Packet data convergence protocol enhancement method for serial number gap report

Abstract

The invention provides a packet data convergence protocol enhancement method for serial number gap reporting. The packet data convergence protocol enhancement method comprises various solutions of a control protocol data unit PDU for data packet data convergence protocol PDCP enhancement to report a serial number SN gap. A transmitting device may obtain one or more PDCP service data units (SDUs) from an upper layer. The transmitting device detects that one or more PDCP SDUs are discarded prior to successful transmission to the receiving device, each PDCP SDU being associated with one PDCP SN. The transmitting device may then transmit one PDCP control PDU to the receiving device. The PDCP control PDU may indicate a PDCP SN gap report related to the PDCP SDU that is dropped.

Description

Technical Field

[0001] The present application relates generally to mobile communications, and more particularly to enhancements to a packet data convergence protocol (PDCP) on a control protocol data unit (PDU) for sequence number (SN) gap reporting. Background Art

[0002] Unless otherwise indicated in this section, the approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.

[0003] The Packet Data Convergence Protocol (PDCP) is a (sub)layer specified by the Third Generation Partnership Project (3GPP) for the fourth-generation (4G) Long Term Evolution (LTE) or the fifth-generation (5G) New Radio (NR). In the radio protocol stack of 4G LTE or 5G NR, the PDCP layer sits above the Radio Link Control (RLC) layer and below the Radio Resource Control (RRC) layer (in the control plane) or the Internet Protocol (IP) layer (in the user plane). From the PDCP perspective, packets received from upper layers (e.g., the RRC, IP, and / or application (AP) layers) are called Service Data Units (SDUs), while packets submitted to lower layers (e.g., the RLC layer) (after PDCP processing) are called PDUs. Generally, the PDCP layer supports processing functions such as data transmission (user plane and / or control plane), maintenance of PDCP sequence numbers (SNs), header / data compression and decompression, ciphering and deciphering, integrity protection and verification, timer-based SDU discard, reordering, and in-sequence delivery.

[0004] In the current 3GPP PDCP standard, minimizing the SN gap after SDU discard (also called PDCP SN gap) depends on the implementation of the user equipment UE when a PDCP SDU that has been associated with a PDCP SN is discarded. For the case where a single PDCP SDU is discarded, the UE may be able to handle the SN gap on its own. However, for the case where many PDCP SDUs are discarded, it will be difficult for the UE to handle the SN gap alone, and the SN gap will cause reordering delays at the receiving end. In addition, after the PDU set feature is introduced in Release 18 of the 3GPP standard, the problem of SN gap may become worse. More specifically, a PDU set contains one or more PDUs that carry a payload of a unit of information generated at the application layer, and all PDUs in the PDU set are associated with the same discard timer. Figure 1 An example scenario 100 of single SDU discard and PDU set discard is shown. Figure 1Part (A) describes the discard of a single SDU, while part (B) describes the discard of a PDU set. When a PDU in a PDU set fails to be successfully delivered to the receiver before the discard timer expires, the SDUs corresponding to all PDUs in the PDU set will be discarded. Figure 2 An example scenario 200 is shown for the SN gap problem in PDU set discard. Figure 2 As shown in Figure 2, at the transmitting end, the discarding of a PDU set will result in a relatively large SN gap (for example, the SN gap may be from SN=2 to SN=5) compared to the discarding of a single PDU. At the receiving end, it is not aware of the SN gap problem and it only relies on the expiration of the t-Reordering timer to detect the SN gap. That is, for the detection of the SN gap, the receiving end must wait for the expiration of the t-Reordering timer, which causes an undesirable delay (i.e., reordering delay). In addition, the problem of SN gap also exists in the case of traffic dispatch on split bearers, such as Figure 3 As shown, traffic from one PDCP entity may be dispatched to two different RLC entities (or RLC legs), but the imbalance in traffic dispatch between the two RLC legs may cause SN gaps because the physical (PHY) capacities of the two RLC legs may be difficult to know at runtime and are likely to be different (for example, the capacity of one PHY is better than that of the other PHY).

[0005] Therefore, it is necessary to provide appropriate solutions to solve this problem. Summary of the Invention

[0006] The following summary is provided for informational purposes only and is not intended to be limiting in any way. That is, the following summary is intended to introduce the concepts, highlights, advantages, and benefits of the novel and non-obvious technologies described herein. Selected embodiments are further described in the detailed description below. Therefore, the following summary is not intended to identify essential features of the subject matter nor to determine the scope of the subject matter.

[0007] An object of the present disclosure is to provide solutions, concepts, designs, systems, methods, and / or devices related to packet data convergence protocol (PDCP) enhanced control protocol data unit (PDU) for sequence number (SN) gap reporting. By implementing one or more of the proposed solutions, it is believed that the above-described problems will be avoided or alleviated.

[0008] In one aspect, a method may involve a transmitting device obtaining one or more PDCP service data units (SDUs) from an upper layer. The method may also involve the transmitting device detecting that one or more PDCP SDUs are discarded before successful transmission to a receiving device, each PDCP SDU being associated with a PDCP sequence number (SN). The method may also involve the transmitting device transmitting a PDCP control PDU to the receiving device, wherein the PDCP control PDU indicates a PDCP SN gap report associated with the discarded PDCP SDUs.

[0009] In one aspect, a method may involve a receiving device receiving a PDCP control PDU from a transmitting device, wherein the PDCP control PDU indicates a PDCP SN gap report associated with one or more PDCP SDUs. The method may also involve the receiving device determining that the PDCP SDU is discarded. The method may also involve the receiving device delivering all stored PDCP SDUs and the PDCP SDU determined to be discarded to an upper layer.

[0010] It is worth noting that although the description provided herein may be in the context of certain wireless access technologies, networks and network topologies such as Long Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, fifth generation (5G), new radio (NR), Internet of Things (IoT), narrowband Internet of Things (NB-IoT), industrial Internet of Things (IIoT), beyond 5G (B5G) and sixth generation (6G), the concepts, solutions and any variants / derivatives thereof may be implemented in, used for and implemented by other types of wireless access technologies, networks and network topologies. Therefore, the scope of the present disclosure is not limited to the examples described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A diagram illustrating example scenarios of single SDU discard and PDU set discard according to the present disclosure.

[0012] Figure 2 A diagram illustrating an example scenario of the SN gap problem in PDU set discard according to the present disclosure.

[0013] Figure 3 A diagram illustrating an example scenario of traffic allocation on a split bearer according to the present disclosure.

[0014] Figure 4 Diagram illustrating example scenarios of communication environments according to various solutions and aspects of the present disclosure.

[0015] Figure 5 is a diagram illustrating an example scenario of PDCP operations at a transmitting side and a receiving side according to one embodiment of the present disclosure.

[0016] Figure 6 A diagram illustrating an example scenario of PDCP Control PDUs for PDCP SN gap reporting according to one embodiment of the present disclosure.

[0017] Figure 7 A diagram illustrating an example scenario of another PDCP Control PDU for PDCP SN gap reporting according to one embodiment of the present disclosure.

[0018] Figure 8 A schematic diagram of a communication system according to an embodiment of the present disclosure is shown.

[0019] Figure 9 A flowchart illustrating an example process according to one embodiment of the present disclosure is shown.

[0020] Figure 10 A flowchart illustrating another example process according to one embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0021] Detailed embodiments and implementations of the present application are disclosed herein. However, it should be understood that the disclosed embodiments and implementations are merely illustrative of the present application and may be embodied in various forms. The present disclosure may be embodied in many different forms and should not be limited to being limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided to make the description of the present disclosure comprehensive and complete and to fully convey the scope of the present disclosure to those skilled in the art. In the following description, details of well-known features and technologies may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

[0022] Implementations according to the present disclosure involve various technologies, methods, schemes, and / or solutions for enhancing PDCP control PDUs for SN gap reporting. According to the present disclosure, various possible solutions may be implemented individually or in combination. That is, although these possible solutions may be described individually, two or more of these possible solutions may be implemented in one or another combination.

[0023] Figure 4An example scenario 400 is shown in a communication environment in which various solutions and schemes according to the present disclosure may be implemented. Scenario 400 involves a user equipment (UE) 410 wirelessly communicating with a network 420 (e.g., a wireless network including a non-terrestrial network (NTN) and a TN) via at least one terrestrial network node 422 (e.g., a base station (BS), such as an evolved Node-B (eNB), a next-generation Node-B (gNB), or a transmission / reception point (TRP)) and / or at least one non-terrestrial network node 424 (e.g., a satellite). For example, the terrestrial network node 422 may form a TN serving cell for wireless communication with the UE 410, or the terrestrial network node 422 and / or the non-terrestrial network node 424 may form an NTN serving cell for wireless communication with the UE 410. In some implementations, the network 420 may be a 4G / 5G / B5G / 6G network, and the UE 410 may be a smartphone, tablet, laptop, or notebook computer. Alternatively, the network 420 may be an IoT / NB-IoT / IIoT network, and the UE 410 may be an IoT device, such as an NB-IoT UE or an enhanced machine type communication (eMTC) UE (e.g., a bandwidth-reduced low complexity (BL) UE or a coverage-enhanced (CE) UE). In such a communication environment, the UE 410, the network 420, the terrestrial network node 422, and / or the non-terrestrial network node 424 may implement various schemes for enhancing the PDCP on the control PDU related to the present disclosure, as described below. It is worth noting that although the various proposed schemes may be described separately or individually, in actual implementation, some or all of the proposed schemes may be used or implemented in combination. Of course, each proposed scheme may be used or implemented separately or individually.

[0024] In the current 5G NR framework, minimizing the SN gap after SDU discard depends on the UE implementation when a discarded PDCP SDU already associated with a PDCP SN exists. However, as mentioned above, in the case where many PDCP SDUs (e.g., PDU sets) are discarded and / or traffic is scheduled on split bearers, the SN gap created by the sender will cause reordering delays at the receiver. Therefore, the reordering delay will affect application layer throughput and user experience.

[0025] In view of the above situation, the present disclosure proposes some solutions for enhancing PDCP on control PDU for SN gap reporting. According to the solution of the present disclosure, a new PDCP control PDU specifically for PDCP SN gap reporting, as well as corresponding sending and receiving operations, is provided. Therefore, the sender (for example, a sending PDCP entity in a BS for a downlink scenario, or a sending PDCP entity in a UE for an uplink scenario) can allow the transmission of a new PDCP control PDU when a PDCP SN gap is detected with a discarded PDCP SDU, so that the receiver (for example, a receiving PDCP entity in a UE for a downlink scenario, or a receiving PDCP entity in a BS for an uplink scenario) can be notified of the PDCP SN gap in a timely manner to eliminate reordering delays.

[0026] Figure 5 An example scenario 500 of the operation of a PDCP at a sender and a receiver according to the present disclosure is shown. Figure 5 As shown, when it is detected that a PDCP SDU that has been associated with a PDCP SN is discarded, the sender may transmit a PDCP control PDU to the receiver to indicate a PDCP SN gap report (marked as PDCP SN=2 to 5) associated with the discarded PDCP SDU. When the PDCP control PDU is received, the receiver may consider that the PDCP SDU indicated in the PDCP control PDU is discarded (i.e., the sender will no longer transmit these PDCP SDUs). The receiver may then pass all stored PDCP SDUs and the PDCP SDUs that are considered discarded to upper layers (e.g., RRC, IP and / or AP layers) and update corresponding state variables (e.g., RX_NEXT, RX_DELIV and / or RX_REORD). In addition, or optionally, the receiver may stop and reset the t-Reordering timer. It is worth noting that due to the notification of the new PDCP control PDU, the receiver has almost no reordering delay (or only a very small reordering delay). Although scenario 500 depicts a one-to-one mapping between PDCP entities and RLC entities, the solution proposed in this disclosure can also be applied to the case of traffic scheduling on split bearers (i.e., one PDCP entity is mapped to or associated with two or more RLC entities, similar to Figure 3 Scene 300).

[0027] More specifically, the new PDCP Control PDU may indicate PDCP SN gap reporting by including an indication of the PDCP SN of at least one first discarded PDCP SDU. Additionally or alternatively, the new PDCP Control PDU may further indicate PDCP SN gap reporting by including an additional indication of the PDCP SN of subsequently discarded PDCP SDUs.

[0028] In some implementations, the indication of the PDCP SN of the first discarded PDCP SDU may be a first discard count (FDC), i.e., the COUNT value of the first discarded PDCP SDU within the reordering window. The COUNT value consists of the hyperframe number (HFN) and the PDCP SN. The HFN portion is equal to 32 minus the length of the PDCP SN.

[0029] In some implementations, the indication of the PDCP SN of the first discarded PDCP SDU may be the PDCP SN of the first discarded PDCP SDU itself. The length of the PDCP SN is 12 bits (e.g., for signaling radio bearers SRBs, unacknowledged mode UM data radio bearers DRBs, acknowledged mode AM DRBs (including sidelink SRBs and sidelink DRBs), UM multicast radio bearers MRBs, and AM MRBs) or 18 bits (e.g., for UM DRBs, AM DRBs (including sidelink DRBs for unicast), UM MRBs, and AM MRBs).

[0030] In some implementations, the additional indication of the PDCP SNs of the subsequently discarded PDCP SDUs may be a discard bitmap indicating which PDCP SDUs are discarded and which are not discarded at the transmitter.

[0031] In some implementations, an additional indication of the PDCP SNs of subsequent discarded PDCP SDUs may be the COUNT value of the last discarded PDCP SDU, assuming that the discarded PDCP SDUs (e.g., belonging to the same PDU set) are associated with consecutive PDCP SNs.

[0032] In some implementations, an additional indication of the PDCP SNs of subsequently discarded PDCP SDUs may be the number of discarded PDCP SDUs.

[0033] Figure 6 An example scenario 600 is shown in which a PDCP Control PDU is used for PDCP SN gap reporting according to an implementation of the present disclosure. Figure 6 (A) describes the format of the PDCP Control PDU used for PDCP SN gap reporting. Figure 6 (B) describes the interpretation of the PDU Type value. Figure 6The format of the FDC field is described in (C). Specifically, the new PDCP Control PDU may contain: (i) a PDU type with a value (e.g., bit value = '100') for PDCP SN gap reporting, (ii) an FDC indicating the minimum COUNT value among the COUNT values ​​associated with discarded PDCP SDUs, and (iii) a discard bitmap indicating which PDCP SDUs are discarded and which are not discarded at the transmitter.

[0034] Figure 7 An example scenario 700 is shown in which a PDCP Control PDU is used for PDCP SN gap reporting according to an implementation of the present disclosure. Figure 7 (A) describes the format of the PDCP Control PDU for PDCP SN gap reporting, which is applicable to data radio bearers (DRBs) with 18-bit PDCP SN. Figure 7 (B) The interpretation of the PDU type value is described in detail in Section 1. Specifically, the new PDCP Control PDU may contain: (i) a PDU type with a value (e.g., bit value = '100') for PDCP SN gap reporting, (ii) a PDCP SN indicating the minimum PDCP SN among the PDCP SNs associated with the discarded PDCP SDUs, and (iii) a discard bitmap indicating which PDCP SDUs are discarded and which PDCP SDUs are not discarded at the transmitter.

[0035] Figure 8 An example communication system 800 according to an implementation of the present disclosure is shown, including an example communication device 810 and an example network device 820. The communication device 810 and the network device 820 can each perform various functions to implement the schemes, techniques, processes, and methods described herein for controlling PDUs for SN gap reporting related to PDCP enhancements, including the scenarios / schemes described above and processes 900 and 1000 described below.

[0036] Communication device 810 may be part of an electronic device, which may be a two-way device comprising one or more user equipment (UE), such as a portable or mobile device, a wearable device, a wireless communication device, or a computing device. For example, communication device 810 may be implemented in a smartphone, a smartwatch, a personal digital assistant, an electronic control unit (ECU) in a vehicle, a digital camera, or a computing device, such as a tablet, a laptop, or a notebook computer. Communication device 810 may also be part of a machine-type device, such as an Internet of Things (IoT), narrowband Internet of Things (NB-IoT), enhanced machine-type communication (eMTC), or Industrial Internet of Things (IIoT) user equipment, such as a fixed or stationary device, a home device, a roadside unit (RSU), a wired communication device, or a computing device. For example, communication device 810 may be implemented in a smart thermostat, a smart refrigerator, a smart door lock, a wireless speaker, or a home control center. Alternatively, communication device 810 may be implemented in the form of one or more integrated circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more reduced instruction set computing (RISC) processors, or one or more complex instruction set computing (CISC) processors. The communication device 810 may include Figure 8 At least some of the components shown in FIG8 , such as processor 812. The communication device 810 may also include one or more other components not related to the solution proposed in the present disclosure (e.g., internal power supply, display device and / or user interface device), so for the sake of brevity, these components of the communication device 810 are not shown in FIG8 . Figure 8 It is not shown in the , nor described below.

[0037] The network device 820 may be part of an electronic device, which may be a network node, such as a satellite, a base station (BS), a small base station, a router, or a gateway of a 4G / 5G / B5G / 6G, New Radio (NR), Internet of Things (IoT), Narrowband Internet of Things (NB-IoT), or Industrial Internet of Things (IIoT) network. Alternatively, the network device 820 may be implemented in the form of one or more IC chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more RISC or CISC processors. The network device 820 may include Figure 8 820, such as processor 822. Network device 820 may also include one or more other components not related to the solutions proposed in the present disclosure (e.g., internal power supply, display device and / or user interface device), so for the sake of brevity, these components of network device 820 are not shown in FIG. Figure 8 It is not shown in the , nor described below.

[0038] In one aspect, processor 812 and processor 822 can be implemented in the form of one or more single-core processors, one or more multi-core processors, or one or more complex instruction set computing (CISC) processors, respectively. That is, although the singular term "a processor" is used herein to refer to processor 812 and processor 822, according to certain embodiments of the present disclosure, each processor 812 and processor 822 may include multiple processors in some implementations and a single processor in other implementations. In another aspect, each processor 812 and processor 822 can be implemented in the form of hardware (and, optionally, firmware), whose electronic components include but are not limited to one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors and / or one or more variable capacitors, which are configured and arranged according to various embodiments of the present disclosure to achieve specific purposes. In other words, in at least some implementations, each processor 812 and processor 822 is a special-purpose machine that is specifically designed, arranged, and configured to perform specific tasks, including wireless protocol stack operations (e.g., PDCP operations), in a device (e.g., represented by communication device 810) and in a network node (e.g., represented by network device 820) in accordance with various embodiments of the present disclosure.

[0039] In some implementations, the communication device 810 may also include a transceiver 816 connected to the processor 812 and capable of wirelessly transmitting and receiving data. In some implementations, the transceiver 816 may be capable of wirelessly communicating with different types of user equipment (UE) and / or wireless networks using different radio access technologies (RATs). In some implementations, the transceiver 816 may be equipped with multiple antenna ports (not shown), for example, four antenna ports. That is, the transceiver 816 may be equipped with multiple transmit antennas and multiple receive antennas for multiple-input, multiple-output (MIMO) wireless communication. In some implementations, the network device 820 may also include a transceiver 826 connected to the processor 822. The transceiver 826 may include a transceiver capable of wirelessly transmitting and receiving data. In some implementations, the transceiver 826 may be capable of wirelessly communicating with different types of UEs using different RATs. In some implementations, the transceiver 826 may be equipped with multiple antenna ports (not shown), for example, four antenna ports. That is, the transceiver 826 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

[0040] In some implementations, the communication device 810 may further include a memory 814 coupled to and accessible by the processor 812 and storing data therein. In some implementations, the network device 820 may further include a memory 824 coupled to and accessible by the processor 822 and storing data therein. Each of the memory 814 and the memory 824 may include a type of random access memory (RAM), such as dynamic RAM (DRAM), static RAM (SRAM), thyristor RAM (T-RAM), and / or zero-capacitance RAM (Z-RAM). Alternatively, or in addition, each of the memory 814 and the memory 824 may include a type of read-only memory (ROM), such as mask ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), and / or electrically erasable programmable ROM (EEPROM). Alternatively, or in addition, each of memory 814 and memory 824 may include a type of non-volatile random access memory (NVRAM), such as flash memory, solid-state memory, ferroelectric RAM (FeRAM), magnetoresistive RAM (MRAM), and / or phase change memory.

[0041] The communication device 810 and the network device 820 may be communication entities capable of communicating with each other using various solutions proposed in the present disclosure. For illustrative purposes and without limiting the scope, the following provides a description of the capabilities of the communication device 810 as a user equipment (UE) and the network device 820 as a network node (e.g., a base station BS), which is related to processes 900 and 1000.

[0042] Figure 9 An example process 900 is shown according to an embodiment of the present disclosure. Process 900 may be an example implementation of the above-described scenario / scheme, whether partial or complete, regarding PDCP enhancements to SN gap reporting on control PDUs. Process 900 may represent one aspect of an implementation feature of the network device 820 for a downlink scenario or the communication device 810 for an uplink scenario. Process 900 may include one or more operations, actions, or functions, as shown in one or more blocks 910 to 930. Although shown as discrete blocks, the various blocks of process 900 may be divided into more blocks, combined into fewer blocks, or eliminated depending on the desired implementation. In addition, the blocks of process 900 may be arranged in Figure 9The steps 900 may be performed in the order shown, or in a different order. Process 900 may be implemented by network device 820 or communication device 810 (or any suitable UE or machine-type device), as well as variations thereof. For illustrative purposes only and without limiting the scope, process 900 is described below in the context of a downlink scenario where network device 820 acts as a transmitter (e.g., a base station) and communication device 810 acts as a receiver (e.g., a user equipment terminal), or in the context of an uplink scenario where communication device 810 acts as a transmitter (e.g., a user equipment terminal) and network device 820 acts as a receiver (e.g., a base station). Process 900 may begin at block 910.

[0043] At 910 , process 900 may involve processor 822 / 812 of a transmitting device (eg, network / communication device 820 / 810 ) obtaining one or more PDCP SDUs from an upper layer (eg, RRC, IP, or AP layer).

[0044] At 920 , process 900 may involve processor 822 / 812 detecting one or more PDCP SDUs that were discarded before successful transmission to a receiving device (e.g., communication / network device 810 / 820 ), each PDCP SDU being associated with a PDCP SN. Process 900 may proceed from 920 to 930 .

[0045] At 930 , process 900 may involve the processor 822 / 812 transmitting a PDCP control PDU to a receiving device (eg, communication / network device 810 / 820 ) via the transceiver 826 / 816 , wherein the PDCP control PDU indicates a PDCP SN gap report associated with the discarded PDCP SDU.

[0046] In some implementations, a PDCP Control PDU may include a PDU type with a PDCP SN gap reporting value.

[0047] In some implementations, the PDCP Control PDU may include an FDC indicating a minimum count value among count values ​​associated with discarded PDCP SDUs.

[0048] In some implementations, the PDCP control PDU may further include a discard bitmap indicating which PDCP SDUs are discarded and which PDCP SDUs are not discarded in the transmitting device.

[0049] In some implementations, each count value associated with a discarded PDCP SDU may include a HFN and a PDCP SN.

[0050] In some implementations, process 900 may involve the processor 822 / 812 starting a discard timer when obtaining one of the PDCP SDUs from the upper layer, wherein if the discard timer expires for the PDCP SDU and all PDCP SDUs belong to a PDU set, and the PDCP SDU also belongs to the PDU set, then these PDCP SDUs will be discarded together with the corresponding PDCP data PDU. In some implementations, the corresponding PDCP data PDU in the PDU set may include a payload of a unit of information generated at the application layer. In some implementations, the information may include one or more frames or video slices for extended reality (XR) services. In some implementations, the PDCP SDU may be processed by a PDCP entity associated with two RLC entities. In some implementations, the sending device and the receiving device may include a network node (e.g., a base station BS) and a user equipment (UE).

[0051] Figure 10 An example process 1000 is shown according to an implementation scheme of the present disclosure. Process 1000 may represent one aspect of implementing the various designs, concepts, schemes, systems and methods proposed above, whether in part or in whole, regarding the enhancement of PDCP to SN gap reporting on control PDUs. Process 1000 may represent one aspect of implementing the features of communication device 810 for downlink scenarios or network device 820 for uplink scenarios. Process 1000 may include one or more operations, actions or functions, as shown in one or more blocks 1010 to 1030. Although shown as discrete blocks, the various blocks of process 1000 may be divided into more blocks, combined into fewer blocks, or eliminated depending on the desired implementation. In addition, the blocks / sub-blocks of process 1000 may be arranged as follows: Figure 10 , or in a different order. Process 1000 may be implemented by communication device 810 (or any suitable UE or machine-type device) or network device 820, as well as variations thereof. For illustrative purposes only and without limiting the scope, process 1000 is described below in the context of a downlink scenario where communication device 810 acts as a receiving device (e.g., a UE) and network device 820 acts as a transmitting device (e.g., a base station BS), or in the context of an uplink scenario where network device 820 acts as a receiving device (e.g., a base station BS) and communication device 810 acts as a transmitting device (e.g., a UE). Process 1000 may begin at block 1010.

[0052] At 1010, process 1000 may involve the processor 812 / 822 of the receiving device (e.g., the communication / network device 810 / 820) receiving a PDCP control PDU from the transmitting device (e.g., the network / communication device 820 / 810) via the transceiver 816 / 826, wherein the PDCP control PDU indicates a PDCP SN gap report associated with one or more PDCP SDUs. Process 1000 may continue from 1010 to 1020.

[0053] At 1020 , process 1000 may involve processor 812 / 822 determining that the PDCP SDU is to be discarded. Process 1000 may continue from 1020 to 1030 .

[0054] At 1030 , process 1000 may involve processor 812 / 822 delivering all stored PDCP SDUs and PDCP SDUs determined to be discarded to upper layers.

[0055] In some implementations, a PDCP Control PDU may include a PDU Type with a value for PDCP SN Gap reporting.

[0056] In some implementations, the PDCP control PDU may include an FDC indicating a minimum count value among the count values ​​associated with the PDCP SDUs determined to be discarded.

[0057] In some implementations, the PDCP control PDU may further include a discard bitmap indicating which PDCP SDUs are discarded and which PDCP SDUs are not discarded in the transmitting device.

[0058] In some implementations, each count value associated with a PDCP SDU may include a HFN and a PDCP SN.

[0059] In some implementations, process 1000 may involve processor 812 / 822 updating PDCP state variables and stopping and resetting a reordering timer.

[0060] In some implementations, one or more PDCP data PDUs associated with a PDCP SDU may belong to a PDU set and include a payload of a unit of information generated at the application layer.

[0061] In some implementations, this information may include one or more frames or video slices for the XR service.

[0062] In some implementations, a PDCP SDU may be processed by a PDCP entity associated with two RLC entities.

[0063] In some implementations, the transmitting apparatus and the receiving apparatus may include a network node (eg, a base station BS) and a UE.

[0064] The subject matter described herein sometimes shows different components contained within, or connected to, other different components. It should be understood that the architectures depicted in this manner are merely examples, and that many other architectures can actually be implemented to achieve the same functionality. Conceptually, any arrangement of components to achieve the same functionality is actually "associated" in order to achieve the desired functionality. Therefore, any two components combined here to achieve a particular functionality can be considered to be "associated" with each other in order to achieve the desired functionality, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered to be "operably connected" or "operably coupled" to each other in order to achieve the desired functionality, and any two components that can be so associated can also be considered to be "operably coupled" to each other in order to achieve the desired functionality. Specific examples of operable coupling include, but are not limited to, physically matable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interacting components.

[0065] Furthermore, with respect to virtually any plural and / or singular terms used herein, one having skill in the art can translate from the plural to the singular and / or from the singular to the plural as appropriate to the context and / or application. Various singular / plural permutations may be expressly provided herein for the sake of clarity.

[0066] Furthermore, those skilled in the art will understand that, in general, the terms used herein, particularly in the appended claims, such as the terms of the claim bodies, are generally considered to be "open" terms. For example, the word "comprising" should be interpreted as "including, but not limited to," the word "having" should be interpreted as "having at least," and the word "including" should be interpreted as "including, but not limited to," etc. Those skilled in the art will further understand that if an introduced claim recitation is intended to specify a particular number, such intent will be explicitly stated in the claim, and in the absence of such a statement, such intent is absent. For example, to aid understanding, the following appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of these phrases should not be construed to mean that any particular claim introducing a claim recitation with the indefinite article "a" or "an" only includes one implementation of such a recitation, even if the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an." For example, "a" and / or "an" should be interpreted as "at least one" or "one or more." The same applies to the use of definite articles used to introduce claim recitations. Furthermore, even if an introduced claim recitation explicitly recites a particular quantity, one skilled in the art will recognize that such recitation should be interpreted to include at least the stated quantity, e.g., merely reciting "two recitations," without other modifiers, means at least two recitations, or two or more recitations. Furthermore, where a convention similar to "at least one of A, B, and C, etc." is used, such construction is generally to be interpreted in accordance with the meaning understood by one skilled in the art, e.g., "a system having at least one of A, B, and C" would include, but is not limited to, systems consisting of only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc. Where a convention similar to "at least one of A, B, or C, etc." is used, such construction is generally to be interpreted in accordance with the meaning understood by one skilled in the art, e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems consisting of only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc. Those skilled in the art will further understand that almost any disjunctive word and / or phrase presenting two or more alternative terms in the description, claims, or drawings should be understood to include the possibility of one, either, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "only A," "only B," or "A and B."

Claims

1. A packet data convergence protocol enhancement method for sequence number gap reporting, characterized in that: include: A processor of a transmitting device obtains one or more Packet Data Convergence Protocol (PDCP) service data units (SDUs) from an upper layer; detecting, by the processor, that one or more PDCP SDUs are discarded before successful transmission to a receiving device, each PDCP SDU being associated with a PDCP sequence number SN; as well as The processor transmits a PDCP control protocol data unit (PDU) to the receiving device, wherein the PDCP control PDU indicates a PDCP SN gap report associated with the discarded PDCP SDU.

2. The method according to claim 1, wherein The PDCP control PDU includes a PDU type having a value for the PDCP SN gap report.

3. The method according to claim 1, wherein The PDCP control PDU includes a first discard count FDC, wherein the first FDC indicates a minimum count value among count values ​​associated with discarded PDCP SDUs.

4. The method according to claim 3, wherein The PDCP control PDU further includes a discard bitmap, wherein the discard bitmap indicates which PDCP SDUs are discarded and which PDCP SDUs are not discarded in the transmitting device.

5. The method according to claim 3, wherein Each count value associated with the discarded PDCP SDU includes a hyperframe number HFN and the PDCP SN.

6. The method according to claim 1, wherein Further including: The processor starts a discard timer when obtaining one of the PDCP SDUs from the upper layer. The PDCP SDU is discarded together with a corresponding PDCP data PDU if the discard timer expires for the PDCP SDU, and all PDCP SDUs belong to a PDU set, and the PDCP SDU also belongs to the PDU set.

7. The method according to claim 6, wherein The corresponding PDCP data PDU includes a payload of a unit of information generated at the application layer in the PDU set.

8. The method according to claim 7, wherein The unit information includes one or more frames or video slices for extended reality (XR) services.

9. The method according to claim 1, wherein The PDCP SDU is processed by a PDCP entity associated with two radio link control (RLC) entities.

10. The method according to claim 1, wherein The sending device and the receiving device include a network node and a user equipment UE.

11. A packet data convergence protocol enhancement method for sequence number gap reporting, characterized in that: include: A processor of a receiving device receives a PDCP control protocol data unit (PDU) from a sending device, wherein the PDCP control PDU indicates a PDCP SN gap report associated with one or more PDCP service data units (SDUs); Determining, by the processor, that the PDCP SDU is discarded; The processor delivers all stored PDCP SDUs and PDCP SDUs determined to be discarded to upper layers.

12. The method according to claim 11, wherein The PDCP control PDU includes a PDU type having a value for PDCP SN gap reporting.

13. The method according to claim 11, wherein The PDCP control PDU includes a first discard count FDC, wherein the first FDC indicates a minimum count value among count values ​​associated with the PDCP SDUs determined to be discarded.

14. The method according to claim 13, wherein The PDCP control PDU further includes a discard bitmap, which indicates which PDCP SDUs are discarded and which PDCP SDUs are not discarded in the transmitting device.

15. The method according to claim 13, wherein Each count value associated with the PDCP SDU includes a hyperframe number HFN and a PDCP SN.

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