Wireless communication method and device

Abstract

A wireless communication method is provided. A transmission device transmits, to a reception device, a control PDU indicating serial number SN information of a plurality of protocol data units (PDUs) discarded by a protocol layer entity of the transmission device. The control PDU comprises one or more SN windows, and in the SN windows, the SNs of the plurality of PDUs which are discarded are continuous.

Description

Technical Field

[0001] The present disclosure relates to the field of telecommunications, and in particular to a wireless communication method and device. Background Art

[0002] Wireless communication systems, such as the third generation (3G) mobile phone standards and technologies, are well known. Such 3G standards and technologies are developed by the Third Generation Partnership Project (3GPP). The third generation of wireless communications is generally developed to support macrocellular mobile phone communications. Communication systems and networks have evolved into broadband and mobile systems. In a cellular wireless communication system, a user equipment (UE) is connected to a radio access network (RAN) via a radio link. The RAN includes a set of base stations (BS) that provide radio links for the UEs located in the cells covered by the base stations and interface with a core network (CN) that provides overall network control. It is understood that the RAN and CN each perform corresponding functions related to the overall network. The Third Generation Partnership Project developed the so-called Long Term Evolution (LTE) system, i.e., the Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN), for mobile access networks, in which one or more macro cells are supported by base stations called eNodeBs or eNBs (evolved NodeBs). Recently, LTE has evolved further towards the so-called 5G or New Radio (NR) systems, in which one or more cells are supported by base stations called gNBs. Technical issues

[0003] The 5G wireless communication system is designed to provide enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), and massive machine type communication (MTC) services. In 5G or NR, the functions supporting eMBB, URLLC, and mMTC were introduced in Release 15 and enhanced in Releases 16 and 17.

[0004] Extended reality (XR) is an umbrella term that covers augmented reality (AR), mixed reality (MR), and virtual reality (VR). XR applications typically require high throughput and low latency, and cloud gaming is another application with the same requirements. XR and cloud gaming are important applications that 5G will enable.

[0005] XR services are characterized by their special traffic flows in real time, high data rate and low latency. XR video streams contain different frames / video slices. For example, a group of pictures (GOP) includes I / P / B frames. Some special characteristics of such XR service flows should be considered and supported in 5G.

[0006] On the one hand, the data size of different frames is different, and a frame can be divided into a group of data packets. However, the application can only decode these frames / video slices when all data packets of the frame / video slice are successfully received. A group of data packets belonging to a frame / video slice (hereinafter referred to as a data packet group) should be processed as a unit.

[0007] On the other hand, some types of data packet groups may depend on other data packet groups. For example, the data packets of P frames and B frames depend on the data packets of the I frames, and the data packets of B frames depend on the data packets of the P frames. In other words, there is a dependency relationship between different data packet groups.

[0008] Since the XR service is a real-time service, the outdated data packets are usually useless and should be discarded as soon as possible. In addition, due to the dependency of the data packet group of the XR service, the outdated data packet is usually a group of data packets. In another case, if the data packet transmission fails within a predefined time, the lost data packet will also cause a group of data packets to be discarded according to the dependency. The problems include: · how to transmit the discard indication; · How to handle the sequence number (SN) caused by the discard at the receiving side gap. Summary of the invention

[0009] The object of the present disclosure is to provide a wireless communication method and device.

[0010] In a first aspect, an embodiment of the present invention provides a wireless communication method, which may be executed in a wireless communication device, including: Transmitting a control protocol data unit PDU to a receiving device, wherein the control PDU indicates sequence number SN information of a protocol data unit PDU discarded by a protocol layer entity of the sending device; The control PDU includes one or more SN windows, in which the SNs of the discarded PDUs are continuous.

[0011] In a second aspect, an embodiment of the aforementioned invention provides a wireless communication apparatus, comprising a processor configured to call and run a computer program stored in a memory, so that a device equipped with the processor executes the method.

[0012] In a third aspect, the embodiments of the aforementioned invention provide a wireless communication method, which may be performed in a wireless communication device, comprising: receiving a control protocol data unit (PDU) from a sending device, wherein the control PDU indicates sequence number (SN) information of a plurality of protocol data units (PDUs) discarded by the sending device; The control PDU includes one or more SN windows, in which the SNs of the discarded multiple PDUs are continuous.

[0013] In a fourth aspect, an embodiment of the aforementioned invention provides a wireless communication apparatus, comprising a processor configured to call and run a computer program stored in a memory so that a device equipped with the processor executes the method.

[0014] The method may be implemented in a chip. The chip may include a processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the method.

[0015] The method may be programmed as computer-executable instructions stored in a non-transitory computer-readable medium. When the non-transitory computer-readable medium is loaded into a computer, it instructs the processor of the computer to execute the method.

[0016] The non-temporary computer-readable medium may include at least one of the following groups: a hard disk, a read-only compact disk (CD-ROM), an optical storage device, a magnetic storage device, a read-only memory (Read-Only Memory), a programmable read-only memory (Programmable Read-Only Memory), an erasable programmable read-only memory (ErasableProgrammable Read-Only Memory, EPROM), an electrically erasable programmable read-only memory (ElectricallyErasableProgrammableRead-OnlyMemory) and a flash memory.

[0017] The method can be programmed as a computer program product to enable a computer to execute the method.

[0018] The method can be programmed as a computer program to make a computer execute the method. Beneficial Effects

[0019] An embodiment of the present disclosure provides a method in which a sending device transmits a discard indication to enable a receiving device to correctly handle a sequence number (SN) gap caused by discarding a group of PDUs.

[0020] An embodiment of the present disclosure provides a method in which a receiving device receives a plurality of protocol data units (PDUs) according to a discard control PDU, so that PDU reception can work smoothly and correctly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments or related technologies of the present disclosure, the following figures will be briefly introduced in the embodiments. Obviously, the figures are only some embodiments of the present disclosure, and ordinary technicians in this field can obtain other figures based on these figures without paying any prerequisites.

[0022] Figure 1 A schematic diagram of a telecommunication system is shown.

[0023] Figure 2 A schematic diagram showing a network embodiment of the wireless communication method.

[0024] Figure 3 A schematic diagram showing the protocol layers of a sending device and a receiving device.

[0025] Figure 4 A schematic diagram of a wireless communication method according to an embodiment of the present disclosure is shown.

[0026] Figure 5 Schematic diagram showing an example of packet dropping.

[0027] Figure 6 Schematic diagram showing an example of packet dropping.

[0028] Figure 7 A schematic diagram of a Packet Data Convergence Protocol (PDCP) discard indication protocol data unit (PDU) is shown.

[0029] Figure 8 A schematic diagram of a Radio Link Control (RLC) discard indication PDU with a 12-bit SN is shown.

[0030] Fig. 9 A schematic diagram of a PDU discarding method in a receiving PDCP layer entity is shown.

[0031] Fig.10 A schematic diagram showing modified PDU reception in a receiving RLC layer entity is shown.

[0032] Fig.11 A schematic diagram of a PDU discarding method in a receiving PDCP layer entity is shown.

[0033] Fig.12 A schematic diagram showing modified PDU reception in a receiving RLC layer entity is shown.

[0034] Fig.13 is a block diagram of a wireless communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] The embodiments of the present disclosure are described in detail as follows with reference to the accompanying drawings in combination with the technical matters, structural features, implementation objectives and effects. Specifically, the terms described in the embodiments are only used for the purpose of describing the specific embodiments, and are not intended to limit the present disclosure. The abbreviations used in the description herein are listed in the following table: Table 1

[0036] The present invention discloses a wireless communication method for processing XR traffic in an extended reality (XR) service. The XR service may include augmented reality (AR), virtual reality (VR) or mixed reality (MR).

[0037] In the description herein, a data packet may be a protocol data unit (PDU) or a service data unit (SDU) of a protocol layer. For simplicity, the term "data packet" may refer to a PDU or an SDU, and the term "PDU" may refer to a PDU or an SDU.

[0038] In the description of this article, the dependent data unit is called the dependent data unit, and the data unit that depends on the dependent data unit is called the dependent data unit. For example, the dependent data radio bearer (DRB) is called the dependent DRB, and the DRB that depends on the dependent DRB is called the dependent DRB. Similarly, the dependent PDU set is called the dependent PDU set, and the PDU set that depends on the dependent PDU set is called the dependent PDU set. The dependent data packet is called the dependent data packet, and the data packet that depends on the dependent data packet is called the dependent data packet. The dependent quality of service flow (QoSFlow) is called the dependent QoS flow, and the QoS flow that depends on the dependent QoS flow is called the dependent QoS flow. The dependent sub-QoS flow is called the dependent sub-QoS flow, and the sub-QoS flow that depends on the dependent sub-QoS flow is called the dependent sub-QoS flow.

[0039] As an enhancement to the current QoS framework to support XR services, 3GPP SA2 introduced a concept called “PDU Set” in the Technical Report (TR) 23.700-60.

[0040] A PDU set consists of one or more PDUs carrying a payload of an information unit generated by the application layer (e.g., a frame or video slice of an XR service, as used in TR 26.926). In some implementations, the application layer requires all PDUs in a PDU set to use the information unit. In other implementations, the application layer may recover part or all of the information unit when some PDUs are missing.

[0041] For XR traffic, such as one or more service traffic flows, a PDU set can be a group of packets or PDUs that can be decoded or processed as a whole unit at the application layer. XR traffic has some potential dependencies between packets within a PDU set and / or between PDU sets. A service traffic flow for an XR service may include multiple types of PDU sets with different importance levels and QoS requirements.

[0042] Reference Figure 1 A telecommunication system including a user equipment (UE) 10a, a UE 10b, a base station (BS) 20a and a network entity device 30 performs the method according to an embodiment of the present disclosure. Figure 1For example only and not limitation, the system may include more UE, BS and core network (CN) entities. The connections between devices and device components are shown as lines and arrows in the figure. The UE 10a may include a processor 11a, a memory 12a and a transceiver 13a. The UE 10b may include a processor 11b, a memory 12b and a transceiver 13b. The base station 20a may include a processor 21a, a memory 22a and a transceiver 23a. The network entity device 30 may include a processor 31, a memory 32 and a transceiver 33. Each of the processors 11a, 11b, 21a and 31 may be configured to implement the functions, processes and / or methods proposed in the description herein. The various layers of the wireless interface protocol may be implemented in the processors 11a, 11b, 21a and 31. Each of the memories 12a, 12b, 22a and 32 stores various programs and information in an operational manner to operate the connected processors. Each of the transceivers 13a, 13b, 23a and 33 is operatively coupled to a connected processor to send and / or receive wireless signals or wired signals. The UE 10a can communicate with the UE 10b via a side link. The base station 20a can be one of an evolved Node B (eNB), a next generation Node B (gNB) or other types of wireless nodes, and can configure wireless resources for the UE 10a and UE 10b.

[0043] The network entity device 30 may be a node in CN. CN may include Long Term Evolution (LTE) CN or 5G Core (5G Core, 5GC), including User Plane Function (UPF), Session Management Function (SMF), 5G Core Access and Mobility Management Function (AMF), Unified Data Management (UDM), Policy Control Function (PCF), Control Plane (CP) / User Plane (UP) Separation (CUPS), Authentication Server Function (AUSF), Network Slice Selection Function (NSSF) and the Network Exposure Function (NEF).

[0044] The example of the UE described in this article may include one of the UE 10a or the UE 10b. The example of the base station described in this article may include the base station 20a. The transmission of an uplink (UL) control signal or data may be a transmission operation from the UE to the base station. The transmission of a downlink (DL) control signal or data may be a transmission operation from the base station to the UE. The downlink control signal may include a downlink control information (DCI) or a radio resource control (RRC) signal from the base station to the UE.

[0045] Figure 2 It is a transmission network model of XR services supported by the 5G system. UE 10 is a 5G terminal that supports XR services and XR applications, and can be called a client, a client terminal or an XR client. gNB 20 is a 5G wireless node. The gNB 20 communicates with the UE 10 and provides the UE with NR user plane and control plane protocol termination through the New Radio (NR) Uu interface. The gNB 20 is connected to the 5G Core (5G Core, 5GC) 300 through the NG interface. UPF 30b is the User Plane Function (UPF) in the 5GC 300, that is, the 5G Core Network. Data Network (DN) 40 is the data network where the XR server 41 providing XR services is located. The DN 40 can provide network operator services, Internet access or third-party services. The XR server 41 may include a processor 411, a memory 412 and a transceiver 413. The processor 411 may be configured to implement the XR service-related functions, processes and / or methods described in the description of this article. Each layer of the wireless interface protocol may be implemented in the processor 411. The memory 412 operatively stores various programs and information to operate the connected processor. The transceiver 413 operatively couples with the connected processor to send and / or receive wireless signals or wired signals.

[0046] Each of the processors 411, 11a, 11b, 21a and 31 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. Each of the memories 412, 12a, 12b, 22a and 32 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium and / or other storage devices. Each of the transceivers 413, 13a, 13b, 23a and 33 may include a baseband circuit and a radio frequency (RF) circuit to process radio frequency signals. When the embodiments are implemented in software, the techniques described herein may be implemented by modules, processes, functions, entities, etc. that perform the functions described herein. The modules may be stored in a memory and executed by the processor. The memory may be implemented inside the processor or outside the processor, and in the latter case, may be communicatively coupled to the processor in various ways known in the art. The device that performs the wireless communication method may be a sending device that sends an XR traffic stream of an XR service to a receiving device, or a receiving device that receives the XR traffic stream. The XR traffic flow may include one or more service traffic flows of the XR service. For example, the device that performs the wireless communication method may include the gNB 20, the XR server 41 in the data network 40, or the UE. That is, the XR server 41 in the data network 40 may be used as a sending device that performs the wireless communication method in certain XR traffic transmission scenarios, and one or more XR clients (for example, one or more of the UE 10, UE 10a, and UE 10b) receive the XR traffic flow sent from the sending device as a receiving device. Similarly, an XR client (for example, one or more of the UE 10, UE 10a, and UE 10b) may perform the wireless communication method as a sending device in certain XR traffic transmission scenarios, and another XR client or the XR server 41 receives the XR traffic flow sent from the sending device as a receiving device. Alternatively, the sending device may include an intermediate device between the UE 10 and the XR server 41. The UE 10 may include an embodiment of the UE 10a or UE 10b. The gNB 20 may include an embodiment of the base station 20a. Note that although the gNB 20 and UPF / 5GC 30b are used as examples in the description herein, the wireless communication method may be performed by a base station, such as another gNB, an eNB, a base station integrating an eNB and a gNB, or a base station for technologies above 5G. The UPF / 5GC 30b may include another network entity of the 5GC.

[0047] A service traffic flow 5, such as an XR flow of an XR service, is established between the UE 10 and the XR server 41. The flow 5 includes a traffic flow 51 from the XR server 41 to the UE 10 and a traffic flow 52 from the UE 10 to the XR server 41.

[0048] In the description herein, a layer, such as an application layer, a PDCP layer, an RLC layer, a MAC layer, or a physical layer (Physical Layer, PHY layer or L1 layer), may be a protocol layer entity in a transmitting device or a receiving device. The protocol layer entity may be implemented by a program or software module executed by a processor, or by a hardware module in an integrated circuit (IC).

[0049] Reference Figure 3 , an example of the sending device is shown as a sending device 10c, and an example of the receiving device is shown as a receiving device 10d. The sending device 10c includes a physical layer (PHY layer or L1 layer) 14c, a MAC layer 15c, an RLC layer 16c, a PDCP layer 17c, an RRC layer 18c, and an application layer 19c. The receiving device 10d includes a physical layer (PHY layer or L1 layer) 14d, a MAC layer 15d, an RLC layer 16d, a PDCP layer 17d, an RRC layer 18d, and an application layer 19d. For example, when the application layer 19c of the sending device 10c sends a PDU to the application layer 19d of the receiving device 10d through a lower layer (i.e., the PDCP layer 17c, the RLC layer 16c, the MAC layer 15c, and the physical layer 14c), the layers in the sending device 10c serve as a sending protocol layer entity on the sending side, and the layers in the receiving device 10d serve as a receiving protocol layer entity on the receiving side. The embodiments of the present disclosure may be implemented in the PDCP layer or the RLC layer. One or more steps (or blocks) in the embodiments of the present disclosure may be implemented as a computer program, instruction, software module stored in a memory of the transmitting device, or a circuit or hardware module in a processor of the transmitting device, or an IC chip, circuit or plug-in of the transmitting device.

[0050] The video stream of the XR service will be quasi-periodically encoded and compressed in the form of frames, with the respective frame periodicity of 1 / 60, 1 / 90 or 1 / 120 seconds. Since the sending device can divide the video stream of the XR service into multiple transmission units, encapsulate and transmit each of the transmission units as a transmission data packet transmitted through the network, the transmission mechanism of the XR service is actually based on data packets rather than frames. The size of each of the data packets is variable, and the number of each of the data packets is variable and can be configured based on one or more parameters of the QoS requirements and the characteristics of the XR service, such as packet delay budget (PDB), packet error rate (PER), packet loss rate (PLR), frame error rate, frame delay budget, resolution, frame rate and / or data rate.

[0051] Reference Figure 4 , the sending device 10c and the receiving device 10d execute the embodiment of the method and start the XR service.

[0052] The sending device 10c sends a control PDU to the receiving device 10d, wherein the control PDU indicates sequence number SN information (310) of multiple protocol data units (PDUs) discarded by the protocol layer entity of the sending device. The control PDU includes one or more SN windows, in which the SNs of the discarded multiple PDUs are continuous.

[0053] The receiving device 10d receives a control PDU from the sending device 10c, the control PDU indicating sequence number SN information of a plurality of protocol data units (PDUs) discarded by the sending device (303).

[0054] The control PDU includes one or more SN windows, in which the SNs of the discarded multiple PDUs are continuous. The control PDU may be a control PDU of a protocol layer, such as PDCP, RLC and / or others. The control PDU includes an E field, and the E field indicates whether another SN window is configured after the E field. Therefore, multiple SN windows may be indicated in one control PDU. 301 and 303 may be performed at the protocol layer.

[0055] In one embodiment, the control PDU is a Data Packet Convergence Protocol (PDCP) discard indication PDU, comprising a PDU type field for indicating a PDU type of the PDCP discard indication PDU.

[0056] The PDCP discard indication PDU includes a configuration of an SN window in the one or more SN windows, and the configuration of the SN window includes: The MinDC field in the PDCP discard indication PDU indicates a minimum discard count (Minimum DiscardCOUNT), corresponding to the minimum PDCP PDU SN in the SN window; The MaxDC field in the PDCP discard indication PDU indicates a maximum discard count (Maximum DiscardCOUNT), corresponding to the maximum PDCP PDU SN in the SN window.

[0057] In one embodiment, the receiving protocol layer entity discards the received multiple PDUs in the SN window when receiving the PDCP data PDU from the lower layer.

[0058] In one embodiment, the protocol layer entity is a PDCP layer and the lower layer is a Radio Link Control (RLC) layer.

[0059] In one embodiment, the protocol layer entity modifies a parameter indicating a waiting PDU count value in the PDCP layer of the receiving device to MaxDC+1 when receiving a PDCP data PDU from a lower layer, wherein the waiting PDU has not yet been transmitted to an upper layer. In one embodiment, the parameter is RX_DELIV or RX_NEXT.

[0060] In one embodiment, when the timer t-Reordering times out, the protocol layer entity modifies a parameter indicating a waiting PDU count value in the PDCP layer of the receiving device to MaxDC+1, wherein the waiting PDU has not yet been transmitted to the upper layer. In one embodiment, the parameter is RX_DELIV.

[0061] In one embodiment, the control PDU is a radio link control (RLC) discard indication PDU, comprising a PDU type field for indicating the PDU type of the RLC discard indication PDU.

[0062] The RLC discard indication PDU includes a configuration of an SN window in the one or more SN windows, and the configuration of the SN window includes: The MinSN field in the RLC discard indication PDU indicates a minimum discard SN (Minimum Discard SN), corresponding to the minimum RLC PDU SN in the SN window; The MaxSN field in the RLC discard indication PDU indicates a maximum discard SN (Maximum Discard SN), corresponding to the maximum RLC PDU SN in the SN window.

[0063] In one embodiment, the receiving protocol layer entity discards the received plurality of PDUs in the SN window upon receiving a UMD PDU from a lower layer.

[0064] In one embodiment, the protocol layer entity is an RLC layer, and the lower layer is a Medium Access Control (MAC) layer.

[0065] In one embodiment, when the protocol layer entity places the UMD PDU in the receiving buffer of the RLC layer, it modifies a parameter indicating the earliest SN for reassembly in the RLC layer of the receiving device to MaxSN + 1. In one embodiment, the parameter is RX_Next_Reassembly or RX_Next_Highest.

[0066] In one embodiment, when the timer t-Reassembly times out, the protocol layer entity modifies a parameter indicating the earliest SN for reassembly in the RLC layer of the receiving device to MaxSN + 1. In one embodiment, the parameter is RX_Next_Reassembly.

[0067] Packet drops and indications:

[0068] Since a PDU set may include multiple data packets or PDUs, including dependent PDUs and dependent PDUs, the PDU discarding may include discarding a group of data packets of one or more PDU sets. Figure 5 As shown in FIG. 1 , multiple PDUs in PDU set (SN=n+1) and PDU set (SN=n+2) are discarded. Figure 6 As shown, multiple PDUs in PDU set (SN=n+1) and PDU set (SN=n+3) are discarded.

[0069] When the packet discard occurs on the DRB, an SN gap will be generated, which may affect the receiving operation. A method for processing the SN gap caused by the packet discard is disclosed below, which is particularly applicable to transmission based on PDCP and UM RLC protocols.

[0070] The sending device sends a control PDU to the receiving device to indicate SN information of the discarded multiple PDUs. The indicated SN information includes one or more of the following: ●The minimum SN among the discarded multiple PDUs; The maximum SN of the discarded multiple PDUs; One or more SN windows, in which the SNs of the discarded multiple PDUs are continuous, each window comprising: ■The minimum SN of the SN window; ■The maximum SN of the SN window.

[0071] In one embodiment, the PDU discard is performed in PDCP and can be defined as follows: Figure 7 The PDCP control PDU is shown and named as PDCP discard indication PDU: ●For the PDU type field in the PDCP discard indication PDU, a new PDU type is defined as the PDU discard indicator (ie, the PDU type of the PDCP discard indication PDU). ●The MinDC field in the PDCP discard indication PDU indicates the minimum discard count (Minimum DiscardCOUNT), corresponding to the minimum PDCP PDU SN in the SN window. The MaxDC field in the PDCP discard indication PDU indicates the maximum discard count (Maximum DiscardCOUNT), which corresponds to the maximum PDCP PDU SN in the SN window. MinDC and MaxDC are configurations of the SN window. ●The E field in the PDCP discard indication PDU is an optional extension bit used to indicate whether there is another SN window following. The E field value of 1 indicates that there is another SN window following, and the value of 0 indicates that there is no other SN window following. Specifically, the E field value of 1 indicates that the configuration of the subsequent SN window follows the configuration of the SN window before the E field, and the value of 0 indicates that there is no other SN window configuration following the configuration of the SN window before the E field.

[0072] In one embodiment, the PDU discard is performed in RLC. Figure 8 As shown, an RLC control PDU may be defined for RLC UM data transmission and named RLC discard indication PDU: ●Define a new Control PDU Type (CPT) field in the RLC discard indication PDU as the PDU discard indicator (ie, the PDU type of the RLC discard indication PDU). ●The MinSN field in the RLC discard indication PDU indicates the minimum discard SN (Minimum Discard SN), which corresponds to the minimum RLC PDU SN in the SN window. The MaxSN field in the RLC discard indication PDU indicates the maximum discard SN (Maximum Discard SN), which corresponds to the maximum RLC PDU SN in the SN window. MinDC and MaxDC are the configurations of the SN window. ●The E field in the RLC discard indication PDU is an optional extension bit used to indicate whether there is another SN window following. The E field value of 1 indicates that there is another SN window following, and the value of 0 indicates that there is no other SN window following. Specifically, the E field value of 1 indicates that the configuration of the subsequent SN window follows the configuration of the SN window before the E field, and the value of 0 indicates that there is no other SN window configuration following the configuration of the SN window before the E field. ●The length of the SN may be different, and the format of the RLC control PDU may be correspondingly different.

[0073] PDU reception based on the discard indication:

[0074] The following definitions are used in this description. The definitions are consistent with and can be found in 3GPP TS 38.323:

[0075] RX_NEXT: This state variable indicates the count (COUNT) value of the next PDCP SDU expected to be received. The initial value is 0, unless used for sidelink broadcast and multicast, and Signaling Radio Bearers (SRBs) for which state variable persistence is configured. For broadcast and multicast of New Radio (NR) sidelink communications, the initial value of the SN part of the RX_NEXT is (x+1) modulo (2[sl-PDCP-SN-Size]), where x is the SN of the first received PDCP data PDU. For a target SRB for which state variable persistence is configured, the initial value is the value stored in the PDCP entity for the corresponding source SRB. For a source SRB for which state variable persistence is configured, the initial value is the value stored in the PDCP entity for the corresponding target SRB.

[0076] For broadcast and multicast of NR sidelink communications, depending on the UE implementation, the HFN part of the RX_NEXT is selected so that the initial value of RX_DELIV should be positive.

[0077] RX_DELIV: This state variable indicates the COUNT value of the first PDCP SDU that has not yet been delivered to the upper layer but is still pending. The initial value is 0, except for sidelink broadcast and multicast, and SRBs with state variable persistence configured. For broadcast and multicast of NR sidelink communications, the initial value of the SN part of the RX_DELIV is (x – 0.5× 2[sl-PDCP-SN-Size–1]) modulo (2[sl-PDCP-SN-Size]), where x is the SN of the first received PDCP data PDU. For a target SRB with state variable persistence configured, the initial value is the value stored in the PDCP entity for the corresponding source SRB. For a source SRB with state variable persistence configured, the initial value is the value stored in the PDCP entity for the corresponding target SRB.

[0078] The parameter sl-PDCP-SN-Size is defined in 3GPP TS 38.331. sl-PDCP-SN-Size is the length of the PDCP sequence number for unicast NR sidelink communications, 12 bits or 18 bits, as specified in TS38.323. For multicast and broadcast NR sidelink communications, only 18 bits apply.

[0079] RX_REORD: This state variable indicates the COUNT value after the COUNT value associated with the PDCP data PDU that triggered t-Reordering. For a target SRB with state variable persistence configured, the initial value is the value stored in the PDCP entity for the corresponding source SRB. For a source SRB with state variable persistence configured, the initial value is the value stored in the PDCP entity for the corresponding target SRB.

[0080] t-Reordering: The duration of the timer t-Reordering is configured by upper layers as specified in TS 38.331, except in the case of NR sidelink communication. For NR sidelink communication, the t-Reordering timer is determined by the UE implementation. This timer is used to detect the loss of PDCP data PDUs as specified in TS 38.323 clause 5.2.2. If t-Reordering is running, t-Reordering should not be started again, i.e. only one t-Reordering is run per receiving PDCP entity at a given time.

[0081] The receiving device receives the multiple PDUs according to the discard control PDU as follows:

[0082] In one embodiment, the PDU discard is performed in PDCP, and the PDCP control PDU is defined as Figure 7 After the PDCP entity receives the PDCP discard indication PDU, based on the current PDCP protocol, the receiving operation is shown below, as an enhancement to TS 38.323, and the emphasized content is a newly added part: Table 2

[0083] Reference Fig. 9 , the receiving device performs the following operations:

[0084] The protocol layer entity (eg, PDCP layer) in the receiving device receives and decodes a PDCP discard indication PDU from the sending device (C101). The protocol layer entity decodes the PDCP discard indication PDU to determine whether any SN window is indicated in the PDCP discard indication PDU.

[0085] When one or more SN windows are indicated in the PDCP discard indication PDU, the protocol layer entity obtains each of the one or more SN windows as the current SN window, and performs the following operations on each SN window. Upon receiving a PDCP data PDU (C102), the protocol layer entity obtains the current SN window with [MinCD, MaxCD] (C103), and determines whether the parameter RCVD_COUNT associated with the PDCP data PDU is within the range [MinCD, MaxCD] (C104), that is, whether the RCVD_COUNT associated with the PDCP data PDU satisfies the condition MinCD≤RCVD_COUNT≤MaxCD.

[0086] When the RCVD_COUNT associated with the PDCP data PDU satisfies the condition MinCD≤RCVD_COUNT≤MaxCD, the protocol layer entity discards the PDCP data PDU (C106).

[0087] When the RCVD_COUNT associated with the PDCP data PDU does not satisfy the condition MinCD≤RCVD_COUNT≤MaxCD, the protocol layer entity determines whether the SN window is the last SN window among the windows indicated by the PDCP discard indication PDU (C105). If the SN window is not the last SN window, the protocol layer entity obtains the next one of the one or more SN windows indicated by the PDCP discard indication PDU as the current SN window (C107), and executes step C104. If the SN window is the last SN window, the execution is terminated.

[0088] Reference Fig.10 , the receiving device performs the following operations:

[0089] A protocol layer entity (e.g., a PDCP layer) in the receiving device receives and decodes a PDCP discard indication PDU from the sending device (C201). The protocol layer entity decodes the PDCP discard indication PDU to determine whether a plurality of SN windows are indicated in the PDCP discard indication PDU and the plurality of SN windows indicated in the PDCP discard indication PDU are not sorted (C203).

[0090] When multiple SN windows are indicated in the PDCP discard indication PDU and are not sorted, the protocol layer entity sorts all the SN windows in ascending order according to the MinCD and MaxCD values ​​of each SN window (C204), obtains each of the one or more SN windows as the current SN window, and performs the following operations on each SN window.

[0091] When receiving the PDCP data PDU (C205), the protocol layer entity obtains the current SN window with [MinCD, MaxCD] (C206), and determines whether the parameter RX_DELIV associated with the PDCP data PDU is within the range [MinCD, MaxCD] (C207), that is, whether the RX_DELIV associated with the PDCP data PDU satisfies the condition MinCD≤RX_DELIV≤MaxCD.

[0092] When the RX_DELIV associated with the PDCP data PDU does not satisfy the condition MinCD≤RX_DELIV≤MaxCD, the protocol layer entity does not perform any operation on the RX_DELIV and executes C209.

[0093] When the RX_DELIV associated with the PDCP data PDU satisfies the condition MinCD≤RX_DELIV≤MaxCD, the protocol layer entity updates the RX_DELIV to MaxDC+1 (C208).

[0094] The protocol layer entity determines whether the SN window is the last SN window among the windows indicated by the PDCP discard indication PDU (C209). If the SN window is not the last SN window, the protocol layer entity obtains the next one of the one or more SN windows indicated by the PDCP discard indication PDU as the current SN window (C210), and executes step C207. If the SN window is the last SN window, the execution is terminated.

[0095] The following definitions are used in the embodiments. The definitions are consistent with and can be found in 3GPP TS 38.322:

[0096] TX_NEXT: TX_Next - UM transmission state variable. This state variable stores the SN value assigned to the next newly generated UMD PDU with segment. It is initially set to 0 and is updated after the UM RLC entity submits the UMD PDU containing the last segment of the RLC SDU to the lower layer.

[0097] RX_Next_Reassembly: RX_Next_Reassembly is a UM receive state variable. This state variable holds the earliest SN value still considered for reassembly. It is initially set to 0. For multicast and broadcast of NR sidelink communications, it is initially set to the SN of the first received UMD PDU containing an SN.

[0098] RX_Next_Highest: RX_Next_Highest is the highest receiving state variable. This state variable stores the SN value after the SN of the RLC SDU with the highest SN among the received RLC SDUs. It is initially set to 0.

[0099] t-Reassembly: The t-Reassembly timer is used by the receiving side of the AM RLC entity and the receiving UM RLC entity to detect the loss of lower layer RLC PDUs (see subclauses 5.2.2.2 and 5.2.3.2 of TS 38.322). If a t-Reassembly is running, then a t-Reassembly should not be started again, i.e. only one t-Reassembly is running per RLC entity at a given time.

[0100] In one embodiment, the PDU discard is performed in RLC UM data transmission, and the RLC control PDU is defined as Figure 8 After the RLC entity of the receiving device receives the RLC discard indication PDU, based on the current RLC protocol, the receiving operation is provided as follows, as an enhancement to TS 38.322, and the emphasized content is a newly added part: Table 3

[0101] Reference Fig.11 , the receiving device performs the following operations:

[0102] The protocol layer entity (eg, RLC layer) in the receiving device receives and decodes an RLC discard indication PDU from the sending device (D101). The protocol layer entity decodes the RLC discard indication PDU to determine whether any SN window is indicated in the RLC discard indication PDU.

[0103] When one or more SN windows are indicated in the RLC discard indication PDU, the protocol layer entity obtains each of the one or more SN windows as the current SN window, and performs the following operations on each SN window. Upon receiving an RLC data PDU (D102), the protocol layer entity obtains the current SN window having [MinSN, MaxSN] (D103), and determines whether the SN associated with the RLC data PDU is within the range [MinSN, MaxSN] (D104), that is, whether the SN associated with the RLC data PDU satisfies the condition MinSN≤SN≤MaxSN.

[0104] When the SN associated with the RLC data PDU satisfies the condition MinSN≤SN≤MaxSN, the protocol layer entity discards the RLC data PDU (D106).

[0105] When the SN associated with the RLC data PDU does not satisfy the condition MinSN≤SN≤MaxSN, the protocol layer entity determines whether the SN window is the last SN window among the windows indicated by the RLC discard indication PDU (D105). If the SN window is not the last SN window, the protocol layer entity obtains the next one of the one or more SN windows indicated by the RLC discard indication PDU as the current SN window (D107), and executes step D104. If the SN window is the last SN window, the execution terminates.

[0106] Reference Fig.12 , the receiving device performs the following operations:

[0107] The protocol layer entity (e.g., RLC layer) in the receiving device receives and decodes an RLC discard indication PDU from the sending device (D201). The protocol layer entity decodes the RLC discard indication PDU to determine whether multiple SN windows are indicated in the RLC discard indication PDU and the multiple SN windows indicated in the RLC discard indication PDU are not sorted (D203).

[0108] When multiple SN windows are indicated in the RLC discard indication PDU and are not sorted, the protocol layer entity sorts all the SN windows in ascending order according to the MinSN and MaxSN values ​​of each SN window (D204), obtains each of the one or more SN windows as the current SN window, and performs the following operations on each SN window.

[0109] Upon receiving the RLC data PDU (D205), the protocol layer entity obtains the current SN window having [MinSN, MaxSN] (D206), and determines whether the parameter RX_NEXT associated with the RLC data PDU is within the range [MinSN, MaxSN] (D207), that is, whether the RX_NEXT associated with the RLC data PDU satisfies the condition MinSN≤RX_NEXT≤MaxSN. The RX_NEXT may include RX_Next_Reassembly and / or RX_Next_Highest.

[0110] When the RX_NEXT associated with the RLC data PDU does not satisfy the condition MinSN≤RX_NEXT≤MaxSN, the protocol layer entity does not perform any operation on the RX_NEXT and executes D209.

[0111] When the RX_NEXT associated with the RLC data PDU satisfies the condition MinSN≤RX_NEXT≤MaxSN, the protocol layer entity updates the RX_NEXT to MaxDC+1 (D208).

[0112] The protocol layer entity determines whether the SN window is the last SN window among the windows indicated by the RLC discard indication PDU (D209). If the SN window is not the last SN window, the protocol layer entity obtains the next one of the one or more SN windows indicated by the RLC discard indication PDU as the current SN window (D210), and executes step D206. If the SN window is the last SN window, the execution is terminated.

[0113] Fig.13 7 is a block diagram of an exemplary system 700 for wireless communication according to an embodiment of the present disclosure. The embodiments described herein may be implemented in the system using any suitably configured hardware and / or software. Fig.13 The system 700 is shown, including a radio frequency (RF) circuit 710, a baseband circuit 720, a processing unit 730, a memory / storage 740, a display 750, a camera 760, a sensor 770 and an input / output (I / O) interface 780, which are coupled to each other as shown.

[0114] The processing unit 730 may include circuits such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors and application processors). The processor may be coupled to the memory / storage and configured to execute instructions stored in the memory / storage to enable various applications and / or operating systems running on the system.

[0115] The wireless control function may include, but is not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuit may support communications with 5G New Radio (NR), Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (EUTRAN) and other wireless metropolitan area networks (WMAN), wireless local area networks (WLAN), and wireless personal area networks (WPAN). An embodiment in which the baseband circuit is configured to support wireless communications of multiple wireless protocols may be referred to as a multi-mode baseband circuit. In various embodiments, the baseband circuit 720 may include circuits for operating signals that are not strictly regarded as baseband frequencies. For example, in some embodiments, the baseband circuit may include circuits for operating signals having an intermediate frequency between a baseband frequency and a radio frequency.

[0116] In various embodiments, the system 700 may be a mobile computing device, such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, etc. In various embodiments, the system may have more or fewer components, and / or a different architecture. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

[0117] The described embodiments of the present disclosure are a combination of techniques / processes that may be adopted in 3GPP specifications to create a final product.

[0118] If the software functional unit is implemented as a product and used and sold, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution proposed in the present disclosure can be essentially or partially implemented in the form of the software product. Alternatively, a part of the technical solution that is beneficial to the traditional technology can be implemented in the form of the software product. The computer software product is stored in a storage medium and includes multiple commands for causing a computing device (such as a personal computer, a server, or a network device) to run all or part of the steps disclosed in the embodiment of the present disclosure. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other medium capable of storing program code.

[0119] While the present disclosure has been described in connection with what is considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements within the scope thereof without departing from the broadest interpretation of the appended claims.

Claims

1. A wireless communication method, which may be performed in a wireless communication device, wherein the wireless communication device operates as a transmitting device, the method comprising: Sending a control protocol data unit PDU to a receiving device, wherein the control PDU indicates sequence number SN information of a plurality of protocol data units PDUs discarded by a protocol layer entity of the sending device; The control PDU includes one or more SN windows, in which the SNs of the discarded multiple PDUs are continuous.

2. The method of claim 1, wherein the discarded plurality of PDUs are discarded by a Packet Convergence Protocol (PDCP) layer entity or a Radio Link Control (RLC) entity of the sending device.

3. The method of claim 1, wherein the control PDU is a Packet Convergence Protocol (PDCP) discard indication PDU, comprising a PDU type field for indicating a PDU type of the PDCP discard indication PDU.

4. The method of claim 3, wherein the PDCP discard indication PDU comprises a configuration of an SN window in the one or more SN windows, the configuration of the SN window comprising: The MinDC field in the PDCP discard indication PDU indicates a minimum discard count (MinimumDiscard COUNT), corresponding to the minimum PDCP PDU SN in the SN window; The MaxDC field in the PDCP discard indication PDU indicates a maximum discard count (MaximumDiscard COUNT), corresponding to the maximum PDCP PDU SN in the SN window.

5. The method according to claim 1, wherein the control PDU is a radio link control (RLC) discard indication PDU, comprising a PDU type field for indicating a PDU type of the RLC discard indication PDU.

6. The method of claim 5, wherein the RLC discard indication PDU comprises a configuration of an SN window in the one or more SN windows, the configuration of the SN window comprising: The MinSN field in the RLC discard indication PDU indicates the minimum discard SN. Discard SN), corresponding to the minimum RLC PDU SN in the SN window; The MaxSN field in the RLC discard indication PDU indicates the maximum discard SN. Discard SN), corresponding to the maximum RLC PDU SN in the SN window.

7. The method of claim 1, wherein the control PDU includes an E field, the E field indicating whether another SN window is configured after the E field.

8. A wireless communication device, comprising: A processor configured to call and run a computer program stored in a memory so that a device equipped with the processor executes the method according to any one of claims 1 to 7.

9. A chip, comprising: The processor is configured to call and run the computer program stored in the memory so that the device equipped with the chip executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored therein, wherein the computer program causes a computer to execute the method according to any one of claims 1 to 7.

11. A computer program product comprising a computer program, wherein the computer program causes a computer to execute the method according to any one of claims 1 to 7.

12. A computer program, wherein the computer program causes a computer to execute the method according to any one of claims 1 to 7.

13. A wireless communication method, which may be performed in a wireless communication device, wherein the wireless communication device operates as a receiving device, the method comprising: receiving a control PDU from a sending device, the control PDU indicating sequence number SN information of a plurality of protocol data units PDUs discarded by the sending device; The control PDU includes one or more SN windows, in which the SNs of the discarded multiple PDUs are continuous.

14. The method of claim 13, wherein the control PDU is a Packet Convergence Protocol (PDCP) discard indication PDU, comprising a PDU type field for indicating a PDU type of the PDCP discard indication PDU.

15. The method of claim 14, wherein the PDCP discard indication PDU comprises a configuration of an SN window in the one or more SN windows, the configuration of the SN window comprising: The MinDC field in the PDCP discard indication PDU indicates a minimum discard count (MinimumDiscard COUNT), corresponding to the minimum PDCP PDU SN in the SN window; The MaxDC field in the PDCP discard indication PDU indicates a maximum discard count (MaximumDiscard COUNT), corresponding to the maximum PDCP PDU SN in the SN window.

16. The method of claim 15, further comprising: When a PDCP data PDU is received from a lower layer, the received plurality of PDUs in the SN window are discarded.

17. The method of claim 16, wherein the lower layer is a Radio Link Control (RLC) layer.

18. The method of claim 15, further comprising: When a PDCP data PDU is received from a lower layer, a parameter indicating a waiting PDU count value in the PDCP layer of the receiving device is modified to MaxDC+1, wherein the waiting PDU has not yet been transmitted to an upper layer.

19. The method of claim 18, wherein the parameter is RX_DELIV or RX_NEXT.

20. The method of claim 15, further comprising: When the timer t-Reordering times out, a parameter indicating a waiting PDU count value in the PDCP layer of the receiving device is modified to MaxDC+1, wherein the waiting PDU has not yet been transmitted to an upper layer.

21. The method of claim 18, wherein the parameter is RX_DELIV.

22. The method of claim 13, wherein the control PDU is a Radio Link Control (RLC) discard indication PDU, comprising a PDU type field for indicating a PDU type of the RLC discard indication PDU.

23. The method of claim 22, wherein the RLC discard indication PDU comprises a configuration of an SN window in the one or more SN windows, the configuration of the SN window comprising: The MinSN field in the RLC discard indication PDU indicates the minimum discard SN. Discard SN), corresponding to the minimum RLC PDU SN in the SN window; The MaxSN field in the RLC discard indication PDU indicates the maximum discard SN. Discard SN), corresponding to the maximum RLC PDU SN in the SN window.

24. The method of claim 23, further comprising: When a UMD PDU is received from a lower layer, the received multiple PDUs in the SN window are discarded.

25. The method of claim 24, wherein the lower layer is a medium access control (MAC) layer.

26. The method of claim 23, further comprising: When placing the UMD PDU in the receiving buffer of the RLC layer, a parameter indicating the earliest SN for reassembly in the RLC layer of the receiving device is modified to MaxSN+1.

27. The method of claim 26, wherein the parameter is RX_Next_Reassembly or RX_Next_Highest.

28. The method of claim 23, further comprising: When the timer t-Reassembly times out, a parameter indicating the earliest SN for reassembly in the RLC layer of the receiving device is modified to MaxSN+1.

29. The method of claim 26, wherein the parameter is RX_Next_Reassembly.

30. The method of claim 13, wherein the control PDU includes an E field, the E field indicating whether another SN window is configured after the E field.

31. A wireless communication device, comprising: A processor configured to call and run a computer program stored in a memory so that a device equipped with the processor executes a method as claimed in any one of claims 13 to 30.

32. A chip, comprising: The processor is configured to call and run the computer program stored in the memory so that the device equipped with the chip executes the method according to any one of claims 13 to 30.

33. A computer-readable storage medium having a computer program stored therein, wherein the computer program causes a computer to execute the method according to any one of claims 13 to 30.

34. A computer program product comprising a computer program, wherein the computer program causes a computer to perform the method of any one of claims 13 to 30.

35. A computer program, wherein the computer program causes a computer to perform the method of any one of claims 13 to 30.

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