Method and apparatus for handling augmented reality packet drop in wireless network

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments herein provide a method for handling augmented reality packet drop in a wireless communication network. The method includes receiving a configuration message including information of a first discard timer, a second discard timer, and PDU set discard parameters for low importance, the first discard timer being set to a value shorter than a value of the second discard timer, obtaining at least one packet data convergence protocol (PDCP) service data unit (SDU) from at least one upper layer, the PDU set discard parameters being set to a value shorter than a value of the first discard timer, and the PDU set discard parameters being set to a value lower than a value of the second discard timer. And performing a transmission operation including PDCP SDU discard for at least one PDCP SDU based on the first discard timer, the second discard timer and the PDU set discard parameter.

Description

Technical Field

[0001] This disclosure relates to telecommunications networks. More specifically, this disclosure relates to the importance of processing protocol data units (PDUs) during packet drop in extended reality in wireless communication networks. Background Technology

[0002] Fifth-generation (5G) mobile communication technology defines a wide frequency band, enabling high transmission rates and new services. This can be achieved not only in "sub-6GHz" bands such as 3.5GHz, but also in "above 6GHz" bands, including 28GHz and 39GHz, known as mmWave. Furthermore, to achieve transmission rates fifty times faster than 5G and ultra-low latency one-tenth that of 5G, 6G mobile communication technology (referred to as "super 5G systems") has been considered for implementation in terahertz bands (e.g., the 95GHz to 3THz band).

[0003] At the outset of 5G mobile communication technology development, to support services and meet performance requirements associated with enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), ongoing standardization has been established for the following: beamforming and massive MIMO to mitigate radio wave path loss and increase radio wave transmission distance in mmWave; support for basic parameter sets (e.g., operating multiple subcarrier spacings) for dynamic operation that effectively utilizes mmWave resources and time slot formats; initial access technologies to support multi-beam transmission and broadband; definition and operation of BWPs; new channel coding and decoding methods, such as LDPC (Low Density Parity Check) codes for large data transmissions and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing to provide dedicated networks for specific services.

[0004] Currently, given the services to be supported by 5G mobile communication technology, there is ongoing discussion about improvements and performance enhancements to the initial 5G mobile communication technology, and physical layer standardization has already been established for technologies such as: V2X (Vehicle-to-Everything), used to assist autonomous vehicles in making driving decisions based on information sent by the vehicle about its location and status, and to enhance user convenience; NR-U (New Radio Unlicensed), designed to comply with the various regulatory requirements related to unlicensed frequency bands; NR UE power saving; Non-Terrestrial Network (NTN), which is UE-satellite direct communication used to provide coverage in areas where communication with terrestrial networks is unavailable; and positioning.

[0005] Furthermore, there is ongoing standardization regarding air interface architectures / protocols for technologies such as: Industrial Internet of Things (IIoT) for supporting new services through interoperability and convergence with other industries; IAB (Integrated Access and Backhaul) for providing nodes for network service area extension by supporting radio backhaul links and access links in an integrated manner; mobility enhancements including conditional handover and DAPS (Dual Active Stack) handover; and two-step random access (two-step RACH for NR) for simplifying random access procedures. There is also ongoing standardization regarding system architectures / services for: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies; and mobile edge computing (MEC) for UE-based location reception services.

[0006] With the commercialization of 5G mobile communication systems, the already exponentially growing number of connected devices will connect to the communication network, and correspondingly, enhanced functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices, are expected to be necessary. To this end, new research has been arranged related to: extended reality (XR) for effectively supporting AR (augmented reality), VR (virtual reality), MR (mixed reality), etc.; and improving 5G performance and reducing complexity by leveraging artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, the development of this 5G mobile communication system will not only serve as the foundation for developing: new waveforms to provide coverage in the terahertz band of 6G mobile communication technology; multi-antenna transmission technologies, such as full-dimensional MIMO (FD-MIMO), array antennas, and massive MIMO; metamaterial-based lenses and antennas to improve terahertz band signal coverage; and high-dimensional spatial multiplexing technologies using OAM (orbital angular momentum) and RIS (reconfigurable smart surfaces); but also as the foundation for developing: full-duplex technology to improve the frequency efficiency of 6G mobile communication technology and enhance system networks; AI-based communication technologies to optimize systems by leveraging satellites and AI (artificial intelligence) from the design phase and internalizing end-to-end AI support capabilities; and next-generation distributed computing technologies to deliver services at a complexity level exceeding the limitations of UE operational capabilities by utilizing ultra-high-performance communication and computing resources.

[0008] Extended Reality (XR) is a collective term for different realities, including Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR), and is considered an essential technology for enabling digital twins / metaverses. XR was incorporated into 5G Advanced (3GPP Release 18) as an agreed work item, with the goal of providing a communication system framework that meets the challenging requirements of high data rates, very low latency, and power-efficient connectivity for XR applications.

[0009] The Protocol Data Convergence Protocol (PDCP) is a Layer 2 sublayer and is involved in multiple functions of data plane processing for transmitted and received packets. These functions include, but are not limited to, Service Data Unit (SDU) drop, encryption and integrity protection, header compression and reordering on the transmitting side, decryption and integrity verification, deduplication, and header decompression on the receiving side. Each radio bearer (RB) is associated with a transmitting PDCP entity and / or a receiving PDCP entity. The SDU drop procedure involves dropping the PDCP SDU when an associated timer expires or when, for example, successful delivery of the PDCP SDU is confirmed from a peer PDCP entity via a PDCP status report.

[0010] For XR applications, existing PDCP SDU dropping mechanisms may not be efficient or effective because XR applications are more tightly coupled with the transmission of frame or PDU sets than with IP packet transmissions that are typically mapped one-to-one to PDCP SDUs. Therefore, existing mechanisms can lead to inefficient SDU dropping operations, excessive processing overhead, and / or wasted transmission resources. Furthermore, different frame or PDU sets may have different importance (e.g., one PDU set is needed to decode other PDU sets), and their dropping operations may require differentiated processing. This aspect is completely lacking in the existing technology. Therefore, it is desirable to address the aforementioned shortcomings or other deficiencies, or at least provide a useful alternative to PDCP dropping mechanisms for extended reality in wireless networks. Summary of the Invention

[0011] Technical issues

[0012] The primary objective of the embodiments described herein is to provide a method and network apparatus for processing PDU set importance (PSI) during extended reality packet drop in a wireless communication network.

[0013] Another objective of the embodiments described herein is to handle PDCP operations for PSI-based SDU discarding.

[0014] Another objective of the embodiments described herein is to provide configuration and operation of a PSI-based drop timer. The PSI-based drop timer has a shorter value than a normal drop timer.

[0015] Another objective of the embodiments described herein is to provide PSI value configuration from the application and to provide PSI value signaling via the GTP header.

[0016] Another objective of the embodiments described herein is to process subsequently received SDUs of the PDU set after the discard timer for at least one SDU of the PDU set has expired.

[0017] Another objective of the embodiments described herein is to provide configuration signaling for PSI-based SDU drop parameters for each radio bearer.

[0018] Another objective of the embodiments described herein is to activate and deactivate PSI-based SDU dropping.

[0019] Another objective of the embodiments described herein is to provide drop configuration parameters for each radio bearer based on a set of PDUs.

[0020] Another objective of the embodiments described herein is to implement a PSI-based SDU discarding mechanism for XR.

[0021] Another objective of the embodiments described herein is to improve UE and network performance for XR applications.

[0022] Solution to the problem

[0023] In one embodiment, these objectives are achieved by providing a method for handling extended reality (XR) packet dropping in a wireless communication network by a user equipment (UE), comprising: receiving a configuration message including information for a first drop timer, a second drop timer, and a PDU set drop parameter for low importance, wherein the first drop timer is configured to be shorter than the second drop timer; obtaining at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from at least one upper layer; and performing a transmission operation including PDCP SDU dropping for at least one PDCPSDU based on the first drop timer, the second drop timer, and the PDU set drop parameter.

[0024] In one example, these objectives are achieved by providing a method for handling extended reality packet dropping in a wireless communication network by a network device, comprising: sending a configuration message including information including a first drop timer, a second drop timer, and a PDU set drop parameter for low importance; receiving at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from a user equipment (UE); identifying at least one PDCP SDU dropped by the UE based on the first drop timer, the second drop timer, and the PDU set drop parameter; and sending a PDCP status report to the UE to confirm the reception of at least one PDCP SDU.

[0025] In one example, these objectives are achieved by providing a user equipment (UE) for handling packet drop in extended reality (XR) in a wireless communication network, the UE comprising: an I / O interface and a packet drop processor communicatively coupled to the I / O interface, wherein the packet drop processor is configured to: receive a configuration message including information for a first drop timer, a second drop timer, and PDU set drop parameters for low importance, wherein the first drop timer is configured to be shorter than the second drop timer; obtain at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from at least one upper layer; and perform a transmission operation including PDCP SDU drop for at least one PDCPSDU based on the first drop timer, the second drop timer, and the PDU set drop parameters.

[0026] In one example, these objectives are achieved by providing a network apparatus for processing extended reality packet drop in a wireless communication network, the network apparatus comprising: an I / O interface and a packet drop processor communicatively coupled to the I / O interface, wherein the packet drop processor is configured to: send a configuration message including information for a first drop timer, a second drop timer, and a PDU set drop parameter for low importance; receive at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from a user equipment (UE); identify at least one PDCP SDU dropped by the UE based on the first drop timer, the second drop timer, and the PDU set drop parameter; and send a PDCP status report to the UE to confirm the reception of at least one PDC SDU.

[0027] In one example, these objectives are achieved by providing a method for handling PDU set importance (PSI) during packet drop in Extended Reality (XR) in a wireless communication network. The method includes configuring a first drop timer, a second drop timer, and a PDU set integration processing indication (PSIHI) configured by a transmitting PDCP entity based on a received XR radio bearer configuration message for low importance. Furthermore, the method includes receiving at least one PDCP SDU along with a PSI value associated with at least one PDU set from at least one upper layer by the transmitting PDCP entity. Additionally, the method includes determining whether the at least one PDCP SDU is the first SDU of at least one PDU set and whether PDU set drop is configured as true (TRUE) by the transmitting PDCP entity. Furthermore, the method includes starting the first drop timer for low importance when the at least one PDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a low importance PSI, and when PDU set drop is configured as true. In addition, at least one set of PDUs is discarded when the first discard timer for at least one PDCP SDU of at least one PDU set for low importance expires, or when a PDCP status report is received from the receiving PDCP entity.

[0028] Furthermore, the method includes: starting a second discard timer when at least one PDCP SDU is the first PDCP SDU of at least one received PDU set, when the PDCP SDU is associated with a high-importance PSI, and when PDU set discard is configured as true. Additionally, at least one PDU set is discarded when the second discard timer for at least one PDCP SDU of at least one PDU set expires or when a PDCP status report is received from the receiving PDCP entity. Furthermore, the method includes: starting a first discard timer for low importance when at least one PDCP SDU is received, when the PDCP SDU is associated with a low-importance PSI, and when PDU set discard is configured as false (FALSE). Additionally, at least one PDCP SDU is discarded when the first discard timer for low importance expires or when a PDCP status report is received from the receiving PDCP entity.

[0029] Furthermore, the method includes: starting a second discard timer when at least one PDCP SDU is received, when the PDCP SDU is associated with a high-importance PSI, and when the PDU set discard is configured as false. Additionally, at least one PDCP SDU is discarded when the second discard expires or when a PDCP status report is received from the receiving PDCP entity.

[0030] In an embodiment, when the PDCP entity is at the user equipment, a PSI value associated with at least one set of PDUs is received from at least one upper layer, wherein the upper layer is at least one SDAP layer, application layer, or service layer.

[0031] In an embodiment, when the PDCP entity is at the network entity, a PSI value associated with at least one PDU set is received from at least one upper layer in the GTP header of at least one PDCP SDU, wherein the upper layer is at least one SDAP layer, application layer, or service layer.

[0032] In one embodiment, the method includes: determining, by the sending PDCP entity, whether a first discard timer or a second discard timer for low importance has expired for at least one PDCP SDU associated with a PDU set. Furthermore, the method includes: when the first discard timer or the second discard timer for low importance for at least one PDCP SDU associated with a PDU set has expired, discarding, by the sending PDCP entity, at least one PDCP SDU subsequently received from the upper layer and associated with the PDU set.

[0033] In an embodiment, for a specific data radio bearer (DRB) providing XR services, at least one of a first drop timer and a second drop timer for low importance is configured for a PDCP entity that transmits only.

[0034] In one embodiment, the duration of the first discard timer for low importance is shorter than the duration of the second discard timer, and it is configured in the XR radio bearer configuration message via RRC signaling messages.

[0035] In one embodiment, the method includes: upon receiving a PDCP SDU belonging to a low-importance PDU set from an upper layer, the sending PDCP entity initiates a first discard timer for low importance. Furthermore, the method includes: upon receiving a PDCP SDU that does not belong to a low-importance PDU set from an upper layer, the sending PDCP entity initiates a second discard timer.

[0036] In an embodiment, the XR radio bearer configuration message includes a first discard timer for low importance, applicable to at least one PSI value associated with at least one set of PDUs.

[0037] In one embodiment, the method includes receiving a request from an upper layer by a sending PDCP entity to discard a set of PDUs. Furthermore, the method includes the sending PDCP entity discarding all PDCP SDUs and PDCP PDUs of at least one set of PDUs.

[0038] In an embodiment, the method includes: the sending PDCP entity instructing the discarding of PDCP SDUs of the PDU set by setting an indication field in the PDCP header of the first PDCPPDU of the next PDU set.

[0039] In one embodiment, the method includes: when PDU set discarding is configured to true, and when a first discard timer for low importance expires at the PDCP and one or more PDCP SDUs or PDUs belonging to the same PDU set are submitted to the RLC, instructing the transmitting radio link control (RLC) entity to discard all PDCP SDUs or PDUs of at least one PDU set of low importance. Furthermore, the method includes: when PDU set discarding is configured to true, and when a second discard timer expires at the PDCP and one or more PDCP SDUs or PDUs belonging to the same PDU set are submitted to the RLC, instructing the transmitting RLC entity to discard all PDCP SDUs or PDUs of at least one PDU set of high importance.

[0040] Furthermore, the method includes: when PDU set discarding is configured as false, when a first discard timer for low importance expires at the PDCP layer and at least one PDCP SDU or PDU belonging to the same PDU set is submitted to the RLC layer, instructing the sending RLC entity to discard at least one PDCP SDU or PDU of at least one PDU set of low importance. Furthermore, the method includes: when PDU set discarding is configured as false, when a second discard timer expires at the PDCP layer and at least one PDCP SDU or PDU belonging to the same PDU set is submitted to the RLC layer, instructing the sending RLC entity to discard at least one PDCP SDU or PDU of at least one PDU set of high importance.

[0041] In one embodiment, the method includes: when the sending PDCP entity indicates to the sending RLC entity to discard and the sending RLC entity has not yet sent at least one PDCP SDU or PDU of at least one PDU set, the sending RLC entity discards at least one PDCP SDU or PDU of at least one PDU set. Furthermore, the method includes: when the sending PDCP entity indicates to the sending RLC entity to discard and the sending RLC entity has already sent at least one PDCP SDU or PDU of at least one PDU set, the sending RLC entity discards at least one PDCP SDU or PDU of at least one PDU set. Additionally, the method includes: when the sending PDCP entity indicates to the sending RLC entity to discard and the sending RLC entity has already sent at least one PDCP SDU or PDU of at least one PDU set, the sending RLC entity skips discarding at least one PDCP SDU or PDU of at least one PDU set.

[0042] In this embodiment, the sending PDCP entity is at least one of the UE and the network entity, and the receiving PDCP entity is at least one of the UE and the network entity.

[0043] In an embodiment, the method includes: when discarding PDCP SDUs or PDCP PDUs of at least one PDU set, the sending PDCP entity continues to receive PDCP SDUs or PDCP PDUs of at least one PDU set that have been initially assigned sequence numbers, and discards PDCP SDUs or PDCP PDUs of at least one PDU set that have not yet been assigned sequence numbers. Furthermore, the method includes: the sending PDCP entity assigning a consecutive sequence number relative to the last sequence number assigned to the PDCP SDU of the previous PDU set to the first PDCP SDU of the next PDU set. Furthermore, the method includes: the sending PDCP entity using bits, bitmaps, or fields in the PDCP header of the next PDU set to indicate the discarding of at least one PDCP SDU or PDCP PDU of at least one PDU set.

[0044] In an embodiment, the method includes: based on an implementation that does not require configuration from the network, a sending PDCP entity performs a priority mapping from at least one set of PDUs belonging to a Quality of Service (QoS) flow to a Data Radio Bearer (DRB) based on metadata received from the application layer, wherein the metadata may include PSI values, PSI thresholds, and drop thresholds.

[0045] In an embodiment, the PDCP SDU associated with a high-importance PSI is a PDCP SDU that is not indicated by a low-importance PSI.

[0046] In one embodiment, the UE capability message indicates support for PSI-based drop capability.

[0047] Therefore, embodiments of this document provide a method for PDU set importance handling mechanisms during extended reality packet drop in a wireless communication network. The method includes: configuring a PDU set-level reordering timer, a PDU set-level indication for in-order delivery, a PDU set-level indication for out-of-order delivery, and a PDU set integration processing indication (PSIHI) configured by a receiving PDCP entity based on a received XR radio bearer configuration message. Furthermore, the method includes: receiving at least one SDU of at least one PDU set from a sending PDCP entity. Furthermore, the method includes: starting a PDU set-level reordering timer by the receiving PDCP entity when at least one SDU of at least one PDU set is received from the sending PDCP entity. Furthermore, the method includes: discarding received PDCPPDUs of at least one PDU set with lower importance by the receiving PDCP entity when the PDU set-level reordering timer expires. Furthermore, the method includes: sending a PDCP status report to the sending PDCP entity to confirm the reception of at least one PDCP SDU of the PDU set. In addition, the method includes: the receiving PDCP entity sending received PDUs of at least one set of PDUs of higher importance to the upper layer.

[0048] In an embodiment, the PSI value includes at least one of a set of values, a range of values, a field, a flag, a bit, a bitmap, and an index.

[0049] In an embodiment, the method includes: receiving an indication from a receiving PDCP entity for discarding at least one PDCP SDU and at least one PDCP PDU of at least one PDU set indicated in an indication field of the PDCP header of a first PDCP PDU for the next PDU set. Furthermore, the method includes: discarding received PDCP SDUs of at least one incompletely received PDU set by the receiving PDCP entity; and continuing to process the next PDU set.

[0050] In one example, these objectives are achieved by providing a transmitting PDCP entity for handling PDU set importance (PSI) during packet drop in Extended Reality (XR) within a wireless communication network. The transmitting PDCP entity comprises a processor and a packet drop processor communicatively coupled to the processor. The packet drop processor configures a first drop timer, a second drop timer, and a PDU set integration processing indication (PSIHI) as indicated by the PDU set drop parameter configuration based on received XR radio bearer configuration messages.

[0051] Furthermore, at least one PDCP SDU along with a PSI value associated with at least one PDU set is received from at least one upper layer. Further, it is determined whether the at least one PDCP SDU is the first SDU of the at least one PDU set, and whether PDU set discard is configured to true. Additionally, when the at least one PDCP SDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a low-importance PSI, and when PDU set discard is configured to true, a first discard timer for low importance is started. Furthermore, when the first discard timer for low importance of at least one PDCP SDU of the at least one PDU set expires, or when a PDCP status report is received from the receiving PDCP entity, at least one PDU set is discarded. Furthermore, when the at least one PDCP SDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a high-importance PSI, and when PDU set discard is configured to true, the packet discarding processor starts a second discard timer.

[0052] Furthermore, at least one PDU set is discarded when the second discard timer for at least one PDCP SDU in at least one PDU set expires or when a PDCP status report is received from the receiving PDCP entity. Additionally, when at least one PDCP SDU is received, if the PDCP SDU is associated with a low-importance PSI, and if PDU set discard is configured as false, the packet discard processor starts a first discard timer for low importance. Furthermore, at least one PDCP SDU is discarded when the first discard timer for low importance expires or when a PDCP status report is received from the receiving PDCP entity. Furthermore, when at least one PDCP SDU is received, if the PDCP SDU is associated with a high-importance PSI, and if PDU set discard is configured as false, the packet discard processor starts a second discard timer. Furthermore, at least one PDCP SDU is discarded when the second discard timer expires or when a PDCP status report is received from the receiving PDCP entity.

[0053] In one example, these objectives are achieved by a receive PDCP entity that provides a mechanism for handling PDU set importance during packet drop in extended reality within a wireless communication network. The receive PDCP entity comprises a processor and a packet drop processor communicatively coupled to the processor. The packet drop processor configures a PDU set-level reordering timer, a PDU set-level indication for in-order delivery, a PDU set-level indication for out-of-order delivery, and a PDU set integration processing indication (PSIHI) represented by the PDU set drop parameter configuration based on received XR radio bearer configuration messages. Furthermore, the packet drop processor receives at least one SDU from at least one PDU set from the send PDCP entity (200). Additionally, when at least one SDU from at least one PDU set is received from the send PDCP entity, the PDU set-level reordering timer is started.

[0054] Furthermore, when the PDU set-level reordering timer expires, the packet discarding processor discards received PDCP PDUs from at least one PDU set of lower importance. Additionally, the packet discarding processor sends a PDCP status report to the sending PDCP entity to acknowledge the reception of at least one PDCP SDU from the PDU set. Furthermore, the packet discarding processor forwards received PDUs from at least one PDU set of higher importance to the upper layer.

[0055] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and accompanying drawings. However, it should be understood that while the following description indicates preferred embodiments and many specific details therein, it is given in an illustrative rather than limiting manner. Many changes and modifications are possible within the scope of the embodiments herein.

[0056] Before proceeding with the detailed description below, it may be advantageous to define certain words and phrases used throughout this patent document: the terms “comprising” and “including” and their derivatives mean including but not limited to; the term “or” is inclusive, referring to and / or; the phrases “associated with” and “associated with” and their derivatives may mean including, being included in, interconnected with, containing, contained within, connected to or connected to, coupled to or coupled to, able to communicate with, cooperate with, intertwine, juxtapose, proximate, bound to or bound to, having, possessing the properties of, etc.; and the term “controller” means any device, system or part thereof that controls at least one operation, such device may be implemented in hardware, firmware or software or some combination of at least two of these. It should be noted that the functionality associated with any particular controller can be centralized or distributed, whether local or remote.

[0057] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof adapted to be implemented in suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of media accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media in which data can be permanently stored and media in which data can be stored and later rewritten, such as rewritable optical discs or erasable memory devices.

[0058] Definitions of certain words and phrases are provided throughout this patent document, and those skilled in the art will understand that, in many cases (if not most), such definitions apply to the prior and future use of the words and phrases defined in this way. Attached Figure Description

[0059] These and other features, aspects, and advantages of this embodiment are illustrated in the accompanying drawings, throughout which the same reference numerals indicate corresponding portions in the various drawings. The embodiments herein will be better understood from the following description with reference to the accompanying drawings, in which:

[0060] Figure 1 A system architecture for processing the importance of PDU sets during packet drop in extended reality in a wireless communication network, according to embodiments of the present disclosure, is illustrated.

[0061] Figure 2A A transmitting PDCP entity for processing the importance of PDU sets during packet drop in extended reality in a wireless communication network, according to an embodiment of the present disclosure, is illustrated.

[0062] Figure 2B A received PDCP entity for processing the importance of PDU sets during packet drop in extended reality in a wireless communication network, according to an embodiment of the present disclosure, is illustrated.

[0063] Figure 3 A flowchart is shown illustrating a method for processing the importance of a set of PDUs during extended reality packet drop by a transmitting PDCP entity in a wireless communication network, according to embodiments of the present disclosure; and

[0064] Figure 4 A flowchart is shown for a method for processing the importance of a set of PDUs when a packet is dropped in extended reality by a receiving PDCP entity in a wireless communication network, according to an embodiment of the present disclosure;

[0065] It will be noted that, to the extent possible, the same reference numerals have been used to denote the same elements in the figures. Furthermore, those skilled in the art will appreciate that the elements in the figures are shown for simplicity and may not necessarily be drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to others to aid in understanding various aspects of this disclosure. Additionally, elements may already be represented in the figures by conventional symbols, and the figures may show only those specific details relevant to understanding embodiments of this disclosure, so as not to obscure the figures with details that would readily be apparent to those skilled in the art who have benefited from the description herein. Detailed Implementation

[0066] The following discussion Figures 1 to 4 The various embodiments used to describe the principles of this disclosure in this patent document are illustrative only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitable system or device.

[0067] The embodiments described herein, along with their various features and advantageous details, are explained more fully with reference to the non-limiting embodiments illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques have been omitted to avoid unnecessarily obscuring the embodiments herein. Furthermore, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments may be combined with one or more other embodiments to form new embodiments. Unless otherwise indicated, the term "or" as used herein means non-exclusive or. The examples used herein are intended only to facilitate understanding of how the embodiments described herein can be practiced and to further enable those skilled in the art to practice the embodiments described herein. Therefore, the examples should not be construed as limiting the scope of the embodiments described herein.

[0068] As is customary in the art, embodiments are described and illustrated based on blocks that perform one or more functions as described herein. These blocks, referred to herein as managers, units, modules, hardware components, etc., are physically implemented by analog and / or digital circuitry (such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuitry, passive electronic components, active electronic components, optical components, hardwired circuitry, etc.) and optionally driven by firmware and software. For example, the circuitry is embodied in one or more semiconductor chips or on a substrate support such as a printed circuit board. The circuitry constituting a block is implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware performing some functions of the block and a processor performing other functions of the block. Without departing from the scope of the provided methods, each block of the embodiments is physically divided into two or more interactive and discrete blocks. Similarly, without departing from the scope of the provided methods, the blocks of the embodiments are physically combined into more complex blocks.

[0069] The accompanying drawings are provided to aid in the easy understanding of the various technical features, and it should be understood that the embodiments presented herein are not limited to the drawings. Therefore, the methods provided are to be interpreted as extending to any modifications, equivalents, and substitutions other than those specifically set forth in the drawings. Although the terms first, second, etc., are used herein to describe various elements, these elements should not be limited by these terms. These terms are generally used to distinguish one element from another.

[0070] Therefore, embodiments disclose a method for handling PDU set importance (PSI) during packet drop in Extended Reality (XR) in a wireless communication network. The method includes: configuring a first drop timer, a second drop timer, and a PDU set integration processing indication (PSIHI) configured by a transmitting PDCP entity based on a received XR radio bearer configuration message for low importance. Furthermore, the method includes: receiving at least one PDCP SDU along with a PSI value associated with at least one PDU set from at least one upper layer by the transmitting PDCP entity.

[0071] Furthermore, the method includes: determining, by the sending PDCP entity, whether at least one PDCP SDU is the first SDU of at least one PDU set, and whether PDU set discard is configured to true. Furthermore, the method includes: starting a first discard timer for low importance when at least one PDCPSDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a low-importance PSI, and when PDU set discard is configured to true. Furthermore, at least one PDU set is discarded when the first discard timer for low importance of at least one PDCP SDU of the at least one PDU set expires, or when a PDCP status report is received from the receiving PDCP entity. Furthermore, the method includes: starting a second discard timer when at least one PDCP SDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a high-importance PSI, and when PDU set discard is configured to true.

[0072] Furthermore, at least one PDU set is discarded when a second discard timer for at least one PDCP SDU in at least one PDU set expires or when a PDCP status report is received from the receiving PDCP entity. Additionally, the method includes: starting a first discard timer for low importance when at least one PDCP SDU is received, when the PDCP SDU is associated with a low-importance PSI, and when PDU set discard is configured as false. Furthermore, at least one PDCP SDU is discarded when the first discard timer for low importance expires or when a PDCP status report is received from the receiving PDCP entity. Furthermore, the method includes: starting a second discard timer when at least one PDCP SDU is received, when the PDCP SDU is associated with a high-importance PSI, and when PDU set discard is configured as false. Furthermore, at least one PDCP SDU is discarded when the second discard timer expires or when a PDCP status report is received from the receiving PDCP entity.

[0073] Therefore, embodiments of this document provide a method for handling PDU set importance during packet drop in extended reality in a wireless communication network. The method includes: configuring a PDU set-level reordering timer, a PDU set-level indication for in-order delivery, a PDU set-level indication for out-of-order delivery, and a PDU set integration processing indication (PSIHI) represented by PDU set drop parameters, based on a received XR radio bearer configuration message, by a receiving PDCP entity. Furthermore, the method includes: receiving at least one SDU from at least one PDU set from a transmitting PDCP entity. Additionally, the method includes: activating a PDU set-level reordering timer by the receiving PDCP entity when at least one SDU from at least one PDU set is received from the transmitting PDCP entity.

[0074] Furthermore, the method includes: when a PDU set-level reordering timer expires, the receiving PDCP entity discards received PDCP PDUs of at least one PDU set with lower importance. Furthermore, the method includes: the receiving PDCP entity sending a PDCP status report to the sending PDCP entity to confirm the reception of at least one PDCP SDU of the PDU set. Furthermore, the method includes: the receiving PDCP entity sending received PDUs of at least one PDU set with higher importance to the upper layer.

[0075] Therefore, embodiments disclose a transmitting PDCP entity for handling PDU set importance (PSI) during packet drop in Extended Reality (XR) in a wireless communication network. The transmitting PDCP entity includes a processor and a packet drop processor communicatively coupled to the processor. The packet drop processor configures a first drop timer, a second drop timer, and a PDU set integration processing indication (PSIHI) configured by PDU set drop parameters based on received XR radio bearer configuration messages. Furthermore, at least one PDCP SDU along with a PSI value associated with at least one PDU set is received from at least one upper layer. Further, it is determined whether the at least one PDCP SDU is the first SDU of the at least one PDU set, and whether PDU set drop is configured to true. Additionally, when the at least one PDCP SDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a low-importance PSI, and when PDU set drop is configured to true, the first drop timer for low importance is started.

[0076] Furthermore, at least one PDU set is discarded when the first discard timer for at least one PDCP SDU of at least one PDU set for low importance expires, or when a PDCP status report is received from the receiving PDCP entity. Additionally, when at least one PDCP SDU is the first PDCP SDU of at least one received PDU set, when the PDCP SDU is associated with a high-importance PSI, and when PDU set discard is configured as true, the packet discard processor starts a second discard timer. Furthermore, at least one PDU set is discarded when the second discard timer for at least one PDCP SDU of at least one PDU set expires, or when a PDCP status report is received from the receiving PDCP entity. Additionally, when at least one PDCPSDU is received, when the PDCP SDU is associated with a low-importance PSI, and when PDU set discard is configured as false, the packet discard processor starts a first discard timer for low importance.

[0077] Furthermore, at least one PDCP SDU is discarded when the first discard timer for low importance expires or when a PDCP status report is received from the receiving PDCP entity. Additionally, when at least one PDCP SDU is received, when the PDCPSDU is associated with a high-importance PSI, and when the PDU set discard is configured as false, the packet discard processor starts a second discard timer. Furthermore, at least one PDCP SDU is discarded when the second discard expires or when a PDCP status report is received from the receiving PDCP entity.

[0078] Therefore, embodiments disclose a receiving PDCP entity for a PDU set importance processing mechanism during extended reality packet drop in a wireless communication network. The receiving PDCP entity includes a processor and a packet drop processor communicatively coupled to the processor. The packet drop processor configures a PDU set level reordering timer, a PDU set level indication for in-order delivery, a PDU set level indication for out-of-order delivery, and a PDU set integration processing indication (PSIHI) represented by PDU set drop parameter configuration based on received XR radio bearer configuration messages. Furthermore, the packet drop processor receives at least one SDU from at least one PDU set from a transmitting PDCP entity.

[0079] Furthermore, when at least one SDU from at least one PDU set is received from the sending PDCP entity, a PDU set-level reordering timer is started. Additionally, when the PDU set-level reordering timer expires, the packet discarding processor discards the received PDCP PDUs from at least one PDU set of lower importance. Furthermore, the packet discarding processor sends a PDCP status report to the sending PDCP entity to acknowledge the reception of at least one PDCP SDU from the PDU set. Finally, the packet discarding processor forwards the received PDUs from at least one PDU set of higher importance to the upper layer.

[0080] Therefore, the provided solution implements an efficient method for a PSI-based drop mechanism for XR. Furthermore, the provided solution improves UE and network performance for XR applications.

[0081] Figure 1 A system architecture for processing the importance of PDU sets during packet drop in extended reality in a wireless communication network, according to an embodiment of the present disclosure, is shown. Figure 1 A wireless communication network comprising a user equipment (101) and a network device (103) is depicted. The UE (101) and the network device (103) communicate with each other to handle PSI-based packet dropping for XR applications. The UE (101) can be any end-user device connected to the network device (103) to access network services, including but not limited to laptops, handheld computers, desktop computers, mobile phones, smartphones, personal digital assistants (PDAs), tablets, wearable devices, Internet of Things (IoT) devices, virtual reality devices, televisions, connected cars, foldable devices, flexible devices, display devices, and immersive systems. Furthermore, the network device (103) is a device that creates, manages, and facilitates communications within the telecommunications network.

[0082] A telecommunications network is a system of communication devices and infrastructure that allows interconnection of information exchange over long distances. Telecommunications networks can be classified as local area networks (LANs), wide area networks (WANs), metropolitan area networks (MANs), etc. In some embodiments, a telecommunications network can be a wireless communication network, which can be classified as Long Term Evolution (LTE), 4G, 5G, and 6G. For example, a network device (103) can be, but is not limited to, a base station, transceiver, server, gateway, and access point. The UE (101) and network device (103) contain Packet Data Convergence Protocol (PDCP) entities, Radio Link Control (RLC) entities, and Media Access Control (MAC) entities. The PDCP entity at the UE (101) or network device (103) performing the transmitting function can be a transmitting PDCP entity. Similarly, the PDCP entity at the UE (101) performing the receiving PDCP entity can be a receiving PDCP entity. Furthermore, the RLC entity at the UE (101) or network device that can perform the transmitting function can be a transmitting RLC entity, and the RLC entity that also performs the receiving function can be a receiving RLC entity.

[0083] The UE (101) sends a UE capability message to the network device (103) to indicate its ability to support PSI-based discarding. This enables the network device to configure the UE to perform PSI-based discarding. Furthermore, the network device (103) sends an XR radio bearer configuration message to the UE (101) to configure a first discard timer, a second discard timer, and a PDU set integration processing indication (PSIHI) as configured by the PDU set discard parameters for low importance.

[0084] The RRC layer in the UE (101) can provide the PDCP entity associated with the UE (101) with a received first drop timer for low importance, a second drop timer, and a PDU set integration processing indication (PSIHI) configured by the PDU set drop parameters. The PDCP entity can use the received first drop timer for low importance, second drop timer, and PDU set integration processing indication (PSIHI) configured by the PDU set drop parameters to process PDU set importance (PSI) during packet drop.

[0085] Similarly, the UE (101) can receive from the network device (103) a PDU set level reorder timer, a PDU set level indication for in-order delivery, a PDU set level indication for out-of-order delivery, and a PDU set integration processing indication (PSIHI) represented by the PDU set discard parameter configuration. In addition, the RRC layer in the UE (101) can provide the received information to the PDCP entity associated with the UE (101).

[0086] Figure 2AA transmitting PDCP entity for processing the importance of a set of PDUs during packet drop in an extended reality wireless communication network, according to an embodiment of the present disclosure, is shown. The transmitting PDCP entity (200) includes several components, including a processor (201), an I / O interface (203), a memory (205), and a packet drop handler (207).

[0087] The processor (201) that sends the PDCP entity (200) communicates with the memory (205), I / O interface (203), and packet drop processor (207), executes instructions stored in the memory (205), and performs various processes. It can consist of one or more processors, such as a general-purpose CPU (central processing unit), AP (application processor), GPU (graphics processing unit), VPU (visual processing unit), and / or AI (artificial intelligence) dedicated NPU (neural processing unit).

[0088] The memory (205) of the transmitting PDCP entity (200) includes storage locations addressable by the processor (201). The memory (205) may store at least one of the following: a PSI value received from the upper layer of the transmitting PDCP entity (200), a PDCP SDU of a set of PDUs received from the network device (103), and an XR radio bearer configuration message received from the network device (103). The memory (205) is not limited to volatile and / or non-volatile memory. Furthermore, the memory (205) may include one or more computer-readable storage media. The memory (205) may include non-volatile storage elements. For example, non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memory, or various forms of electrically programmable memory (EPROM) or electrically erasable and programmable (EEPROM) memory. The memory (205) may store media streams, such as audio streams, video streams, haptic feedback, etc.

[0089] The I / O interface (203) transmits information between the memory (205) and external peripheral devices. The peripheral devices are input-output devices associated with the transmitting PDCP entity (200). The I / O interface (203) receives configuration from the associated network device (103) in the wireless communication network. The I / O interface (203) can receive PSI values ​​associated with a PDCP SDU or PDU set from the upper layer. Furthermore, the I / O interface (203) receives signaling messages from the network device (103) and transmits signaling messages to the network device (103). Signaling messages may include, but are not limited to, PDCP configuration messages and XR radio bearer configuration messages.

[0090] The packet drop processor (207) that sends PDCP entities (200) communicates with I / O interfaces (203) and memory (205) to handle the importance of PDU sets during extended reality packet drop in wireless communication networks. The packet drop processor (207) is innovative hardware implemented through both analog and digital circuits, including logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive and active electronic components, and optical components.

[0091] The packet drop processor (207) configures at least one of a first drop timer, a second drop timer, and a PDU set integration processing indication (PSIHI) indicated by the PDU set drop parameter configuration for low importance based on the received XR radio bearer configuration message. The XR radio bearer configuration message can be received from the upper layer at the sending PDCP entity.

[0092] The packet discarding processor (207) receives at least one PDCP SDU along with a PSI value associated with at least one PDU set from at least one upper layer. The packet discarding processor (207) determines whether the at least one PDCP SDU is the first SDU of the at least one PDU set and / or whether PDU set discard is configured to true. When the at least one PDCP SDU is the first PDCP SDU of the received at least one PDU set, when the PDCP SDU is associated with a low importance PSI, and / or when PDU set discard is configured to true, the packet discarding processor (207) starts a first discard timer for low importance. When the first discard timer for low importance of at least one PDCP SDU of the at least one PDU set expires or when a PDCP status report is received from the receiving PDCP entity, the packet discarding processor (207) discards the at least one PDU set.

[0093] When at least one PDCP SDU is the first PDCP SDU of at least one received PDU set, when the PDCPSDU is associated with a high-importance PSI, and / or when PDU set drop is configured to true, the packet drop processor (207) starts a second drop timer. When the second drop timer of at least one PDCP SDU of at least one PDU set expires, or when a PDCP status report is received from the receiving PDCP entity, the packet drop processor (207) drops at least one PDU set.

[0094] When at least one PDCP SDU is received, when the PDCP SDU is associated with a low-importance PSI, and / or when PDU set discard is configured as false, the packet discard processor (207) starts a first discard timer for low importance. When the first discard timer for low importance expires or when a PDCP status report is received from the receiving PDCP entity, the packet discard processor (207) discards at least one PDCP SDU. When at least one PDCP SDU is received, when the PDCP SDU is associated with a high-importance PSI, and / or when PDU set discard is configured as false, the packet discard processor (207) starts a second discard timer. When the second discard timer expires or when a PDCP status report is received from the receiving PDCP entity, the packet discard processor (207) discards at least one PDCP SDU.

[0095] In an embodiment, the UE (101)'s transmitting PDCP entity (200) is provided with a PDU Set Importance (PSI) value for at least one PDU set in the uplink direction by an upper layer. For example, the upper layer may include, but is not limited to, the Serving Data Adaptation Protocol (SDAP) layer, the application layer, and the service layer. The PSI value can be a set of values, a range of values, a field, a flag, a bit, a bitmap, or an index. In an embodiment, the PSI may be provided or notified along with the PDU set, or as in-band signaling (e.g., in a header field) within at least one SDU or PDU of the PDU set (e.g., the first SDU / PDU of the PDU set).

[0096] In embodiments, the transmitting PDCP entity (200) of the network device (103) (e.g., RAN or gNB) provides a PDU set importance (PSI) value for at least one PDU set in the downlink direction, either by a higher layer (e.g., SDAP layer), application layer, or service layer, or by indicating it in a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) packet received from the core network (CN). The PSI value can be a set of values, a range of values, a field, a flag, a bit, a bitmap, or an index. In embodiments, the PSI can be provided or notified along with the PDU set, or as in-band signaling (e.g., in a header field of a GTP PDU) in at least one SDU / PDU of the PDU set (e.g., the first SDU / PDU of the PDU set).

[0097] In an embodiment, the PSI can be notified to a peer entity (e.g., network (103) to UE (101) or UE (101) to network (103) by adding the PSI value to the header field of at least one PDCP SDU / PDU of the PDU set (e.g., the first SDU / PDU of the PDU set).

[0098] In an embodiment, the sending PDCP entity (200) is configured with multiple discard timer values ​​for different PSI values ​​of the PDU set, and a corresponding timer with an appropriate discard timer value is started and associated with the PSI of the PDU set received from the higher layer.

[0099] In this embodiment, a higher value for the discard timer is configured for the higher PSI value (higher importance) of the PDU set. When the first discard timer for the PDU set with a lower PSI value (lower importance) expires, the SDUs of the relevant PDU set (with lower PSI value) are discarded; however, if the corresponding first discard timer for low importance is still running, the SDUs of the PDU set (with higher PSI value) are not discarded.

[0100] In one embodiment, a lower value for the first discard timer for low importance is configured for higher PSI values ​​(higher importance) of the PDU set.

[0101] In this embodiment, a discard timer value is configured only for the PDU set with lower importance (i.e., lower PSI value) and the PDU set with higher importance (i.e., higher PSI value). However, when the second discard timer expires for the PDU set with lower PSI, the SDUs of that PDU set are discarded. However, when the discard timer expires for the PDU set with higher PSI, the SDUs of that PDU set are not discarded and are still considered for transmission, taking into account their higher importance.

[0102] In an embodiment, when the relevant QoS flow is configured with a PDU Set Integration Processing Indicator (PSIHI) set to true, the sending PDCP entity (200) is configured with and / or utilizes a single timer (e.g., a first discardTimer or an XR discardTimer) for the PDU set. Otherwise, if the PSIHI of the QoS flow is set to false, the sending PDCP entity (200) is configured with and / or utilizes a conventional timer (e.g., a second discardTimer) for each SDU in the PDU set of the relevant QoS flow. The upper layer can indicate the PSIHI of the QoS flow to the PDCP entity associated with the QoS flow.

[0103] In an embodiment, when configured for XR radio bearer use, the second discardTimer (for per SDU discard) can act as the first discardTimer. In another embodiment, the second discardTimer acts as a discard timer based on the PDU set rather than an SDU discard timer for XR radio bearer use. In yet another embodiment, one or more values ​​of the second discardTimer are configured for different values ​​of the PSI of the PDU set.

[0104] In one embodiment, when an upper layer requests the discarding of PDCP for XR (i.e., requests the discarding of the PDU set), the sending PDCP entity (200) may discard all stored PDCP SDUs and PDCP PDUs belonging to the PDU set. In an alternative embodiment, when an upper layer requests the discarding of PDCP for XR, the sending PDCP entity may discard all stored PDCP SDUs and PDCPPDUs.

[0105] In the embodiment, the PSI value of the PDU set is used only based on the congestion status, for example, when the PDCP entity (200) determines the congestion situation or when the network notifies or signals the congestion situation to the UE (101) in a broadcast signaling message such as a system information block or a dedicated signaling message such as an RRC message, MAC control element or downlink control information DCI signaling.

[0106] In the embodiment, the PSI value of the PDU set is used regardless of the congestion state (i.e., whether the sending PDCP entity (200) determines the congestion situation, or whether the UE (101) is notified by the network or signals the congestion situation).

[0107] In this embodiment, the QoS parameters based on the PDU set can be the same for all PDU sets within a QoS flow, but multiple QoS flows can be mapped to a single DRB. In this embodiment, the sending PDCP entity (200) is configured by the network device (103) with parameters based on the PDU set for each QoS flow mapped to the DRB and / or the sending PDCP entity (200) is signaled by the network device (103) to provide parameters based on the PDU set for each QoS flow mapped to the DRB. The DRB can be configured with at least one of the following: an XR-specific drop timer for each QoS flow, a drop threshold for each QoS, a congestion timer for each QoS flow, a PSIHI parameter 30 for each QoS flow, and a PSI range for each QoS flow.

[0108] In this embodiment, the DRB is configured with a threshold for the PSI value of each QoS flow mapped to the DRB and / or the common PSI level of all QoS flows mapped to the DRB. If the value is below the threshold, the sending PDCP entity (200) may need to perform PDU set dropping when congestion is detected or when the congestion is notified to the sending PDCP entity (200).

[0109] In this embodiment, when a PDCP entity (200) is sent, the DRB is configured with a PSI-to-common priority level mapping rule. This rule is used to convert the PSI values ​​of PDU sets belonging to different QoS flows mapped to the DRB into a common priority level. In this embodiment, the DRB uses this common priority level to perform PDU set-based dropping during congestion.

[0110] In another embodiment, the priority mapping of the PDU set is accomplished based on the UE (101) implementation and does not require configuration from the network. This can be accomplished based on input from the application layer, such as metadata 20 information marked with packets from the encoder.

[0111] In an embodiment, the sending PDCP entity (200) is configured by the network device (103) and / or signaled for SDU discarding based on the PDU set and / or indicates whether to discard the entire PDU set if one or more SDUs constituting the PDU set are discarded (e.g., when discardTimer or XRdiscardTimer expires). Alternatively, the network device (103) may configure at least one of a threshold (e.g., the number or percentage of SDUs constituting the PDU set that, if discarded, could cause the sending PDCP entity (200) to discard the entire PDU set), congestion condition applicability (e.g., if congestion conditions are determined or signaling is applicable to discarding the PDU set), and PSIHI (e.g., if DRB is applicable to PDU set-based discarding).

[0112] When one or more PDCP SDUs belonging to the set of discarded PDUs are already associated with a PDCP sequence number (SN), there may be SN gaps in the transmitted PDCP PDUs, which may lead to an increase in PDCP reordering delay in the receiving PDCP entity.

[0113] In this embodiment, to overcome the aforementioned increased reordering delay problem, the sending PDCP entity (200) continues with the PDCP data PDUs of the PDU set that have already been assigned SNs, but still discards the PDCP SDUs of the PDU set that have not yet been assigned SNs. Furthermore, the first PDCP SDU of the next PDU set is assigned a next-order SN that has not yet been assigned. At the receiving PDCP entity, in order to know that there has been a discard of PDCP SDUs of a PDU set and that the PDCP SNs are still in order (i.e., without any SN gaps), the PDCP header of the first PDCP PDU of the next PDU set carries an indication field or bit or bitmap to indicate that the earlier PDU set was discarded.

[0114] The receiving PDCP entity can discard or remove received PDCP SDUs from an incomplete set of XR PDUs and continue processing the next set of XR PDUs. In an embodiment, the number of XR PDU sets discarded can be one or more at the sending PDCP entity, and correspondingly, one or more at the network device (103) during reordering.

[0115] In an embodiment, when a PDU belonging to a PDU set (the PDU set belongs to a DRB configured as true by PSIHI) has its discard timer expire at the PDCP entity, and if one or more other PDCPPDUs belonging to the same PDU set are submitted to the RLC entity, the PDCP entity instructs the RLC entity to discard all PDUs belonging to that PDU set.

[0116] In an embodiment, if a packet has already been sent, the RLC entity may not discard a PDU that the PDCP entity has indicated should be discarded.

[0117] In this embodiment, if a packet has not yet been sent, the RLC entity may discard a PDU that the PDCP entity has indicated should be discarded. In this embodiment, the RLC entity may discard a PDU that the PDCP entity has indicated should be discarded, regardless of whether the packet has been sent or not. In this embodiment, due to the PDU-based discarding at the RLC entity, the RLC entity can ensure that there are no gaps in the RLC SN.

[0118] In an embodiment, when a PDU belonging to a PDU set (which is subordinate to a PSIHI configured as a false DRB) has its discard timer expire at the PDCP entity, and if one or more other PDCP PDUs belonging to the same PDU set are submitted to the RLC entity, the sending PDCP entity (200) does not instruct the RLC entity to discard one or more other PDUs belonging to the PDU set.

[0119] In one embodiment, the sending PDCP entity (200) may instruct the RLC entity to discard PDUs whose discard timers have expired at the PDCP entity. In another embodiment, if a packet has already been sent, the RLC entity may not discard PDUs instructed to be discarded by the sending PDCP entity (200). In yet another embodiment, if a packet has not been sent, the RLC entity may discard PDUs instructed to be discarded by the sending PDCP entity (200). In yet another embodiment, the RLC entity may discard PDUs instructed to be discarded by the sending PDCP entity (200) regardless of whether the packet has been sent or not. In yet another embodiment, due to the PDU-based discarding at the RLC entity, the RLC entity can ensure that there are no gaps in the RLC SN.

[0120] In an embodiment, when a PDU belonging to a set of PDUs with a higher PSI value (which belongs to a DRB with PSIHI configured as true and congestion status true) has its discard timer expire at the PDCP, and if one or more other PDCP PDUs belonging to the same PDU set are submitted to the RLC, the PDCP may not instruct the RLC to discard the PDUs belonging to that PDU set.

[0121] In an embodiment, when a PDU belonging to a set of PDUs with a lower PSI value (which belongs to a DRB with PSIHI configured as true and congestion status true) has its discard timer expire at the PDCP, and if one or more other PDCP PDUs belonging to the same PDU set are submitted to the RLC, the PDCP may instruct the RLC to discard the PDUs belonging to that PDU set.

[0122] In one embodiment, the receiving PDCP entity may be configured with a PDU set-level reordering timer, and when the PDU set-level reordering timer expires, all SDUs belonging to the incompletely received PDU set are discarded or delivered to the upper layer. In another embodiment, received PDUs from the incompletely received PDU set with a lower PSI value are discarded. In yet another embodiment, received PDUs from the incompletely received PDU set with a higher PSI value are not discarded and / or delivered to the upper layer.

[0123] In an embodiment, when the sending PDCP entity receives a first PDCP SDU (i.e., an IP packet) constituting a PDU set with an associated PSI (if configured), from an upper layer, a first discardTimer for that PDU set is started. Furthermore, when subsequent PDCP SDUs constituting that PDU set (i.e., second, third, etc.) are received, the operation of the first discardTimer for the PDU set with the associated PSI is unaffected (i.e., the timer continues to run). Additionally, subsequent PDCP SDUs constituting that PDU set are linked to the same first discardTimer for the PDU set with the associated PSI (if configured).

[0124] In an embodiment, if the first discardTimer for the set of PDUs with associated PSI has expired, and subsequently, the sending PDCP entity (200) receives further PDCP SDUs (i.e., IP packets) from the upper layer, the sending PDCP entity discards these received PDCP SDUs and does not store them in its buffer or send them.

[0125] In this embodiment, PDCP replication is employed for XR. Furthermore, PDCP replication is selectively configured and / or utilized for one or more PDU sets with different PSI values ​​belonging to the same XR service. Additionally, for XR RBs, the sending PDCP entity (200) activates (or deactivates) PDCP replication for the XR RB from the first PDCP SDU in the PDU set when configuring (or deconfiguring) PDCP replication. In this embodiment, the sending PDCP entity (200) may be configured with PDU sets with different PSI values, applying selective replication for different PSI values. In this embodiment, PDCP replication is selectively applied for at least one of the higher PSI values ​​configured, notified, or signaled for the PDU set of the DRB.

[0126] Table 1 shows a sample description of the changes introduced in the sending PDCP entity (200) operation to support selective replication.

[0127] [Table 1]

[0128]

[0129] In this embodiment, PDCP routing is employed for XR. Furthermore, routing at the PDCP is selectively configured and / or utilized for one or more PDU sets with different PSI values ​​belonging to the same XR service. PDCP routing involves mapping PDCP PDUs to different RLC branches / logical channels based on the PSI value of the PDU set to which the PDU belongs. In this embodiment, differential processing can be applied to RLC branches / logical channels belonging to PDU sets with different PSI values. For example, this differential processing may include Logical Channel Priority (LCP) at the MAC layer (e.g., assigning higher logical channel priority to logical channels belonging to PDU sets with higher PSI values), buffer status reporting and scheduling request (SR) transmissions, packet dropping at the RLC layer, etc.

[0130] In the embodiment, the UE (101) indicates to the network, in one of the UE capability information message, UE auxiliary information message, RRC setup complete, RRC recovery complete or any other RRC message and NAS message, the UE capability that supports PSI-based PDCP discard support for XR (e.g., represented by the psi-BasedDiscard parameter) as one or more fields, bits, bitmaps, features, flags.

[0131] Table 2 shows a sample description of the changes introduced in the sending PDCP entity (200) operation to support PSI-based routing.

[0132] [Table 2]

[0133]

[0134] In an embodiment, when the relevant DRB for XR is configured with a PDU Set Integration Processing Indicator (PSIHI) set to true (also represented by the PDU Set Discard Parameter), the transmitting PDCP entity (200) configures and / or utilizes a single timer (e.g., a first discardTimer or an XR discardTimer) for the PDU set. Otherwise, if the PSIHI of the DRB for XR is set to false, the transmitting PDCP entity (200) configures and / or utilizes a conventional timer (e.g., a second discardTimer) for each SDU in the PDU set for the relevant DRB. The configuration for PSIHI is indicated in the RRC reconfiguration message for the relevant radio bearer configuration for XR.

[0135] Table 3 shows a sample description of the transmission operations introduced into the PDCP entity to support changes to the PDU-based XR discard timer based on PSIHI.

[0136] [Table 3]

[0137]

[0138] In this embodiment, the configuration of the XR bearer is carried in the RRCReconfiguration message as part of the PDCP configuration or as part of the XRBearerConfiguration separately.

[0139] Table 4 shows a sample ASN structure of PDCP-Config containing XR bearer-related PDCP layer configuration.

[0140] [Table 4]

[0141]

[0142]

[0143] According to embodiments of this disclosure, a set of configuration parameters introduced in the 3GPP specification is provided as follows.

[0144] XRDiscardThresholdPdus is the number of PDUs to be discarded while congestion-based discarding is active and in progress. XRDiscardThresholdBytes.

[0145] The total number of bytes to be discarded when congestion-based drop is activated and in progress. kb1 indicates 1 kilobyte of data, kb2 indicates 2 kilobytes of data, and so on.

[0146] XRCongestionTimer is a timer that starts when congestion is detected, and while running, it performs PSI-based drop at PDCP. Upon expiration, the PSI-based drop is deactivated.

[0147] PSIDiscardTimer provides the timer value to be used for a PDU, which is associated with a set of PDUs that have PSI values ​​listed as part of PSIList.

[0148] PSIHI_Indication (also represented by the PDU set drop parameter) provides the PSIHI configuration for the DRB or the associated QoS flow of the DRB, and indicates whether it is set to true or false.

[0149] Table 5 shows a sample description of the transmission operations introduced into the transmission PDCP entity (200) to support changes to the PDU set-based XR discard timer based on PSI.

[0150] [Table 5]

[0151]

[0152] In the embodiments, the PDCP discarding mechanism at the transmit PDCP entity (200) for XR takes into account the PSIHI of the radio bearer and the PSI of the PDU set. Table 6 shows a sample description of the transmit operations introduced into the PDCP entity to support changes in the XR discarding timer based on the PSIHI and PSI.

[0153] [Table 6]

[0154]

[0155] Figure 2B A receive PDCP entity for processing the importance of a set of PDUs during packet drop in extended reality in a wireless communication network, according to an embodiment of the present disclosure, is illustrated.

[0156] The receiving PDCP entity (208) comprises several components, including a processor (209), an I / O interface (211), a memory (213), and a packet discarding processor (215).

[0157] The processor (209) receiving the PDCP entity (208) communicates with the memory (213), I / O interface (211), and packet drop processor (215) to execute instructions stored in the memory (213) and perform various processes. It may include one or more processors, such as a general-purpose CPU, AP, GPU, VPU, and / or AI-specific NPU.

[0158] The memory (213) receiving the PDCP entity (208) includes storage locations addressable by the processor (209). The memory (213) may store at least one of the PSI values ​​received from the upper layer, the PDCP SDU of the PDU set received from the UE (101), and signaling messages from the transmitting PDCP entity (200). The memory (213) is not limited to volatile memory and / or non-volatile memory. The memory (213) may include one or more computer-readable storage media. The memory (213) may include non-volatile storage elements. For example, non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memory, or various forms of electrically programmable memory (EPROM) or electrically erasable and programmable (EEPROM) memory.

[0159] The I / O interface (211) transmits information between the memory (213) and external peripheral devices. The peripheral devices are input-output devices associated with the receiving PDCP entity (208). The I / O interface (211) receives at least one of the following: a PSI value received from the upper layer, a PDCP SDU from the set of PDUs of the transmitting PDCP entity (200), and a signaling message from the transmitting PDCP entity (200). The signaling message may include, but is not limited to, PDCP configuration messages and XR radio bearer configuration messages.

[0160] The packet drop processor (215), which receives the PDCP entity (208), communicates with the I / O interface (209) and memory (213) to process PDU set importance during extended reality packet drop in a wireless communication network. The packet drop processor (215) is innovative hardware implemented using both analog and digital circuits, including logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive and active electronic components, and optical components. The packet drop processor (215) configures a first drop timer, a second drop timer, and a PDU set integrated processing indication (PSIHI) for low importance based on the received XR radio bearer configuration message.

[0161] The packet discarding processor (215) can receive at least one set of PDUs and a configuration message. The configuration message includes a PDU set-level reordering timer, a PDU set-level indication for in-order delivery, and a PDU set-level indication for out-of-order delivery. When the first SDU of at least one PDU set is received from the sending PDCP entity, the packet discarding processor (215) can start the PDU set-level reordering timer. When the PDU set-level reordering timer expires, the packet discarding processor (215) can discard the received PDCP PDUs of at least one PDU set of lower importance. The packet discarding processor (215) can send a PDCP status report to the sending PDCP entity to confirm the receipt of at least one PDCP SDU of the PDU set. The packet discarding processor (215) can send the received PDUs of at least one PDU set of higher importance to the upper layer.

[0162] In an embodiment, the receiving PDCP entity (208) configures a first discardTimer for low importance for the XR radio bearer via RRC signaling (e.g., an RRC reconfiguration carrying a RadioBearerConfig consisting of a first discard Timer for XRRB). Instead of a second discardTimer configuration (for per SDU discard) or other than a discardTimer configuration, a configuration for the first discardTimer for low importance can be provided. In an embodiment, one or more values ​​for the first discardTimer and / or the second discardTimer for low importance are configured for different values ​​of the PSI of the PDU set. The configuration signaling may include a mapping between the values ​​of the XR discardTimer and / or the discardTimer and the PSI values.

[0163] In this embodiment, the receiving PDCP entity (208) configures a priority filter for the UE Non-Access Stratum (NAS). This priority filter is used to mark PDUs belonging to different PDU sets from different QoS flows using priority levels. In this embodiment, the application layer indicates the priority level and QFI (QoS Flow Identifier) ​​value to the UE Access Stratum (AS). The PDCP layer uses the priority level to perform differential processing of PDU sets in the AS layer, such as selective drop operations, selective duplication, etc.

[0164] In one embodiment, the receiving PDCP entity (208) may be configured with one or more PDU set-level reordering timers based on the PSI of the PDU set. In another embodiment, when a PDU set-level reordering timer expires, all SDUs belonging to the incompletely received PDU set are discarded or delivered to the upper layer. In yet another embodiment, when a PDU set-level reordering timer with a lower PSI expires, all SDUs belonging to that PDU set are discarded and delivered to the upper layer. In yet another embodiment, when a PDU set-level reordering timer with a higher PSI expires, all SDUs belonging to that PDU set are neither discarded nor delivered to the upper layer.

[0165] In an embodiment, the receiving PDCP entity (208) may be configured with a PDU set-level indication for whether sequential delivery is required; that is, the receiving PDCP may be configured with frame-level outof-order delivery, separate from the traditional (SDU-level) outof-order delivery in the current NR system. In an embodiment, frame-level outof-order delivery and / or outof-order delivery are configured separately for PDU sets with different PSI values.

[0166] In an embodiment, if all SDUs associated with a frame or PDU set are received in the PDCP receive buffer, the receive PDCP entity (208) can be configured to deliver to the upper layer without waiting for the reordering timer to expire. Table 7 shows the PDCP entities configured to be delivered to the upper layer.

[0167] [Table 7]

[0168]

[0169] In the embodiments, as shown in Table 8, procedures for managing received PDCP data PDUs at the receiving PDCP entity (208) for XR radio bearers are described.

[0170] [Table 8]

[0171]

[0172]

[0173] Figure 3 A method for processing PDU set importance during extended reality packet drop by a UE in a wireless communication network, according to embodiments of the present disclosure, is illustrated. At least one of the operations described below can be performed by a transmitting PDCP entity 200 (e.g., processor 201 and / or packet drop processor 207). According to embodiments, at least one of the blocks described below may be omitted, modified, or ordered.

[0174] refer to Figure 3 At block 301, the sending PDCP entity (200) can configure a first drop timer, a second drop timer, and a PDU set integration processing indication (PSIHI) for low importance based on the received XR radio bearer configuration message.

[0175] At block 303, the sending PDCP entity (200) can receive at least one PDCP SDU along with a PSI value associated with at least one set of PDUs from at least one upper layer.

[0176] At block 305, the sending PDCP entity (200) can determine whether at least one PDCP SDU is the first SDU of at least one PDU set, and whether PDU set discard is configured to true.

[0177] At block 307, when at least one PDCP SDU is the first PDCP SDU of at least one received PDU set, when the PDCP SDU is associated with a low importance PSI, and when the PDU set discard is configured to true, and when the PDCPSDU is associated with a low importance PSI, the sending PDCP entity (200) may start a first discard timer for low importance.

[0178] At block 309, when the first discard timer for at least one PDCP SDU of at least one PDU set for low importance expires, or when a PDCP status report is received from the receiving PDCP entity, the sending PDCP entity (200) may discard at least one PDU set.

[0179] At block 311, when at least one PDCP SDU is the first PDCP SDU of at least one received PDU set, when the PDCP SDU is associated with a high-importance PSI, and when the PDU set discard is configured to true, the sending PDCP entity (200) may start a second discard timer.

[0180] At block 313, when the second discard timer of at least one PDCP SDU of at least one PDU set expires, or when a PDCP status report is received from the receiving PDCP entity, the sending PDCP entity (200) may discard at least one PDU set.

[0181] At block 315, when at least one PDCP SDU is received, when the PDCP SDU is associated with a low-importance PSI, and when the PDU set drop is configured to false, the sending PDCP entity (200) may start a first drop timer for low-importance.

[0182] At block 317, the sending PDCP entity (200) may discard at least one PDUSDU when the first discard timer for at least one PDCP SDU for low importance expires or when a PDCP status report is received from the receiving PDCP entity.

[0183] At block 319, the sending PDCP entity (200) may start a second discard timer when the PDCP SDU is associated with a high-importance PSI, when the PDCP SDU is associated with a low-importance PSI, and when the PDU set discard is configured to false.

[0184] At block 321, the sending PDCP entity (200) may discard at least one PDU SDU when the second discard timer of at least one PDCP SDU expires or when a PDCP status report is received from the receiving PDCP entity.

[0185] In an embodiment, when the relevant QoS flow is configured with a PDU set integration processing indication (PSIHI) set to true, the transmitting PDCP entity (200) may be configured with and / or utilize a single timer (e.g., XRdiscardTimer) for the PDU set. Otherwise, if the PSIHI for the QoS flow is set to false, the UE is configured with and / or utilizes a conventional timer (e.g., discardTimer) for each SDU in the PDU set for the relevant QoS flow. The upper layer may indicate the PSIHI for the QoS flow to the PDCP entity associated with the QoS flow.

[0186] In an embodiment, when the relevant DRB for XR is configured with a PDU set integration processing indication (PSIHI) set to true, the transmitting PDCP entity (200) may be configured with and / or utilize a single timer (e.g., XRdiscardTimer) for the PDU set. Otherwise, if the PSIHI for the DRB for XR is set to false, the UE is configured with and / or utilizes a conventional timer (e.g., discardTimer) for each SDU in the PDU set for the relevant DRB. The configuration for PSIHI is indicated in the RRC reconfiguration message for the relevant radio bearer configuration for XR.

[0187] Table 9 shows the transmission operations at the transmitting PDCP entity. The transmission operations at the transmitting PDCP entity (200) are performed to support the PSIHI-based XR discard timer using the PDU set, based on the steps in Table 9.

[0188] [Table 9]

[0189]

[0190] Table 10 shows the transmission operations at the transmitting PDCP entity. The transmission operations at the transmitting PDCP entity (200) are performed to support the PSIHI-based XR discard timer using the PDU set, based on the steps in Table 10.

[0191] [Table 10]

[0192]

[0193] Figure 4 A flowchart is shown of a method for processing the importance of a set of PDUs when a packet is dropped in an extended reality wireless communication network by a receiving PDCP entity 208, according to an embodiment of the present disclosure. According to the embodiment, at least one of the blocks described below may be omitted, modified, or ordered.

[0194] refer to Figure 4 At block 401, the receiving PDCP entity (208) may configure at least one of the following based on the received XR radio bearer configuration message: a PDU set level reordering timer, a PDU set level indication for in-order delivery, and a PDU set integration processing indication (PSIHI) indicated by the PDU set discard parameter configuration.

[0195] At block 403, the receiving PDCP entity (208) can receive at least one PDCP SDU of the PDU set from the sending PDCP entity.

[0196] At block 405, when the receiving PDCP entity (208) receives at least one SDU of at least one PDU set from at least one PDU set, the receiving PDCP entity (208) may start a PDU set-level reordering timer.

[0197] At block 407, when the PDU set-level reordering timer expires, the receiving PDCP entity (208) may discard the received PDCP PDUs of at least one PDU set of lower importance.

[0198] At block 409, the receiving PDCP entity (208) may send a PDCP status report to the sending PDCP entity to confirm the reception of at least one PDCP SDU of the PDU set.

[0199] At block 411, the receiving PDCP entity (208) can send the received PDUs of at least one set of PDUs of higher importance to the upper layer.

[0200] The provided solution ensures efficient PDCP SDU drop operations. Furthermore, it reduces excessive processing overhead and minimizes resource waste during PDCP SDU packet transmission.

[0201] Various actions, behaviors, blocks, steps, etc., in the method are executed in the order they are presented, in different orders, or simultaneously. Furthermore, in some embodiments, some actions, behaviors, blocks, steps, etc., may be omitted, added, modified, or skipped without departing from the scope of the provided method.

[0202] The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can readily modify and / or adapt various applications of such specific embodiments by applying present knowledge without departing from the general conception, and therefore, such adaptations and modifications are intended to be understood as being within the meaning and scope of equivalents of the disclosed embodiments. It should be understood that the wording or terminology used herein is for descriptive purposes and not for limitation. Therefore, although the embodiments herein have been described according to preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the scope of the embodiments described herein.

[0203] Although this disclosure has been described with reference to various embodiments, various changes and modifications may be suggested to those skilled in the art. This disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

Claims

1. A method for handling packet dropping of Extended Reality (XR) in a wireless communication network by a User Equipment (UE), the method comprising: Receive a configuration message, the configuration message including information on a first discard timer, a second discard timer, and protocol data unit (PDU) set discard parameters for low importance, wherein, The first discard timer is set to a value shorter than the value of the second discard timer; Obtain at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from at least one upper layer; and Based on the first discard timer, the second discard timer, and the PDU set discard parameters, a transmission operation including PDCP SDU discard is performed for at least one PDCP SDU.

2. The method according to claim 1, wherein, Performing the sending operation includes at least one of the following: The UE's transmitting PDCP entity determines whether the first discard timer is configured and whether the at least one PDCP SDU belongs to a designated PDU set associated with the low importance, and whether the PDU set discard parameter is configured to true; Based on the first discard timer, the configured first discard timer and the at least one PDCP SDU belonging to the specified PDU set, the first discard timer for the low importance is started; The second discard timer is started based on the determination that the first discard timer is not configured or that at least one PDCP SDU does not belong to the specified PDU set; Based on the determination that at least one PDCP SDU, the first discard timer, or the second discard timer has expired, and the PDU set discard parameter is configured to true, one or more PDCPSDUs belonging to the specified PDU set are discarded; as well as Based on the determination that the at least one PDCP SDU, the first discard timer, or the second discard timer has expired, and the PDU set discard parameter is not configured to true, the at least one PDCP SDU and the corresponding PDCP data PDU are discarded.

3. The method according to claim 1, wherein, The at least one PDCP SDU receives a PDU set importance (PSI) value associated with at least one PDU set from the at least one upper layer in the General Packet Radio Service (GPRS) Tunneling Protocol (GTP) header of the at least one PDCP SDU, wherein the at least one upper layer comprises at least one of the Service Data Application Protocol (SDAP) layer, the application layer, and the service layer.

4. The method according to claim 1, further comprising: The UE's transmitting PDCP entity determines whether the first or second discard timer for the low-importance PDCP SDU has expired for the at least one PDCP SDU associated with the PDU set; and When the first or second discard timer for at least one PDCP SDU associated with the PDU set for the low importance has expired, the sending PDCP entity discards at least one PDCP SDU subsequently received from the upper layer and associated with the PDU set.

5. The method according to claim 1, wherein, For at least one specific data radio bearer (DRB) providing XR services, at least one of the first discard timer and the second discard timer for the low importance is configured for the UE's transmission PDCP entity and is configured in the XR radio bearer configuration message via radio resource control (RRC) signaling messages.

6. The method of claim 1, further comprising at least one of the following: When the PDCP SDU belonging to the low-importance PDU set is received from the upper layer, the UE's transmitting PDCP entity initiates a first discard timer for low importance; and When a PDCP SDU that does not belong to the low-importance PDU set is received from the upper layer, the sending PDCP entity starts the second discard timer.

7. The method of claim 1, further comprising: The UE's transmitting PDCP entity receives a request from the at least one upper layer to discard the PDU set; and The sending PDCP entity discards at least one set of PDCP SDUs and PDCP PDUs.

8. The method according to claim 1, further comprising: The PDCP entity transmitting the UE indicates the PDCP SDU of the next PDU set to be discarded by setting the indication field in the PDCP header of the first PDCP PDU of the next PDU set.

9. The method of claim 1, further comprising at least one of the following: When the PDU set drop parameter is configured to true, when the first drop timer for low importance expires at the PDCP layer and one or more PDCP SDUs or PDUs belonging to the same PDU set are submitted to the RLC layer, the transmitting PDCP entity instructs the transmitting radio link control (RLC) entity of the UE to drop the entire PDCP SDU or PDU of at least one PDU set of low importance. When the PDU set discard parameter is configured to true, when the second discard timer expires at the PDCP layer and one or more PDCP SDUs or PDUs belonging to the same PDU set are submitted to the RLC layer, the sending PDCP entity instructs the sending RLC entity to discard the entire PDCP SDUs or PDUs of the at least one PDU set of high importance. When the PDU set discard parameter is configured to false, when the first discard timer for low importance expires at the PDCP layer and at least one PDCP SDU or PDU belonging to the same PDU set is submitted to the RLC layer, the sending PDCP entity instructs the sending RLC entity to discard at least one PDCP SDU or PDU of the at least one PDU set of low importance. as well as When the PDU set discard parameter is configured to false, when the second discard timer expires at the PDCP layer and at least one PDCP SDU or PDU belonging to the same PDU set is submitted to the RLC layer, the sending RLC entity is instructed to discard at least one PDCP SDU or PDU of the at least one PDU set of high importance.

10. The method of claim 9, further comprising at least one of the following: When the sending PDCP entity indicates to the sending RLC entity to discard and the at least one PDCP SDU or PDU of the at least one PDU set has not yet been sent by the sending RLC entity, the sending RLC entity discards the at least one PDCP SDU or PDU of the at least one PDU set; When the sending PDCP entity indicates to the sending RLC entity to discard and the at least one PDCP SDU or PDU of the at least one PDU set has already been sent by the sending RLC entity, the sending RLC entity discards the at least one PDCP SDU or PDU of the at least one PDU set; as well as When the sending PDCP entity indicates to the sending RLC entity to discard and the at least one PDCP SDU or PDU of the at least one PDU set has already been sent by the sending RLC entity, the sending RLC entity skips discarding the at least one PDCP SDU or PDU of the at least one PDU set.

11. The method of claim 1, further comprising at least one of the following: When discarding a PDCP SDU or PDCP PDU of at least one PDU set, the PDCP transmitting entity of the UE continues to initialize the PDCP SDU or PDCP PDU of the at least one PDU set with assigned sequence numbers, and discards the PDCP SDU or PDCP PDU of the at least one PDU set that has not yet been assigned a sequence number. The sending PDCP entity assigns a consecutive sequence number to the first PDCP SDU in the next PDU set, relative to the last sequence number of the PDCP SDU assigned to the previous PDU set; and The sending PDCP entity uses bits, bitmaps, or fields in the PDCP header of the next PDU set to indicate that the at least one PDCP SDU or PDCP PDU of the at least one PDU set should be discarded.

12. The method of claim 1, further comprising: Based on an implementation that does not require configuration from the network, the UE's transmitting PDCP entity performs a priority mapping from at least one set of PDUs belonging to the Quality of Service (QoS) flow to the Data Radio Bearer (DRB) based on metadata received from the application layer, wherein, The metadata includes PDU set importance (PSI) value, PSI threshold, and discard threshold.

13. A method for processing packet dropping of extended reality (XR) in a wireless communication network by a network device, the method comprising: A configuration message is sent, which includes information on a first discard timer, a second discard timer, and discard parameters for protocol data unit (PDU) sets for low importance. The first discard timer is set to a value shorter than the value of the second discard timer; Receive at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from the User Equipment (UE). Based on the first discard timer, the second discard timer, and the PDU set discard parameters, at least one PDCP SDU is identified as being discarded by the UE; and Send a PDCP status report to the UE to confirm the receipt of the at least one PDCP SDU.

14. A user equipment (UE) for processing packet drop in extended reality (XR) in a wireless communication network, the UE comprising: I / O interfaces; and A packet discarding processor is communicatively coupled to the I / O interface, wherein... The packet discard processor is configured to: Receive a configuration message, the configuration message including information on a first discard timer, a second discard timer, and a protocol data unit (PDU) set discard parameter for low importance, wherein the first discard timer is set to a value shorter than the value of the second discard timer; Obtain at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from at least one upper layer; and Based on the first discard timer, the second discard timer, and the PDU set discard parameters, a transmission operation including PDCP SDU discarding is performed for the at least one PDCP SDU.

15. A network apparatus for processing packet dropping of extended reality (XR) in a wireless communication network, the network apparatus comprising: I / O interfaces; and A packet discarding processor is communicatively coupled to the I / O interface, wherein... The packet discard processor is configured to: Send a configuration message, the configuration message including information on a first discard timer, a second discard timer, and a protocol data unit (PDU) set discard parameter for low importance, wherein the first discard timer is set to a value shorter than the value of the second discard timer; Receive at least one Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) from the User Equipment (UE). Based on the first discard timer, the second discard timer, and the discard parameters of the PDU set, at least one PDCP SDU is identified as being discarded by the UE; and Send a PDCP status report to the UE to confirm the receipt of the at least one PDCP SDU.

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