Data retransmission methods, apparatus, equipment and storage media

Abstract

This application discloses a data retransmission method, apparatus, device, and storage medium, belonging to the field of communications. The method is executed by a first device, which operates a first intermediate access control (MAC) entity and a first packet data aggregation protocol (PDCP) entity. The method includes: when the first MAC entity determines that data has been lost in a Hybrid Automatic Repeat Request (HARQ) transmission, the first MAC entity triggers the first PDCP entity to perform an Automatic Repeat Request (ARQ) retransmission on the data. This method, by having the first MAC entity trigger the first PDCP entity to perform ARQ retransmission, achieves fast data retransmission and reduces data retransmission latency.

Description

Technical Field

[0001] This application relates to the field of communications, and in particular to a data retransmission method, apparatus, device, and storage medium. Background Technology

[0002] Hybrid Automatic Repeat ReQuest (HARQ) technology is a data transmission technology that combines forward error correction and Automatic Repeat ReQuest (ARQ). The forward error correction function of HARQ retransmission is completed by the Medium Access Control (MAC) layer and the Physical (PHY) layer together.

[0003] In related technologies, if the maximum number of HARQ retransmissions is reached and the data is still not successfully transmitted, the receiver's Radio Link Control (RLC) layer sends a Status Protocol Data Unit (PDU) to the sender's RLC layer. Upon receiving the Status PDU, the sender's RLC layer knows that the data has been lost and then retransmits the data using ARQ in the RLC's Acknowledged Mode (AM).

[0004] However, the ARQ retransmission latency of RLC's AM mode is 4-5 times that of HARQ's maximum retransmission time. How to reduce data retransmission latency is a problem that needs to be solved. Summary of the Invention

[0005] This application provides a data retransmission method, apparatus, device, and storage medium. The technical solution is as follows:

[0006] According to one aspect of this application, a data retransmission method is provided, the method being executed by a first device, the first device running a first MAC entity and a first Packet Data Convergence Protocol (PDCP) entity, the method comprising:

[0007] If the first MAC entity determines that data has been lost during HARQ transmission, the first MAC entity triggers the first PDCP entity to retransmit the data via ARQ.

[0008] According to one aspect of this application, a data retransmission method is provided, the method being executed by a second device having a second MAC entity, the method comprising:

[0009] If the second MAC entity determines that data has been lost in the HARQ transmission, the second MAC entity sends a data loss notification to the first MAC entity of the first device.

[0010] According to one aspect of this application, a data retransmission apparatus is provided, the apparatus comprising:

[0011] The triggering module is used to trigger the first PDCP entity to retransmit the data in ARQ when the first MAC entity determines that data has been lost in HARQ transmission.

[0012] According to one aspect of this application, a data retransmission apparatus is provided, the apparatus comprising:

[0013] The sending module is configured to send a data loss notification to the first MAC entity of the first device when the second MAC entity determines that data has been lost in the HARQ transmission.

[0014] According to another aspect of the present disclosure, a terminal is provided, the terminal comprising:

[0015] processor;

[0016] A transceiver connected to the processor;

[0017] The processor is configured to load and execute executable instructions to implement the data retransmission methods described above.

[0018] According to another aspect of the present disclosure, a network device is provided, the network device comprising:

[0019] processor;

[0020] A transceiver connected to the processor;

[0021] The processor is configured to load and execute executable instructions to implement the data retransmission methods described above.

[0022] According to another aspect of the present disclosure, a chip is provided that includes programmable logic circuitry and / or program instructions, which, when the chip is running, are used to implement the data retransmission method as described above.

[0023] According to another aspect of the present disclosure, a computer-readable storage medium is provided that stores at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the data retransmission method as described above.

[0024] According to another aspect of the present disclosure, a computer program product is provided, the computer program product including computer instructions stored in a computer-readable storage medium; a processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the data retransmission method as described above.

[0025] The technical solutions provided in this application embodiment may have the following beneficial effects:

[0026] This method enables the first PDCP entity to retransmit the data in ARQ after the first MAC entity determines that data has been lost in HARQ transmission. This achieves rapid initiation of ARQ retransmission of data, reduces the latency of data retransmission, and improves communication efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a wireless communication system provided in one embodiment of this application;

[0028] Figure 2 This is a schematic diagram illustrating the protocol hierarchy of HARQ and ARQ technologies in related technologies;

[0029] Figure 3 This is a flowchart of a data retransmission method provided in one embodiment of this application;

[0030] Figure 4 This is the service plane protocol stack architecture of a data retransmission method provided in one embodiment of this application;

[0031] Figure 5 This is a schematic diagram of the structure of a MAC PDU provided in one embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the segmentation and reassembly function of the first MAC entity in a data retransmission method provided in an embodiment of this application;

[0033] Figure 7 This is a flowchart of a data retransmission method provided in one embodiment of this application;

[0034] Figure 8 This is a schematic diagram illustrating the correspondence between HARQ process number and MACSN, ​​PDCP SN in a data retransmission method provided in one embodiment of this application;

[0035] Figure 9 This is a schematic diagram of the data retransmission method provided in one embodiment of this application;

[0036] Figure 10 This is a flowchart of a data retransmission method provided in one embodiment of this application;

[0037] Figure 11 This is a schematic diagram of the data retransmission method provided in one embodiment of this application;

[0038] Figure 12 This is a flowchart of a data retransmission method provided in one embodiment of this application;

[0039] Figure 13 This is a schematic diagram of the data retransmission method provided in one embodiment of this application;

[0040] Figure 14 This is a schematic diagram of a transmission scenario where the data retransmission method of this application is not required for optimization;

[0041] Figure 15 This is a schematic diagram of an optimization method for QoS non-compliance in a data retransmission method provided in one embodiment of this application;

[0042] Figure 16 This is a schematic diagram illustrating the principle of the active synchronization window in the case of QoS non-compliance in a data retransmission method provided in one embodiment of this application;

[0043] Figure 17 This is a flowchart of a data retransmission method provided in one embodiment of this application;

[0044] Figure 18 This is a block diagram of a data retransmission apparatus provided in one embodiment of this application;

[0045] Figure 19 This is a block diagram of a data retransmission apparatus provided in one embodiment of this application;

[0046] Figure 20 This is a schematic diagram of the structure of a terminal provided in one embodiment of this application;

[0047] Figure 21 This is a block diagram of a network device provided in one embodiment of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0049] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0050] Figure 1A schematic diagram of a wireless communication system provided in one embodiment of this application is shown. Terminal 10 may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem, as well as various forms of user equipment (UE), mobile stations (MS), etc. For ease of description, in this embodiment, the devices mentioned above are collectively referred to as terminals.

[0051] Network device 20 is a device deployed in an access network to provide wireless communication functionality to terminal 10. Network device 20 may include various forms of macro base stations, micro base stations, relay stations, access points, etc. In systems employing different wireless access technologies, the name of the device with network device functionality may differ; for example, in a 5G NR system, it is called an access network device, gNodeB, or gNB. As communication technologies evolve, the name "network device" may change. For ease of description, in this embodiment, the aforementioned device providing wireless communication functionality to terminal 10 is collectively referred to as a network device.

[0052] The "5G NR system" in this disclosure can also be referred to as a 5G system or an NR system, but those skilled in the art will understand its meaning. The technical solutions described in this disclosure are applicable to 5G NR systems and also to subsequent evolution systems of 5G NR systems.

[0053] In the forward error correction mechanism of HARQ, the sender transmits the frame sequence sequentially. For HARQ process frames without errors, the receiver sends an acknowledgment (ACK); for HARQ process frames with errors, the receiver sends a negative ACK (NACK). For the j-th frame of HARQ process frames with errors, the receiver sends a NACK. j The sender retransmits the j-th HARQ process frame. The receiver continues to receive other frames as usual, and after receiving the retransmitted j-th HARQ process frame, it sorts them in the correct order.

[0054] Figure 2 The diagram illustrates the protocol layer distribution of HARQ and ARQ technologies in related technologies. As shown in the diagram, the MAC layer is used for HARQ transmission, the RLC layer is used for data segmentation and ARQ retransmission, and the RLC layer and PDCP layer together complete the reordering of retransmitted frames.

[0055] In related technologies, when the HARQ retransmission count reaches its maximum and data transmission still fails, the sender's MAC layer knows the data has been lost, but the sender's RLC layer is unaware of this. Only after the sender's RLC layer successfully receives the Status PDU sent by the receiver's RLC layer will it attempt to retransmit the ARQ data in AM mode. The ARQ retransmission latency in this AM mode is as high as 4-5 times the maximum HARQ retransmission count, resulting in reduced data retransmission efficiency.

[0056] However, in the data retransmission method described in this application, the MAC layer of the sender can quickly initiate ARQ retransmission when it confirms that data has been lost in HARQ transmission, which greatly reduces the latency of data retransmission.

[0057] Figure 3 A flowchart of a data retransmission method according to an embodiment of this application is shown. The method is executed by a first device and may include the following steps:

[0058] In step 220, if the first MAC entity determines that data has been lost during HARQ transmission, the first MAC entity triggers the first PDCP entity to retransmit the data via ARQ.

[0059] The first device is the sender of HARQ transmission. This first device runs a first MAC entity and a first PDCP entity. The MAC entity is used to implement the protocol stack corresponding to the MAC layer, and the PDCP entity is used to implement the protocol stack corresponding to the PDCP layer.

[0060] For example, if the number of HARQ retransmissions of data reaches the maximum and a NACK is still received, the first MAC entity determines that the data has been lost; or, if a data loss notification is received from the second MAC entity of the second device, the first MAC entity determines that the data has been lost, and the second device is the receiver of the HARQ transmission; or, if the number of HARQ retransmissions of data reaches the maximum and a retransmission schedule or new transmission schedule is received from the second device, the first MAC entity determines that the data has been lost, and the second device is both the receiver and the scheduler of the HARQ transmission.

[0061] That is, in at least one of the three scenarios, the first MAC entity determines that data has been lost during HARQ transmission.

[0062] Scenario 1: The first MAC entity learns of a data transmission error through the NACK feedback from HARQ, and then corrects it through HARQ retransmission; when the maximum number of HARQ retransmissions is reached but a NACK is still received, the first MAC entity determines that data has been lost in the HARQ transmission.

[0063] Scenario 2: The second device (receiver) receives incorrect data and sends a NACK to the first device (sender); the first device decodes the NACK into an ACK. Since the first device believes the data has been transmitted correctly, it directly initiates the transmission of new data. In this case, the second MAC entity of the second device can proactively notify the first MAC entity of the first device that data has been lost; that is, upon receiving a data loss notification from the second MAC entity of the second device, the first MAC entity determines that data has been lost during HARQ transmission.

[0064] Scenario 3: The receiver (second device) is also the scheduler. The second device can directly initiate retransmission or newtransmission scheduling for unsuccessfully received data based on the correctness of the received data. If data transmission fails after reaching the maximum number of HARQ retransmissions, the first MAC entity of the first device proactively notifies the first PDCP entity of the first device that the data has been lost. That is, if the number of HARQ retransmissions reaches the maximum and the first MAC entity receives retransmission or newtransmission scheduling from the second device, the first MAC entity determines that data loss has occurred during HARQ transmission.

[0065] In some embodiments, if the first MAC entity determines that data has been lost in HARQ transmission in any of the above scenarios, the first MAC entity triggers the first PDCP entity to retransmit the lost data via ARQ.

[0066] In some embodiments, the first MAC entity sends a data retransmission notification to the first PDCP entity; the first PDCP entity performs ARQ retransmission of the data based on the data retransmission notification.

[0067] In some embodiments, the data retransmission notification carries index information of the data. After the first MAC entity sends the data retransmission notification to the first PDCP entity, the first PDCP entity identifies the data based on the data index information and provides the data to the first MAC entity; the first MAC entity then retransmits the data based on the currently available authorization. The currently available authorization is used to indicate the currently available transmission resources, or to indicate the amount of data that the currently available transmission resources can transmit.

[0068] In some embodiments, the index information includes at least the HARQ procedure number of the data and the carrier sequence number of the data.

[0069] In some embodiments, if the amount of currently available authorized data is greater than the amount of data, the first MAC entity packages and transmits all or part of the data and the next data; if the amount of currently available authorized data is equal to the amount of data, the first MAC entity retransmits the data; if the amount of currently available authorized data is less than the amount of data, the first MAC entity segments the data and retransmits the segmented data.

[0070] That is, the first MAC entity has the function of segmenting transmitted data. In order to make the most of transmission resources, the first MAC entity packages, segments, or transmits the data directly based on the amount of currently available authorized data.

[0071] In some embodiments, the first MAC entity caches the data to be transmitted that has been pre-packed by the first PDCP entity.

[0072] In some embodiments, when the first MAC entity and the first PDCP entity are deployed separately, the first MAC entity caches the data to be transmitted that has been pre-packed by the first PDCP entity.

[0073] When the first MAC entity buffers the data to be transmitted that has been pre-packed by the first PDCP entity, the size of the buffer is determined by the internal implementation or negotiated through the protocol interface, and this application does not impose any restrictions on this.

[0074] In summary, the method provided in this embodiment quickly initiates ARQ retransmission by triggering the first PDCP entity to retransmit the lost data after the first MAC entity determines that the HARQ transmission has been lost. The data retransmission latency using this method is less than twice the time required for the maximum number of HARQ retransmissions, significantly reducing retransmission latency and improving data transmission efficiency.

[0075] Figure 4 The service plane protocol stack architecture of a data retransmission method provided in one embodiment of this application is illustrated. Figure 4 The MAC entity in the system has segmentation and enhanced automatic hybrid repeat request (enHARQ) functions; where enHARQ means that the MAC entity can directly trigger the higher layer (i.e., the PDCP layer) to perform ARQ retransmission of data. Figure 4The PDCP entity in the code has at least one of the following functions: Robust Header Compress (ROHC), Security, Reorder, and Auxiliary Automatic Repeat Request (auxARQ). Among them, auxARQ refers to the PDCP entity assisting enHARQ for fast retransmission. The auxiliary function includes providing the MAC entity with the original data that needs to be retransmitted after receiving the data retransmission notification from the MAC entity. The PDCP entity is also responsible for reliable transmission when the MAC entity switches over.

[0076] and Figure 2 Compared to the protocol stack architecture of the data retransmission method in the related technologies described above, Figure 4 The architecture of this application shown in the figure does not require the use of the RLC layer in data retransmission. The segmentation function of the original RLC layer is moved to the MAC layer, and the ARQ retransmission function of the original RLC layer is moved to the PDCP layer. This architecture reduces the packet header processing of one protocol layer, simplifies the protocol stack architecture, improves the processing efficiency of the protocol stack, and further increases the peak communication rate.

[0077] To support the above segmentation functionality at the MAC layer, Figure 5 An embodiment of this application is shown. Figure 4 The diagram shows the structure of a MAC PDU under the shown architecture. This MAC PDU supports both unsegmented and segmented configurations.

[0078] Figure 5 The top left corner shows a possible MAC PDU header, which occupies 3 bytes. The Reserved (R) field indicates reserved bits, the Logical Channel Identifier (LCID) field identifies the logical channel, the Length (L) field indicates the length of the SDU or control message, and the Format (F) field indicates the size of the L field.

[0079] The MAC PDU header can be combined with three sequence numbering methods to form three different MAC PDU structures: 14-bit sequence number, 22-bit sequence number (without segmentation), and 22-bit sequence number (with segmentation). The 2-bit Segmentation Info (SI) field indicates whether the PDU contains a complete SDU or a segment of an SDU, while the Sequence Number (SN) field indicates the PDU's sequence number. In the 14-bit SN method, SI and SN together occupy 2 bytes, with data starting from the 6th byte. In the 22-bit SN (without segmentation) method, SI and SN together occupy 3 bytes, with data starting from the 7th byte. In the 22-bit SN (with segmentation) method, a 2-byte Segment Offset (SO) field is also included, with SI, SN, and SO together occupying 5 bytes, with data starting from the 9th byte.

[0080] Figure 5 The top right corner shows another possible MAC PDU header, which occupies 4 bytes. In addition to the aforementioned R, LCID, L, and F fields, this header also includes a 1-byte extended Logical Channel IDentifier (eLCID).

[0081] The MAC PDU header can also be combined with three sequence numbering methods to form three different MAC PDU structures: 14-bit sequence number, 22-bit sequence number (without segmentation), and 22-bit sequence number (with segmentation). The 2-bit SI field indicates that the PDU contains a complete SDU or a segment of an SDU, and the SN field indicates the PDU's sequence number. In the 14-bit SN method, SI and SN occupy a total of 2 bytes, with data starting from the 7th byte. In the 22-bit SN (without segmentation) method, SI and SN occupy a total of 3 bytes, with data starting from the 8th byte. In the 22-bit SN (with segmentation) method, a 2-byte Segment Offset (SO) field is also included, with SI, SN, and SO occupying a total of 5 bytes, with data starting from the 10th byte.

[0082] In order to enable the data to be transmitted quickly and improve the data transmission efficiency during the data transmission process, the first PDCP entity pre-packets the data to be transmitted.

[0083] The first MAC entity and the first PDCP entity in the first device can be deployed in two architectures: separate deployment and joint deployment. When the first MAC entity and the first PDCP entity are deployed in a joint manner (e.g., the user plane protocol stack on the UE side), the first PDCP entity and the first MAC entity are deployed on the same processor and share the same memory. Therefore, the first MAC entity does not need to cache the data to be transmitted that has been pre-packed by the first PDCP entity. When the first MAC entity and the first PDCP entity are deployed separately (e.g., a centralized unit (CU) + distributed unit (DU) architecture on the network side), the first MAC entity needs to obtain the data to be transmitted from the first PDCP entity. To improve data transmission efficiency, the first MAC entity partially caches the data to be transmitted that has been pre-packed by the first PDCP entity.

[0084] That is, in an architecture where the first MAC entity and the first PDCP entity are not separated, the first PDCP entity caches data that has been pre-assembled into packets, and the first MAC entity can choose to cache pre-assembled data to be transmitted, or it can choose not to cache it to save resources; however, in an architecture where the first MAC entity and the first PDCP entity are separated, the first MAC entity caches pre-assembled data to be transmitted.

[0085] It is important to note that the first MAC entity caches the pre-assembled data to be transmitted by the first PDCP entity to improve transmission efficiency. In the joint deployment architecture of the first MAC entity and the first PDCP entity, the first MAC entity does not cache the pre-assembled data to be transmitted by the first PDCP entity to reduce the size of duplicate caching. However, whether the first MAC entity caches the pre-assembled data to be transmitted is a relatively independent process from the data retransmission method of this application. The next data is only involved in retrieving the cached pre-assembled data to be transmitted during the process when the first MAC entity packages and transmits all or part of the (to be retransmitted) data and the next data to be newly transmitted.

[0086] Figure 6 This illustration shows a schematic diagram of the segmentation and reassembly function of the first MAC entity in a data retransmission method provided in an embodiment of this application.

[0087] The first PDCP entity pre-assembles all messages, for example... Figure 6The topmost pre-assembled packets n to n+m are cached in the first PDCP entity; they are also cached in the first MAC entity under a PDCP and MAC separation architecture, but it is recommended not to cache them in the first MAC entity under a PDCP and MAC non-separation architecture to save resources. The size of pre-assembled packet n is x1, the size of pre-assembled packet n+1 is x2, and the size of pre-assembled packet n+2 is x3.

[0088] Given that the currently available authorized data size is x1+x2+x3+x4, pre-assembled packets n, n+1, and n+2 do not need to be changed. The last pre-assembled packet n+m is reassembled. That is, the last pre-assembled packet is segmented, creating a new pre-assembled packet n+m segment 1 of size x4. This segment is then reassembled with the aforementioned three pre-assembled packets and sent as a single MAC PDU in this transmission.

[0089] Figure 6 The image shows the packet structure without segmentation and the packet structure with segmentation. A comparison reveals that after a pre-assembled packet is segmented and reassembled, its packet structure needs to be updated based on the amount of currently available authorized data; a 2-byte MAC SO field is added to its MAC header structure to indicate the segment offset.

[0090] Figure 7 A flowchart of a data retransmission method according to an embodiment of this application is shown. The method is executed by a first device, which is the sender of HARQ transmission. The first device operates a first MAC entity and a first PDCP entity. The MAC entity is used to implement the protocol stack corresponding to the MAC layer, and the PDCP entity is used to implement the protocol stack corresponding to the PDCP layer. The method may include the following steps:

[0091] In step 312, if the number of HARQ retransmissions of the data reaches the maximum number and a NACK is still received, the first MAC entity determines that the data has been lost.

[0092] For example, the first MAC entity learns of a data transmission error through the NACK feedback from HARQ, and then corrects it through HARQ retransmission; if the number of HARQ retransmissions reaches the maximum number but a NACK is still received, it indicates that HARQ error correction has failed, and the first MAC entity determines that data has been lost during HARQ transmission.

[0093] In step 322, the first MAC entity sends a data retransmission notification to the first PDCP entity.

[0094] In some embodiments, the data retransmission notification carries index information of the data.

[0095] In some embodiments, the index information includes at least the HARQ procedure number of the data and the carrier sequence number of the data.

[0096] In some embodiments, the first MAC entity sends a data retransmission notification carrying index information of the data to the first PDCP entity in order to obtain the data to be retransmitted from the first PDCP entity.

[0097] In step 324, the first PDCP entity determines the data based on the data's index information and provides the data to the first MAC entity.

[0098] For example, the data retransmission notification carries the data's index information. The first PDCP entity identifies the data based on the index information and provides the data to the first MAC entity.

[0099] In some embodiments, the first MAC entity caches the data to be transmitted that has been pre-packed by the first PDCP entity.

[0100] In some embodiments, when the first MAC entity and the first PDCP entity are deployed separately, the first MAC entity caches the data to be transmitted that has been pre-packed by the first PDCP.

[0101] Figure 8 This illustration shows a schematic diagram of the correspondence between HARQ process number and MAC SN, PDCP SN in a data retransmission method provided in an embodiment of this application.

[0102] The PDCP real SN depends on the current available license size, application layer packet size, and number of radio bearers; the MAC real SN is equivalent to the PDCP real SN.

[0103] Figure 8 HARQ process 1 is used to transmit data with PDCP SN number 1. After three consecutive transmission failures in HARQ process 1, the maximum number of HARQ transmissions is reached, and PDCP SN number 1 is lost. The first MAC entity of the first device sends a data retransmission notification to the first PDCP entity, which carries the data's index information. The first PDCP entity identifies the data based on this index information and provides it to the first MAC entity. The first MAC entity retransmits the data in HARQ process 8, and the retransmitted data is successfully received by the second device, thus successfully receiving PDCP SN number 1.

[0104] In step 326, the first MAC entity retransmits the data based on the currently available authorization.

[0105] For example, the currently available authorization is used to indicate the currently available transport resources, or to indicate the amount of data that the currently available transport resources can transmit.

[0106] In some embodiments, the first MAC entity determines whether to retransmit directly, transmit in packets, or transmit in segments by comparing the amount of currently available authorized data with the size of the data to be retransmitted, so that transmission resources are fully utilized.

[0107] In some embodiments, if the amount of data currently available for authorization is greater than the amount of data to be transmitted, the first MAC entity packages and transmits all or part of the (to be retransmitted) data and the next (to be newly transmitted) data to make full use of the currently available authorization; if the amount of data currently available for authorization is equal to the amount of data to be transmitted, the first MAC entity retransmits the data; if the amount of data currently available for authorization is less than the amount of data to be transmitted, the first MAC entity segments the data and retransmits the segmented data. For example, the segmented data includes a first segment and a second segment, where the first segment is retransmitted based on the currently available authorization, and the second segment is retransmitted based on subsequent available authorizations.

[0108] Figure 9 A schematic diagram of the data retransmission method provided in one embodiment of this application is shown.

[0109] exist Figure 9 In the HARQ error correction failure scenario 1 above, the first MAC entity and PHY entity of the first device send data P1 (PDCP SN number 1, marked as P1a in the diagram) to the second device. After receiving P1a, the second device reports a CRC check error and sends a NACK to the first device. After receiving the NACK, the first device retransmits data P1 to the second device (marked as P1b in the diagram). After receiving P1b, the second device still reports a CRC check error and sends a NACK to the first device. After multiple error correction failures, the HARQ retransmission count reaches the maximum, but the data is still not transmitted correctly. When the first device receives a NACK even after the maximum HARQ retransmission count has been reached, the first MAC entity determines that the data in the HARQ transmission has been lost, i.e., PDCP SN number 1 is lost.

[0110] In this case, the first MAC entity of the first device sends a data retransmission notification to the first PDCP entity; the first PDCP entity performs ARQ retransmission of the data based on the data retransmission notification. Figure 9The optimization scheme for HARQ error correction failure scenario 1 below illustrates this process. In scenario 1, the first MAC entity and the first PDCP entity are on the same hardware carrier. The first MAC entity notifies the first PDCP entity of the original data that needs to be retransmitted, and then retransmits the data. In scenario 2, the first MAC entity and the first PDCP entity are not on the same hardware carrier. The first MAC entity caches the data to be transmitted that has been pre-assembled by the first PDCP. After the first MAC entity notifies the first PDCP entity of the original data that needs to be retransmitted, the first MAC entity segments and reassembles the original data to be retransmitted and the cached data based on the current available authorized data volume, and then retransmits the data.

[0111] Figure 10 A flowchart of a data retransmission method according to an embodiment of this application is shown. The method is executed by a first device, which is the sender of HARQ transmission. The first device runs a first MAC entity and a first PDCP entity. The MAC entity is used to implement the protocol stack corresponding to the MAC layer, and the PDCP entity is used to implement the protocol stack corresponding to the PDCP layer. The method may include the following steps:

[0112] In step 412, upon receiving a data loss notification from the second MAC entity of the second device, the first MAC entity determines that data has been lost.

[0113] For example, the second device is the receiver of the HARQ transmission.

[0114] In some embodiments, if the second device receives incorrect data, it sends a NACK to the first device; the first device decodes the NACK into an ACK. Since the first device believes the data has been transmitted correctly, it directly initiates the transmission of new data. In this case, the second MAC entity of the second device can proactively notify the first MAC entity of the first device that data has been lost; that is, upon receiving a data loss notification from the second MAC entity of the second device, the first MAC entity determines that data has been lost during HARQ transmission.

[0115] In some embodiments, when the PHY layer provides authorization via the PHY layer control channel, it indicates whether the transmitted data is new data or old data.

[0116] In some embodiments, the second device is both the receiver and the scheduler of HARQ transmissions. When the maximum number of HARQ transmissions is reached, if the first device has no new data to continue scheduling transmission, the second MAC entity proactively notifies the first device's first MAC entity that the data has been lost.

[0117] In some embodiments, the second device acts as both the receiver and scheduler of HARQ transmissions. The second device provides feedback on whether the data sent by the first device is correct via ACK or NACK. If the first device misdetects a NACK as an ACK, the second MAC entity proactively notifies the first device's first MAC entity that the data has been lost.

[0118] In some embodiments, the second MAC entity sends a data loss notification to the first MAC entity via a MAC control element (CE).

[0119] In some embodiments, the MAC CE used for sending data loss notifications can be designed in various ways. For example, a MAC CE for reporting a single maximum transmission error includes a 4-5 bit HARQ procedure number and a 3-bit carrier sequence number; a MAC CE for reporting multiple maximum transmission errors includes a 5-bit buffer size. This application does not impose any limitations on this.

[0120] Please refer to steps 422 to 426. Figure 7 Steps 322 to 326 in the illustrated embodiment will not be repeated here.

[0121] Figure 11 A schematic diagram of the data retransmission method provided in one embodiment of this application is shown.

[0122] exist Figure 11 In the HARQ error correction failure scenario 2 above, the MAC and PHY entities of the first device send data P1 (PDCP SN number 1, marked as P1a in the diagram) to the second device; after receiving P1a, the second device reports a CRC check error and sends a NACK to the first device; after receiving the NACK, the first device retransmits data P1 to the second device (marked as P1b in the diagram); after receiving P1b, the second device still reports a CRC check error and sends a NACK to the first device; after receiving the NACK, the first device retransmits data P1 to the second device (marked as P1c in the diagram); after receiving P1c, the second device still reports a CRC check error and sends a NACK to the first device.

[0123] However, the NACK returned by the second device was mistakenly detected as ACK by the first device. Therefore, the first device assumed the data had been transmitted correctly and directly initiated the transmission of new data. That is, the second device did not successfully receive data, but it discovered that the first device had already started transmitting new data. At this point, the second MAC entity of the second device actively notified the first MAC entity of the first device that the data had been lost. Upon receiving the data loss notification from the second MAC entity, the first MAC entity determined that data had been lost during HARQ transmission, specifically PDCP SN sequence number 1. In this case, the first MAC entity of the first device sent a data retransmission notification to the first PDCP entity; the first PDCP entity then performed ARQ retransmission of the data based on the data retransmission notification.

[0124] Figure 11 The optimization scheme for the HARQ error correction failure scenario 2.1 shows that the second MAC entity and PHY entity of the second device failed to decode the data and did not reach the maximum number of HARQ retransmissions. However, the second device actively notified the second MAC entity of the lost data after the first device started a new transmission. Figure 11 The optimization scheme for HARQ error correction failure scenario 2.2 below shows that the second MAC entity and PHY entity of the second device failed to decode the data and reached the maximum number of HARQ retransmissions. After the second device detects that the first device has started a new transmission, the second MAC entity of the second device actively notifies of the data loss.

[0125] In HARQ error correction failure scenarios 2.1 and 2.2, there are two deployment methods for the first MAC entity and the first PDCP entity. In scenario 1, the first MAC entity and the first PDCP entity are on the same hardware platform. The first MAC entity notifies the first PDCP entity of the original data that needs to be retransmitted, and then the data is retransmitted. In scenario 2, the first MAC entity and the first PDCP entity are not on the same hardware platform. The first MAC entity caches the data to be transmitted that has been pre-assembled by the first PDCP. After the first MAC entity notifies the first PDCP entity of the original data that needs to be retransmitted, the first MAC entity segments and reassembles the original data to be retransmitted and the cached data based on the current available authorized data volume, and then retransmits the data.

[0126] Figure 12 A flowchart of a data retransmission method according to an embodiment of this application is shown. The method is executed by a first device, which is the sender of HARQ transmission. The first device operates a first MAC entity and a first PDCP entity. The MAC entity is used to implement the protocol stack corresponding to the MAC layer, and the PDCP entity is used to implement the protocol stack corresponding to the PDCP layer. The method may include the following steps:

[0127] In step 512, if the number of HARQ retransmissions of the data reaches the maximum and a retransmission schedule or new transmission schedule is received from the second device, the first MAC entity determines that the data has been lost.

[0128] For example, the second device is both the receiver and the scheduler of HARQ transmissions.

[0129] In some embodiments, the second device can directly initiate retransmission or newtransmission scheduling by determining the correctness of the received data. If the data cannot be recovered even after reaching the maximum number of HARQ retransmissions, the first MAC entity of the first device actively notifies the first PDCP entity of the first device that the data has been lost. That is, if the number of HARQ retransmissions reaches the maximum and a retransmission or newtransmission schedule is received from the second device, the first MAC entity determines that data has been lost during HARQ transmission.

[0130] In some embodiments, the second device performs retransmission scheduling or newtransmission scheduling via downlink control information (DCI).

[0131] Please refer to steps 522 to 526. Figure 7 Steps 322 to 326 in the illustrated embodiment will not be repeated here.

[0132] Figure 13 A schematic diagram of the data retransmission method provided in one embodiment of this application is shown. Figure 13 In the scenario shown, the receiver is also the scheduler, meaning the second device is both the receiver and the scheduler. When the second device detects a received bit error, it directly initiates a retransmission without using ACK or NACK for feedback.

[0133] exist Figure 13In the HARQ error correction failure scenario 3 above, the first MAC entity and PHY entity of the first device send data P1 (PDCP SN number 1, marked as P1a in the diagram) to the second device. After receiving P1a, the second device reports a CRC check error and sends a retransmission schedule to the first device. After receiving the retransmission schedule, the first device retransmits data P1 to the second device (marked as P1b in the diagram). After receiving P1b, the second device still reports a CRC check error and sends a retransmission schedule to the first device. After receiving the retransmission schedule, the first device retransmits data P1 to the second device (marked as P1c in the diagram). After receiving P1c, the second device still reports a CRC check error and sends a new transmission schedule to the first device. If the number of HARQ retransmissions reaches the maximum and the first device still receives a retransmission schedule or new transmission schedule from the second device, the first MAC entity determines that data loss has occurred during HARQ transmission, i.e., PDCP SN number 1 is lost. In this case, the first MAC entity of the first device sends a data retransmission notification to the first PDCP entity; the first PDCP entity performs ARQ retransmission of the data based on the data retransmission notification.

[0134] In this case, the first MAC entity of the first device sends a data retransmission notification to the first PDCP entity; the first PDCP entity performs ARQ retransmission of the data based on the data retransmission notification. Figure 11 The optimization scheme for HARQ error correction failure scenario 3 below illustrates this process. In scenario 1, the first MAC entity and the first PDCP entity are on the same hardware carrier. The first MAC entity notifies the first PDCP entity of the original data that needs to be retransmitted, and then retransmits the data. In scenario 2, the first MAC entity and the first PDCP entity are not on the same hardware carrier. The first MAC entity caches the data to be transmitted that has been pre-assembled by the first PDCP. After the first MAC entity notifies the first PDCP entity of the original data that needs to be retransmitted, the first MAC entity segments and reassembles the original data to be retransmitted and the cached data based on the current available authorized data volume, and then retransmits the data.

[0135] Figure 14 A schematic diagram is shown of a transmission scenario where the data retransmission method of this application is not required for optimization.

[0136] In scenario 1 where no optimization is required, the data transmitted by HARQ is successfully corrected through the HARQ forward error correction mechanism, and the second device successfully receives the data and sends back an ACK. Therefore, no optimization is needed for this scenario.

[0137] In scenario 2, where no optimization is required, the ACK returned by the second device is mistakenly detected as a NACK by the first device, and the first device retransmits the data corresponding to the NACK. That is, Figure 14 The data corresponding to PDCP sequence number 1 in the first device is transmitted repeatedly. The second device's PDCP simply discards the duplicate data after receiving it repeatedly. This scenario will only have a minor impact on latency and requires no optimization.

[0138] In scenario 3, where no optimization is required, the second device acts as both the receiver and the scheduler. Instead of using ACK and NACK for HARQ feedback, the second device directly sends retransmission or new transmission schedules to the first device. If error correction is successful during the HARQ retransmission process, no optimization is needed.

[0139] For example, the first device also operates a first Radio Resource Control (RRC) entity. In the event that data loss results in a failure to meet Quality of Service (QoS) requirements, the first PDCP entity reports an active data loss to the first RRC entity once.

[0140] Optionally, if the maximum delay exceeds the validity period of the data packet, active data loss that does not meet QoS requirements may occur.

[0141] It is important to note that the first PDCP entity reporting active data loss to the first RRC entity is not the same as the reporting of reaching the maximum retransmission count in the AM mode of RLC in existing technologies. Reaching the maximum retransmission count in the AM mode of RLC requires the RRC connection to be re-established, but if only the QoS of some service plane data is temporarily not meeting the requirements, the RRC connection does not necessarily have to be rebuilt.

[0142] For example, the first RRC entity in timer T qos Within the time window, counter N appears. qos If the QoS requirements are not met, the current RRC link is determined to be unacceptable, and the RRC link is released into an idle state. In other words, the first RRC entity determines whether to rebuild the RRC connection based on the cumulative number of active data losses due to QoS non-compliance and the time interval between these losses.

[0143] For example, T qos and N qos Configuration can be made by the network via RRC messages, by the network via system information broadcasts, or by predefined communication protocols.

[0144] Optionally, in the event of a QoS non-compliance, such as when the packet error ratio exceeds an expected value, the first PDCP entity notifies the Non-Access Stratum (NAS) and the Application Layer of the current QoS non-compliance and detailed QoS statistics (e.g., latency, packet loss rate, rate, etc.). The NAS and Application Layers can choose to reduce the application layer rate or adjust the encoding / decoding rate. This application does not impose any restrictions on how the NAS and Application Layers handle QoS non-compliance.

[0145] Optionally, when using QoS parameters for retransmission judgment, as long as the packet delay budget does not exceed the application's allowed range, the first MAC entity and the first PDCP entity can retransmit in different scenarios.

[0146] Optionally, the packet delay budget can be used to provide retransmission services based on the radio bearer or logical channel, i.e., different packet delay budgets can be set for different radio bearers or logical channels; or, if the application can provide a packet delay budget for each IP packet separately, retransmission services can be provided based on the packet delay budget of each IP packet.

[0147] Optionally, the UE can report whether it supports the data transmission method of this application by adding capability parameters to the UE Capability Information in the RRC. Figure 4 The new architecture shown.

[0148] Figure 15 This illustration shows a schematic diagram of an optimization method for QoS non-compliance in a data retransmission method provided in an embodiment of this application.

[0149] Figure 15 In this scenario, both enHARQ and auxARQ retransmission mechanisms consistently fail to retransmit. When packet delay exceeds the budget, data is proactively discarded, and the first PDCP entity reports one instance of proactive data loss to the first RRC entity. When packet error exceeds the budget, the RRC, NAS, or application layer is proactively notified.

[0150] Figure 15 The upper right corner shows the RRC reconnection process based on QoS parameters. In the first phase, the first RRC entity reconnects at timer T. qos Within the time window, counter N appears. qosIf the QoS requirements are not met, the current RRC link is determined to not meet the minimum service quality requirements, and the RRC link is released into an idle state. Thus, the first RRC entity enters the second stage of the idle state, that is, the radio bearer cannot meet the requirements.

[0151] Figure 15 The top left corner shows the optimization scheme of the first PDCP entity when QoS is not met. In the event of QoS failure, the first PDCP entity actively reports one data loss to the first RRC entity; in the event that the QoS packet error rate cannot be met, the first PDCP entity actively notifies the application layer.

[0152] Figure 16 This illustration shows a schematic diagram of the principle of the active synchronization window in the case of QoS not being met in the data retransmission method provided in one embodiment of this application.

[0153] Figure 16 The diagram illustrates a scenario where enHARQ and auxHARQ retransmissions fail repeatedly, exceeding the delay budget, and data is intentionally lost. In this scenario, PDCP SN numbers 1 and 4 are lost. The first device's PDCP entity actively notifies the second device to discard data via a PDCP discard report message in PDCP control PDU format, thus synchronizing the sliding windows of both devices. Figure 16 The format of the message is shown in the lower right corner.

[0154] Optionally, the size of the sliding window affects the reliability and latency of the transmission, and this application does not limit the size of the sliding window.

[0155] In summary, the method provided in this application, after the first MAC entity determines that data loss has occurred, sends a data retransmission notification to the first PDCP entity, triggering the first PDCP entity to perform ARQ retransmission, thereby achieving fast data retransmission. In related technologies, the ARQ retransmission latency of RLC in AM mode is as high as 4-5 times the maximum number of HARQ retransmissions, while the retransmission latency of this solution is less than twice the maximum number of HARQ retransmissions, significantly reducing data transmission latency.

[0156] Furthermore, this data retransmission method replaces the original ARQ retransmission method in AM mode of RLC under the new architecture. It removes the RLC layer during the data retransmission process, reduces the header processing of one protocol layer, simplifies the protocol stack architecture, improves the processing efficiency of the protocol stack, and is conducive to further improving the peak communication rate.

[0157] In addition, this method reduces the size of the Layer 2 duplicate buffer (excluding PDCP), which is beneficial to improving the peak communication rate. Moreover, the new architecture and changes in buffer size in this method will not affect the handover function or the evolution function of various network deployment architectures.

[0158] Furthermore, this method considers the impact of QoS parameters in data retransmission, directly taking into account packet delay errors and packet delay budgets. As long as the buffer time of the data packet does not exceed the packet delay budget range, retransmission is possible. For different scenarios, PDCP's auxARQ retransmission and MAC's enHARQ retransmission are used respectively. Moreover, AM and UM modes are no longer distinguished for higher-layer applications. All applications can enjoy the retransmission function provided by the protocol stack. Different levels of retransmission services are flexibly matched and provided according to different QoS requirements.

[0159] Furthermore, this method can provide QoS guarantee services per radio bearer or per individual IP packet (provided that the application layer can provide the expected packet delay budget or the expected IP packet lifetime for each IP packet).

[0160] In addition, the new retransmission solution improves the original RRC link reconstruction mechanism. The new RRC link reconstruction mechanism more directly reflects that when QoS cannot be satisfied, the RRC link will enter an idle state.

[0161] Furthermore, when QoS requirements are not met, the first PDCP entity of the first device will actively discard timed-out data and notify the second PDCP entity of the second device to synchronously refresh the receive window. Since PDCP communication is primarily bidirectional, both the UE and network device-side PDCP can send the PDCP Control PDU format for PDCP discard report message. This message can also be used to release PDCP buffers.

[0162] Figure 17 A flowchart of a data retransmission method according to an embodiment of this application is shown. The method is executed by a second device, which runs a second MAC entity. The MAC entity is used to implement the protocol stack corresponding to the MAC layer. The method may include the following steps:

[0163] In step 620, if the second MAC entity determines that data has been lost in the HARQ transmission, the second MAC entity sends a data loss notification to the first MAC entity of the first device.

[0164] In some embodiments, the second device also acts as the scheduler for HARQ transmissions. If the maximum number of HARQ retransmissions is reached and the received data is still incorrect, the second MAC entity determines that data loss has occurred.

[0165] In some embodiments, if the second device receives incorrect data, it sends a NACK to the first device; the first device decodes the NACK into an ACK. Since the first device believes the data has been transmitted correctly, it directly initiates the transmission of new data. In this case, the second MAC entity of the second device determines that data loss has occurred in the HARQ transmission; that is, if the second device receives new data from the first device after sending a NACK to the first device, the second device determines that data loss has occurred in the HARQ transmission. See also... Figure 11 The example shown.

[0166] In some embodiments, the second device also acts as the scheduler for HARQ transmissions. When the maximum number of HARQ transmissions is reached, if the first device has no new data to continue scheduling transmission, the second MAC entity proactively notifies the first device's first MAC entity that the data has been lost.

[0167] In some embodiments, the second device acts as both the receiver and scheduler of HARQ transmissions. The second device provides feedback on whether the data sent by the first device is correct via ACK or NACK. If the first device misdetects a NACK as an ACK, the second MAC entity proactively notifies the first device's first MAC entity that the data has been lost.

[0168] In some embodiments, the second device also acts as the scheduler for HARQ transmissions. The second MAC entity sends retransmission or newtransmission schedules to the first MAC entity, which implicitly indicate data loss notification. See also Figure 13 The example shown.

[0169] In some embodiments, the second MAC entity sends a data loss notification to the first MAC entity of the first device via the MAC CE.

[0170] In some embodiments, the MAC CE used for sending data loss notifications can be designed in various ways. For example, a MAC CE for reporting a single maximum transmission error includes a 4-5 bit HARQ procedure number and a 3-bit carrier sequence number; a MAC CE for reporting multiple maximum transmission errors includes a 5-bit buffer size. This application does not impose any limitations on this.

[0171] In summary, the method provided in this application embodiment, by having the second MAC entity send a data loss notification to the first MAC entity when it is determined that the data transmitted by HARQ has been lost, enables the first device to quickly initiate ARQ retransmission, which greatly reduces the latency of data retransmission and improves the efficiency of data transmission.

[0172] Figure 18 A block diagram of a data retransmission apparatus provided in an exemplary embodiment of the present disclosure is shown, the apparatus comprising:

[0173] The triggering module 720 is used to trigger the first PDCP entity to perform Automatic Repeat Request (ARQ) retransmission on the data when the first MAC entity determines that data has been lost in the HARQ transmission.

[0174] In one possible design of this embodiment, if the number of HARQ retransmissions of the data reaches the maximum number and a negative acknowledgment (NACK) is still received, the first MAC entity determines that the data has been lost.

[0175] In one possible design of this embodiment, upon receiving a data loss notification from the second MAC entity of the second device, the first MAC entity determines that the data has been lost, and the second device is the receiver of the HARQ transmission.

[0176] In one possible design of this embodiment, when the number of HARQ retransmissions of the data reaches the maximum and a retransmission schedule or new transmission schedule is received from the second device, the first MAC entity determines that the data has been lost, and the second device is both the receiver and the scheduler of the HARQ transmission.

[0177] In one possible design of this embodiment, the triggering module 720 is used to send a data retransmission notification from the first MAC entity to the first PDCP entity; the first PDCP entity performs ARQ retransmission of the data based on the data retransmission notification.

[0178] In one possible design of this embodiment, the data retransmission notification carries index information of the data; the triggering module 720 is used for the first PDCP entity to determine the data based on the index information of the data and to provide the data to the first MAC entity; the first MAC entity retransmits the data based on the currently available authorization.

[0179] In one possible design of this embodiment, the index information includes at least the HARQ process number of the data and the carrier sequence number of the data.

[0180] In one possible design of this embodiment, the triggering module 720 is configured to, when the amount of currently available authorized data is greater than the amount of data, package and transmit all or part of the data and the next data together; when the amount of currently available authorized data is equal to the amount of data, retransmit the data; and when the amount of currently available authorized data is less than the amount of data, segment the data and retransmit the segmented data.

[0181] In one possible design of this embodiment, the triggering module 720 is used by the first MAC entity to cache the data to be transmitted that has been pre-packed by the first PDCP entity.

[0182] In one possible design of this embodiment, the triggering module 720 is used to cache the data to be transmitted that has been pre-packed by the first PDCP when the first MAC entity and the first PDCP entity are deployed separately.

[0183] In one possible design of this embodiment, the triggering module 720 is used to have the first PDCP entity report active data loss once to the first RRC entity when the data loss causes the QoS requirements to be unmet.

[0184] In one possible design of this embodiment, the trigger module 720 is used by the first RRC entity to trigger timer T. qos Within the time window, counter N appears. qos If the QoS requirements are not met, the current RRC link is determined to not meet the minimum service quality requirements, and the RRC link is released and enters an idle state.

[0185] In one possible design of this embodiment, the trigger module 720 is used for the T qos and the N qos Configuration can be made by the network via RRC messages, by the network via system information broadcasts, or by predefined communication protocols.

[0186] Figure 19 A block diagram of a data retransmission apparatus provided in an exemplary embodiment of the present disclosure is shown, the apparatus comprising:

[0187] The sending module 820 is configured to send a data loss notification to the first MAC entity of the first device when the second MAC entity determines that data has been lost in the Hybrid Automatic Repeat Request (HARQ) transmission.

[0188] In one possible design of this embodiment, the second device is also the scheduler of the HARQ transmission; the sending module 820 is used to determine that the data has been lost when the number of HARQ retransmissions of the data reaches the maximum number and the received data is still incorrect.

[0189] In one possible design of this embodiment, the second device is also the scheduler of the HARQ transmission; the sending module 820 is used for the second MAC entity to send the retransmission scheduling or newtransmission scheduling of the data to the first MAC entity, and the retransmission scheduling or newtransmission scheduling is used to implicitly indicate the data loss notification.

[0190] In one possible design of this embodiment, the sending module 820 is used to send the data loss notification from the second MAC entity to the first MAC entity of the first device through the Media Access Control Unit (MAC CE).

[0191] Figure 20 The diagram shows a schematic of a terminal provided in one embodiment of this application. The terminal includes a processor 1301, a receiver 1302, a transmitter 1303, a memory 1304, and a bus 1305.

[0192] The processor 1301 includes one or more processing cores. The processor 1301 executes various functional applications and information processing by running software programs and modules.

[0193] The receiver 1302 and the transmitter 1303 can be implemented as a communication component, which can be a communication chip.

[0194] The memory 1304 is connected to the processor 1301 via the bus 1305.

[0195] The memory 1304 can be used to store at least one instruction, and the processor 1301 can execute the at least one instruction to implement the various steps in the above method embodiments.

[0196] Furthermore, the memory 1304 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: magnetic disks or optical disks, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), static random-access memory (SRAM), read-only memory (ROM), magnetic storage, flash memory, and programmable read-only memory (PROM).

[0197] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory including instructions that can be executed by a terminal's processor to complete the aforementioned data retransmission method. For example, the non-transitory computer-readable storage medium may be a ROM, random-access memory (RAM), compact disc read-only memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0198] Figure 21 This is a block diagram of a network device 1400 provided in one embodiment of this application. The network device 1400 may be a base station.

[0199] Network device 1400 may include: processor 1401, receiver 1402, transmitter 1403, and memory 1404. Receiver 1402, transmitter 1403, and memory 1404 are respectively connected to processor 1401 via a bus.

[0200] The processor 1401 includes one or more processing cores and executes the data retransmission method provided in this embodiment by running software programs and modules. The memory 1404 can be used to store software programs and modules. Specifically, the memory 1404 can store an operating system 14041 and at least one application module 14042 required for a given function. The receiver 1402 is used to receive communication data sent by other devices, and the transmitter 1403 is used to send communication data to other devices.

[0201] For details not described in this embodiment, please refer to the embodiments above, which will not be repeated here.

[0202] In some embodiments, this application also provides a computer-readable storage medium storing a computer program that is loaded and executed by a sensing participating device to enable the sensing participating device to implement the method for obtaining the custom identifier on the first device side described above.

[0203] Optionally, the computer-readable storage medium may include: ROM (Read-Only Memory), RAM (Random-Access Memory), SSD (Solid State Drives), or optical disc, etc. The random access memory may include ReRAM (Resistance Random Access Memory) and DRAM (Dynamic Random Access Memory).

[0204] In some embodiments, this application also provides a chip, the chip including programmable logic circuits or programs, the chip being used to implement the above-described method for obtaining a custom identifier on the first device side.

[0205] In some embodiments, this application also provides a computer program product, the computer program product or computer program including computer instructions stored in a computer-readable storage medium, the sensing participating device reading from the computer-readable storage medium and executing the computer instructions to enable the sensing participating device to implement the above-described method for generating a custom identifier on the second device side.

[0206] It should be understood that the term "instruction" mentioned in the embodiments of this application can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0207] In the description of the embodiments of this application, the term "correspondence" may indicate that there is a direct or indirect correspondence between two things, or that there is an association between two things, or that there is a relationship of instruction and being instructed, configuration and being configured, etc.

[0208] In this article, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0209] The term "less than or equal to" as used in this article can mean less than or equal to, or less than.

[0210] Furthermore, the step numbers described herein are merely illustrative of one possible execution order between steps. In some other embodiments, the steps may not be executed in the order of their numbers, such as two steps with different numbers being executed simultaneously, or two steps with different numbers being executed in the reverse order of the illustration. This application does not limit this.

[0211] Those skilled in the art will recognize that the functions described in the embodiments of this application in one or more of the above examples can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0212] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A data retransmission method, characterized in that, The method is executed by a first device, which operates a first intermediate access control (MAC) entity and a first packet data aggregation protocol (PDCP) entity. The method includes: If the first MAC entity determines that data has been lost in the Hybrid Automatic Repeat Request (HARQ) transmission, the first MAC entity sends a data retransmission notification to the first PDCP entity. The data retransmission notification carries index information of the data, and the index information includes at least the HARQ procedure number and the carrier sequence number of the data. The first PDCP entity determines the data based on the index information of the data and provides the data to the first MAC entity; The first MAC entity retransmits the data based on currently available authorization.

2. The method according to claim 1, characterized in that, The method further includes: If the HARQ retransmission count of the data reaches the maximum number and a negative acknowledgment (NACK) is still received, the first MAC entity determines that the data has been lost.

3. The method according to claim 1, characterized in that, The method further includes: Upon receiving a data loss notification from the second MAC entity of the second device, the first MAC entity determines that the data has been lost, and the second device is the recipient of the HARQ transmission.

4. The method according to claim 1, characterized in that, The method further includes: If the number of HARQ retransmissions of the data reaches the maximum and a retransmission schedule or new transmission schedule is received from the second device, the first MAC entity determines that the data has been lost, and the second device is both the receiver and the scheduler of the HARQ transmission.

5. The method according to claim 1, characterized in that, The first MAC entity retransmits the data based on currently available authorization, including: If the amount of currently available authorized data is greater than the amount of data, the first MAC entity will package and transmit all or part of the data and the next data. If the amount of currently available authorized data is equal to the amount of data, the first MAC entity will retransmit the data; If the amount of currently available authorized data is less than the amount of data, the first MAC entity will segment the data and then retransmit the segmented data.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The first MAC entity caches the data to be transmitted that has been pre-packed by the first PDCP entity.

7. The method according to claim 6, characterized in that, The first MAC entity buffers the data to be transmitted that has been pre-assembled by the first PDCP, including: When the first MAC entity and the first PDCP entity are deployed separately, the first MAC entity caches the data to be transmitted that has been pre-packed by the first PDCP.

8. The method according to any one of claims 1 to 5, characterized in that, The first device also operates a first Radio Resource Control (RRC) entity, and the method further includes: If the data loss results in a failure to meet the Quality of Service (QoS) requirements, the first PDCP entity will report the active data loss once to the first RRC entity.

9. The method according to claim 8, characterized in that, The method further includes: If the first RRC entity fails to meet the QoS requirements for Nqos times within the timer Tqos window, it is determined that the current RRC link does not meet the minimum service quality requirements, and the RRC link is released and enters an idle state.

10. The method according to claim 9, characterized in that, The Tqos and Nqos are configured by the network via RRC messages, or by the network via system information broadcasts, or by predefined communication protocols.

11. A data retransmission method, characterized in that, The method is executed by a second device, which operates a second intermediate access control (MAC) entity, and the method includes: If the second MAC entity determines that data has been lost in a Hybrid Automatic Repeat Request (HARQ) transmission, the second MAC entity sends a data loss notification to the first MAC entity of the first device. The data loss notification is used by the first MAC entity to determine that data has been lost in the HARQ transmission, so that the first MAC entity can send a data retransmission notification to the first PDCP entity. The data retransmission notification carries index information of the data, which includes at least the HARQ procedure number and the carrier sequence number of the data. The data index information is used by the first PDCP entity to identify the data and provide the data to the first MAC entity, so that the first MAC entity can retransmit the data based on the currently available license.

12. The method according to claim 11, characterized in that, The second device also acts as the scheduler for the HARQ transmission; The method further includes: If the number of HARQ retransmissions of the data reaches the maximum and the received data is still incorrect, the second MAC entity determines that the data has been lost.

13. The method according to claim 11, characterized in that, The second device also acts as the scheduler for the HARQ transmission; The second MAC entity sends a data loss notification to the first MAC entity of the first device, including: The second MAC entity sends a retransmission schedule or a new transmission schedule for the data to the first MAC entity. The retransmission schedule or the new transmission schedule is used to implicitly indicate the data loss notification.

14. The method according to claim 11, characterized in that, The second MAC entity sends a data loss notification to the first MAC entity of the first device, including: The second MAC entity sends the data loss notification to the first MAC entity of the first device via the Media Access Control Unit (MAC CE).

15. A data retransmission device, characterized in that, The device includes: The triggering module is configured to send a data retransmission notification to the first PDCP entity when the first MAC entity determines that data has been lost in the Hybrid Automatic Repeat Request (HARQ) transmission. The data retransmission notification carries index information of the data, and the index information includes at least the HARQ procedure number and the carrier sequence number of the data. The first PDCP entity determines the data based on the index information of the data and provides the data to the first MAC entity; The first MAC entity retransmits the data based on currently available authorization.

16. A data retransmission device, characterized in that, The device includes: The sending module is configured to, when the second MAC entity determines that data has been lost in the Hybrid Automatic Repeat Request (HARQ) transmission, send a data loss notification to the first MAC entity of the first device. The data loss notification is used by the first MAC entity to determine that data has been lost in the HARQ transmission, so that the first MAC entity can send a data retransmission notification to the first PDCP entity. The data retransmission notification carries index information of the data, which includes at least the HARQ procedure number and the carrier sequence number of the data. The index information is used by the first PDCP entity to identify the data and provide it to the first MAC entity, so that the first MAC entity can retransmit the data based on currently available licenses.

17. A terminal, characterized in that, The terminal includes: processor; A transceiver connected to the processor; The processor is configured to load and execute executable instructions to implement the data retransmission method as described in any one of claims 1 to 10.

18. A network device, characterized in that, The network device includes: processor; A transceiver connected to the processor; The processor is configured to load and execute executable instructions to implement the data retransmission method as described in any one of claims 11 to 14.

19. A chip, characterized in that, The chip includes programmable logic circuitry and / or program instructions, which, when the chip is running, are used to implement the data retransmission method as described in any one of claims 1 to 10, or the data retransmission method as described in any one of claims 11 to 14.

20. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one program, which is loaded and executed by a processor to implement the data retransmission method as described in any one of claims 1 to 10, or the data retransmission method as described in any one of claims 11 to 14.

21. A computer program product, characterized in that, The computer program product includes computer instructions stored in a computer-readable storage medium; a processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the data retransmission method as described in any one of claims 1 to 10, or the data retransmission method as described in any one of claims 11 to 14.

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