at the same time, and the second data packet includes multiple data packets, and the first data packet is the data packet with the largest sequence number in the second data packet.

[0154] In some possible examples, the method further includes that, when the remaining time of the data packet is less than or equal to the remaining time threshold, the data packet is retransmitted. In this case, the data packet in the second data packet is also transmitted, but only the first data packet is added with the first probe indication for retransmission.

[0155] In the method, the first protocol layer can be a PDCP layer, and the second protocol layer can be an RLC layer.

[0156] It can be understood that, based on the discard configuration of the PDU set, if there is one second data packet in the PDU set, all the data packets in the PDU set are second data packets. According to the indication information of the first protocol layer, it can be determined that the first data packet is the second data packet sent to the second protocol layer latest, so that the first data packet in the PDU set can be determined, and the first data packet is the data packet with the largest sequence number sent to the second protocol layer. In this way, the second protocol layer can know that all the data packets in the PDU set are second data packets, and can determine the first data packet in the second data packet, and the first seeking indication can be added in the first data packet, so that the efficiency of the timely retransmission can be improved.

[0157] S702, the first device adds the first seeking indication in the first data packet, and the first seeking indication is used to request the first status report.

[0158] The first status report can refer to the description of the foregoing status report, and includes the receiving status of the data packet. However, in the embodiment of the present application, the data packet sought by the first status report can be any data packet, or can be the receiving status of the second data packet with a sequence number less than or equal to the first data packet, or can be the receiving status of the data packet or the second data packet with a remaining time less than or equal to a remaining time threshold, and the like. That is, the first status report can at least include the receiving status of the first data packet and the receiving status of the second data packet before the first data packet.

[0159] In some feasible examples, the first data packet belongs to a PDU set, and the first seeking indication is used to request the receiving status of the data packet of the PDU set.

[0160] For example, referring to FIG. 8A, FIG. 8A is a schematic diagram of reporting seeking information provided by an embodiment of the present application. As shown in FIG. 8A, the PDU set includes eight data packets SDU1 to SDU8. In the case that SDU1 is a second data packet, each data packet in the PDU set is a second data packet. The first data packet is the second data packet with the largest sequence number, and the first data packet is SDU8. After adding the first seeking indication in the first data packet, the receiving status of each data packet in SDU1 to SDU8 in the PDU set can be requested. It can be understood that, based on the granularity of the PDU set, the first seeking indication is added in one data packet, so that it can be avoided that the first seeking indication is added in each data packet in the PDU set, and signaling can be saved.

[0161] Alternatively, in another feasible example, the first data packet does not belong to the PDU set, and the first seeking indication is used to request the receiving status of the second data packet with a sequence number less than or equal to the first data packet.

[0162] For example, referring to FIG. 8B, FIG. 8B is a schematic diagram of reporting the seeking information according to an embodiment of the present application. As shown in FIG. 8B, there are eight data packets, i.e., SDU1 to SDU8. Among them, SDU1, SDU3, SDU5 and SDU6 are second data packets. The first data packet is the second data packet with the largest sequence number, and the first data packet is SDU6. After adding the first seeking indication in the first data packet, the receiving status of SDU6 and the data packets before SDU6, i.e., the receiving status of SDU1 to SDU6, can be requested. In this way, the first seeking indication is added in the second data packet with the largest sequence number to indicate the receiving status of the data packets before the second data packet, and there is no need to add the seeking indication in each data packet, thereby saving signaling.

[0163] The present application does not limit how to add the first seeking indication in the first data packet. In some examples, the first seeking indication can be a current poll indication. The current poll indication can be understood as the seeking indication defined in the prior art or not using the seeking indication defined in the present application. The seeking indication defined in the prior art can refer to the definition described above, and will not be described here.

[0164] In some feasible examples, the first seeking indication is located in a second protocol layer subheader. The second protocol layer subheader includes a first field, and the first field is used to indicate one of the following: normal seeking, enhanced seeking for a single data packet, and enhanced seeking for a PDU set.

[0165] The second protocol layer subheader is a data packet subheader of the second protocol layer. Adding the first seeking indication of the first data packet can refer to FIG. 9A or FIG. 9B. In FIG. 9A, the first field can be an enhanced poll (EP) field, which is used to indicate the seeking type, as shown in the following table 6:

[0166] Table 6

[0167] In FIG. 9B, the first field can be a D field, which is used to indicate the seeking type, as shown in the following table 7:

[0168] Table 7

[0169] In some feasible examples, the second protocol layer subheader further includes a second field, and the second field is used to indicate whether to send the seeking indication. As shown in FIG. 9B, the second field can be a P field. The description of the P field can refer to the foregoing, as shown in table 4, which is not limited here. It can be understood that whether to send the seeking indication or whether to request the first status report is determined according to the second field, which can improve the flexibility of the indication.

[0170] In some possible examples, when the first field is the first value, the first field is used to indicate the enhanced probe for the PDU set, and the second protocol layer subheader further includes a third field; or when the first field is not the first value, the first field is used to indicate one of the following: the normal probe, the enhanced probe for the single data packet, the enhanced probe for the PDU set, and the second protocol layer subheader does not include the third field.

[0171] The third field is used to indicate a sequence number (PDU set SN) of the PDU set. In this way, the sequence number of the PDU set in the enhanced probe for the PDU set can be determined through the third field.

[0172] Further, in some possible examples, the second protocol layer subheader further includes a fourth field, and the fourth field is used to indicate a sequence number of a data packet in the PDU set that is sent to the second protocol layer latest, and the third field is located after the fourth field.

[0173] The fourth field is used to indicate a sequence number of a data packet in the PDU set that is sent to the second protocol layer latest, and the third field is located after the fourth field. In this way, the sequence number of the first data packet in the PDU set that is sent to the second protocol layer latest can be determined through the fourth field.

[0174] As shown in Table 7 and FIG. 9B, when the first field is 11, it can be determined that the probe type is the enhanced probe for the PDU set, and the fourth field is the sequence number of the PDU set, and the sequence number before the fourth field is the sequence number of the first data packet. As shown in Table 7, when the first field is not 11, and is 00, 01 or 10, it is determined that the probe type is the normal probe, the enhanced probe for the single data packet, or the enhanced probe for the PDU set, and there is no sequence number of the PDU set subsequently, that is, the second protocol layer subheader does not include the third field.

[0175] The application does not limit the probe indication of the normal probe and the enhanced probe, and the following examples are based on the first probe indication being the enhanced probe. In some possible examples, the triggering time of the first status report is less than the triggering time of the third status report. The third status report is triggered by the normal probe. In this way, compared with sending the probe indication of the normal probe, the status report can be received more timely by sending the probe indication of the enhanced probe, which is beneficial to improving the timely retransmission.

[0176] S703, the first device sends, to the second device, a first data packet to which the first probe indication is added.

[0177] Correspondingly, the second device receives the first data packet to which the first probe indication is added by the first device. The first data packet to which the first probe indication is added can be understood as the first data packet carrying the first probe indication.

[0178] In some possible examples, the method can further include: starting, by the first device, the first timer based on sending the first data packet with the first probe indication added. That is, the first timer starts counting when the first data packet with the first probe indication added is sent.

[0179] The first timer is configured to determine whether to resend the first probe indication. It can be understood that, in the case that the first timer expires, if no first status report is received, or the received first status report does not include the reception status of the SN number of the first data packet, the first probe indication can be resent. The resent first probe indication can be carried in a data packet with a remaining time less than or equal to a remaining time threshold, which can be a data packet with the largest SN number among all data packets with a remaining time less than or equal to the remaining time threshold. The first timer is a timer for data packets with a remaining time less than or equal to the remaining time threshold, that is, the first timer is configured to indicate whether to resend the data packet with a remaining time less than or equal to the remaining time threshold. The first timer is started only when the data packet with a remaining time less than or equal to the remaining time threshold carries the first probe indication, or when the data packet with a remaining time less than or equal to the remaining time threshold is retransmitted and the first probe indication is added in the data packet.

[0180] For example, in some possible examples, the method can further include: retransmitting, by the first device, a data packet with a remaining time less than or equal to a remaining time threshold and / or a received reception status not received and / or not discarded, in the case that the first timer expires or a first status report is received. Correspondingly, the second device receives the data packet with a remaining time less than or equal to a remaining time threshold and / or a received reception status not received and / or not discarded. In this way, the data packet with a remaining time less than or equal to a remaining time threshold and / or a received reception status not received and / or not discarded can be retransmitted in time, which facilitates improving the effectiveness of data transmission. The received reception status can include an unconfirmed reception status and an un-received status, as described above. The reception status can be ACK information or NACK information fed back in a status report.

[0181] In some possible examples, the method can further include: determining, by the first device, a third data packet; adding, by the first device, the first probe indication in the third data packet; sending the third data packet with the first probe indication added; and restarting, by the first device, the first timer based on sending the third data packet with the first probe indication added.

[0182] Correspondingly, the second device receives the third data packet with the first probe indication added.

[0183] The sequence number of the third data packet is greater than the sequence number of the first data packet, and the remaining time of the third data packet is less than or equal to the remaining time threshold. As described above, the first timer is used to indicate whether the second data packet with the remaining time less than or equal to the remaining time threshold is retransmitted. It can be understood that, based on sending the first data packet with the added first search indication, after starting the first timer, if it is determined that the sequence number of the third data is greater than the sequence number of the first data packet, and the remaining time of the third data packet is less than or equal to the remaining time threshold, the first search indication can be added in the third data packet, the third data packet with the added first search indication is sent, and the first timer is restarted. In this way, the receiving state of the second data packet before the third data packet, i.e., the receiving state of the second data packet before the first data packet, or even the data packet before the third data packet with the remaining time less than the remaining time threshold, can be searched, and the accuracy of data retransmission can be improved.

[0184] In some possible examples, the method can further include that the first device starts a first prohibition timer based on sending the first data packet with the added first search indication. The first prohibition timer is used to indicate that the data packet with the remaining time less than the threshold is not sent within a first prohibition duration, and the first search indication can be sent in a case where the first prohibition timer is timed out or stopped. That is, in a case where the first prohibition timer is not timed out, if the third data packet is determined, the first search indication is not added in the third data packet, so that the first search indication is not sent, and the third data packet with the added first search indication is not sent. However, in a case where the first prohibition timer is timed out, if the third data packet is determined, the first search indication can be added in the third data packet, and the third data packet with the added first search indication is sent, so as to realize retransmission of the first search indication, and the first timer can also be restarted. Similarly, the first device can also restart the first prohibition timer based on sending the third data packet with the added first search indication. In this way, the first search indication can be prevented from being frequently sent.

[0185] Optionally, the first prohibition duration is less than the timing duration of the first timer. The first prohibition timer can be started at the same time as the first timer, or can be started when a preset duration after the first timer is started arrives, and the like, which is not limited herein.

[0186] In a case where the first timer is restarted, the following step can also be performed: the first device retransmits the data packet with the receiving state not received and / or the remaining time less than or equal to the remaining time threshold and not discarded in a case where the first timer is timed out or the first status report is received. Correspondingly, the second device receives the data packet with the receiving state not received and / or the remaining time less than or equal to the remaining time threshold and not discarded.

[0187] For example, refer to FIG. 10A. FIG. 10A is a schematic diagram of data transmission according to an embodiment of the present application. As shown in FIG. 10A, the first device sends the first data packet with the first seeking indication to the second device, and starts the first timer to seek the receiving status of the first data packet and other data packets. If the third data packet is determined, the first device sends the third data packet with the first seeking indication to the second device, and restarts the first timer to seek the receiving status of the first data packet and the third data packet and other data packets. In the case that the first timer expires or the first status report is received, the first device retransmits the data packets whose receiving status is not confirmed and / or whose remaining time is less than or equal to the remaining time threshold, such as the first data packet and the third data packet.

[0188] In some possible examples, the data packet whose receiving status is not confirmed is determined by the reassembly timer expiration, or is determined based on the sequence number of the inquiry, or is determined based on the data packet that has been received and discarded; and the data packet whose receiving status is not confirmed is the data packet that is not determined by the reassembly timer as not confirmed and not received. Wherein, the receiving status not confirmed can refer to the description of state 1, and the receiving status not confirmed can refer to the description of state 2, which will not be repeated here.

[0189] After the first device (or the sending end) receives the status report sent by the second device (or the receiving end), if it is determined according to the status report that there is a data packet not received, the data packet can be retransmitted. Alternatively, both the data packet whose receiving status is not confirmed and the data packet whose receiving status is not confirmed are retransmitted, and the retransmission number of the data packet is incremented by 1 after retransmission. Alternatively, the data packet whose receiving status is not confirmed is retransmitted, and the retransmission number of the data packet is incremented by 1 after retransmission; the data packet whose receiving status is not confirmed is retransmitted, and the retransmission number of the data packet is not incremented by 1 after retransmission. That is, both the data packet of state 1 and the data packet of state 2 can be retransmitted. Wherein, the data packet of state 1 can be incremented by 1 or not incremented by 1 after retransmission, and the data packet of state 2 can not be incremented by 1 after retransmission. In this way, the retransmission number of the data packet whose receiving status is not confirmed and which is actually discarded can not be increased.

[0190] The present application does not limit the stopping condition of the first timer, which can include the following six first conditions, wherein:

[0191] The first condition is that the first data packet or the third data packet is discarded;

[0192] The second condition is that the second data packet is discarded;

[0193] The third condition is that the data packet whose remaining time is less than or equal to the remaining time threshold is discarded;

[0194] The fourth condition is that the second timer expires;

[0195] fifth, obtaining the reception status of the data packet whose remaining time is less than or equal to the remaining time threshold;

[0196] sixth, receiving the first status report, and the first status report includes the reception status of the first data packet or the third data packet or the second data packet.

[0197] As described above, the data packet whose remaining time is less than or equal to the remaining time threshold includes the second data packet, and the second data includes the first data packet and the third data packet. In the case of satisfying the first condition of the first kind, it indicates that the first data packet or the third data packet in the second data in the data packet whose remaining time is less than or equal to the remaining time threshold is discarded, and the first data packet or the third data packet does not need to be retransmitted, and the first timer can be stopped. In the case of satisfying the second condition of the first kind, it indicates that the second data in the data packet whose remaining time is less than or equal to the remaining time threshold is discarded, and the second data packet does not need to be retransmitted, and the first timer can be stopped. In the case of satisfying the third condition of the first kind, it indicates that the data packet whose remaining time is less than or equal to the remaining time threshold is discarded, and the data packet does not need to be retransmitted, and the first timer can be stopped, so that the data packet whose remaining time is less than or equal to the remaining time threshold is not retransmitted.

[0198] For example, refer to FIG. 10B. FIG. 10B is a schematic diagram of another data transmission provided by the embodiment of the application. As shown in FIG. 10B, the first device sends the first data packet added with the first probing indication to the second device, and starts the first timer to probe the reception status of the data packet such as the first data packet. If the third data packet is determined, the first device sends the third data packet added with the first probing indication to the second device, and restarts the first timer to probe the reception status of the data packet such as the first data packet and the third data packet. If the first data packet, the third data packet or the second data packet is discarded, the first timer is stopped. Or in the case of not shown in FIG. 10B, the reception status of the data packet whose remaining time is less than or equal to the remaining time threshold is received, and the first timer can also be stopped.

[0199] In the embodiments of the present application, the second timer can be a timer started for sending a second probe indication based on a second condition, which can be understood as the aforementioned reorganization timer, i.e., a trigger condition for receiving a status report in the prior art. The second probe indication is used for requesting a second status report, which can be understood as a status report in the prior art. The second condition includes at least one of the following: the number or byte number of newly sent data packets is greater than or equal to a threshold; there is no data packet in the buffer that needs to be newly transmitted or retransmitted. The second timer is not for data packets with a remaining time less than or equal to a remaining time threshold, and the data packets in the second status report include data packets with a remaining time less than or equal to the remaining time threshold, and can also include data packets with a remaining time greater than the remaining time threshold. It can be understood that, in the case of timeout of the second timer, the status report of the data packets with a remaining time less than or equal to the remaining time threshold and the data packets with a remaining time greater than the remaining time threshold is not sent, the first timer can be stopped, the second timer can be restarted, or the data packets that are not discarded or not received can be retransmitted, or even the data packets that are not discarded and not received can be retransmitted.

[0200] It should be noted that the first timer and the second timer in the present application can also be executed separately. That is, the first timer and the second timer can be decoupled, so that the running of the first timer is not affected by the timeout of the second timer. Or the first timer and the second timer can be associated, such as stopping the first timer when the first condition is the timeout of the second timer, so that the running of the first timer is affected by the second timer. The present application does not limit the timing duration of the first timer and the timing duration of the second timer.

[0201] In the case of starting the second timer, the second prohibition timer can also be started. The second prohibition timer is used to indicate that the second probe indication is not sent within a second prohibition duration, and the second probe indication can be sent in the case of timeout of the second prohibition timer. That is, in the case of not timeout of the second prohibition timer, if the second condition is met, the second probe indication is not sent. But in the case of timeout of the second prohibition timer, if the second condition is met, the second probe indication is sent. In this way, the second probe indication can be prevented from being frequently sent.

[0202] Optionally, the second prohibition duration is less than the timing duration of the second timer. The second prohibition timer can be started at the same time as the second timer, or can be started when a preset duration after the second timer is started arrives, etc., which is not limited here. The second prohibition duration can be equal to or different from the first prohibition duration.

[0203] It can be understood that, in the case that the reception status of the data packet with the remaining time less than or equal to the remaining time threshold is acquired, it can be determined that the first probe indication triggers the second device to send the reception status of the data packet, and the first timer can be stopped. In the case that the first status report is received and the first status report includes the reception status of the first data packet or the third data packet, it can be determined that the first probe indication triggers the second device to send the first status report, and the first timer can be stopped.

[0204] It should be noted that the above six first conditions are only examples. In fact, other first conditions or a combination condition of at least two of the above six first conditions, or a combination of one or more of the above six first conditions and other first conditions can be included. For example, the second timer is timed out, and the data packet with the remaining time less than or equal to the remaining time threshold is retransmitted.

[0205] Optionally, in the case that the retransmission number of the data packet is greater than a threshold, it is necessary to indicate to the upper layer that the maximum number of retransmissions has been reached, and the upper layer triggers a radio link failure.

[0206] S704, the second device sends a first status report to the first device, and the first status report is used to indicate the reception status of the data packet. The reception status includes an unreceived reception status, and the unreceived reception status includes an unacknowledged reception status and an unreceived status.

[0207] Correspondingly, the first device receives the first status report of the second device.

[0208] Optionally, in the case that the second device receives the data packet carrying the first probe indication, it is determined that the SN number of the data packet corresponding to the first probe indication is less than RX_Highest_Status, or greater than or equal to RX_Next+AM_Window_Size, or the segmented data packet is received and discarded, the first device is triggered to send the first status report; otherwise, the first status report is delayed until the SN number of the data packet corresponding to the first probe indication is less than RX_Highest_Status, or greater than or equal to RX_Next+AM_Window_Size.

[0209] The first status report can refer to the aforementioned unacknowledged reception status, and will not be limited herein. In some possible examples, the reception status includes an acknowledged reception status. That is, the reception status of the data packet indicated in the first status report is either the unacknowledged reception status or the acknowledged reception status. In other possible examples, the reception status does not include the acknowledged reception status. The acknowledged reception status can be understood as the reception status of the data packet corresponding to the ACK information. That is, the second device can only report the reception status of the unacknowledged data packet. Alternatively, the second device can report the reception status of the unacknowledged data packet, and can also report the acknowledged reception status of the data packet.

[0210] It can be understood that in the method shown in FIG. 7, the first seeking indication is added in the first data packet, and the first seeking indication is used to request the first status report. The first data packet is the second data packet with the largest sequence number, and the remaining time of the second data packet is less than or equal to the remaining time threshold. In this way, the seeking indication can be reported for the data packet with the largest sequence number among the data packets with the remaining time less than or equal to the remaining time threshold (for example, delay critical data, etc.), signaling can be saved, the retransmission efficiency of such data packets can be improved, and the effectiveness of data transmission can be improved.

[0211] Taking the first protocol layer as the PDCP layer, the second protocol layer as the RLC layer, and the second data as delay critical data packets as an example. The PDCP layer determines that the data packet is a delay critical data packet, and in the case that the data packet is a data packet in the PDU set and the discard configuration of the PDU set, the PDCP layer sends indication information to the RLC layer to indicate that the data packet is a delay critical data packet and the data packet is the latest submitted data packet in the PDU set. The RLC sending end receives the indication and determines the delay critical data packet, and adds a first seeking indication in the delay critical data packet. The first seeking indication is used to inquire the reception status of the data packet corresponding to the PDU set. The RLC receiving end receives the first seeking indication, and returns the reception status of the data packet in the PDU set. If the data packet has been received, the ACK information of the data packet can be returned to indicate that the reception status of the data packet is the acknowledged reception status. If the data packet has not been received, the NACK information of the data packet can be returned to indicate that the reception status of the data packet is the unacknowledged reception status.

[0212] Optionally, the method further comprises: the first device updating a state variable of the sending window based on the receiving state of the data packet in the status report. Correspondingly, the second device updates a state variable of the receiving window based on the receiving state of the data packet in the status report. The status report comprises a first status report and a second status report. The state variable of the receiving window and the state variable of the sending window can refer to the description of FIG. 3 and FIG. 4, which will not be repeated here. In this way, the state variable of the receiving window or the sending window is updated based on the receiving state of the data packet in the status report, which facilitates improving the accuracy of data retransmission.

[0213] Optionally, the method further comprises the following steps: the first device determines the discarded data packet; and the first device updates the state variable of the sending window according to the discarded data packet. For example, after the PDCP layer discards the data packet according to the discard timer, the PDCP layer indicates the RLC that the data packet is discarded, so that the RLC layer can discard the data packet. In the case where the SN number of the discarded data packet is equal to TX_Next_Ack, TX_Next_Ack is updated to the SN number of the retransmission data packet, which is a data packet that is not discarded and has not received an acknowledgement.

[0214] The above describes the method of the embodiments of the present application in detail, and the device of the embodiments of the present application is provided below.

[0215] Please refer to FIG. 11, which is a structural schematic diagram of a communication device provided by an embodiment of the present application. As shown in FIG. 11, the communication device can comprise a transceiver unit 1001 and a processing unit 1002. The transceiver unit 1001 can be a device with input (reception) or output (transmission) of signals, and is used for signal transmission with other devices or other components in the device.

[0216] The processing unit 1002 can be a device with processing function, and can comprise one or more processors. The processor can be a general-purpose processor or a special-purpose processor, etc. The processor can be a baseband processor or a central processing unit. The baseband processor can be used for processing communication protocols and communication data, and the central processing unit can be used for controlling the device (such as a host node, a relay node or a chip, etc.), executing software programs, and processing data of the software programs.

[0217] The communication apparatus can be the first apparatus or the second apparatus. In the present application, the first apparatus and the second apparatus can be terminal devices or network devices, or can be devices (for example, chips, or chip systems, or circuits, or means, etc.) in terminal devices or network devices to perform. The first apparatus can be understood as a sending end of a data packet, and the first apparatus can send a probe indication, etc. in addition to sending the data packet, and can receive a status report to indicate a receiving status of the data packet. The second apparatus can be understood as a receiving end of the data packet, and the second apparatus can also be understood as a sending end of the status report.

[0218] When the communication apparatus is the first apparatus, wherein:

[0219] a processing unit configured to determine a first data packet, the first data packet being a second data packet with a largest sequence number, and a remaining time of the second data packet being less than or equal to a remaining time threshold;

[0220] a transceiving unit configured to add a first probe indication in the first data packet, wherein the first probe indication is used to request a first status report;

[0221] The transceiving unit is further configured to send the first data packet with the first probe indication added.

[0222] In some possible examples, the processing unit is further configured to start a first timer based on sending the first data packet with the first probe indication added.

[0223] In some possible examples, the processing unit is further configured to determine a third data packet, wherein a sequence number of the third data packet is greater than a sequence number of the first data packet, and a remaining time of the third data packet is less than or equal to the remaining time threshold, add the first probe indication in the third data packet, and restart the first timer based on sending the third data packet with the first probe indication added.

[0224] In some possible examples, the transceiving unit is further configured to retransmit a data packet with an un-received receiving status and / or a remaining time less than or equal to the remaining time threshold and not discarded, in a case that the first timer is timed out or the first status report is received.

[0225] In some possible examples, the processing unit is further configured to stop the first timer based on a first condition.

[0226] In some possible examples, the first condition comprises at least one of the following: the first data packet or the third data packet is discarded; the second data packet is discarded; a data packet with a remaining time less than or equal to the remaining time threshold is discarded; a second timer is timed out; a reception status of a data packet with a remaining time less than or equal to the remaining time threshold is acquired; the first status report is received, and the first status report comprises a reception status of the first data packet or the third data packet or the second data packet; wherein the second timer is a timer started based on a second condition sending a second probe indication, the second probe indication being used to request a second status report; and the second condition comprises at least one of the following: a number of newly sent data packets or a number of newly sent bytes is greater than or equal to a threshold; and there is no data packet in a buffer that needs to be newly transmitted or retransmitted.

[0227] In some possible examples, the processing unit is further configured to determine the first data packet based on a discard configuration of a protocol data unit (PDU) set; wherein the discard configuration of the PDU set is used to indicate discarding based on the PDU set.

[0228] In some possible examples, the first data packet belongs to the PDU set, and the first probe indication is used to request a reception status of a data packet of the PDU set.

[0229] In some possible examples, the transceiver is further configured to acquire, based on the discard configuration of the PDU set, indication information of a first protocol layer; wherein the indication information is used to indicate, in a case that a data packet of the PDU set is the second data packet, a data packet of the PDU set that is transmitted to a second protocol layer latest is the first data packet.

[0230] In some possible examples, the first probe indication is located in a second protocol layer subheader, and the second protocol layer subheader comprises a first field, the first field being used to indicate one of the following: a normal probe, an enhanced probe for a single data packet, and an enhanced probe for the PDU set.

[0231] In some possible examples, the second protocol layer subheader further comprises a second field, the second field being used to indicate whether a probe indication is transmitted.

[0232] In some possible examples, in a case that the first field is a first value, the first field is used to indicate the enhanced probe for the PDU set, and the second protocol layer subheader further comprises a third field; or, in a case that the first field is not the first value, the first field is used to indicate one of the following: the normal probe, the enhanced probe for the single data packet, and the enhanced probe for the PDU set, and the second protocol layer subheader does not comprise the third field; wherein the third field is used to indicate a sequence number of the PDU set.

[0233] In some possible examples, the second protocol layer subheader further includes a fourth field, the fourth field being used to indicate a sequence number of a data packet sent to the second protocol layer latest in the PDU set, the third field being located after the fourth field.

[0234] In some possible examples, the first probe indication is an enhanced probe, a triggering time of the first status report is less than a triggering time of a third status report, the third status report being triggered by a normal probe.

[0235] When the communication device is a second device, wherein:

[0236] The transceiver is configured to receive a first data packet with a first probe indication added.

[0237] The transceiver is configured to send a first status report, the first status report being used to indicate a receiving status of a data packet, the receiving status including an unreceived receiving status, the unreceived receiving status including an unacknowledged receiving status and an unreceived status.

[0238] In some possible examples, the receiving status includes an acknowledged receiving status.

[0239] In some possible examples, the unacknowledged receiving status is a data packet determined to be unacknowledged receiving by a reassembly timer timeout, or a data packet determined to be unacknowledged receiving based on a sequence number of a probe, or a data packet discarded based on having been received; the unreceived status is a data packet unacknowledged receiving and unreceived.

[0240] In some possible examples, the transceiver is further configured to receive a data packet in the unreceived receiving status and / or a remaining time of the data packet being less than or equal to the remaining time threshold.

[0241] In some possible examples, the first data packet belongs to a protocol data unit (PDU) set, the first probe indication being used to request a receiving status of a data packet of the PDU set.

[0242] In some possible examples, the first probe indication is located in a second protocol layer subheader, the second protocol layer subheader including a first field, the first field being used to indicate one of: a normal probe, an enhanced probe for a single data packet, an enhanced probe for the PDU set.

[0243] In some possible examples, the second protocol layer subheader further includes a second field, the second field being used to indicate whether to send a probe indication.

[0244] In some possible examples, when the first field is a first value, the first field is used to indicate an enhanced probe type of the PDU set, and the second protocol layer subheader further includes a third field; or when the first field is not the first value, the first field is used to indicate one of the following: a normal probe type, an enhanced probe type for a single data packet, an enhanced probe type for the PDU set, and the second protocol layer subheader does not include the third field; and the third field is used to indicate a sequence number of the PDU set.

[0245] In some possible examples, the second protocol layer subheader further includes a fourth field, and the fourth field is used to indicate a sequence number of a data packet that is sent to the second protocol layer latest in the PDU set, and the third field is located after the fourth field.

[0246] In some possible examples, the first probe indication is an enhanced probe, the trigger time of the first status report is less than the trigger time of a third status report, and the third status report is triggered by a normal probe.

[0247] The implementation of the transceiver unit 1001 and the processing unit 1002 can refer to the related description of the method embodiment shown in FIG. 7, and details are not described herein.

[0248] Referring to FIG. 12, FIG. 12 is a structural schematic diagram of another communication apparatus provided in an embodiment of the present application. As shown in FIG. 12, the communication apparatus can include a processor 111, a memory 112, and a communication interface 113, and the processor 111, the memory 112, and the communication interface 113 are connected to each other through a bus 114.

[0249] The processor 111 can also be referred to as a processing unit, and can implement certain control functions. The memory 112 is any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer. The communication interface 113 is used to receive and send data and / or signaling.

[0250] Optionally, the communication apparatus can be used to execute any method described in FIG. 7 in the embodiments of the present application.

[0251] The communication apparatus described in the above embodiments can be a terminal device or a network device, but the scope of the apparatus described in the present application is not limited to this, and the structure of the communication apparatus can not be limited to FIG. 12. The communication apparatus can be an independent device, such as a module, a unit, an element, a circuit, a chip, or an interface, or can be a part of a larger device, and is used to implement the method described in the method embodiment.

[0252] Please refer to FIG. 13, which is a structural schematic diagram of a terminal device provided in an embodiment of the present application. For ease of illustration, FIG. 13 only shows main components of the terminal device. As shown in FIG. 13, the terminal device includes a processor, a memory, a control circuit, an antenna, and an input / output device. The processor is mainly used for processing communication protocols and communication data, controlling the entire terminal device, executing software programs, and processing data of the software programs. The memory is mainly used for storing software programs and data. The radio frequency circuit is mainly used for conversion between baseband signals and radio frequency signals and processing of the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touch screen, a display screen, a keyboard, etc., is mainly used for receiving data input by a user and outputting data to the user.

[0253] When the terminal device is powered on, the processor can read the software programs in the storage unit, parse and execute instructions of the software programs, and process data of the software programs. When data needs to be transmitted wirelessly, the processor performs baseband processing on the data to be transmitted, and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit processes the baseband signal to obtain a radio frequency signal, and transmits the radio frequency signal in the form of electromagnetic waves through the antenna. When data is transmitted to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna. The radio frequency signal is further converted into a baseband signal, and the baseband signal is output to the processor. The processor converts the baseband signal into data and processes the data.

[0254] For ease of illustration, FIG. 13 only shows one memory and one processor. In an actual terminal device, multiple processors and memories can exist. The memory can also be referred to as a storage medium or a storage device, etc., and the embodiments of the present application do not limit this.

[0255] In one embodiment, the antenna is configured to perform operations performed by the transceiver 1001 in the above embodiments. The processor is configured to perform operations performed by the processing unit 1002 in the above embodiments. The terminal device can also be configured to perform the method performed by the terminal device in the method embodiment of FIG. 7, and details are not described herein again.

[0256] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program or instructions. When the computer program or instructions are executed by a processor, the computer program or instructions can implement the related processes in the communication method provided in the above method embodiments.

[0257] The embodiments of the present application also provide a computer program product, which, when running on a computer or a processor, causes the computer or the processor to execute one or more steps in any of the above communication methods. The constituent modules of the devices involved in the above description can be stored in a computer readable storage medium if they are realized in the form of software function units and sold or used as independent products.

[0258] The embodiments of the present application further provide a chip system, comprising at least one processor and a communication interface, the communication interface and the at least one processor are interconnected through a line, and the at least one processor is configured to run computer programs or instructions to execute part or all of the steps of any one of the embodiments of the method shown in FIG. 7. The chip system can be composed of a chip, or can include a chip and other discrete devices.

[0259] The embodiments of the present application further provide a communication system, which comprises a terminal device and a network device, or units therein, such as a transmission object, and the specific description can refer to any one of the communication methods shown in FIG. 7.

[0260] It should be understood that the memory mentioned in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a hard disk drive (HDD), a solid-state drive (SSD), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced SDRAM (ESDRAM), synch link DRAM (SLDRAM) and direct ram bus RAM (DR RAM). The memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures and capable of being accessed by a computer, but is not limited to this. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing the storage function, used for storing program instructions and / or data.

[0261] It should also be understood that the processor mentioned in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor or can be any conventional processor.

[0262] It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, the memory (storage module) is integrated in the processor.

[0263] It should be noted that the memory described herein is intended to include, but not limited to, these and any other suitable type of memory.

[0264] It should be understood that the size of the sequence number of each process described above in various embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0265] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments provided herein can be realized in electronic hardware, or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0266] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0267] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0268] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or can be physically present as individual units, or two or more units can be integrated in one unit.

[0269] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that make contributions to the technology or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk, and various media that can store program codes.

[0270] The steps in the embodiment method of the present application can be adjusted, combined and deleted in sequence according to actual needs. The steps of each embodiment can be partially executed (for example, the terminal device can not execute the steps executed by the terminal device in the above embodiments). The execution order of different steps can be changed. The embodiments described herein can be combined with other embodiments, different embodiments can be combined with each other, and different steps of different embodiments in this paper can be combined.

[0271] The modules / units in the embodiment device of the present application can be combined, divided and deleted according to actual needs.

[0272] In this paper, the phrase "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, and is not an independent or alternative embodiment that is not mutually exclusive with other embodiments.

[0273] The terms "first", "second", "third", "fourth" and the like (if any) in the embodiments of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0274] In the embodiments of the present application, "comprising" can be a containing relationship or can be an equal relationship. For example, A includes B, which can be that A contains B and other contents, or A and B are the same content.

[0275] In the description of the present application, unless otherwise specified, " / " represents that the objects before and after the " / " are in an "or" relationship, for example, A / B can represent A or B; "and / or" in the present application is only a description of the relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent: A exists alone, A and B exist together, and B exists alone, of which A and B can be singular or plural. And in the description of the present application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or the like means any combination of the items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

[0276] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A communication method characterized by comprising: comprising: determining a first data packet; wherein the first data packet is a second data packet with a largest sequence number, and a remaining time of the second data packet is less than or equal to a remaining time threshold; adding a first probe indication in the first data packet; wherein the first probe indication is used to request a first status report; sending the first data packet with the first probe indication added.

2. The method of claim 1, wherein, further comprising: starting a first timer based on sending the first data packet with the first probe indication added.

3. The method of claim 2, wherein, further comprising: determining a third data packet; wherein a sequence number of the third data packet is larger than a sequence number of the first data packet, and a remaining time of the third data packet is less than or equal to the remaining time threshold; adding the first probe indication in the third data packet; sending the third data packet with the first probe indication added; restarting the first timer based on sending the third data packet with the first probe indication added.

4. The method according to claim 2 or 3, characterized in that, further comprising: in a case that the first timer expires or the first status report is received, retransmitting a data packet with a receiving status not received and / or a remaining time less than or equal to the remaining time threshold and not discarded.

5. The method according to any one of claims 2 to 4, characterized in that, further comprising: stopping the first timer based on a first condition.

6. The method of claim 5, wherein, the first condition comprises at least one of: the first data packet or the third data packet is discarded; the second data packet is discarded; a data packet with a remaining time less than or equal to the remaining time threshold is discarded; a second timer expires; a receiving status of a data packet with a remaining time less than or equal to the remaining time threshold is obtained; the first status report is received, and the first status report comprises a receiving status of the first data packet or the third data packet or the second data packet; wherein the second timer is a timer started based on a second probe indication sent based on a second condition, and the second probe indication is used to request a second status report; the second condition comprises at least one of: a number of newly sent data packets or a number of bytes greater than or equal to a threshold; there is no data packet in a buffer that needs to be newly sent or retransmitted.

7. The method according to any one of claims 1 to 6, characterized in that, further comprising: determining the first data packet based on a discard configuration of a protocol data unit (PDU) set; wherein the discard configuration of the PDU set is used to indicate discarding based on the PDU set.

8. The method of claim 7, wherein, the first data packet belongs to the PDU set, and the first probe indication is used to request a receiving status of a data packet of the PDU set.

9. The method of claim 7, wherein, further comprising: obtaining indication information of a first protocol layer based on the discard configuration of the PDU set; wherein the indication information is used to indicate, in a case that a data packet of the PDU set is the second data packet, a data packet of the PDU set that is sent to a second protocol layer latest is the first data packet.

10. The method according to any one of claims 1 to 9, characterized in that, the first probe indication is located in a second protocol layer subheader, and the second protocol layer subheader comprises a first field, and the first field is used to indicate one of: a normal probe, an enhanced probe for a single data packet, and an enhanced probe for the PDU set.

11. The method of claim 10, wherein, the second protocol layer subheader further comprises a second field, and the second field is used to indicate whether to send a probe indication.

12. The method of claim 10, wherein In a case where the first field is a first value, the first field is used to indicate an enhanced probe for the PDU set, and the second protocol layer subheader further comprises a third field; or In a case where the first field is not the first value, the first field is used to indicate one of a normal probe, an enhanced probe for a single data packet, and an enhanced probe for the PDU set, and the second protocol layer subheader does not comprise the third field. The third field is used to indicate a sequence number of the PDU set.

13. The method of claim 12, wherein, The second protocol layer subheader further comprises a fourth field, the fourth field is used to indicate a sequence number of a data packet in the PDU set that is sent to the second protocol layer latest, and the third field is located after the fourth field.

14. The method according to any one of claims 1 to 13, characterized in that, The first probe indication is an enhanced probe, and a trigger time of the first status report is less than a trigger time of a third status report, and the third status report is triggered by a normal probe.

15. A method of communication, comprising: Comprise: Receiving a first data packet with a first probe indication added; Sending a first status report, the first status report is used to indicate a receiving status of a data packet, and the receiving status comprises an unreceived receiving status, and the unreceived receiving status comprises an unacknowledged receiving status and an unreceived status.

16. The method of claim 15, wherein, The receiving status comprises an acknowledged receiving status.

17. The method of claim 15, wherein The unacknowledged receiving status data packet is a data packet determined to be unacknowledged receiving by a reassembly timer timeout, or a data packet determined to be unacknowledged receiving based on a sequence number of a poll, or a data packet discarded based on having been received; The unreceived status data packet is a data packet determined to be unreceived and unacknowledged receiving by the reassembly timer.

18. The method of any one of claims 15-17, wherein, Further comprise: Receiving a data packet with an unreceived and / or an undiscarded remaining time less than or equal to a remaining time threshold.

19. The method according to any one of claims 15 to 18, characterized in that, The first data packet belongs to a protocol data unit (PDU) set, and the first probe indication is used to request a receiving status of a data packet of the PDU set.

20. The method of claim 19, wherein, The first probe indication is located in a second protocol layer subheader, and the second protocol layer subheader comprises a first field, and the first field is used to indicate one of a normal probe, an enhanced probe for a single data packet, and an enhanced probe for the PDU set.

21. The method of claim 20, wherein, The second protocol layer subheader further comprises a second field, and the second field is used to indicate whether to send a probe indication.

22. The method of claim 20, wherein In a case where the first field is a first value, the first field is used to indicate an enhanced probe type for the PDU set, and the second protocol layer subheader further comprises a third field; or In a case where the first field is not the first value, the first field is used to indicate one of a normal probe type, an enhanced probe type for a single data packet, and an enhanced probe type for the PDU set, and the second protocol layer subheader does not comprise the third field. The third field is used to indicate a sequence number of the PDU set.

23. The method of claim 21, wherein, The second protocol layer subheader further comprises a fourth field for indicating a sequence number of a data packet latest sent to the second protocol layer in the PDU set, the third field being located after the fourth field.

24. The method of any one of claims 15-23, wherein, The first probing indication is an enhanced probing, and a triggering time of the first status report is less than a triggering time of a third status report, the third status report being triggered by a normal probing.

25. A communications device, characterized by A computer program product comprising instructions for performing the method of any of claims 1-24.

26. A communications device, characterized by A processor for executing instructions stored in a memory, the instructions when executed implementing the communication method of any of claims 1-24.

27. A computer readable storage medium or computer program product, characterized in that, An instruction or computer program that, when executed by a processor, causes the method of any of claims 1-24 to be performed.

28. A chip or chip system, characterized by At least one processor for recalling and executing instructions or computer programs stored in a memory, such that a communication device installed with a chip or chip system performs the method of any of claims 1-24.

29. A communication system, characterized by A first device for performing the method of any of claims 1-14 and a second device for performing the method of any of claims 15-24.

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