Method and apparatus for transmission and reception of data in wireless communication system

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Provided are a method and an apparatus for transmission and reception of data in a wireless communication system. The method performed by a first node includes receiving a first message from a second node, where the first message includes first information about a dependency of a quality of service (QoS) flow, receiving second information about a dependency of a protocol data unit (PDU) set from a third node, and communicating a dependent PDU set based on the first information and the second information. The invention provides an enhanced method of transmission and reception of data.

Description

METHOD AND APPARATUS FOR TRANSMISSION AND RECEPTION OF DATA IN WIRELESS COMMUNICATION SYSTEM

[0001] The disclosure relates to wireless communication technology, and more specifically, to a method and an apparatus for transmission and reception of data in a wireless communication system.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in “Sub 6GHz” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] The present disclosure provides method and apparatus for transmission and reception of data in a wireless communication system.

[0009] According to an aspect of an exemplary embodiment, there is provided method and apparatus for transmission and reception of data in a wireless communication system.

[0010] Aspects of the present disclosure provide efficient communication methods in a wireless communication system.

[0011] In order to illustrate the technical schemes of the embodiments of the disclosure more clearly, the drawings of the embodiments of the disclosure will be briefly introduced below. Apparently, the drawings described below only refer to some embodiments of the disclosure, and do not limit the disclosure. In the drawings:

[0012] FIG. 1 illustrates an exemplary system architecture 100 of system architecture evolution (SAE);

[0013] FIG. 2 illustrates an exemplary system architecture 200 according to various embodiments of the disclosure;

[0014] FIG. 3 illustrates a schematic diagram of the configuration of a distributed unit and a centralized unit of a base station according to exemplary embodiments of the disclosure;

[0015] FIG. 4 illustrates an example in which an intra-coded picture frame (I frame for short) and a predictive-coded picture frame (P frame for short) constitute a group of pictures (GOP) in video data transmission according to exemplary embodiments of the disclosure;

[0016] FIG. 5 illustrates an example of a field of view (FOV) picture and a non-FOV picture in video data transmission according to exemplary embodiments of the disclosure;

[0017] FIG. 6 illustrates examples of transmission modes and cases of protocol data unit (PDU) sets with dependency and different data types according to exemplary embodiments of the disclosure;

[0018] FIG. 7 illustrates a flowchart of PDU session establishment according to exemplary embodiments of the disclosure;

[0019] FIG. 8 illustrates an example of synchronization of dependent PDU sets on different QoS flows according to exemplary embodiments of the disclosure;

[0020] FIG. 9 illustrates an example of packet discarding of dependent PDU sets on different QoS flows according to exemplary embodiments of the disclosure;

[0021] FIG. 10 illustrates an example of configuring corresponding CG resources for data on different QoS flows according to exemplary embodiments of the disclosure;

[0022] FIG. 11 illustrates examples in which data applies corresponding CG resources on different QoS flows according to exemplary embodiments of the disclosure;

[0023] FIG. 12 illustrates examples in which data applies corresponding CG resources on different QoS flows according to exemplary embodiments of the disclosure;

[0024] FIG. 13 illustrates an example of a method for a UE to retransmit uplink data according to exemplary embodiments of the disclosure;

[0025] FIG. 14 illustrates an example of communicating information on whether PDU set QoS handling is supported between inter cells according to exemplary embodiments of the disclosure;

[0026] FIG. 15 illustrates a flowchart of a method performed by a first node (e.g., a RAN node such as a base station) according to some embodiments of the disclosure;

[0027] FIG. 16 illustrates a flowchart of a method performed by a second node (e.g., SMF) according to some embodiments of the disclosure;

[0028] FIG. 17 illustrates a flowchart of a method performed by a third node (e.g., UPF) according to some embodiments of the disclosure;

[0029] FIG. 18 illustrates a flowchart of a method performed by a fourth node (e.g., UE) according to some embodiments of the disclosure;

[0030] FIG. 19 is a block diagram of a configuration of a first node according to some embodiments of the disclosure;

[0031] FIG. 20 is a block diagram of a configuration of a second node according to some embodiments of the disclosure;

[0032] FIG. 21 is a block diagram of a configuration of a third node according to some embodiments of the disclosure;

[0033] FIG. 22 is a block diagram of a configuration of a fourth node according to some embodiments of the disclosure.

[0034] In order to meet the increasing demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also called "Beyond 4G networks" or "Post-LTE systems".

[0035] Wireless communication is one of the most successful innovations in modern history. Recently, a number of subscribers of wireless communication services has exceeded 5 billion, and it continues growing rapidly. With the increasing popularity of smart phones and other mobile data devices (such as tablet computers, notebook computers, netbooks, e-book readers and machine-type devices) in consumers and enterprises, a demand for wireless data services is growing rapidly. In order to meet rapid growth of mobile data services and support new applications and deployments, it is very important to improve efficiency and coverage of wireless interfaces.

[0036] In order to make the purpose, technical schemes and advantages of the embodiments of the disclosure clearer, the technical schemes of the embodiments of the disclosure will be described clearly and completely with reference to the drawings of the embodiments of the disclosure. Apparently, the described embodiments are a part of the embodiments of the disclosure, but not all embodiments. Based on the described embodiments of the disclosure, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the protection scope of the disclosure.

[0037] Before undertaking the DETAILED DESCRIPTION below, it can be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and / or. The phrase "associated with," as well as derivatives thereof, means to include, be included within, connect to, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term "controller" means any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether locally or remotely. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items can be used, and only one item in the list can be needed. For example, "at least one of: A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. For example, "at least one of: A, B, or C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A, B and C.

[0038] Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from 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, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a 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 medium capable of being accessed by a computer, such as Read-Only Memory (ROM), Random Access Memory (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer-readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

[0039] Terms used herein to describe the embodiments of the disclosure are not intended to limit and / or define the scope of the present invention. For example, unless otherwise defined, the technical terms or scientific terms used in the disclosure shall have the ordinary meaning understood by those with ordinary skills in the art to which the present invention belongs.

[0040] It should be understood that "first", "second" and similar words used in the disclosure do not express any order, quantity or importance, but are only used to distinguish different components. Similar words such as singular forms "a", "an" or "the" do not express a limitation of quantity, but express the existence of at least one of the referenced item, unless the context clearly dictates otherwise. For example, reference to "a component surface" includes reference to one or more of such surfaces.

[0041] As used herein, any reference to "an example" or "example", "an implementation" or "implementation", "an embodiment" or "embodiment" means that particular elements, features, structures or characteristics described in connection with the embodiment is included in at least one embodiment. The phrases "in one embodiment" or "in one example" appearing in different places in the specification do not necessarily refer to the same embodiment.

[0042] As used herein, "a portion of" or "a part of" something means "at least some of" the thing, and as such may mean less than all of, or all of, the thing. As such, "a portion of" a thing includes the entire thing as a special case, i.e., the entire thing is an example of a portion of the thing.

[0043] As used herein, the term "set" may mean one or more. Accordingly, a set of items may be a single item or a collection of two or more items.

[0044] In the disclosure, to determine whether a specific condition is satisfied or fulfilled, expressions, such as "greater than / larger than" or "less than / smaller than" are used by way of example and expressions, such as "greater than or equal to" or "less than or equal to" are also applicable and not excluded. For example, a condition defined with "greater than or equal to" may be replaced by "greater than" (or vice-versa), a condition defined with "less than or equal to" may be replaced by "less than" (or vice-versa), etc.

[0045] It will be further understood that similar words such as the term "include" or "comprise" mean that elements or objects appearing before the word encompass the listed elements or objects appearing after the word and their equivalents, but other elements or objects are not excluded. Similar words such as "connect" or "connected" are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. "Upper", "lower", "left" and "right" are only used to express a relative positional relationship, and when an absolute position of the described object changes, the relative positional relationship may change accordingly.

[0046] The various embodiments discussed below for describing the principles of the disclosure in the patent document are for illustration only and should not be interpreted as limiting the scope of the disclosure in any way. Those skilled in the art will understand that the principles of the disclosure can be implemented in any suitably arranged wireless communication system. For example, although the following detailed description of the embodiments of the disclosure will be directed to LTE and / or 5G communication systems, those skilled in the art will understand that the main points of the disclosure can also be applied to other communication systems with similar technical backgrounds and channel formats with slight modifications without departing from the scope of the disclosure. The technical schemes of the embodiments of the present application can be applied to various communication systems, and for example, the communication systems may include global systems for mobile communications (GSM), code division multiple access (CDMA) systems, wideband code division multiple access (WCDMA) systems, general packet radio service (GPRS) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunications system (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, 5th generation (5G) systems or new radio (NR) systems, etc. In addition, the technical schemes of the embodiments of the present application can be applied to future-oriented communication technologies.

[0047] Hereinafter, the embodiments of the disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the same reference numerals in different drawings will be used to refer to the same elements already described.

[0048] The text and drawings are provided as examples only to help readers understand the disclosure. They are not intended and should not be interpreted as limiting the scope of the disclosure in any way. Although certain embodiments and examples have been provided, based on the content disclosed herein, it will be apparent to those skilled in the art that changes may be made to the illustrated embodiments and examples without departing from the scope of the disclosure.

[0049] FIGS. 1 to 3 discussed below and various embodiments for describing the principles of the present disclosure in this patent document are only for illustration and should not be interpreted as limiting the scope of the disclosure in any way. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0050] FIG. 1 is an exemplary system architecture 100 of system architecture evolution (SAE). User equipment (UE) 101 is a terminal device for receiving data. An evolved universal terrestrial radio access network (E-UTRAN) 102 is a radio access network, which includes a macro base station (eNodeB / NodeB) that provides UE with interfaces to access the radio network. A mobility management entity (MME) 103 is responsible for managing mobility context, session context and security information of the UE. A serving gateway (SGW) 104 mainly provides functions of user plane, and the MME 103 and the SGW 104 may be in the same physical entity. A packet data network gateway (PGW) 105 is responsible for functions of charging, lawful interception, etc., and may be in the same physical entity as the SGW 104. A policy and charging rules function entity (PCRF) 106 provides quality of service (QoS) policies and charging criteria. A general packet radio service support node (SGSN) 108 is a network node device that provides routing for data transmission in a universal mobile telecommunications system (UMTS). A home subscriber server (HSS)109 is a home subsystem of the UE, and is responsible for protecting user information including a current location of the user equipment, an address of a serving node, user security information, and packet data context of the user equipment, etc.

[0051] FIG. 2 is an exemplary system architecture 200 according to various embodiments of the present disclosure. Other embodiments of the system architecture 200 can be used without departing from the scope of the present disclosure.

[0052] User equipment (UE) 201 is a terminal device for receiving data. A next generation radio access network (NG-RAN) 202 is a radio access network, which includes a base station (a gNB or an eNB connected to 5G core network 5GC, and the eNB connected to the 5GC is also called ng-gNB) that provides UE with interfaces to access the radio network. An access control and mobility management function entity (AMF) 203 is responsible for managing mobility context and security information of the UE. A user plane function entity (UPF) 204 mainly provides functions of user plane. A session management function entity SMF 205 is responsible for session management. A data network (DN) 206 includes, for example, services of operators, access of Internet and service of third parties.

[0053] In NR systems, in order to support network function virtualization and more efficient resource management and scheduling, a base station (e.g., gNB / ng-eNB) that provides wireless network interfaces for terminals (e.g., UEs) can be further divided into a central unit (CU) (e.g., gNB-CU / ng-eNB-CU (gNB central unit / ng-eNB central unit)) and a distributed unit (DU) (for example, gNB-DU / ng-eNB-DU (gNB distributed unit / ng-eNB distributed unit), as shown in (a) of FIG. 3.

[0054] The gNB-CU has a radio resource control (RRC) layer, a service data adaptation protocol (SDAP) layer and a packet data convergence protocol (PDCP) layer, etc. The ng-eNB-CU has a RRC layer and a PDCP layer. The gNB-DU / ng-eNB-DU has a radio link control protocol (RLC) layer, a medium access control (MAC) layer and a physical layer, etc. There is a standardized open interface F1 between the gNB-CU and the gNB-DU, and a standardized open interface W1 between the ng-eNB-CU and the ng-eNB-DU. The F1 interface can be divided into a control plane F1-C and a user plane F1-U. The transport network layer of the F1-C is transmitted based on IP. In order to transmit signaling more reliably, a SCTP protocol is added above the IP. The protocol of an application layer can be F1AP. The SCTP can provide reliable transmission of the application layer message. The transport layer of the F1-U is UDP / IP, and GTP-U above the UDP / IP is used to carry user plane protocol data units (PDUs).

[0055] Further, for the gNB-CU, as shown in FIG. 3 (b), the gNB-CU may include a gNB-CU-CP (a control plane part of the central unit of the base station) and a gNB-CU-UP (a user plane part of the central unit of the base station). The gNB-CU-CP contains functions of the control plane of the base station, with the RRC layer and the PDCP protocol layer, and the gNB-CU-UP contains functions of the user plane of the base station, with the SDAP layer and the PDCP protocol layer. There is a standardized open interface E1 between the gNB-CU-CP and the gNB-CU-UP, and the protocol can be E1AP. The interface between the control plane part of the central unit of the base station and the distributed unit of the base station is a F1-C interface, that is, a control plane interface of F1; the interface between the user plane part of the central unit of the base station and the distributed unit of the base station is a F1-U interface, that is, a user plane interface of F1.

[0056] In addition, in NR systems, a base station that provides a E-UTRA user plane and a control plane and accesses a 5G core network can be called ng-eNB. In order to support virtualization, such base station (ng-eNB) may also be further divided into a central unit ng-eNB-CU (gNB central unit / ng-eNB central unit) and a distributed unit ng-eNB-DU (gNB distributed unit / ng-eNB distributed unit) (abbreviated as CU and DU in embodiments of the disclosure), as shown in (c) of FIG. 3. The ng-eNB-CU has a RRC layer and a PDCP layer. The gNB-DU / ng-eNB-DU has a radio link control protocol (RLC) layer, a medium access control (MAC) layer and a physical layer, etc. There is a standardized open interface W1 between the ng-eNB-CU and the ng-eNB-DU. The W1 interface can be divided into a control plane W1-C and a user plane W1-U. The transport network layer of the W1-C is transmitted based on IP. In order to transmit signaling more reliably, the SCTP protocol is added over the IP. The protocol of an application layer can be W1AP. The transport layer of the W1-U is UDP / IP, and the GTP-U above the UDP / IP is used to carry user plane protocol data units (PDUs).

[0057] With continued reference to FIG. 3, for NR base stations, the radio protocol of the next generation mobile communication system may include PDCP, RLC and MAC. The main functions of PDCP can include some of the following functions:

[0058] - header compression and decompression: ROHC only

[0059] - transmission of user data

[0060] - sequential delivery of upper layer protocol data units (PDU)

[0061] - out-of-order delivery of upper layer PDUs

[0062] - PDCP PDU reordering for reception

[0063] - repeated detection of lower layer SDU

[0064] - retransmission of PDCP SDU

[0065] - encryption and decryption

[0066] - timer-based SDU discard in uplink

[0067] The reordering function of an NR PDCP device refers to a function of sequentially reordering PDCP PDUs received from a lower layer based on PDCP sequence numbers (SNs), and may include a function of transmitting data to an upper layer in the reordered order, a function of transmitting data regardless of the order, a function of reordering sequences and recording lost PDCP PDUs, a function of providing a status report on the lost PDCP PDUs to a transmitting side, and a function of requesting retransmission of the lost PDCP PDUs.

[0068] The main functions of RLC may include some of the following functions:

[0069] - transfer of upper layer PDUs

[0070] - sequential delivery of upper layer PDUs

[0071] - out-of-order delivery of upper layer PDUs

[0072] - error correction through ARQ

[0073] - concatenation, segmentation and reassembly of RLC SDUs

[0074] - re-segmentation of RLC data PDUs

[0075] - reordering of RLC data PDUs

[0076] - duplicate detection

[0077] - protocol error detection

[0078] - RLC SDU discard

[0079] - RLC re-establishment

[0080] The sequential delivery function of the NR RLC device refers to a function of transmitting RLC SDUs received from the lower layer to the upper layer in a receiving sequence, and may include a function of reassembling and transmitting multiple RLC SDUs if one RLC SDU is initially segmented into the multiple RLC SDUs and received; a function of reordering the received RLC PDUs based on RLC sequence numbers (SNs) or PDCP SNs; a function of reordering sequences and recording lost RLC PDUs; a function of providing a status report on the lost RLC PDUs to the transmitting side; and a function of requesting retransmission of the lost RLC PDUs.

[0081] The out-of-order delivery function of the NR RLC device refers to a function of directly transmitting RLC SDUs received from the lower layer to the upper layer regardless of the order, and if one RLC SDU is initially segmented into multiple RLC SDUs and received, it may include: a function of reassembling the multiple RLC SDUs and transmitting them; and a function of storing the RLC SNs or PDCP SNs of the received RLC PDUs, reordering the sequence, and recording the lost RLC PDUs.

[0082] The MAC can be connected to multiple RLC layer devices configured in a UE, and the main functions of the MAC can include some of the following functions:

[0083] - mapping between logical channels and transport channels

[0084] - multiplexing / de-multiplexing of MAC SDUs

[0085] - scheduling information reporting

[0086] - error correction through HARQ

[0087] - priority handling between logical channels of one UE

[0088] - priority handling between UEs by means of dynamic scheduling

[0089] - MBMS service identification

[0090] - transport format selection

[0091] - padding

[0092] The PHY layer may perform operations of channel coding and modulation of upper layer data, forming the upper layer data into an OFDM symbol, transmitting the OFDM symbol through a radio channel, or of demodulating an OFDM symbol received through a radio channel, channel-decoding the OFDM symbol, and transmitting the OFDM symbol to an upper layer.

[0093] The example of the radio protocol architecture of NR systems described above can also be applied to a UE.

[0094] Communication technology has faster and faster transmission speed, so it can provide more kinds of communication services for users. The extended reality (XR) service is regarded as the key application service to promote the development of communication technology, which can be, for example, the floorboard of three service types: augmented reality (AR), virtual reality (VR) and mixed reality (MR). The XR service has high requirement for transmission speed and delay, so it needs more network resources to support the normal operation of the service. At the same time, for the portability of XR equipment, the size of the battery is greatly limited, and how to reduce energy consumption has become a big challenge. Therefore, in order to improve the user experience of XR users, it is necessary to conduct more in-depth research on reducing power consumption, improving network capacity, and improving XR perception.

[0095] At present, the concept of PDU set is proposed. For example, PDU sets may be applied to the XR field. A PDU set may consist of one or more PDUs. A PDU set may be a slice of a service. For example, a PDU set may be a frame or a video slice in XR service. A PDU set is mapped to only one QoS flow, and / or all parameters related to PDU sets on a QoS flow (for example, QoS related parameters of PDU sets, in the embodiments of the disclosure, which may be called PDU set QoS parameters, or simply referred to as QoS parameters, such as PDU set delay budget (PSDB), PDU set error rate (PSER) and / or PDU set integrated handling indication (PSIHI)) are the same. Different PDU sets may have different importance levels (or importance), and / or different PDU sets on a same QoS flow may have different importance levels. For example, a parameter related to the importance of a PDU set (in the embodiments of the disclosure, which may be called PDU set importance (PSI); for example, the value of PSI may be 'high', 'medium' and 'low', indicating relatively high importance, medium importance and relatively low importance, respectively; for another example, the value of PSI may be 0-N (for example, N may be a positive integer such as 7, indicating the importance from low to high (or from high to low), respectively) to represent or indicate the importance level (or importance) of the PDU set. PSI may be notified to RAN by UPF through GTP-U header, for example. When the network congestion occurs in the RAN, the corresponding PDU sets may be discarded according to the PSI values (for example, some PDU sets with smaller PSI values are discarded), so as to alleviate or solve the network congestion. For example, the PDU set QoS parameters may be determined by a network element such as policy control function (PCF), for example, according to the service-related information provided by application function (AF), and sent to SMF as a part of policy and charging control (PCC) rule, and then sent to RAN by SMF as a part of QoS profile. In an embodiment of the disclosure, the RAN may include a base station, such as gNB.

[0096] FIG. 4 illustrates an example in which an intra-coded picture frame (I frame for short) and a predictive-coded picture frame (P frame for short) constitute a group of pictures (GOP) in video data transmission according to exemplary embodiments of the disclosure.

[0097] A typical video data transmission mode in XR service includes video frame transmission in the form of I frame and P frame, as shown in FIG. 4. When a UE receives an I frame, it may only decode the I frame data and present the picture of the frame to the user. P frame is a forward reference frame. Generally, the data of P frame is smaller than that of I frame, and the difference between P frame and previous I / P frame is transmitted. Therefore, it may be necessary to refer to the data information of previous frame to obtain the final picture data of current P frame, and it may not be possible to decode it by the data of current P frame alone. Generally, one I frame and n (for example, n is a positive integer) P frames form a group of pictures (GOP), and a UE or a RAN transmits the uplink and downlink picture frames in the manner of GOP. Another typical video transmission mode is to transmit video pictures in the form of field of view (FOV) and non-FOV. The FOV may be, for example, the field of view that a user can see when wearing an XR head-mounted display device. The non-FOV may be, for example, a panorama corresponding to the field of view seen by the current user (for example, a panorama of 180 or 360 degrees). The resolution of FOV images is generally higher than that of non-FOV images. The purpose of transmitting FOV and non-FOV at the same time may be to prevent black edges from appearing at the edge of the visual field when the user turns his head. The reason for the low resolution of non-FOV is to reduce the amount of data transmitted, thus reducing the network burden. FIG. 5 illustrates an example of a FOV picture and a non-FOV picture in video data transmission according to exemplary embodiments of the disclosure. Thus, I frame is more important than P frame, and FOV data is more important than non-FOV data. P frame is associated with the previous I frame or P frame, because the previous frame is needed for decoding; FOV and non-FOV are also correlated, because FOV and non-FOV need one-to-one correspondence. For different types of data, the QoS parameters required for transmission should be different because of their different importance. A more reasonable way is to transmit different types of data with different importance through different QoS, which may be processed according to different QoS parameters.

[0098] At present, the dependency / correlation between data units (for example, PDUs or PDU sets) has not been considered in data transmission. For some services (for example, XR service), this may lead to a long delay in data transmission, thus affecting the user experience. Therefore, there is a need for an enhanced data transmission method to perform transmission of data units (e.g., PDUs or PDU sets) and / or congestion control and / or synchronization control in consideration of the dependency / correlation between data units (e.g., PDUs or PDU sets).

[0099] Depending on different data types, there may be various transmission modes and cases of PDU sets (PSs) with dependency / correlation (dependent / correlated PDU sets (PSs)), but the further handling of the dependent / correlated PDU sets may need to be further improved.

[0100] The dependency / correlation of two or more PDU sets may mean that the two or more PDU sets are dependent on / correlated to each other, and an example of the dependency / correlation may refer to the following description. FIG. 6 illustrates examples of transmission modes and cases of PDU sets with dependency / correlation and different data types according to exemplary embodiments of the disclosure. It will be understood that the description in connection with FIG. 6 is only an example, and there may be other transmission modes and cases of multiple PDU sets with dependency / correlation.

[0101] Case 1: PDU set 1 and PDU set 2 are two different PDU sets in a same frame.

[0102] Case 2: PDU set 1 is an I frame, and PDU set 2 is the next P frame.

[0103] Case 3: PDU set 1 is of video data type and PDU set 2 is of audio data type; PDU set 3 is of pose / haptic data type.

[0104] Case 4: PDU set 1 is FOV data and PDU set 2 is non-FOV data.

[0105] According to FIG. 6, it can be seen that the PDU sets with correlation but different data types in Cases 1, 3 and 4 need to be transmitted at the same time, while the PDU sets with different data types in Case 2 need to be transmitted according to time sequence. At this time, the network may need to synchronize different PDU sets to be transmitted at the same time. Because the different PDU sets in Case 1 constitute the same frame, they have the same PDU set QoS parameters; while the PDU sets with different data types in Cases 2, 3 and 4 have different importance levels, so the PDU sets with different data types in these cases may be transmitted through different QoS flows.

[0106] According to exemplary embodiments of the disclosure, a method and apparatus for transmission of PDU sets of different data types through different QoS flows are proposed.

[0107] According to exemplary embodiments of the disclosure, a method and apparatus for a RAN (e.g., a base station) to obtain PDU set dependency / correlation are proposed.

[0108] According to exemplary embodiments of the disclosure, a method and apparatus for a RAN (e.g., a base station) to synchronize different PDU sets that need to be transmitted simultaneously are proposed.

[0109] According to exemplary embodiments of the disclosure, a method and apparatus for handling PDU sets in multiple modal flows by a RAN when a network is congested are proposed. For example, when the network is congested, the RAN (e.g., base station) may discard PDU set(s) in the multiple modal flows.

[0110] It should be noted that although the XR service may be taken as an example to describe the application scenarios of the embodiments of the disclosure, the embodiments of the disclosure are not limited to this and can be applied to communication systems with similar services.

[0111] Before introducing the specific content, some assumptions and some definitions of the embodiments of the disclosure are given below.

[0112] The message name in the embodiments of the disclosure is just an example, and other message names may be used. Further, a message for indicating / notifying information / information element (IE) may refer to a message including the information / information element (IE) or the information / information element itself. For example, a message for indicating / notifying information / information element (IE) may be used interchangeably with this information / information element (IE).

[0113] The terms "first" and "second" included in the message name of the embodiments of the disclosure are only examples of messages and do not represent the execution order.

[0114] In the embodiments of the disclosure, a detailed description of steps unrelated to the embodiments of the disclosure may be omitted.

[0115] In the embodiments of the disclosure, the steps in each process may be performed in combination with each other or independently. The execution steps of each process are only examples, and other possible execution orders are not excluded.

[0116] In the embodiments of the disclosure, the base station may be a 5G base station (such as gNB, ng-eNB). Alternatively, the base station may also be a 4G base station (such as an eNB), a 6G base station, or other types of access nodes.

[0117] In the embodiments of the disclosure, transmission of data refers to transmitting and / or receiving the data, for example.

[0118] When different PDU sets with dependency / correlation are transmitted through different QoS flows, if a RAN (for example, a base station) knows that there is dependency / correlation between two QoS flows, the RAN may handle all PDU sets on the QoS flow in a per QoS flow manner. For example, in Case 4, when the PDU sets corresponding to FOV and non-FOV are transmitted through different QoS flows, if the network is seriously congested, the RAN may directly discard all the PDU sets corresponding to non-FOV, so as to achieve the purpose of quickly alleviating the network congestion. Therefore, the RAN may need to know whether there is dependency / correlation between different QoS flows. A method for a RAN (e.g., a base station) to obtain dependency / correlation of PDU sets according to some embodiments of the disclosure is described below.

[0119] For the convenience of description, firstly, an example of PDU session establishment process is introduced. FIG. 7 illustrates a flowchart of PDU session establishment according to exemplary embodiments of the disclosure.

[0120] Referring to FIG. 7, in operation S710, a UE may send a PDU Session Establishment Request to an AMF. For example, the PDU Session Establishment Request is used to request the establishment of a data channel. In operation S720, the AMF may send a PDU Session Resource Setup Request to a RAN (e.g., a base station, such as gNB). In operation S730, the RAN (e.g., the base station, such as gNB) may send an RRC Reconfiguration message (e.g., RRCReconfiguration) to the UE. In operation S740, the UE may establish data radio bearer(s) (DRB(s)), for example, based on the received RRC Reconfiguration message. In operation S750, the UE may send an RRC Reconfiguration Complete message (e.g., RRCReconfigurationComplete) to a RAN (e.g., the base station, such as gNB). In operation S760, the RAN (e.g., the base station, such as gNB) may send a PDU Session Resource Setup Response to the AMF. After the PDU session resource is set up, user plane data may be communicated between the UE and the RAN (e.g., the base station, such as gNB), and / or between the RAN (e.g., the base station, such as gNB) and a UPF.

[0121] In some embodiments, the RAN (e.g., the base station, such as gNB) may receive a first message from a core network (e.g., 5GC), which may be used to indicate / inform a dependency / correlation between QoS flows. For example, SMF may send the first message to the AMF over an NG interface, and the AMF may send the first message to the RAN.

[0122] -The first message may be used to indicate the dependency / correlation between QoS flows to the RAN, such as which QoS flows are dependent on / correlated to each other, or which QoS flows are dependent on / correlated to a certain QoS, or one or more dependent QoS flows, or one or more QoS flows dependent on / correlated to a certain QoS flow. The first message may be a list including QFIs (QoS flow identifiers) of one or more dependent QoS flows. For example, the list may include one or more QFIs (QFIs of one or more QoS flows) to indicate that a certain QFI (for convenience of description, it may be called the first QFI) is dependent on / correlated to the one or more QFIs in the list, that is, the QoS flow with the first QFI is dependent on / correlated to the one or more QoS flows with the one or more QFIs in the list. A QFI may also have a dependency / correlation indication index (similar to the dependency / correlation indication index of a PDU set). Multiple QFIs with the same dependency / correlation indication index value has relevance. For example, the first message may include information of QoS flow(s) dependent on / correlated to a QoS flow and / or information indicating a dependency / correlation of QoS flows.

[0123] -The first message may be called, for example, an associated / dependent / correlated QoS flow list, or any other suitable name, which is not limited by the embodiments of the disclosure.

[0124] -The first message may be sent to the RAN through a newly defined NGAP message or an existing NGAP message, which is not limited by the embodiments of the disclosure. For example, the first message may be added to a PDU Session Resource Establishment Request or a PDU Session Resource Modification Request. Table 1 illustrates an example of a QoS flow setup request list in the first message according to exemplary embodiments of the disclosure. For example, as shown in Table 1, the QoS flow setup request message may include a QoS flow identifier (for example, the identifier of the above-mentioned first QoS flow) and a list indicating one or more QoS flows dependent on / correlated to a QoS flow with the QoS flow identifier (for example, the above-mentioned first QoS flow), where the list includes identifiers (QFIs) of the one or more QoS flows. In Table 1, "maxnoofQoSFlows" indicates the maximum number of QoS flows. The QoS flow setup request message may further include a packet discarding type. The packet discarding type may include partial packet discarding, all packet discarding, no packet discarding, packet discarding based on the priorities of QoS flows, packet discarding based on PSI and so on. The details about the packet discarding method may refer to the method described later that the RAN discards dependent PDU sets on different QoS flows.

[0125] -When the RAN receives the first message, it may know which of the other QFIs the QFI (for example, the identifier of the first QoS flow mentioned above) is dependent on / correlated to.

[0126]

[0127] When the RAN knows which QoS flows are dependent / correlated, it may also need to know which PDU sets in these dependent / correlated QoS flows are dependent / correlated. When the network congestion is not serious (for example, the degree of the network congestion is less than a congestion threshold; for example, when a parameter indicating the degree of the network congestion (such as packet loss rate, etc.) is less than a certain threshold), the RAN may discard only a part of PDU sets to alleviate the network congestion, instead of discarding all the PDU sets on the QoS flow. Take Case 4 in FIG. 6 as an example, in which FOV data and non-FOV data are transmitted through a QoS flow with QFI1 (which may be used interchangeably with QFI1) and a QoS flow with QFI2 (which may be used interchangeably with QFI2), respectively. PDU set 1 and PDU set 2 in QFI1 are dependent on / correlated to PDU set 4 and PDU set 3 in QFI2, respectively. When the network congestion is not serious, it is unnecessary for RAN to discard all PDU sets in QFI2. If the congestion is relieved after discarding PDU set 4, both PDU set 2 and PDU set 3 may be sent to the UE. Therefore, the RAN may need to know the dependency / correlation between different PDU sets in different QoS flows.

[0128] In some embodiments, a sequence number (SN) of a PDU set dependent on / correlated to a certain PDU set may be added in the header of the certain PDU set to indicate / inform the dependency / correlation. Table 2 illustrates an example of indicating a dependent PDU set according to exemplary embodiments of the disclosure. As shown in Table 2, the header of a PDU set may include an importance level, the SN of the PDU set, the SN of a PDU within the PDU set, the start mark of the PDU set (only valid for the first PDU of the PDU set), and the SN(s) of dependent PDU set(s). As a concrete example, if PDU set 1 is dependent on / correlated to PDU sets 2 and 3, the SNs of PDU sets 2 and 3 may need to be added to the header of PDU set 1, and the SNs of PDU sets 1 and 3 may need to be added to the header of PDU set 2. If the number of dependent PDU sets is large, the signaling overhead of each PDU set header may increase.

[0129]

[0130] In some embodiments, a second message may be added to the header of a PDU set to indicate / inform the RAN that the PDU set is related to other PDU set(s). In this way, signaling overhead may be reduced. For example, one or more of the following ways may be adopted.

[0131] -The second message may be added / included in the PDU set header, which may be called, for example, a dependency / correlation indication index, or any other suitable name, which is not limited by the embodiments of the disclosure. The second message may be an integer, for example, an integer with a value range of 0 to n. The embodiments of the disclosure do not limit the value range, nor do it limit the value of the maximum value n. The schematic diagram is shown in Table 3.

[0132] -The second message may be used to indicate the RAN that for different PDU sets in different QFIs, if the dependency / correlation indication index values of the PDU sets are the same, the PDU sets are dependent / correlated. As shown in Table 4, PDU set 1 and PDU set 2 are transmitted through QFI1, and PDU set 3 and PDU set 4 are transmitted through QFI2. Because the value of the dependency / correlation indication index in the header of PDU set 1 in QFI1 is 1, which is the same as that in the header of PDU set 4 in QFI2, PDU set 1 is dependent on / correlated to PDU set 4. Similarly, PDU set 2 is dependent on / correlated to PDU set 3.

[0133] -When the header of a PDU set includes / carries the second message, the RAN may consider that the PDU set has other dependent / correlated PDU set(s); when the second message is not included / carried in the header of a PDU set, the RAN may consider that the PDU set has no other PDU set(s) dependent on / correlated to it.

[0134] -Or, when the value of the second message in the header of a PDU set is a specific value, the RAN considers that the PDU set has no other PDU set(s) dependent on / correlated to it; when the value of the second message is not the specific value, the RAN considers that the PDU set has other dependent / correlated PDU set(s). The specific value may be 0 or other values, which is not limited by the embodiments of the disclosure.

[0135]

[0136]

[0137] The above describes the method for the RAN to obtain the dependency / correlation between QoS flows and the dependency / correlation between PDU sets according to exemplary embodiments of the disclosure. The RAN may allocate resources and schedule data based on the obtained dependency / correlation between QoS flows and / or PDU sets, so that dependent / correlated QoS flows and / or dependent / correlated PDU sets in dependent / correlated QoS flows can reach the UE at the same time, thus achieving the purpose of data synchronization. When the network is congested, packet discarding may also be handled according to the dependency / correlation between data, so as to alleviate the network congestion and minimize the impact on the quality of service of UE.

[0138] Different PDU sets may have different service characteristics. For example, in XR service, different types of data have different service characteristics. For example, in Case 3, the service characteristics of video, audio and pose data are different, as shown in Table 5- Table 8. In multiple modal flows, video, audio and pose / haptic data are transmitted through different QoS flows. If the RAN knows the service characteristics of the data types (such as period or data size), it is more beneficial for the RAN to schedule and allocate resources for different types of data. For example, after the RAN knows the period, it may synchronize the dependent / correlated data through data scheduling. For another example, after the RAN knows the data size, it may configure different semi-persistent scheduling (SPS) / configured grant (CG) resource configurations for different types of data transmission. Therefore, the RAN may need to know the service characteristics of different data types in different QoS flows.

[0139]

[0140]

[0141]

[0142]

[0143] In some embodiments, the UE may inform the RAN of the service characteristics of different data types through a third message.

[0144] -The third message may be an RRC message or other messages; the third message may be a newly defined message or an existing message, which is not limited by the embodiments of the disclosure.

[0145] -The third message may include a QFI, and information related to at least one of the following: a transmission period or transmission interval of data transmitted through the QFI, a data size, a requirement of a packet delay budget (PDB) or PSDB, a data rate, a remaining PDB or PSDB, a data type, and / or the like. For example, the PDB may be defined as the upper bound for the time that a packet may be delayed between the RAN and the UE.

[0146] -The UE may send the third message to the RAN through a UE assistance information message (e.g., UEAssistanceInformation message). The third message may also be sent to the RAN through other messages, which is not limited by the embodiments of the disclosure.

[0147] In some embodiments, the SMF may inform the RAN of service characteristics of different data types through a fourth message. For example, the SMF may send information indicating the service characteristics of different data types to the RAN through the fourth message.

[0148] -The fourth message may be an NGAP message, a newly defined message, or a reused existing message, which is not limited here.

[0149] -The fourth message (e.g., information indicating the service characteristics of different data types) may include a QFI, and information related to at least one of the following: a transmission period or transmission interval of data transmitted through the QFI, a data size, a requirement of a PDB or a PSDB, a data rate, a remaining PDB or PSDB, a data type, and / or the like.

[0150] -The SMF may send the fourth message to the RAN through a PDU Session Resource Establishment Request or a PDU Session Resource Modification Request. The fourth message may also be sent to the RAN through other messages, which is not limited by the embodiments of the disclosure. When the fourth message is sent by the SMF through a PDU Session Resource Establishment Request or a PDU Session Resource Modification Request, information related to the dependency / correlation of QoS flows (for example, the above-mentioned first message or information indicated / included by it, or the second message or information indicated / included by it) may be sent to the RAN together with the fourth message. Table 9 illustrates an example of a QoS flow setup request list in the fourth message according to exemplary embodiments of the disclosure. As shown in Table 9, the QoS flow setup request may include one or more of a QoS flow identifier, a QoS flow level QoS parameter, a data period, a data size and a data rate. In Table 9, "maxnoofQoSFlows" indicates the maximum number of QoS flows.

[0151]

[0152] The above describes the method for the RAN to obtain the service characteristics of different data types in different QoS flows according to the exemplary embodiment of the disclosure. After the RAN obtains the service characteristics of data types, it may schedule and allocate resources for different types of data, synchronize related data through data scheduling, and configure different SPS / CG resource configurations for different types of data transmission.

[0153] Because the dependent / correlated PDU sets are transmitted through different QoS flows, there may be a time difference when the dependent / correlated PDU sets arrive at the RAN from UPF. If it is only indicated (for example, through the above-mentioned second message) whether the current PDU set is dependent on / correlated to other PDU sets, it may be impossible to know which PDU sets the PDU set is dependent on / correlated to. In this case, there is a problem that the RAN sends PDU sets to the UE without receiving all the dependent PDU sets. Another problem is that the UE may sometimes successfully decode all the dependent PDU sets only after receiving them (for example, in order to present images to users), so the ideal state is that the UE is able to receive all the dependent PDU sets at the same time. Therefore, it is necessary for the RAN to synchronize the dependent PDU sets and send the same to the UE.

[0154] In some embodiments, the UPF may send all dependent PDU sets to the RAN within a predetermined time range, and then the RAN send all PDU sets to the UE within a predetermined time range. For example, it may be implemented by one or more of the following.

[0155] -A first time threshold (e.g., timer), namely timer1, is set. The first time threshold (timer1) may indicate a time (e.g., a time period (e.g., from the start of sending the first PDU set), a time difference (e.g., the (maximum) time difference between sending the first PDU set and sending the last PDU set), or a maximum time) for the UPF to send dependent PDU sets to the RAN. For example, the UPF sends the dependent PDU sets to the RAN within the period of the first time threshold. The UPF may need to send all the dependent PDU sets to the RAN before the time threshold of timer1 expires (for example, before the time threshold of timer1 elapses). The UPF may no longer send the dependent PDU set or there is no dependent PDU set to send when the time for sending the dependent PDU set to the RAN is longer than the first time threshold (i.e., the time threshold of timer1 elapses or the time threshold of timer1 expires).

[0156] -The RAN may also need to know timer1. The RAN may receive all the dependent PDU sets within the period of timer1. When timer1 expires (for example, after timer1 elapses), even if the dependency indication index value in the header of a PDU set received by the RAN (that is, the value of the second message) is the same as that in the header of a PDU set received within the period of timer1, the RAN does not consider the two PDU sets to be dependent.

[0157] -A second time threshold (e.g., timer), namely timer2, is set. The second time threshold (timer2) may indicate a time (e.g., a time period (e.g., from the start of sending the first PDU set), a time difference (e.g., the (maximum) time difference between the sending of the first PDU set and the sending of the last PDU set), or a maximum time) for the RAN to send dependent PDU sets to the UE. For example, the RAN sends the dependent PDU sets to the UE within the period of the second time threshold. The RAN may need to send all the dependent PDU sets to the UE before the time threshold of timer2 expires. In case that the time for sending the dependent PDU set to the UE is longer than the second time threshold (i.e., the time threshold of timer2 elapses or the time threshold of timer2 expires), the RAN may no longer send the dependent PDU set or there is no dependent PDU set to send. If the UE receives all the dependent PDU sets within the period of timer2, it may be considered that all the dependent PDU sets are received synchronously or simultaneously.

[0158] -timer1 and timer2 may be determined (e.g., generated) by the SMF. The SMF may inform UPF of timer1 by sending a fifth message via a NG interface. The SMF may inform the RAN of timer2 by sending a sixth message via a NG interface. Since there is no direct network interface between the SMF and the RAN, the SMF may first inform the AMF or the UPF of timer1 and / or timer2, and then the AMF or the UPF may send timer1 and / or timer2 to RAN. The AMF may also inform the UE of timer2 through a seventh message. The UE may also judge whether all the dependent PDU sets have been received after knowing timer2. The fifth message and the sixth message may be newly defined messages, or reused existing messages, for example, the fifth message and the sixth message may be added to a PDU Session Resource Establishment Request or a PDU Session Resource Modification Request, which is not limited by the embodiments of the disclosure.

[0159] -timer2 may also be determined (e.g., generated) by the UE. The UE may inform the RAN of timer2 through an eighth message. The eighth message may be an RRC message, or other messages, or a newly defined message, or a reused existing message, which is not limited here. For example, one way may be to add the eighth message to a UE assistance information message (e.g., UEAssistanceInformation message) and send the same to the RAN. An example of synchronization of dependent PDU sets on different QoS flows will be described with reference to FIG. 8.

[0160] The above describes the method for performing downlink communication between the UE and the RAN in consideration of the dependency / correlation of QoS flows and / or dependency / correlation of PDU sets. The method may be similarly applied to uplink communication between the UE and the RAN. In some embodiments, the UE may send dependent PDU set to the RAN based on the information related to the dependency / correlation of QoS flows. For example, the UE may send dependent PDU sets to the RAN based on a time threshold (timer2'). In case that the time for sending dependent PDU sets to the RAN is longer than the time threshold (i.e., the time threshold of timer2' elapses or the time threshold of timer2' expires), the UE may no longer send the dependent PDU set to the RAN. Or, in case that the time for receiving dependent PDU sets from the UE is longer than the time threshold (i.e., the time threshold of timer2' elapses or the time threshold of timer2' expires), the RAN may no longer receive the dependent PDU set from the UE. If the RAN receives all the dependent PDU sets within the period of timer2', it may be considered that all the dependent PDU sets are received synchronously or simultaneously. Similar to timer2, timer2' may be determined (e.g., generated) by the SMF. Alternatively, timer2' may be determined by the UE or the RAN.

[0161] FIG. 8 illustrates an example of synchronization of dependent PDU sets on different QoS flows according to exemplary embodiments of the disclosure.

[0162] Referring to FIG. 8, within the period of the first time threshold (timer1), the UPF sends dependent PDU sets, including PDU sets PS1 and PS2, to the RAN. The PDU sets PS1 and PS2 are respectively on QoS flows QFI1 and QFI3. During the period of the second time threshold (timer2), the RAN sends dependent PDU sets, including PDU sets PS1 and PS2, to the UE. After receiving all of the dependent PDU sets PS1 and PS2, the UE may decode the dependent PDU sets PS1 and PS2 to obtain decoded information (for example, decoded images).

[0163] The above describes the method of synchronous transmission of dependent PDU sets on different QoS flows by the RAN according to the exemplary embodiments of the disclosure. By the method, it may be ensured that the UE receives all dependent PDU sets at the same time. For example, when the transmitted data is image data, this method may reduce the delay of image presentation and ensure the continuity of video playback, thereby improving the user experience.

[0164] When the network is congested, because only one QoS flow is supported for transmission at present, the RAN may perform packet discarding according to the PSI values of different PDU sets in the QoS flow. However, when multiple modal flows are applied to communication services (for example, XR service), it is necessary to consider how to use PSI to discard dependent PDU set(s) in multiple QoS flows. For example, the PSI value corresponding to a PDU set transmitting FOV may be lower than the PSI value corresponding to a PDU set transmitting non-FOV. If the discarding of packets is only based on PSI values, the PDU set corresponding to FOV will be discarded, which is unreasonable.

[0165] Exemplary embodiments of the disclosure propose a method for the RAN to discard dependent PDU sets on different QoS flows.

[0166] In some embodiments, the SMF may indicate a packet discarding mode supported by the corresponding QoS flow to the RAN. RAN may perform packet discarding for each QoS flow based on the mode indicated by the SMF. For example, different PDU sets in a same QoS flow may be discarded in each QoS flow according to the PSI of the PDU sets (for example, in the order of the PSI from low to high). As an example, for the PDU sets in a same QoS flow, PDU sets with lower PSI (PSI values) are discarded first, and then PDU sets with higher PSI (PSI values) are discarded. One or more of the following ways may be adopted.

[0167] -The SMF sends a ninth message via an NG interface, which may indicate a packet discarding mode of each QoS flow to the RAN. The ninth message may be a newly defined message or a reused existing message, which is not limited here. For example, the ninth message may be added to a PDU Session Resource Establishment Request or PDU Session Resource Modification Request and sent to the RAN. Table 10 below illustrates an example of a QoS flow setup request list in the ninth message according to exemplary embodiments of the disclosure. As shown in Table 10, the QoS flow setup request may include one or more of a QoS flow identifier, a QoS flow level QoS parameters, a dependent QoS flow list, and a discarding type. In Table 10, "maxnoofQoSFlows" indicates the maximum number of QoS flows.

[0168] -The packet discarding mode may include partial packet discarding, all packet discarding, no packet discarding, packet discarding based on the priorities of QoS flows, or packet discarding based on a PSI threshold. The packet discarding mode supported by each QoS flow may be the same or different. Each QoS flow may support only one packet discarding mode or multiple packet discarding modes at the same time. For example, depending on the service characteristics of QoS flows, each QoS flow may support only one packet discarding mode or multiple packet discarding modes. As shown in Table 10, "partial" in the item of the discarding type indicates discarding a part of packets, "full" indicates discarding all packets, "no discard" indicates not discarding packets, "priority of QoS flow based" indicates discarding packets based on the priorities of QoS flows, and "PSI based" indicates discarding packets based on a PSI threshold.

[0169] -Partial packet discarding: the RAN may discard a part of packets or PDU sets in the QoS flow.

[0170] -All packet discarding: RAN may discard all packets or PDU sets in the QoS flow.

[0171] -No packet discarding: RAN cannot discard or try not to discard packets or PDU sets in the QoS flow.

[0172] -Packet discarding based on the priorities of QoS flows: a QoS flow with a lower priority is discarded first (preferentially) compared with a QoS flow with a higher priority. For example, first discarding a packet or PDU set in a QoS flow with a lower priority, and then discarding a packet or PDU set in a QoS flow with a higher priority if the network congestion may not be alleviated after discarding the QoS flow with the lower priority.

[0173] -Packet discarding based on a PSI threshold: a corresponding PSI threshold for each QoS flow is set, and the packets to be discarded based on the PSI threshold of each QoS flow. For PDU sets in each QoS flow, a PDU set with PSI lower than the PSI threshold is discarded first (preferentially) compared with a PDU set with PSI higher than the PSI threshold. For example, when there are two QoS flows QFI1 and QFI2, the corresponding threshold Threshold1 is set for QFI1 and the corresponding threshold Threshold2 is set for QFI2. When the network is congested, for each QoS flow, PDU sets with PSI less than the corresponding threshold are preferentially discarded, that is, PDU sets with importance less than the threshold are preferentially discarded. For example, the value of PSI may be 1 to n (n may be an integer greater than 1), and the value of PSI of 1 means that the corresponding PDU set is of the least importance, that is, the corresponding PDU set is the least important; the value of PSI of n indicates that the corresponding PDU set is of the most importance, that is, the corresponding PDU set is the most important). An example of the method of discarding dependent PDU sets on different QoS flows will be described with reference to FIG. 9.

[0174]

[0175] FIG. 9 illustrates an example of packet discarding of dependent PDU sets on different QoS flows according to exemplary embodiments of the disclosure. Referring to FIG. 9, PDU sets PS1 and PS2 are transmitted through QFI1, and PDU sets PS3 and PS4 are transmitted through QFI2. When the RAN may need to send thee PDU sets to the UE, the network may be congested. If the packet discarding mode supported by QFI1 is no packet discarding and the packet discarding mode supported by QFI2 is partial packet discarding, the RAN may discard PDU set 4 with a lower PSI according to PSI (option 1); if the packet discarding mode supported by QFI1 is no packet discarding and the packet discarding mode supported by QFI2 is all packet discarding, the RAN may discard all the PDU sets in QFI2 (option 2); and / or when the congestion degree is not serious, the RAN may also perform partial packet discarding on PDU sets on QFI2 according to the base station's own situation instead of selecting the packet discarding mode of all packet discarding.

[0176] One or more aspects of the above-described method of discarding dependent PDU sets on different QoS flows may be combined with one or more aspects of the above-described method of synchronizing dependent PDU sets on different QoS flows in any suitable way. For example, one or more of the following methods may be adopted.

[0177] - When one of PDU sets in multiple QoS flows (such as QFI1 and QFI3 mentioned above) that need to be synchronized is discarded without affecting the normal decoding of another PDU set,

[0178] -if the packet discarding mode is partial packet discarding, a PDU set with less important (lower PSI) may be discarded, and the dependent PDU sets no longer need to be synchronized;

[0179] -if the packet discarding mode is no packet discarding, the dependent PDU set cannot be discarded, and the synchronization may be still needed at this time.

[0180] - When the discarding of one of PDU sets in multiple QoS flows that need to be synchronized (for example, QFI1 and QFI3 mentioned above) will affect the normal decoding of another PDU set,

[0181] -if the packet discarding mode is partial packet discarding, the dependent PDU set is not discarded first, and if it is not discarded finally, synchronous transmission is still needed; if it may need to be discarded, the dependent PDU sets will be discarded;

[0182] -if the packet discarding mode is no packet discarding, the dependent PDU set cannot be discarded, and synchronization is still needed at this time.

[0183] The above combinations are only examples and may be combined in any suitable way.

[0184] The data transmission of XR service is generally periodic. As shown in Table 5- Table 8, different types of data may have different transmission periods. For periodically transmitted data, the network may configure semi-persistent scheduling (SPS) / configured grant (CG) (SPS / CG configuration), that is, configure fixed periodic time-frequency domain resources, which may reduce the signaling overhead of the network for scheduling UE. Because different types of data have different transmission periods, it is intuitive to configure corresponding SPS / CG for different types of data on different QoS flows. As shown in FIG. 10, the data on the first QoS flow (QFI1) is configured with a first CG(CG1), and the data on the second QoS flow (QFI2) is configured with a second CG(CG2). However, this method may cause the following problems.

[0185] - when data on multiple QoS flows (for example, QFI1 and QFI2) are mapped on a same logical channel (LCH), if the UE needs to retransmit some data after sending data on CG1 through QFI1, the retransmission may preempt CG2's resources. The reason is that after the network allocates a UL grant to the UE, there are not too many restrictions on how the UE applies the UL grant. Therefore, if the retransmitted data on QFI1 occupies the resources on CG2, it will affect the transmission of the newly transmitted data on QFI2, resulting in that the newly transmitted data cannot be sent.

[0186] - when data on multiple QoS flows (for example, QFI1 and QFI2) are mapped to different LCHs, and the priority of the LCH corresponding to QFI1 is higher than that of the LCH corresponding to QFI2, it will also occur that the retransmitted data on QFI1 occupies the resources on CG2, resulting in that the newly transmitted data on QFI2 cannot be sent.

[0187] Exemplary embodiments of the disclosure propose a method in which the RAN configures SPS / CG for multiple modal flows. The method may include one or more of the following:

[0188] -The RAN sends a tenth message to the UE, which indicates a mapping between QoS flows and LCHs for uplink transmission (for example, when the UE sends uplink data). After receiving the tenth message, the UE transmits data on different QoS flows through the corresponding LCHs, respectively. The tenth message may be an RRC message, or it may be other messages, or it may be a newly defined message, or a reused existing message, which is not limited here. For example, the tenth message may be added in an RRC setup message (for example, RRCsetup message) or an RRC Reconfiguration message (for example, RRCReconfiguration message) and sent the same to the UE.

[0189] -When the RAN configures the UE with LCH configuration information (for example, LogicalChannelConfig), the LCH configuration information (for example, in an allowed CG list (for example, allowedCG-list) in LogicalChannelConfig) restricts the data on the corresponding LCH from being transmitted in the indicated CG resources. For example, LCH configuration information (for example, LogicalChannelConfig) may include information indicating CG resources for uplink transmission of data on each LCH. The data on an LCH may only be transmitted by the CG resources mapping to the LCH indicated in the LCH configuration information. The RAN may include the LCH configuration information and the tenth message in a same RRC message and send the same to the UE, or send the LCH configuration information and the tenth message to the UE through different RRC messages, which is not limited here.

[0190] -Referring to FIGS. 11 and 12, for example, after receiving the tenth message, the UE determines that the data on QFI1 is transmitted through the first LCH (LCH1) and the data on QFI2 is transmitted through the second LCH (LCH2) based on the tenth message; After receiving the LCH configuration information (for example, LogicalChannelConfig), the UE may determine that the data on LCH1 may only be transmitted through CG1 and the data on LCH2 may only be transmitted through CG2 based on the information in the LCH configuration information indicating the CG resources for the uplink transmission of data on each LCH. In this way, the data on QFI1 and QFI2 may be transmitted through the resources of CG1 and CG2, respectively, and there will be no situation of competing for resources.

[0191] If there are remaining resources after the data in QFI2 is transmitted through the resources of CG2, the remaining resources may also be used to transmit the data that may need to be retransmitted in QFI1, so as to improve the utilization efficiency of resources.

[0192] In an embodiment:

[0193] -when the RAN configures the UE with LCH configuration information (for example, LogicalChannelConfig), the LCH configuration information (for example, in allowedCG-list in LogicalChannelConfig) indicates that data on the corresponding LCH uses the indicated CG resources for uplink data transmission according to a certain priority.

[0194] -Referring to FIGS. 11 and 12, for example, after receiving the tenth message, the UE determines that the data on QFI1 is transmitted through LCH1 and the data on QFI2 is transmitted through LCH2; after the UE receives the LCH configuration information (for example, LogicalChannelConfig), the UE may determine that the data on LCH1 and LCH2 may be transmitted through CG1 and CG2 based on the information in the LCH configuration information indicating CG resources for the uplink transmission of data on each LCH. CG1 resources may be preferentially used for the data on LCH1. If there are remaining CG1 resources after sending the data on LCH1, the remaining CG1 resources may be used for the data on LCH2. Similarly, CG2 resources may be preferentially used for the data on LCH2. If there are remaining CG2 resources after sending the data on LCH2, the remaining CG2 resources may be used for the data on LCH1.

[0195] -The priorities of CGs may be determined by the order of CG indexes listed in the LCH configuration information (for example, allowedCG-list in LogicalChannelConfig). The priority of a CG may correspond to the index of the CG (for example, the value of the CG index) in the LCH configuration information. For example, a smaller CG index indicates that the corresponding CG has a lower priority, and a larger CG index indicates that the corresponding CG has a higher priority. For another example, a smaller CG index indicates that the corresponding CG has a higher priority, and a larger CG index indicates that the corresponding CG has a lower priority. As a specific example, when configuring LCH1, allowedCG-list: SEQUENCE (CG1, CG2); when configuring LCH2, allowedCG-list: SEQUENCE (CG2, CG1).

[0196] If the data to be retransmitted in QFI1 is more important than the newly transmitted data in QFI2, when the corresponding PDB / PSDB may expire if the data to be retransmitted in QFI1 does not preempt CG2 resources, CG2 resources may be preferentially used to transmit the data to be retransmitted in QFI1. In an embodiment:

[0197] -the RAN may send a third time threshold to the UE through the tenth message. If the retransmitted data in QFI1 is more important (for example, compared with other QFIs) and the remaining PDB / PSDB is less than the third time threshold, the resources of CG2 may be preferentially used for the transmission of the data to be retransmitted in QFI1.

[0198] It should be noted that the method of configuring SPS / CG for multiple modal flows described above may be combined with one or more aspects of the above method of discarding dependent PDU sets on different QoS flows and / or one or more aspects of the above method of synchronizing dependent PDU sets on different QoS flows in any suitable way.

[0199] The above describes the method of configuring SPS / CG for multiple modal flows by the RAN according to exemplary embodiments of the disclosure. By the method, the situation that data of different modal flows preempt resources can be avoided, thereby ensuring the data transmission on each modal flow. In addition, the resource utilization efficiency is improved by setting the priorities of configured grants.

[0200] When the UE sends uplink data, the RAN may not successfully receive the uplink packet sent by the UE. The main reason is the deterioration of the surrounding wireless network environment (for example, a parameter related to the wireless network environment (for example, channel quality parameters such as received signal strength indicator (RSSI), channel quality indicator (CQI), signal-to-noise ratio (SNR) / signal-to-interference-noise ratio (SINR), reference signal power (RSRP), reference signal quality (RSRQ), etc.) is below the threshold). At this time, the RAN may need to reschedule the UE to retransmit the uplink data. However, some service data (for example, XR data transmission) have corresponding PDB / PSDB requirements, and if the corresponding data is not transmitted within the PDB / PSDB time, the data will be useless. If the RAN does not know the remaining PDB / PSDB of the retransmitted data, the RAN may not allocate uplink resources to the UE for retransmission in time. In order to ensure that the UE is able to send the retransmitted data to the RAN in time, one or more of the following methods M1-M3 may be adopted.

[0201] Method M1 may include:

[0202] -When the RAN is aware of that the surrounding wireless network environment is deteriorating (for example, the parameter related to the wireless network environment (such as the channel quality parameters) monitored by the RAN is lower than the threshold), the RAN sends an eleventh message to the UE. The eleventh message may be used to inform the UE that the surrounding wireless network environment is deteriorating, and / or to inform / indicate the UE to report the remaining PDB / PSDB.

[0203] -After receiving the eleventh message, the UE sends the newly transmitted data on the corresponding CG resources, together with the remaining PDB / PSDB of the corresponding data. After the RAN knows the remaining PDB / PSDB, it may timely allocate uplink resources for the UE to retransmit part of the data that failed to transmit.

[0204] Method M2 may include:

[0205] -When the UE is aware of that the surrounding wireless network environment is deteriorating (for example, the parameter related to the wireless network environment (for example, the channel quality parameters) monitored by the UE is lower than the first threshold), the UE sends the newly transmitted data on the corresponding CG resources, together with the remaining PDB / PSDB of the corresponding data. For example, the first threshold may be configured by the RAN for the UE through the twelfth message.

[0206] -After knowing the remaining PDB / PSDB, the RAN may timely allocate uplink resources for the UE to retransmit part of the data that failed to transmit.

[0207] Method M3 may include:

[0208] -The RAN sends a thirteenth message to the UE, which may include information indicating the UE to report the remaining PDB / PSDB corresponding to its uplink data to the RAN when the surrounding wireless network environment deteriorates (for example, the uplink channel quality is lower than the first threshold) and the remaining PDB / PSDB is lower than a second threshold. The thirteenth message may carry the first threshold and / or the second threshold. Alternatively, the first threshold may be configured by the RAN for the UE through the twelfth message.

[0209] -After receiving the thirteenth message, the UE reports the remaining PDB / PSDB of its uplink data to the RAN if it is aware of that the surrounding wireless network environment is deteriorating (for example, the uplink channel quality is lower than the first threshold) and the remaining PDB / PSDB of the uplink data is lower than the second threshold.

[0210] FIG. 13 illustrates a schematic diagram of the above methods M1-M3. Each of the eleventh message, the twelfth message, and the thirteenth message may be an RRC message, other messages, a newly defined message, or a reused existing message, which is not limited by the embodiments of the disclosure.

[0211] The method for uplink data retransmission according to exemplary embodiments of the disclosure has been described above. By the method, when the uplink data is lost, the network may configure the uplink resources for the retransmission data of the UE in time, which ensures the normal transmission of the uplink data, thus improving the user experience.

[0212] PDU set QoS parameters, such as PSDB, PSER and / or PSIHI, may be determined. For example, the PDU set QoS parameters may be determined by a network element such as a PCF. As an example, the PDU set QoS parameters are determined by the PCF according to service-related information provided by an AF, and sent to a SMF as a part of a PCC rule, and then sent to a RAN by the SMF as a part of a QoS profile. The RAN may decide / determine whether to accept the PDU set QoS parameters (whether the PDU set QoS parameters are acceptable) and reply to the SMF with acceptance or rejection. When a UE performs cell handover, the target cell may also send indication information to the SMF to indicate whether the target cell supports PDU set QoS handling (for example, whether to support handling QoS flows based on PDU set QoS parameters; for another example, whether to support the transmission of a QoS flow of PDU set QoS parameters). In fact, however, the PDU set QoS handling is a requirement proposed by the AF, and the PDU set QoS parameters are generated by the PCF, so the AF and core network expect that the base station is able to support the PDU set QoS handling. When the UE performs cell handover, it is advantageous for the source cell to know which neighboring cells support PDU set QoS handling, so that the source cell may handover the UE to a target cell that supports PDU set QoS handling to meet the requirements of the AF and core network.

[0213] Exemplary embodiments of the disclosure propose a method of exchanging information between cells on whether or not to support PDU set QoS handling. For example, in the procedure of establishing Xn interfaces between cells, the cells may interact whether to support PDU set QoS handling with each other.

[0214] FIG. 14 illustrates a schematic diagram of a method of interacting information between cells whether to support PDU set QoS handling according to exemplary embodiments of the disclosure.

[0215] Referring to FIG. 14, in step S1410, a source cell sends an Xn Setup Request message to a neighbor cell, where the Xn Setup Request message carries / includes a fourteenth message which is used to indicate / inform the neighbor cell whether the source cell supports PDU set QoS handling.

[0216] With continued reference to FIG. 14, in step S1420, after receiving the Xn Setup Request message, the neighboring cell responds an Xn Setup Response message to the source cell, where the Xn Setup Response message carries / includes a fifteenth message which is used to indicate / inform the source cell whether the neighboring cell supports PDU set QoS handling.

[0217] The above describes the method of exchanging information between cells on whether to support PDU set QoS handling according to exemplary embodiments of the disclosure. By the method, the source cell can know which neighbor cells support PDU set QoS handling, and when performing handover for the UE, preferentially handover the UE to a target cell that supports PDU set QoS handling to meet the service requirements of the AF and core network.

[0218] FIG. 15 illustrates a flowchart of a method 1500 performed by a first node (e.g., a RAN such as a base station) according to some embodiments of the disclosure.

[0219] Referring to FIG. 15, in operation S1510, a first node receives a first message from a second node, where the first message includes first information about a dependency of a QoS flow.

[0220] Next, in operation S1520, the first node receives second information about a dependency of a PDU set from the third node.

[0221] Next, in operation S1530, the first node communicates a dependent PDU set based on the first information and the second information.

[0222] In some embodiments, one or more of S1510 to S1530 may be performed based on the methods described according to various embodiments of the disclosure (for example, the embodiments described in connection with FIGS.1-14).

[0223] In some embodiments, the method 1500 may omit one or more of operations S1510 to S1530, or may include additional operations, for example, the operations described according to various embodiments of the disclosure (e.g., the embodiments described in connection with FIGS.1-14) that may be performed by the RAN node.

[0224] FIG. 16 illustrates a flowchart of a method 1600 performed by a second node (e.g., SMF) according to some embodiments of the disclosure.

[0225] Referring to FIG. 16, in operation S1610, the second node determines first information about a dependency of a QoS flow.

[0226] Next, in operation S1620, the second node sends a first message to the first node, where the first message includes the first information. The first information is used for the first node to communicate a dependent PDU set, where the communicating of the dependent PDU set is further based on second information about a dependency of a PDU set.

[0227] In some embodiments, one or more of S1610 to S1620 may be performed based on the methods described according to various embodiments of the disclosure (for example, the embodiments described in connection with FIGS.1-14).

[0228] In some embodiments, the method 1600 may omit one or more of operations S1610 to S1620, or may include additional operations, for example, the operations described according to various embodiments of the disclosure (e.g., the embodiments described in connection with FIGS.1-14) that may be performed by a CN node or a network element / function (e.g., SMF).

[0229] FIG. 17 illustrates a flowchart of a method 1700 performed by a third node (e.g., UPF) according to some embodiments of the disclosure.

[0230] Referring to FIG. 17, in operation S1710, the third node transmits second information about a dependency of PDU sets to the first node. The second information is used for the first node to communicate a dependent PDU set, where the communicating of the dependent PDU set is further based on the first information about a dependency of a QoS flow.

[0231] Next, in operation S1720, the third node receives an uplink PDU set from the first node.

[0232] In some embodiments, one or more of S1710 to S1720 may be performed based on the methods described according to various embodiments of the disclosure (for example, the embodiments described in connection with FIGS.1-14).

[0233] In some embodiments, the method 1700 may omit one or more of operations S1710 to S1720, or may include additional operations, such as operations that may be performed by a CN node or network element / function (e.g., UPF) according to various embodiments of the disclosure (e.g., the embodiments described in connection with FIGS.1-14).

[0234] FIG. 18 illustrates a flowchart of a method 1800 performed by a fourth node (e.g., UE) according to some embodiments of the disclosure.

[0235] Referring to FIG. 18, the fourth node receives a dependent PDU set from a first node in operation S1810. The dependent PDU set is transmitted by the first node based on first information about a dependency of a QoS flow and second information about a dependency of a PDU set.

[0236] Next, in operation S1820, the fourth node sends an uplink PDU set to the first node.

[0237] In some embodiments, one or more of S1810 to S1820 may be performed based on methods described according to various embodiments of the disclosure (for example, the embodiments described in connection with FIGS.1-14).

[0238] In some embodiments, the method 1800 may omit one or more of operations S1810 to S1820, or may include additional operations, for example, the operations described according to various embodiments of the disclosure (e.g., the embodiments described in connection with FIGS.1-14) that may be performed by the UE.

[0239] FIG. 19 is a block diagram of the configuration of a first node (e.g., a RAN node such as a base station) according to some embodiments of the disclosure.

[0240] Referring to FIG. 19, the first node includes a transceiver 1910, a controller 1920 and a memory 1930. The controller 1920 may refer to a circuit, an application specific integrated circuit (ASIC) or at least one processor. The transceiver 1910, the controller 1920, and the memory 1930 are configured to perform the operations described above (e.g., in the exemplary embodiments described with reference to FIGS. 1-18) that may be performed by the RAN node. However, the components of the base station are not limited thereto. Although the transceiver 1910, the controller 1920 and the memory 1930 are shown as separate entities, they may be implemented as a single entity, such as a single chip. Or, the transceiver 1910, the controller 1920 and the memory 1930 may be electrically connected or coupled to each other.

[0241] The transceiver 1910 may send and receive signals to and from other network entities (e.g., UE or CN node).

[0242] The transceiver 1910 collectively refers to a base station receiver and a base station transmitter, and may transmit / receive a signal to / from a terminal or a network entity. The signal transmitted or received to or from the terminal or a network entity may include control information and data. The transceiver 1910 may include a RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and a RF receiver for amplifying low-noise and down-converting a frequency of a received signal. However, this is only an example of the transceiver 1910 and components of the transceiver 1910 are not limited to the RF transmitter and the RF receiver.

[0243] Also, the transceiver 1910 may receive and output, to the controller 1920, a signal through a wireless channel, and transmit a signal output from the controller 1920 through the wireless channel.

[0244] The controller 1920 may control the first node to perform a function according to one of the various exemplary embodiments described above.

[0245] The controller 1920 may control a series of processes such that the base station operates as described above. For example, the transceiver 1910 may receive a data signal including a control signal transmitted by the terminal, and the controller 1920 may determine a result of receiving the control signal and the data signal transmitted by the terminal.

[0246] In some exemplary embodiments, the operation of the first node may be implemented using the memory 1930 storing corresponding program codes. Specifically, the first node may be equipped with a memory 1930 to store program codes that realize desired operations. In order to perform a desired operation, the controller 1920 may read and execute program codes stored in the memory 1930 by using at least one processor or central processing unit (CPU).

[0247] The memory 1930 may store a program and data required for operations of the base station. Also, the memory 1930 may store control information or data included in a signal obtained by the base station. The memory 1930 may be a storage medium, such as read-only memory (ROM), random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0248] FIG. 20 is a block diagram of the configuration of a second node (e.g., SMF) according to some embodiments of the disclosure.

[0249] Referring to FIG. 20, the second node includes a transceiver 2010, a controller 2020 and a memory 2030. The controller 2020 may refer to a circuit, an application specific integrated circuit (ASIC) or at least one processor. The transceiver 2010, the controller 2020 and the memory 2030 are configured to perform the operations described above (e.g., in the exemplary embodiments described with reference to FIGS. 1-23) that may be performed by a CN node or a network element / function (e.g., SMF). Although the transceiver 2010, the controller 2020 and the memory 2030 are shown as separate entities, they may be implemented as a single entity, such as a single chip. Or, the transceiver 2010, the controller 2020 and the memory 2030 may be electrically connected or coupled to each other.

[0250] The transceiver 2010 may send and receive signals to and from other network entities (e.g., UPF).

[0251] The controller 2020 may control the second node to perform a function according to one of the various exemplary embodiments described above.

[0252] In some exemplary embodiments, the operation of the second node may be implemented using the memory 2530 storing corresponding program codes. Specifically, the second node may be equipped with a memory 2530 to store a program code that realizes a desired operation. In order to perform a desired operation, the controller 2520 may read and execute program codes stored in the memory 2530 by using at least one processor or central processing unit (CPU).

[0253] FIG. 21 is a block diagram of the configuration of a third node (e.g., UPF) according to some embodiments of the disclosure.

[0254] Referring to FIG. 21, the third node includes a transceiver 2110, a controller 2120 and a memory 2130. The controller 2120 may refer to a circuit, an application specific integrated circuit (ASIC) or at least one processor. The transceiver 2110, the controller 2120 and the memory 2130 are configured to perform the operations described above (e.g., in the exemplary embodiments described with reference to FIGS. 1-23) that may be performed by the operations performed by a CN node or a network element / function (e.g., UPF). Although the transceiver 2110, the controller 2120 and the memory 2130 are shown as separate entities, they may be implemented as a single entity, such as a single chip. Or, the transceiver 2110, the controller 2120 and the memory 2130 may be electrically connected or coupled to each other.

[0255] The transceiver 2110 may transmit and receive signals to and from other network entities (e.g., base stations or SMFs).

[0256] The controller 2120 may control the third node to perform a function according to one of the various exemplary embodiments described above.

[0257] In some exemplary embodiments, the operation of the third node may be implemented using the memory 2130 storing corresponding program codes. Specifically, the third node may be equipped with a memory 2130 to store a program code for realizing a desired operation. In order to perform a desired operation, the controller 2120 may read and execute program codes stored in the memory 2130 by using at least one processor or central processing unit (CPU).

[0258] FIG. 22 is a block diagram of the configuration of a fourth node (e.g., UE(user equipment)) according to some embodiments of the disclosure.

[0259] Referring to FIG. 22, the fourth node includes a transceiver 2210, a controller 2220 and a memory 2230. The controller 2220 may refer to a circuit, an application specific integrated circuit (ASIC) or at least one processor. The transceiver 2210, the controller 2220, and the memory 2230 are configured to perform the operations described above (for example, in the exemplary embodiments described with reference to FIGS. 1- 18) that may be performed by the UE. However, the components of the fourth node (UE) are not limited thereto. Although the transceiver 2210, the controller 2220 and the memory 2230 are shown as separate entities, they may be implemented as a single entity, such as a single chip. Or, the transceiver 2210, the controller 2220 and the memory 2230 may be electrically connected or coupled to each other.

[0260] The transceiver 2210 may transmit and receive signals to and from other network entities (e.g., a RAN node or a CN node).

[0261] The transceiver 2210 collectively refers to a UE receiver and a UE transmitter, and may transmit / receive a signal to / from a base station or a network entity. The signal transmitted or received to or from the base station or a network entity may include control information and data. The transceiver 2210 may include a RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and a RF receiver for amplifying low-noise and down-converting a frequency of a received signal. However, this is only an example of the transceiver 2210 and components of the transceiver 2210 are not limited to the RF transmitter and the RF receiver.

[0262] Also, the transceiver 2210 may receive and output, to the controller 2220, a signal through a wireless channel, and transmit a signal output from the controller 2220 through the wireless channel.

[0263] The controller 2220 may control the fourth node to perform a function according to one of the various exemplary embodiments described above.

[0264] The controller 2220 may control a series of processes such that the UE operates as described above. For example, the transceiver 2210 may receive a data signal including a control signal transmitted by the base station or the network entity, and the controller 2220 may determine a result of receiving the control signal and the data signal transmitted by the base station or the network entity.

[0265] In some exemplary embodiments, the operation of the fourth node may be implemented using a memory 2230 storing corresponding program codes. Specifically, the fourth node may be equipped with a memory 2230 to store program codes that realize desired operations. In order to perform a desired operation, the controller 2220 may read and execute program codes stored in the memory 2230 by using at least one processor or central processing unit (CPU).

[0266] The memory 2230 may store a program and data required for operations of the UE. Also, the memory 2230 may store control information or data included in a signal obtained by the UE. The memory 2230 may be a storage medium, such as read-only memory (ROM), random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0267] According to some aspects of the disclosure, there is provided a method performed by a first node in a wireless communication system. The method includes: receiving a first message from a second node, wherein the first message includes first information about a dependency of a quality of service (QoS) flow; receiving second information about a dependency of a protocol data unit (PDU) set from a third node; and communicating a dependent PDU set based on the first information and the second information.

[0268] In connection with one or more aspects of the method performed by the first node described above, for example, the second information is same for dependent PDU sets.

[0269] In connection with one or more aspects of the method performed by the first node described above, for example, the first information includes at least one of: information of a QoS flow dependent on the QoS flow; or information indicating the dependency of the QoS flow.

[0270] In connection with one or more aspects of the method performed by the first node described above, for example, the first information is same for dependent QoS flows.

[0271] In connection with one or more aspects of the method performed by the first node described above, for example, the information of a QoS flow dependent on the QoS flow includes a list of QoS flows dependent on the QoS flow.

[0272] In connection with one or more aspects of the method performed by the first node described above, for example, the first message includes at least one of a PDU Session Establishment Request message or a PDU Session Resource Modify Request message.

[0273] In connection with one or more aspects of the method performed by the first node described above, for example, the second information is included in a header of the PDU set.

[0274] In connection with one or more aspects of the method performed by the first node described above, for example, the first message further includes third information about data, or the third information about data is received from a fourth node, wherein the third information includes one or more of: a transmission period or a transmission interval of the data; a size of the data; a packet delay budget (PDB) or PDU set delay budget (PSDB); a data rate; a remaining PDB or PSDB; or a data type.

[0275] In connection with one or more aspects of the method performed by the first node described above, for example, communicating a dependent PDU set based on the first information and the second information includes: determining a dependent PDU set in a first time threshold based on the first information and the second information; and sending the dependent PDU set based on a second time threshold.

[0276] In connection with one or more aspects of the method performed by the first node described above, for example, the first time threshold and / or the second time threshold are included in the first message.

[0277] In connection with one or more aspects of the method performed by the first node described above, for example, the method further includes receiving eighth information about discarding of QoS flows, wherein the eighth information includes at least one of information about discarding based on PDU sets, or information about discarding based on QoS flows.

[0278] In connection with one or more aspects of the method performed by the first node described above, for example, the method further includes: sending a fourteenth message to a second RAN node, wherein the fourteenth message includes information about whether the first node supports PDU set QoS handling; and / or receiving a fifteenth message from a second RAN node, the fifteenth message including information about whether the second RAN node supports PDU set QoS handling.

[0279] In connection with one or more aspects of the above-described method performed by the first node, for example, the method further includes: sending ninth information about a mapping between QoS flows and logical channels to the fourth node; sending tenth information about a configured grant resource mapping to a logical channel to a fourth node; receiving data on a QoS flow from a fourth node based on the ninth information and the tenth information.

[0280] In connection with one or more aspects of the method performed by the first node described above, for example, different QoS flows map to different logical channels, wherein receiving data on a QoS flow from the fourth node based on the ninth information and the tenth information includes receiving data on a first QoS flow from the fourth node in a configured grant resource of a first logical channel mapping to the first QoS flow.

[0281] In connection with one or more aspects of the method performed by the first node described above, for example, in case that there is a remaining configured grant resource mapping to the first logical channel after receiving the data on the first QoS flow from the fourth node, the remaining configured grant resource is used for retransmission of data on other QoS flows in the QoS flows.

[0282] In connection with one or more aspects of the method performed by the first node described above, for example, the tenth information includes at least one of a plurality of configured grant resources associated with the logical channel, and information about priorities of the plurality of configured grant resources, and wherein the data on the QoS flow is received based on the priorities of the plurality of configured grant resources.

[0283] In connection with one or more aspects of the method performed by the first node described above, for example, in case that an importance of a first QoS flow of the QoS flows is higher than that of a second QoS flow and a remaining PDB or PSDB is less than a third time threshold, a configured grant resource of the second QoS flow is preferentially used for retransmission of data on the first QoS flow.

[0284] In connection with one or more aspects of the method performed by the first node described above, for example, the method further includes sending information indicating the third time threshold to the fourth node.

[0285] In connection with one or more aspects of the method performed by the first node described above, for example, the method further includes: monitoring that a channel quality is lower than a first threshold; sending eleventh information to a fourth node, wherein the eleventh information indicates that the channel quality is lower than the first threshold or indicates the fourth node to report a remaining PDB or PSDB; and receiving newly transmitted data and / or the reported remaining PDB or PSDB from the fourth node.

[0286] In connection with one or more aspects of the method performed by the first node described above, for example, the method further includes: receiving newly transmitted data and / or reported remaining PDB or PSDB from the fourth node when the channel quality monitored by the fourth node is lower than the first threshold.

[0287] In connection with one or more aspects of the method performed by the first node described above, for example, the method further includes: sending twelfth information to the fourth node, wherein the twelfth information indicates the fourth node to report the remaining PDB or PSDB when the channel quality is lower than the first threshold and the remaining PDB or PSDB is lower than a second threshold; and when the fourth node monitors that the channel quality is lower than the first threshold and the remaining PDB or PSDB is lower than the second threshold, receiving the remaining PDB or PSDB reported by the fourth node.

[0288] In connection with one or more aspects of the method performed by the first node described above, for example, the first node is a radio access network (RAN) node (e.g., a base station).

[0289] In connection with one or more aspects of the method performed by the first node described above, for example, the second node and / or the third node are core network nodes (e.g., 5GC). For example, the second node is a session management function (SMF) entity. For example, the third node is a user plane function (UPF) entity.

[0290] In connection with one or more aspects of the method performed by the first node described above, for example, the fourth node is a user equipment (UE).

[0291] According to some aspects of the disclosure, there is provided a method performed by a second node in a wireless communication system. The method includes: determining first information about a dependency of a quality of service (QoS) flow; and sending a first message to the first node, wherein the first message includes the first information, wherein the first information is used for the first node to communicate a dependent protocol data unit (PDU) set, and the communicating of the dependent PDU set is further based on second information about a dependency of a PDU set.

[0292] In connection with one or more aspects of the method performed by the second node described above, for example, have the second information is same for dependent PDU sets.

[0293] In connection with one or more aspects of the method performed by the second node described above, for example, the first information includes at least one of: information of a QoS flow dependent on the QoS flow; or information indicating the dependency of the QoS flow.

[0294] In connection with one or more aspects of the method performed by the second node described above, for example, the first information is same for dependent QoS flows.

[0295] In connection with one or more aspects of the method performed by the second node described above, for example, the information of a QoS flow dependent on the QoS flow includes a list of QoS flows dependent on the QoS flow.

[0296] In connection with one or more aspects of the method performed by the second node described above, for example, the first message includes at least one of a PDU Session Resource Establishment Request message or a PDU Session Resource Modification Request message.

[0297] In connection with one or more aspects of the method performed by the second node described above, for example, the second information is included in a header of the PDU set.

[0298] In connection with one or more aspects of the method performed by the second node described above, for example, the first message further includes third information about data, wherein the third information includes one or more of: a transmission period or a transmission interval of the data; a size of the data; a packet delay budget (PDB) or PDU set delay budget (PSDB); a data rate; a remaining PDB or PSDB; or a data type.

[0299] In connection with one or more aspects of the method performed by the second node described above, for example, the dependent PDU set is a dependent PDU set in a first time threshold, wherein the dependent PDU set is sent by the first node based on a second time threshold.

[0300] In connection with one or more aspects of the method performed by the second node described above, for example, the method further includes sending the first time threshold and / or the second time threshold to the first node.

[0301] In connection with one or more aspects of the method performed by the second node described above, for example, the method further includes sending eighth information about discarding of QoS flows, wherein the eighth information includes at least one of information about discarding based on PDU sets, or information about discarding based on QoS flows.

[0302] In connection with one or more aspects of the method performed by the second node described above, for example, determining the first information about the dependency of the QoS flow includes receiving policy and charging control (PCC) rule information from the fifth node, and the first information is included in the PCC rule information.

[0303] In connection with one or more aspects of the method performed by the second node described above, for example, the first node is a radio access network (RAN) node (e.g., a base station).

[0304] In connection with one or more aspects of the method performed by the second node described above, for example, the second node and / or the third node are core network nodes (e.g., 5GC). For example, the second node is a session management function (SMF) entity. For example, the third node is a user plane function (UPF) entity.

[0305] In connection with one or more aspects of the method performed by the second node described above, for example, the fifth node is a policy control function (PCF) entity.

[0306] According to some aspects of the disclosure, a method performed by a third node in a wireless communication system is provided. The method includes: sending second information about a dependency of a protocol data unit (PDU) set to a first node; and receiving an uplink PDU set from the first node, wherein the second information is used for the first node to communicate the dependent PDU set, wherein the communicating of the dependent PDU set is further based on first information about a dependency of a quality of service (QoS) flow.

[0307] In connection with one or more aspects of the method performed by the third node described above, for example, the second information is same for dependent PDU sets.

[0308] In connection with one or more aspects of the method performed by the third node described above, for example, the first information includes at least one of: information of a QoS flow dependent on the QoS flow; or information indicating the dependency of the QoS flow.

[0309] In connection with one or more aspects of the method performed by the third node described above, for example, the first information is same for dependent QoS flows.

[0310] In connection with one or more aspects of the method performed by the third node described above, for example, the information of a QoS flows dependent on the QoS flow includes a list of QoS flows dependent on the QoS flow.

[0311] In connection with one or more aspects of the method performed by the third node described above, for example, the second information is included in a header of the PDU set.

[0312] In connection with one or more aspects of the method performed by the third node described above, for example, the dependent PDU set is a dependent PDU set in a first time threshold, wherein the dependent PDU set is sent by the first node based on a second time threshold.

[0313] In connection with one or more aspects of the method performed by the third node described above, for example, the method further includes receiving the first time threshold and / or the second time threshold from the second node; and sending the first time threshold and / or the second time threshold to the first node.

[0314] In connection with one or more aspects of the method performed by the third node described above, for example, the first node is a radio access network (RAN) node (e.g., a base station).

[0315] In connection with one or more aspects of the method performed by the third node described above, for example, the second node and / or the third node are core network nodes (e.g., 5GC). For example, the second node is a session management function (SMF) entity. For example, the third node is a user plane function (UPF) entity.

[0316] According to some aspects of the disclosure, there is provided a method performed by a fourth node in a wireless communication system. The method includes receiving a dependent protocol data unit (PDU) set from a first node; and sending an uplink PDU set to the first node, wherein the dependent PDU set is sent by the first node based on first information about a dependency of a quality of service (QoS) flow and second information about a dependency of a PDU set.

[0317] In connection with one or more aspects of the method performed by the fourth node described above, for example, the second information is same for dependent PDU sets.

[0318] In connection with one or more aspects of the method performed by the fourth node described above, for example, the first information includes at least one of: information of a QoS flow dependent on the QoS flow; or information indicating the dependency of the QoS flow.

[0319] In connection with one or more aspects of the method performed by the fourth node described above, for example, the first information is same for dependent QoS flows.

[0320] In connection with one or more aspects of the method performed by the fourth node described above, for example, the information of a QoS flow dependent on the QoS flow includes a list of QoS flows dependent on the QoS flow.

[0321] In connection with one or more aspects of the method performed by the fourth node described above, for example, the second information is included in a header of the PDU set.

[0322] In connection with one or more aspects of the method performed by the fourth node described above, for example, the method further includes sending third information about data to the first node, wherein the third information includes one or more of: a transmission period or a transmission interval of the data; a size of the data; a packet delay budget (PDB) or PDU set delay budget (PSDB); a data rate; a remaining PDB or PSDB; or a data type.

[0323] In connection with one or more aspects of the method performed by the fourth node described above, for example, the dependent PDU set is a dependent PDU set in a first time threshold, wherein the dependent PDU set is sent by the first node based on a second time threshold.

[0324] In connection with one or more aspects of the method performed by the fourth node described above, for example, the method further includes: receiving ninth information about a mapping between QoS flows and logical channels from the first node; receiving tenth information about a configured grant resource mapping to a logical channel from a first node; and sending data on a QoS flow to the first node based on the ninth information and the tenth information.

[0325] In connection with one or more aspects of the method performed by the fourth node described above, for example, different QoS flows map to different logical channels, wherein sending data on a QoS flow to the first node based on the ninth information and the tenth information includes sending data on a first QoS flow to the first node in a configured grant resource of the first logical channel mapping to the first QoS flow.

[0326] In connection with one or more aspects of the method performed by the fourth node described above, for example, in case that there is a remaining configured grant resource mapping to the first logical channel after sending the data on the first QoS flow to the first node, the remaining configured grant resource is used for retransmission of data on other QoS flows in the QoS flows.

[0327] In connection with one or more aspects of the method performed by the fourth node described above, for example, the tenth information includes at least one of a plurality of configured grant resources associated with the logical channel, and information about priorities of the plurality of configured grant resources, and wherein the data on the QoS flow is received based on the priorities of the plurality of configured grant resources.

[0328] In connection with one or more aspects of the method performed by the fourth node described above, for example, in case that an importance of a first QoS flow of the QoS flows is higher than that of a second QoS flow and a remaining PDB or PSDB is less than a third time threshold, a configured grant resource of the second QoS flow is preferentially used for retransmission of data on the first QoS flow.

[0329] In connection with one or more aspects of the method performed by the fourth node described above, for example, the method further includes receiving information indicating the third time threshold from the first node.

[0330] In connection with one or more aspects of the method performed by the fourth node described above, for example, the method further includes receiving eleventh information from the first node, wherein the eleventh information indicates that the channel quality is lower than the first threshold or indicates the fourth node to report a remaining PDB or PSDB; and sending newly transmitted data and / or reporting the remaining PDB or PSDB to the first node.

[0331] In connection with one or more aspects of the method performed by the fourth node described above, for example, the first node is a radio access network (RAN) node (e.g., a base station).

[0332] In connection with one or more aspects of the method performed by the fourth node described above, for example, the fourth node is a user equipment (UE).

[0333] According to some aspects of the disclosure, there is also provided a first node in a wireless communication system. The first node includes a transceiver, and one or more processors coupled with the transceiver and configured to perform one or more aspects of the method performed by the first node.

[0334] According to some aspects of the disclosure, there is also provided a second node in a wireless communication system. The base station includes a transceiver, and one or more processors coupled with the transceiver and configured to perform one or more aspects of the method performed by the second node.

[0335] According to some aspects of the disclosure, there is also provided a third node in a wireless communication system. The third node includes a transceiver, and one or more processors coupled with the transceiver and configured to perform one or more aspects of the method performed by the third node.

[0336] According to some aspects of the disclosure, there is also provided a fourth node in a wireless communication system. The fourth node includes a transceiver, and one or more processors coupled with the transceiver and configured to perform one or more aspects of the method performed by the fourth node.

[0337] According to some aspects of the disclosure, there is also provided a computer-readable storage medium on which one or more computer programs are stored, wherein one or more aspects of the above-described method performed by the first node can be implemented when the one or more computer programs are executed by one or more processors.

[0338] According to some aspects of the disclosure, there is also provided a computer-readable storage medium on which one or more computer programs are stored, wherein one or more aspects of the above-described method performed by the second node can be implemented when the one or more computer programs are executed by one or more processors.

[0339] According to some aspects of the disclosure, there is also provided a computer-readable storage medium on which one or more computer programs are stored, wherein one or more aspects of the above-described method performed by the third node can be implemented when the one or more computer programs are executed by one or more processors.

[0340] According to some aspects of the disclosure, there is also provided a computer-readable storage medium on which one or more computer programs are stored, wherein one or more aspects of the above-described method performed by the fourth node can be implemented when the one or more computer programs are executed by one or more processors.

[0341] Those skilled in the art will understand that the above illustrative embodiments are described herein and are not intended to be limiting. It should be understood that any two or more of the embodiments disclosed herein may be combined in any combination. Furthermore, other embodiments may be utilized and other changes may be made without departing from the spirit and scope of the subject matter presented herein. It will be readily understood that aspects of the invention of the disclosure as generally described herein and shown in the drawings may be arranged, replaced, combined, separated and designed in various different configurations, all of which are contemplated herein.

[0342] Those skilled in the art will understand that the various illustrative logic blocks, modules, circuits, and steps described in this application may be implemented as hardware, software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in the form of their functional sets. Whether such function sets are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Technicians may implement the described function sets in different ways for each specific application, but such design decisions should not be interpreted as causing a departure from the scope of this application.

[0343] The various illustrative logic blocks, modules, and circuits described in this application may be implemented or performed by a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic devices, discrete gates or transistor logics, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0344] The steps of the method or algorithm described in this application may be embodied directly in hardware, in a software module executed by a processor, or in a combination thereof. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor to enable the processor to read and write information from / to the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a communication apparatus (e.g., a terminal or a base station). In an alternative, the processor and the storage medium may reside in a communication apparatus (e.g., a terminal or a base station) as discrete components.

[0345] In one or more exemplary designs, the functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, each function may be stored as one or more pieces of instructions or codes on a computer-readable medium or delivered through it. The computer-readable medium includes both a computer storage medium and a communication medium, the latter including any medium that facilitates the transfer of computer programs from one place to another. The storage medium may be any available medium that may be accessed by a general purpose or special purpose computer.

[0346] The above description is only an exemplary implementation of the present invention, and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

Claims

1.A method performed by a first node in a communication system, comprising:receiving a first message from a second node, wherein the first message includes first information about a dependency of a quality of service (QoS) flow;receiving a second information about a dependency of a protocol data unit (PDU) set from a third node; andcommunicating a dependent PDU set based on the first information and the second information.2.The method of claim 1, wherein the second information is same for dependent PDU sets.3.The method of claim 1, wherein the first information includes at least one of:information of a QoS flow dependent on the QoS flow; orinformation indicating the dependency of the QoS flow.4.The method of claim 3, wherein the first information is same for dependent QoS flows.5.The method of claim 3, wherein the information of a QoS flow dependent on the QoS flow includes a list of QoS flows dependent on the QoS flow.6.The method of claim 1, wherein the first message includes at least one of a PDU Session Establishment Request message or a PDU Session Resource Modify Request message.7.The method of claim 1, wherein the second information is included in a header of the PDU set.8.The method of claim 1, wherein the first message further includes third information about data, or the third information about data is received from a fourth node,wherein the third information includes one or more of: a transmission period or a transmission interval of the data; a size of the data; a packet delay budget (PDB) or PDU set delay budget (PSDB); a data rate; a remaining PDB or PSDB; or a data type.9.The method of claim 1, wherein communicating a dependent PDU set based on the first information and the second information includes:determining a dependent PDU set in a first time threshold based on the first information and the second information; andsending the dependent PDU set based on a second time threshold.10.The method of claim 9, wherein the first time threshold and / or the second time threshold are included in the first message.11.The method of claim 1, further comprising receiving eighth information about discarding of QoS flows,wherein the eighth information includes at least one of information about discarding based on PDU sets, or information about discarding based on QoS flows.12.The method of claim 1, further comprising:sending a fourteenth message to a second RAN node, wherein the fourteenth message includes information about whether the first node supports PDU set QoS handling; and / orreceiving a fifteenth message from a second RAN node, the fifteenth message including information about whether the second RAN node supports PDU set QoS handling.13.The method of claim 1, further comprising:sending ninth information about a mapping between QoS flows and logical channels to the fourth node;sending tenth information about a configured grant resource mapping to a logical channel to a fourth node;receiving data on a QoS flow from a fourth node based on the ninth information and the tenth information.14.The method of claim 1, further comprising:monitoring that a channel quality is lower than a first threshold;sending eleventh information to a fourth node, wherein the eleventh information indicates that the channel quality is lower than the first threshold or indicates the fourth node to report a remaining PDB or PSDB; andreceiving newly transmitted data and / or the reported remaining PDB or PSDB from the fourth node.15.A first node in a communication system, comprising:a transceiver; andone or more processors coupled with the transceiver and configured to:receive a first message from a second node, wherein the first message includes first information about a dependency of a quality of service (QoS) flow,receive a second information about a dependency of a protocol data unit (PDU) set from a third node,communicate a dependent PDU set based on the first information and the second information.

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