Method and device for supporting delayed budget processing

Abstract

The embodiment of the invention relates to a method and equipment for supporting delayed budget processing. In accordance with an embodiment of the present disclosure, an exemplary method may include receiving information associated with an AN PSDB of a set of PDUs in response to a handover of a UE from a source RAN node to a RAN node; and performing data transmission of the PDU set at least based on the information associated with the AN PSDB.

Description

Technical Field

[0001] Embodiments of the present application generally relate to wireless communication technology, and more particularly to a method and apparatus for supporting delay budget handling (eg, supporting protocol data unit (PDU) set delay budget (PSDB) handling associated with handover). Background Art

[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, etc. Wireless communication systems may employ a variety of access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of wireless communication systems may include fourth generation (4G) systems such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems (5GS) which may also be referred to as new radio (NR) systems.

[0003] On the other hand, extended reality (XR), including augmented reality (AR) and virtual reality (VR) as well as cloud gaming (CG), presents a new and promising category of connected devices, applications and services. Therefore, the 3rd Generation Partnership Project (3GPP) has considered introducing XR into 3GPP and following the 5G media streaming model defined in 3GPP to achieve the integration of XR applications within the 5G system. Therefore, there are a lot of technical problems to be solved in supporting XR services (or applications, or services) in 5GS or in further LTE of the radio access network (RAN). For example, one technical problem to be solved involves XR management (XRM) services to improve the quality of service (QoS) management and scheduling of XR, which is related to delay budget handling. Summary of the invention

[0004] One objective of embodiments of the present application is to provide a technical solution that supports delay budget handling, such as a method and apparatus that supports delay budget handling for XR services.

[0005] Some embodiments of the present application provide a RAN node (e.g., a target gNB) comprising: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to cooperate with the transceiver to perform the following operations: in response to a handover of a user equipment (UE) from a source RAN node to the RAN node, receive information associated with an access network (AN) PSDB (AN PSDB) of a PDU set; and perform data transmission of the PDU set based at least on the information associated with the AN PSDB.

[0006] In some embodiments of the present application, the AN PSDB is the difference between the time when the first PDU in a downlink PDU set arrives at the RAN node and the time when the last PDU or all PDUs in the downlink PDU set are successfully delivered to the UE, or the difference between the time when the first PDU in an uplink PDU set is processed at the UE and the time when the last PDU or all PDUs in the uplink PDU set are successfully transmitted from the UE.

[0007] According to some embodiments of the present application, the information associated with the AN PSDB indicates arrival time information about the first PDU in the PDU set and AN PSDB information, the AN PSDB information indicates the AN PSDB, and the processor is configured to: calculate a remaining portion of the AN PSDB based on the arrival time information about the first PDU in the PDU set and the AN PSDB information; and use the remaining portion of the AN PSDB for data transmission of remaining PDUs in the PDU set. In an example, the information associated with the AN PSDB is received from a source RAN node, the PDU set is a downlink PDU set, and the arrival time information about the first PDU in the PDU set indicates at least one of the following:

[0008] An absolute time at which the first PDU in the PDU set arrives from a core network (CN) node at the source RAN node;

[0009] a system frame number (SFN) timing, which indicates the time at which the first PDU in the PDU set arrives from the CN node to the source RAN node; or

[0010] A buffering time of the first PDU in the PDU set at the source RAN node.

[0011] According to some embodiments of the present application, the information associated with the AN PSDB is received from the source RAN node or the UE, the PDU set is an uplink PDU set, and the arrival time information about the first PDU in the PDU set indicates at least one of the following:

[0012] an absolute time at which a buffer status report (BSR) for transmission of the first PDU in the PDU set is received from the UE;

[0013] an absolute time at which the first PDU reported by the UE arrives at the access stratum (AS) layer;

[0014] an absolute time reported by the UE at which the first PDU is generated in the application layer;

[0015] SFN timing, which indicates the time at which a BSR for transmission of the first PDU in the PDU set is received from the UE;

[0016] SFN timing, which indicates the time when the first PDU reported by the UE arrives at the AS layer;

[0017] SFN timing, which indicates generation of the first PDU in the application layer as reported by the UE; or

[0018] A buffering time of a first uplink PDU in the PDU set at the UE.

[0019] In some embodiments of the present application, the AN PSDB is the difference between the time when the last PDU in a downlink PDU set arrives at the RAN node and the time when the last PDU in the downlink PDU set or all PDUs are successfully delivered to the UE, or the difference between the time when the last PDU in an uplink PDU set is processed at the UE and the time when the last PDU in the uplink PDU set or all PDUs are successfully transmitted from the UE.

[0020] According to some embodiments of the present application, the information associated with the AN PSDB indicates arrival time information about the last PDU in the PDU set and AN PSDB information, the AN PSDB information indicates the AN PSDB, and the processor is configured to: calculate the remaining part of the AN PSDB based on the arrival time information about the last PDU in the PDU set and the AN PSDB information; and use the remaining part of the AN PSDB for data transmission of the remaining PDUs in the PDU set.

[0021] In an example, the information associated with the AN PSDB is received from a source RAN node, the PDU set is a downlink PDU set, and the arrival time information about the last PDU in the PDU set indicates at least one of the following:

[0022] The absolute time at which the last PDU in the PDU set arrives from the CN node to the source RAN node;

[0023] SFN timing, which indicates the time when the last PDU in the PDU set arrives from the CN node to the source RAN node; or

[0024] A buffering time of the last PDU in the PDU set at the source RAN node.

[0025] In another example, the information associated with the AN PSDB is received from the UE, the PDU set is an uplink PDU set, and the arrival time information about the last PDU in the PDU set indicates at least one of the following:

[0026] an absolute time at which a BSR for transmission of the last PDU in the PDU set is received from the UE;

[0027] The absolute time at which the last PDU reported by the UE arrives at the AS layer;

[0028] the absolute time at which the last PDU was generated in the application layer as reported by the UE;

[0029] SFN timing, which represents the time when a BSR for transmission of the last PDU in the PDU set is received from the UE;

[0030] SFN timing, which indicates the time when the last PDU reported by the UE arrives at the AS;

[0031] SFN timing, which indicates the generation of the last PDU in the application layer as reported by the UE; or

[0032] A buffering time of the last PDU in the PDU set at the UE.

[0033] In some embodiments of the present application, the information associated with the AN PSDB indicates AN PSDB information and a passed part of the AN PSDB, the AN PSDB information indicates the AN PSDB, and the processor is configured to: calculate the remaining part of the AN PSDB based on the AN PSDB information and the passed part of the AN PSDB; and use the remaining part of the AN PSDB for data transmission of the remaining PDUs in the PDU set.

[0034] In some embodiments of the present application, the information associated with the AN PSDB indicates a remaining portion of the AN PSDB for the PDU set, and the processor is configured to use the remaining portion of the AN PSDB for data transmission of remaining PDUs in the PDU set.

[0035] In some embodiments of the present application, the information associated with the AN PSDB is received from the source RAN node during the handover via at least one of the following:

[0036] Signaling of handover request;

[0037] Signaling of sequence number (SN) status transmission;

[0038] a user plane protocol carried by a user plane general packet radio service (GPRS) tunneling protocol (GTP-U) extension header; or

[0039] Switch the source to the target transparent container in the relevant signaling.

[0040] In some embodiments of the present application, in response to the success of the switching, the information associated with the AN PSDB is received from the UE via a packet data convergence protocol (PDCP) header or a media access control (MAC) control element (CE) or a PDCP control PDU or a radio resource control (RRC) signaling.

[0041] In some embodiments of the present application, the AN PSDB information indirectly indicates the AN PSDB by including the total PSDB and the CN PSDB, or directly indicates the AN PSDB.

[0042] Some embodiments of the present application provide a wireless communication device (e.g., a source gNB or a UE), comprising: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to cooperate with the transceiver to perform the following operations: receiving first information indicating an AN PSDB of a PDU set; and in response to a switch of the UE occurring during data transmission of the PDU set, transmitting second information associated with the AN PSDB of the PDU set based at least on the first information indicating the AN PSDB.

[0043] In some embodiments of the present application, the AN PSDB is the difference between the time when the first PDU in a downlink PDU set arrives at the RAN node and the time when the last PDU or all PDUs in the downlink PDU set are successfully delivered to the UE, or the difference between the time when the first PDU in an uplink PDU set is processed at the UE and the time when the last PDU or all PDUs in the uplink PDU set are successfully transmitted from the UE.

[0044] According to some embodiments of the present application, the second information associated with the AN PSDB indicates arrival time information about the first PDU in the PDU set and third information, and the third information indicates the AN PSDB.

[0045] In some embodiments of the present application, the second information associated with the AN PSDB indicates third information and a passed part of the AN PSDB, the third information indicates the AN PSDB, and the processor is configured to: calculate the passed part of the AN PSDB based on arrival time information about the first PDU in the PDU set.

[0046] In some embodiments of the present application, the second information associated with the AN PSDB indicates a remaining portion of the AN PSDB of the PDU set, and the processor is configured to:

[0047] calculating a passed portion of the AN PSDB based on arrival time information about the first PDU in the PDU set; and

[0048] The remaining portion of the AN PSDB is calculated based on the passed portion of the AN PSDB and the first information indicative of the AN PSDB.

[0049] According to some embodiments of the present application, the second information associated with the AN PSDB indicates arrival time information about the last PDU in the PDU set or a passed part of the AN PSDB, wherein the passed part of the AN PSDB is calculated based on the arrival time information about the last PDU in the PDU set.

[0050] According to some embodiments of the present application, the exemplary wireless communication device is a source RAN node of the UE, the PDU set is a downlink PDU set, and the arrival time information about the first PDU in the PDU set indicates at least one of the following:

[0051] an absolute time at which the first PDU in the PDU set arrives from the CN node to the source RAN node;

[0052] SFN timing, which indicates the time when the first PDU in the PDU set arrives from the CN node to the source RAN node; or

[0053] A buffering time of the first PDU in the PDU set at the source RAN node.

[0054] According to some embodiments of the present application, the exemplary wireless communication device is a source RAN node of the UE or the UE, the PDU set is an uplink PDU set, and the arrival time information about the first PDU in the PDU set indicates at least one of the following:

[0055] an absolute time at which a BSR for transmission of the first PDU in the PDU set is received from the UE;

[0056] the absolute time at which the first PDU reported by the UE arrives at the AS layer;

[0057] an absolute time reported by the UE at which the first PDU is generated in the application layer;

[0058] SFN timing, which indicates the time at which a BSR for transmission of the first PDU in the PDU set is received from the UE;

[0059] SFN timing, which indicates the time when the first PDU reported by the UE arrives at the AS layer;

[0060] SFN timing, which indicates generation of the first PDU in the application layer as reported by the UE; or

[0061] A buffering time of a first uplink PDU in the PDU set at the UE.

[0062] According to some embodiments of the present application, in a case where the wireless communication device is a source RAN node in a central unit (CU)-distributed unit (DU) split architecture and the DU of the source RAN node receives arrival time information about the first PDU in the PDU set, the CU of the source RAN node receives arrival time information about the first PDU in the PDU set from the DU via F1-AP signaling or F1-U user plane protocol.

[0063] According to some embodiments of the present application, the wireless communication device is the source RAN node of the UE, the PDU set is a downlink PDU set, and in the case where the first PDU in the PDU set arrives at the source RAN node during the execution of the handover or after the handover is completed, the second information associated with the AN PSDB indicates that the entire AN PSDB will be used for data transmission of the PDU set, or the buffering time of the first PDU in the PDU set at the source RAN node is zero.

[0064] According to some embodiments of the present application, the wireless communication device is the UE, the PDU set is an uplink PDU set, and in the case where the first PDU in the PDU set arrives at the UE later than receiving the switching command or during the execution of the switching or after the switching is completed, the second information associated with the AN PSDB indicates that the entire AN PSDB will be used for data transmission of the PDU set, or the buffering time of the first PDU in the PDU set at the UE is zero.

[0065] In some embodiments of the present application, the AN PSDB is the difference between the time when the last PDU in a downlink PDU set arrives at the RAN node and the time when the last PDU in the downlink PDU set or all PDUs are successfully delivered to the UE, or the difference between the time when the last PDU in an uplink PDU set is processed at the UE and the time when the last PDU in the uplink PDU set or all PDUs are successfully transmitted from the UE.

[0066] According to some embodiments of the present application, the second information associated with the AN PSDB indicates arrival time information about the last PDU in the PDU set and third information, and the third information indicates the AN PSDB.

[0067] According to some embodiments of the present application, the second information associated with the AN PSDB indicates third information and a passed part of the AN PSDB, the third information indicates the AN PSDB, and the processor is configured to: calculate the passed part of the AN PSDB based on arrival time information about the last PDU in the PDU set.

[0068] According to some embodiments of the present application, the second information associated with the AN PSDB indicates the remaining portion of the AN PSDB of the PDU set, and the processor is configured to: calculate the passed portion of the AN PSDB based on the arrival time information about the last PDU in the PDU set; and calculate the remaining passed portion of the AN PSDB based on the passed portion of the AN PSDB and the first information indicating the AN PSDB.

[0069] According to some embodiments of the present application, the second information associated with the AN PSDB indicates arrival time information about the last PDU in the PDU set or a passed part of the AN PSDB, wherein the passed part of the AN PSDB is calculated based on the arrival time information about the last PDU in the PDU set.

[0070] According to some embodiments of the present application, the wireless communication device is a source RAN node of the UE, the PDU set is a downlink PDU set, and the arrival time information about the last PDU in the PDU set indicates at least one of the following:

[0071] The absolute time at which the last PDU in the PDU set arrives from the CN node to the source RAN node;

[0072] SFN timing, which indicates the time when the last PDU in the PDU set arrives from the CN node to the source RAN node; or

[0073] A buffering time of the last PDU in the PDU set at the source RAN node.

[0074] According to some embodiments of the present application, the wireless communication device is the UE, the PDU set is an uplink PDU set, and the arrival time information about the last PDU in the PDU set indicates at least one of the following:

[0075] an absolute time at which a BSR for transmission of the last PDU in the PDU set is received from the UE;

[0076] The absolute time at which the last PDU reported by the UE arrives at the AS layer;

[0077] the absolute time at which the last PDU was generated in the application layer as reported by the UE;

[0078] SFN timing, which represents the time when a BSR for transmission of the last PDU in the PDU set is received from the UE;

[0079] SFN timing, which indicates the time when the last PDU reported by the UE arrives at the AS;

[0080] SFN timing, which indicates the generation of the last PDU in the application layer as reported by the UE; or

[0081] A buffering time of the last PDU in the PDU set at the UE.

[0082] According to some embodiments of the present application, the wireless communication device is the source RAN node of the UE, the PDU set is a downlink PDU set, and in the case where the last PDU in the PDU set arrives at the source RAN node during the execution of the handover or after the handover is completed, the second information associated with the AN PSDB indicates that the entire AN PSDB will be used for data transmission of the PDU set, or the buffering time of the last PDU in the PDU set at the source RAN node is zero.

[0083] According to some embodiments of the present application, the wireless communication device is the UE, the PDU set is an uplink PDU set, and in the case where the last PDU in the PDU set arrives at the UE later than receiving the switching command or during the execution of the switching or after the switching is completed, the second information associated with the AN PSDB indicates that the entire AN PSDB will be used for data transmission of the PDU set, or the buffering time of the last PDU in the PDU set at the UE is zero.

[0084] In some embodiments of the present application, the wireless communication device is a source RAN node of the UE, and the second information associated with the ANPSDB is transmitted during the handover via at least one of the following:

[0085] Signaling of handover request;

[0086] Signaling for SN status transmission;

[0087] a user plane protocol carried by a user plane general packet radio service (GPRS) tunneling protocol (GTP-U) extension header; or

[0088] Switch the source to the target transparent container in the relevant signaling.

[0089] In some embodiments of the present application, the wireless communication device is the UE, and in response to the success of the handover, the second information associated with the AN PSDB is transmitted from the UE via a PDCP header or MAC CE or PDCP control PDU or RRC signaling.

[0090] In some embodiments of the present application, the first information indicating the AN PSDB indirectly indicates the AN PSDB by including a total PSDB and a CN PSDB, or directly indicates the AN PSDB.

[0091] In some embodiments of the present application, the third information indicating the AN PSDB indirectly indicates the AN PSDB by including the total PSDB and the CN PSDB, or directly indicates the AN PSDB.

[0092] Some embodiments of the present application also provide a method, such as a method performed by a target gNB, comprising: receiving information associated with an AN PSDB of a PDU set in response to a switching of a UE from a source RAN node to a RAN node; and performing data transmission of the PDU set based at least on the information associated with the AN PSDB.

[0093] Some embodiments of the present application also provide another method, such as a method performed by a source gNB or a UE, comprising: receiving first information indicating an AN PSDB of a PDU set; and in response to a switching of the UE occurring during data transmission of the PDU set, transmitting second information associated with the AN PSDB of the PDU set based at least on the first information indicating the AN PSDB.

[0094] In view of the above, the embodiments of the present application provide a technical solution to support delay budget handling, such as a method and device to support delay budget handling that can be used for XRM services. Therefore, the present application can promote and improve the implementation of NR. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] In order to describe the manner in which the advantages and features of the application can be obtained, the application is described by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of the application and therefore should not be considered limiting of its scope.

[0096] Figure 1 A wireless communication system according to some embodiments of the present application is illustrated.

[0097] Figure 2 is a schematic diagram illustrating the internal structure of a RAN node according to some embodiments of the present application.

[0098] Figure 3 is a schematic diagram of an exemplary AN PSDB illustrating PDU aggregation according to some embodiments of the present application.

[0099] Figure 4 is a flow chart illustrating a method of supporting delay budget handling according to some embodiments of the present application.

[0100] Figure 5 is a flowchart illustrating an exemplary procedure of a method of supporting delay budget handling according to some embodiments of the present application.

[0101] Figure 6 is a flowchart illustrating an exemplary procedure of a method of supporting delay budget handling according to some other embodiments of the present application.

[0102] Figure 7 A block diagram illustrating an apparatus supporting delay budget handling according to some embodiments of the present application is shown.

[0103] Figure 8 A block diagram illustrating an apparatus supporting delay budget handling according to some other embodiments of the present application is shown. DETAILED DESCRIPTION

[0104] The detailed description of the accompanying drawings is intended as a description of the preferred embodiments of the present application, and is not intended to represent the only form in which the present application can be practiced. It should be understood that the same or equivalent functions can be achieved by different embodiments intended to be included in the spirit and scope of the present application.

[0105] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, the embodiments are provided under specific network architectures and new service scenarios (e.g., 3GPP 5G, 3GPP Long Term Evolution (LTE), etc.). Please consider that all embodiments in the present application are also applicable to similar technical problems as network architectures and new service scenarios develop. In addition, the terms described in the present application may be changed, which should not affect the principles of the present application.

[0106] Figure 1 A schematic diagram illustrating an exemplary wireless communication system 100 according to some embodiments of the present application is illustrated.

[0107] like Figure 1 , the wireless communication system 100 includes at least one BS 101 and at least one UE 102. Specifically, for illustrative purposes, the wireless communication system 100 includes one BS 101 and two terminal devices 102 (eg, a first UE 102a and a second UE 102b). Figure 1 A specific number of BSs and terminal devices are illustrated in FIG. 1 , but please consider that in some other embodiments of the present application, the wireless communication system 100 may include more or fewer BSs and terminal devices.

[0108] The wireless communication system 100 is compatible with any type of network capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with wireless communication networks, cellular telephone networks, time division multiple access (TDMA)-based networks, code division multiple access (CDMA)-based networks, orthogonal frequency division multiple access (OFDMA)-based networks, LTE networks, 3GPP-based networks, 3GPP 5G networks, satellite communication networks, high altitude platform networks, and / or other communication networks.

[0109] BS101 may communicate with a CN node (not shown) (e.g., a mobility management entity (MME) or a serving gateway (S-GW), an authentication and mobility management function (AMF), or a user plane function (UPF), etc.) via an interface. BSs are also referred to as access points, access terminals, base stations, macro cells, Node Bs, enhanced Node Bs (eNBs), gNBs, home Node Bs, relay nodes, or devices, or are described using other terms used in the art. In 5G NR, BSs may also be referred to as RAN nodes. Each BS may serve several UEs within a service area (e.g., a cell or a cell sector) via wireless communication links. Neighboring BSs may communicate with each other as needed, such as during a handover procedure of a UE.

[0110] The terminal device (or remote device) 102 (e.g., the first UE 102a and the second UE 102b) may include a computing device, such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart TV (e.g., a TV connected to the Internet), a set-top box, a game console, a security system (including a security camera), a car computer, a network device (e.g., a router, a switch and a modem), etc. According to an embodiment of the present application, the terminal device may include a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identity module, a personal computer, a selective call receiver, or any other device capable of sending and receiving communication signals on a wireless network. In some embodiments, the terminal device may include a wearable device, such as a smart watch, a fitness band, an optical head-mounted display, etc. In addition, the terminal device may be referred to as a subscriber unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal or a device, or described using other terms used in this technology. Herein (throughout the specification), although "UE" is exemplarily used as a classic terminal device for illustrating a terminal device, it should be understood as any type of terminal device.

[0111] Figure 2 is a schematic diagram illustrating the internal structure of a RAN node (eg, BS) according to some embodiments of the present application.

[0112] refer to Figure 2 In the RAN architecture based on CU-DU splitting, the internal structure of the RAN node (eg, BS 101) may be split into a CU 200 and at least one DU 202 (eg, Figure 2 ). Although Figure 2 A specific number of DUs 202 are depicted in FIG. 1 , but please consider that any number of DUs 202 may be included in a BS.

[0113] CU 200 and DU 202 are connected to each other through an interface called F1 as specified in 3GPP standard documents. RRC layer functionality, service data adaptation protocol (SDAP) functionality, and PDCP layer functionality are located in CU 200. Radio link control (RLC) layer functionality, MAC layer functionality, and physical (PHY) layer functionality are located in DU 202.

[0114] When XR applications are integrated into 5GS, PDU sets and PDU set QoS characteristics may be introduced, as discussed in TR 23.700-60. A PDU set consists of one or more PDUs that carry the payload of an information unit generated at the application layer (e.g., a frame or video clip for an XRM service, as used in TR 26.926). In some embodiments, the application layer requires all PDUs in the PDU set to use the corresponding information unit. In some other embodiments, when some PDUs are lost, the application layer can still recover some or all of the information units. PSDB is a PDU set-level QoS parameter that defines the upper limit of the time that a PDU set may be delayed between the N6 termination point at the UE and the UPF. AN PSDB can be determined by subtracting the static value of the CN PSDB from a given PSDB (also referred to as the total PSDB). CN PSDB represents the delay between any N6 termination point at the UPF (for any UPF that may be selected for a PDU session) and the AN. A given PSDB can be configured by the CN side.

[0115] AN PSDB can be interpreted in various ways. For example, some embodiments of the present application provide two definitions of AN PSDB for a PDU set, such as Definition 1 and Definition 2. According to Definition 1, for a downlink PDU set, the AN PSDB (also referred to as DL AN PSDB) is the difference between the time when the first PDU in the downlink PDU set arrives at the RAN node and the time when the last PDU or all PDUs in the downlink PDU set are successfully delivered to the UE; and for an uplink PDU set, the AN PSDB (also referred to as UL AN PSDB) is the difference between the time when the first PDU in the uplink PDU set is processed at the UE and the time when the last PDU or all PDUs in the uplink PDU set are successfully transmitted from the UE. The time when the first PDU in the uplink PDU set is processed at the UE may indicate that the first PDU in the uplink PDU set is generated in the UE application layer, or the first PDU in the uplink PDU set is reaching the UE AS layer, or the UE triggers a BSR procedure for transmitting the first PDU in the uplink PDU set. According to Definition 2, for a downlink PDU set, the AN PSDB is the difference between the time when the last PDU in the downlink PDU set arrives at the RAN node and the time when the last PDU or all PDUs in the downlink PDU set are successfully delivered to the UE; and for an uplink PDU set, the AN PSDB is the difference between the time when the last PDU in the uplink PDU set is processed at the UE and the time when the last PDU or all PDUs in the uplink PDU set are successfully transmitted from the UE. The time when the last PDU in the uplink PDU set is processed at the UE may indicate that the last PDU in the uplink PDU set is generated in the UE application layer, or the last PDU in the uplink PDU set is reaching the UE AS layer, or the UE triggers a BSR procedure for transmitting the last PDU in the uplink PDU set. In addition, according to any definition of the AN PSDB, the same AN ​​PSDB may be used in common for data transmission of both the downlink PDU set and the uplink PDU set, or may be used separately for only one of the data transmission of the downlink PDU set and the uplink PDU set. For example, for DL ​​AN PSDB, in some scenarios, it can be configured only for downlink PDU sets, and in addition to data transmission of downlink PDU sets, it can also be configured for data transmission of uplink PDU sets. Similarly, in some scenarios, UL AN PSDB can be configured only for uplink PDU sets, and in addition to data transmission of uplink PDU sets, it can also be configured for data transmission of downlink PDU sets.

[0116] However, switching may occur during data transmission of a PDU set. Figure 3 is a schematic diagram illustrating an exemplary AN PSDB of a PDU set according to some embodiments of the present application, wherein switching occurs during data transmission of the PDU set.

[0117] refer to Figure 3 , taking a downlink PDU set and Definition 1 as an example, the AN PSDB is the difference between the time when the first PDU in the downlink PDU set arrives at the gNB (e.g., t0) and the time when the last PDU or all PDUs in the PDU set have been successfully delivered to the UE (e.g., t3). It is presumed that according to the AN PSDB, a PDU set containing 8 PDUs will be transmitted to the UE, with the first PDU being transmitted to the UE at time t1. However, switching may occur during the transmission of the PDU set (e.g., at t2). Therefore, some of the PDUs in the PDU set (e.g., PDUs 1, 2, and 3) may have been successfully transmitted by the source gNB, while other PDUs in the PDU set (e.g., PDUs 4 to 8) need to be transmitted by the target gNB. In this case, the target gNB should know the remaining AN PSDB for transmitting the remaining PDUs in the PDU set in order to pursue more accurate QoS management and scheduling. The remaining AN PSDB (i.e., the remaining portion of the AN PSDB) may be determined by subtracting the passed AN PSDB (i.e., the passed portion of the AN PSDB) from the given AN PSDB or the total AN PSDB. Similar issues will also arise when the AN PSDB is interpreted in other ways. For example, considering Definition 2, t0 may refer to the time when the last PDU in the downlink PDU set arrives at the RAN node or the time when the last PDU in the uplink PDU set is processed at the UE, and the description of t1, t2, and t3 will not change.

[0118] At least in view of the above problems, an embodiment of the present application proposes a technical solution to support delay budget handling (e.g., for XRM services). For example, a wireless communication device other than the target RAN node (e.g., a source gNB or UE, etc.) will directly indicate the remaining AN PSDB to the target gNB. In another example, a wireless communication device other than the target RAN node (e.g., a source gNB or UE, etc.) will indirectly indicate the remaining AN PSDB to the target gNB by indicating relevant information, and the target gNB can determine the remaining AN PSDB based on the relevant information.

[0119] In addition, although concepts related to PSDB (including given PSDB, AN PSDB, CN PSDB, etc.) are proposed based on a PDU set proposed for XR services or XR applications, the concepts may change with the evolution of 3GPP specifications and should therefore not be used to be inappropriately limited to the examples illustrated above.

[0120] Figure 4 The present invention is a flowchart illustrating a method for supporting delay budget handling according to some embodiments of the present application, wherein a handover of a UE from a source RAN node to a target RAN node is considered. Although the method is illustrated at a system level between a wireless communication device (e.g., a source RAN node or a remote device) and a target RAN node (e.g., a target gNB), a person skilled in the art should understand that the method implemented in the wireless communication device and the target RAN node may be implemented separately and / or incorporated by other devices having similar functions.

[0121] refer to Figure 4 In step 401, the wireless communication device receives information (hereinafter, first information) indicating an AN PSDB of a PDU set. For example, in a case where the wireless communication device is a source RAN node (e.g., a source gNB), the source RAN node may receive the first information from a CN side (e.g., an AMF). In a case where the wireless communication device is a remote device (e.g., a UE), the UE may receive the first information from a source RAN node or a CN side (e.g., an AMF). The first information may directly indicate an AN PSDB of a PDU set, or indirectly indicate an AN PSDB of a PDU set by including a total PSDB and a CN PSDB. The PDU set may be a downlink PDU set from a CN side (e.g., a UPF) to a UE via a gNB, or an uplink PDU set from a UE to a UPF via a gNB.

[0122] Due to the mobility of the UE, a handover to the target RAN node may occur during the data transmission of a PDU set. In this document, data transmission of a PDU set covers the transmission of a downlink PDU set to the UE and / or the reception or scheduling of an uplink PDU set from the UE, which should be well understood by a person skilled in the art. In addition, the duration of data transmission of a PDU set should be understood in the broadest sense, which should include any PDU set that requires the source RAN node to transmit one or more PDUs to the target RAN node, even if the first PDU in the PDU set arrives at the source RAN node or the first PDU in the PDU set is processed at the UE after the handover is completed.

[0123] In response to the handover of the UE, the wireless communication device will determine the information associated with the AN PSDB of the PDU set (hereinafter, the second information) based on the first information. In step 403, the wireless communication device will transmit the second information to the target RAN node so that the target RAN node can perform QoS management and scheduling on the PDU set. For example, in the case where the wireless communication device is a source RAN node, the source RAN node may transmit the second information during the handover via at least one of the following: signaling of a handover request, signaling of SN status transmission, a user plane protocol carried by a GTP-U extension header, or a source-to-target transparent container within a handover-related signaling. In the case where the wireless communication device is a UE, the UE may transmit the second information in response to the success of the handover (for example) via a PDCP header or a MAC CE or a PDCP control PDU or RRC signaling.

[0124] In step 404, the target RAN node will receive the second information accordingly. The second information may directly or indirectly indicate the remaining AN PSDB. For example, according to definition 1, the second information may indicate the arrival time information about the first PDU in the PDU set and the AN PSDB information indicating the AN PSDB (hereinafter, the third information). Similar to the first information, the third information may directly indicate the AN PSDB or indirectly indicate the AN PSDB by including the total PSDB and the CN PSDB. The first information and the third information may indicate the AN PSDB in the same or different ways, and the AN PSDB determined based on the third information is the same as the AN PSDB determined based on the first information. The target RAN node will calculate the remaining AN PSDB based on the arrival time information about the first PDU in the PDU set and the AN PSDB calculated or determined based on the third information. For example, the target RAN node may first calculate the passed AN PSDB based on the arrival time information about the first PDU in the PDU set, and then calculate the remaining AN PSDB based on the passed AN PSDB and the AN PSDB (for example, by subtracting the passed AN PSDB from the AN PSDB).

[0125] There are also several ways to calculate the passed AN PSDB by the target RAN node. Given the exemplary definition of the AN PSDB, the passed AN PSDB can be calculated by the target RAN node based on the arrival time information about the first PDU in the PDU set according to definition 1 or based on the arrival time information about the last PDU in the PDU set according to definition 2.

[0126] For example, according to Definition 1, an exemplary passed AN PSDB (also referred to as passed DL AN PSDB) calculated by the target RAN node for a downlink PDU set is the difference between the time when the first forwarded PDU in the PDU set arrives at the target RAN node and the arrival time information of the first PDU in the PDU set, that is, the passed DL AN PSDB is the time when the first forwarded PDU in the PDU set arrives at the target RAN node minus the arrival time information of the first PDU. Another exemplary passed DL AN PSDB is the difference between the time when a handover request message or an SN status transfer message, etc. arrives at the target RAN node and the arrival time information of the first PDU in the PDU set, that is, the passed DL AN PSDB is the time when the handover request message or the SN status transfer message, etc. arrives at the target RAN node minus the arrival time information of the first PDU. The target RAN node can calculate the passed AN PSDB for the uplink PDU set (hereinafter, UL passed AN PSDB) in a similar manner to the passed DL AN PSDB.

[0127] Similarly, according to Definition 2, the second information may indicate the arrival time information about the last PDU in the PDU set and the third information, i.e., the AN PSDB information indicating the AN PSDB. The target RAN node will calculate the remaining AN PSDB based on the arrival time information about the last PDU in the PDU set and the AN PSDB calculated or determined based on the AN PSDB information. For example, the target RAN node may first calculate the passed AN PSDB based on the arrival time information about the last PDU in the PDU set, and then calculate the remaining AN PSDB based on the passed AN PSDB and the AN PSDB (e.g., by subtracting the passed AN PSDB from the AN PSDB).

[0128] Similarly, according to Definition 2, the passed DL AN PSDB may be calculated by the target RAN node in various ways. For example, an exemplary passed AN PSDB (also referred to as passed DL AN PSDB) calculated by the target RAN node for a downlink PDU set is the difference between the time when the first forwarded PDU in the PDU set arrives at the target RAN node and the arrival time information of the last PDU in the PDU set, that is, the passed DL AN PSDB is the time when the first forwarded PDU in the PDU set arrives at the target RAN node minus the arrival time information of the last PDU. Another exemplary passed DL AN PSDB calculated by the target RAN node is the difference between the time when a handover request message or an SN status transfer message, etc. arrives at the target RAN node and the arrival time information of the last PDU in the PDU set, that is, the passed DL AN PSDB is the time when the handover request message or the SN status transfer message, etc. arrives at the target RAN node minus the arrival time information of the last PDU. In addition, according to Definition 2, the target RAN node may calculate the passed AN PSDB for the uplink PDU set in a similar manner to the passed DL AN PSDB.

[0129] In another example, the second information may indicate the third information and the passed AN PSDB. The passed AN PSDB may be calculated similarly to the target RAN node as described above. In view of the exemplary definition of the AN PSDB, the passed AN PSDB may be calculated by the wireless communication device based on the arrival time information of the first PDU in the PDU set according to definition 1 or based on the arrival time information of the last PDU in the PDU set according to definition 2.

[0130] For example, according to Definition 1, the passed DL AN PSDB calculated by the source RAN node is the difference between the time when the first forwarded PDU in the PDU set is sent by the source RAN node and the arrival time information of the first PDU, that is, the exemplary passed DL AN PSDB calculated by the source RAN node is the time when the first forwarded PDU in the PDU set is sent by the source RAN node minus the arrival time information of the first PDU. Another exemplary passed DL AN PSDB calculated by the source RAN node is the difference between the time when the handover request message or the SN status transfer message, etc. is sent by the source RAN node and the arrival time information of the first PDU, that is, another exemplary passed DL AN PSDB calculated by the source RAN node is the time when the handover request message or the SN status transfer message, etc. is sent by the source RAN node minus the arrival time information of the first PDU. The source RAN node can calculate the passed AN PSDB for the uplink PDU set in a similar manner to the passed DL AN PSDB.

[0131] Similarly, according to Definition 2, the passed DL AN PSDB calculated by the source RAN node is the difference between the time when the first forwarded PDU in the PDU set is sent by the source RAN node and the arrival time information of the last PDU, that is, the exemplary passed DL AN PSDB calculated by the source RAN node is the time when the first forwarded PDU in the PDU set is sent by the source RAN node minus the arrival time information of the last PDU. Another exemplary passed DL AN PSDB calculated by the source RAN node is the difference between the time when the handover request message or the SN status transfer message, etc. is sent by the source RAN node and the arrival time information of the last PDU, that is, another exemplary passed DL AN PSDB calculated by the source RAN node is the time when the handover request message or the SN status transfer message, etc. is sent by the source RAN node minus the arrival time information of the last PDU. The source RAN node may calculate the passed AN PSDB for the uplink PDU set in a similar manner to the passed DL AN PSDB.

[0132] In the case where the wireless communication device is a UE, the UL passed AN PSDB can be calculated by the UE. For example, according to Definition 1, the exemplary passed AN PSDB calculated by the UE for the uplink PDU set is the difference between the time of receiving the switching command and the arrival time information of the first PDU in the PDU set, that is, the passed UL AN PSDB is the time of receiving the switching command minus the arrival time information of the first PDU. Another exemplary passed UL AN PSDB calculated by the UE is the difference between the time when the switching is completed and the arrival time information of the first PDU in the PDU set, that is, the passed UL AN PSDB is the time when the switching is completed minus the arrival time information of the first PDU. Another exemplary passed UL AN PSDB calculated by the UE is the difference between the time when the passed AN PSDB will be transmitted and the arrival time information of the first PDU in the PDU set, that is, the passed UL AN PSDB is the time when the passed AN PSDB will be transmitted minus the arrival time information of the first PDU. According to Definition 2, the passed UL AN PSDB can be calculated by the UE in a similar manner.

[0133] The target RAN node will then calculate the remaining AN PSDB based on the AN PSDB determined according to the third information and the passed AN PSDB (eg, by subtracting the passed AN PSDB from the AN PSDB).

[0134] In yet another example, the wireless communication device may calculate the remaining AN PSDB by itself. Therefore, the second information may directly indicate the remaining AN PSDB of the PDU set.

[0135] In some other embodiments of the present application, the second information may come from a different wireless communication device, such as a source RAN node, a UE, or even another device. For example, the second information from the UE or the source RAN node may indicate the arrival time information about the first PDU in the PDU set according to definition 1 or the arrival time information about the last PDU in the PDU set according to definition 2, or the AN PSDB that has been passed; but does not indicate the third information. The target RAN node may obtain the ANPSDB in other ways, and then calculate the remaining AN PSDB based on the second information and the AN PSDB. For example, the target RAN node may receive the arrival time information about the first PDU in the PDU set from the UE, for example, via a PDCP control PDU, receive the AN PSDB from the source RAN node, for example, via a handover request, and then determine the remaining AN PSDB based on the arrival time information about the first PDU in the PDU set and the ANPSDB.

[0136] Regardless, based at least on the second information, the target RAN node will determine the remaining AN PSDB and then perform data transmission of the PDU set in step 406. For example, the target RAN node uses the remaining AN PSDB for data transmission of the remaining PDUs in the PDU set.

[0137] A more detailed embodiment of the present application will be illustrated below in view of different scenarios. Those skilled in the art will well know that Definition 1 and Definition 2 are only used as examples, and the basic inventive concept of the present application can also be applied to other AN PSDB definitions or interpretations (if any). For example, the technical methods of how the wireless communication device obtains the first information and how the wireless communication transmits the second information to the target RAN node or other technical methods not determined by the definition of AN PSDB should also be applicable to other scenarios with other AN PSDB definitions (if any). Based on Figure 4 With the disclosure and teachings of the following embodiments, those skilled in the art will be well aware of how to apply the illustrated solutions to other contemplated scenarios.

[0138] Scenario I

[0139] According to some embodiments of the present application, the wireless communication device that transmits the second information (i.e., information associated with the AN PSDB of the PDU set) to the target RAN node is a source RAN node, such as a source gNB. According to definition 1, the PDU set may be a downlink PDU set or an uplink PDU set; and according to definition 2, the PDU may only be a downlink PDU set.

[0140] Figure 5 is a flowchart illustrating an exemplary procedure of a method of supporting delay budget handling according to some embodiments of the present application.

[0141] refer to Figure 5 According to some embodiments of the present application, in step 501, the source gNB may receive first information from a CN node (e.g., AMF) in a PDU session establishment request or a PDU session modification request message, i.e., information indicating an AN PSDB of a PDU set. The AN PSDB may be for each QoS flow level, i.e., the AN PSDB is applied to all PDU sets in the QoS flow. For example, the source gNB may receive the AN PSDB of the PDU set, or receive the CN PSDB and the total PSDB associated with the PDU set. In the case where the source gNB receives the CN PSDB and the total PSDB, the source gNB may calculate or determine the AN PSDB based on the CN PSDB and the total PSDB (e.g., by subtracting the CN PSDB from the total PSDB).

[0142] In response to the switching during the data transmission of the PDU, the data transmission of the remaining PDUs in the PDU set will be performed by the target RAN node instead of the source RAN node, which in some scenarios may include all the PDUs in the PDU set. In scenario I, the source RAN node will transmit the second information (i.e., information associated with the AN PSDB of the PDU set) to the target RAN node in step 503, so that the target RAN node (e.g., the target gNB) can perform the data transmission of the PDU set based on at least the second information in step 505 to achieve more accurate QoS management and scheduling. For example, the source gNB may transmit the second information via (or utilizing) signaling of a handover request in step 503a, or transmit the second information via (or utilizing) signaling of SN status transmission in step 503b, transmit the second information via (or utilizing) a user plane protocol carried by, for example, a GTP-U extension header of any PDU in a PDU set in step 503c, or transmit the second information via (or utilizing) a source to target container in handover-related signaling (e.g., a source next generation (NG)-RAN node to target NG-RAN node transparent container in handover-related signaling) in step 503d.

[0143] As described above, the second information is of various kinds. More specific embodiments are illustrated in view of some exemplary second information.

[0144] According to some embodiments of the present application (hereinafter, Scheme 1-1), according to Definition 1, the second information may indicate arrival time information about the first PDU in the PDU set and third information, the third information indicating the AN PSDB. The arrival time information about the first PDU in the PDU set and the third information may be transmitted to the target gNB in ​​the same or different messages and / or signalings. For example, the source gNB may transmit both the arrival time information about the first PDU in the PDU set and the third information via signaling of a handover request in step 503a. In another example, the source gNB may transmit the third information via signaling of a handover request in step 503a, and transmit the arrival time information about the first PDU in the PDU set via an SN transfer message in step 503b. In another example, the source gNB may transmit the third information via signaling of the handover request in step 503a, and transmit the arrival time information about the first PDU in the PDU set via the user plane protocol in step 503c, for example, by including the arrival time information about the first PDU in the PDU set in a GTP-U extended header of the PDUs in the PDU set.

[0145] The arrival time information about the first PDU in the PDU set may be defined in various ways. For example, in the case where the PDU set is a downlink PDU set, the arrival time information about the first PDU in the PDU set may indicate at least one of the following: the absolute time when the first PDU in the PDU set arrives at the source gNB from the CN node (e.g., UPF); SFN timing, which indicates the time when the first PDU in the PDU set arrives at the source gNB from the CN node (e.g., UPF); or the buffering time of the first PDU in the PDU set at the source gNB.

[0146] An example of the absolute time when the first PDU in the PDU set arrives at the source gNB from the CN node is the Coordinated Universal Time (UTC) time when the first PDU in the downlink PDU set arrives at the source gNB. An exemplary SFN timing representing the time when the first PDU in the PDU set arrives at the source gNB from the CN node is the time difference from the initial SFN boundary (e.g., SFN=0). In the case where the time between the source gNB and the target gNB is not synchronized, the source gNB may send the SFN timing in the source gNB (i.e., the timing difference from the initial SFN boundary of the source gNB (e.g., SFN=0)) plus the SFN offset between the source gNB and the target gNB to the target gNB; or the source gNB may calculate the SFN timing of the target gNB based on the SFN offset between the source gNB and the target gNB (i.e., the timing difference from the initial SFN boundary of the source gNB (e.g., SFN=0)) and then send the SFN timing of the target gNB to the target gNB. An exemplary buffering time for the first PDU in the PDU set in the source gNB is how long the first PDU has been buffered in the source gNB before being sent by the source gNB. In some scenarios, the first PDU in the downlink PDU set may arrive at the source gNB during the execution of a handover or after the handover is completed. For such a PDU set, the source gNB may indicate that the buffering time for the first PDU in the PDU set at the source RAN node is zero.

[0147] In addition, with respect to the special scenario where the first PDU in the downlink PDU set may arrive at the source gNB during the execution of the handover or after the handover is completed, in addition to the above solution, the source gNB may also only indicate the third information to implicitly indicate that the entire AN PSDB will be used for data transmission of the PDU set, or transmit the third information and explicitly indicate that the entire AN PSDB will be used for data transmission of the PDU set. For example, a bit may be used in the user plane protocol from the source gNB to the target gNB to indicate that the entire AN PSDB will be used for data transmission of the PDU set. This bit may be newly added compared to the conventional user plane protocol in the GTP-U extension header.

[0148] In the case where the PDU set is an uplink PDU set, the arrival time information about the first PDU in the PDU set may indicate at least one of the following: the time when the BSR for the transmission of the first PDU in the PDU set is received from the UE; the time when the first PDU reported by the UE, for example, via the PDCP header or in the MAC CE or PDCP control PDU or RRC signaling (for example, in the RRCReconfigurationComplete or UEAssitanceInformation message) arrives at the AS layer; or the time when the first PDU is generated in the application layer reported by the UE, for example, via the PDCP header or in the MAC CE or PDCP control PDU or RRC signaling; or the buffering time of the first uplink PDU in the PDU set at the UE. Similarly, each of the time when the BSR for the transmission of the first PDU in the PDU set is received from the UE, the time when the first PDU reported by the UE arrives at the AS layer, and the time when the first PDU is generated in the application layer reported by the UE may be defined by an absolute time (for example, UTC or SFN timing). For example, the time when the first PDU reported by the UE arrives at the AS layer is the absolute time when the first PDU reported by the UE arrives at the SDAP layer or the PDCP layer, or the SFN timing indicating the time when the first PDU reported by the UE arrives at the SDAP layer or the PDCP layer. In another example, the time when the first PDU is generated in the application layer reported by the UE is the absolute time when the first PDU is generated in the application layer at the SDAP or PDCP layer reported by the UE, or the SFN timing indicating the time when the first PDU is generated in the application layer at the SDAP or PDCP layer reported by the UE.

[0149] In the case where the source gNB is in a CU-DU split architecture and the DU of the source RAN node receives the arrival time information about the first PDU in the PDU set, the DU of the source gNB will transmit the arrival time information about the first PDU in the PDU set to the CU via F1-AP signaling or F1-U user plane protocol. For example, the DU may receive the arrival time of the first PDU in the uplink PDU set reported by the UE at the AS layer via the MAC header or MAC CE, extract the time from the MAC header or MAC CE, and then transmit the received time of the first PDU arriving at the AS layer to the CU via F1-AP signaling or F1-U user plane protocol.

[0150] The target gNB will first calculate the passed AN PSDB of the PDU based on the arrival time information about the first PDU in the PDU set, and then calculate the remaining AN PSDB of the PDU set based on the passed AN PSDB and the total AN PSDB determined according to the third information. The calculation of the passed AN PSDB and the remaining AN PSDB has been illustrated above and will not be repeated in this article.

[0151] According to some other embodiments of the present application (hereinafter, Scheme 1-2), according to Definition 2, the second information indicates the arrival time information about the last PDU in the PDU set and the third information, the third information indicating the AN PSDB. The arrival time information about the last PDU in the PDU set and the third information may be transmitted to the target gNB in ​​the same or different messages and / or signalings. For example, the source gNB may transmit both the arrival time information about the last PDU in the PDU set and the third information via the signaling of the handover request in step 503a. In another example, the source gNB may transmit the third information via the signaling of the handover request in step 503a and transmit the arrival time information about the last PDU in the PDU set via the SN transfer message in step 503b. In another example, the source gNB may transmit the third information via signaling of the handover request in step 503a and transmit the arrival time information about the last PDU in the PDU set via the user plane protocol in step 503c, for example, by including the arrival time information in a GTP-U extended header of the PDUs in the PDU set.

[0152] The arrival time information about the last PDU in the PDU set may be defined in various ways. However, in scheme 1-2, the arrival time information about the last PDU in the PDU set may only be applied to the downlink PDU set. For example, the arrival time information about the last PDU in the downlink PDU set may indicate at least one of the following: the time when the last PDU in the PDU set arrives at the source gNB from the CN node (e.g., UPF), which may be defined in absolute time or SFN timing; or the buffering time of the last PDU in the PDU set at the source RAN node.

[0153] Similarly, an exemplary SFN timing representing the time when the last PDU in the PDU set arrives at the source gNB from the CN node is the time difference from the initial SFN boundary (e.g., SFN=0). In the case where the SFN timing and time between the source gNB and the target gNB are not synchronized, the source gNB may send the SFN timing in the source gNB (i.e., the timing difference from the initial SFN boundary of the source gNB (e.g., SFN=0)) plus the SFN offset between the source gNB and the target gNB to the target gNB, or the source gNB may calculate the SFN timing of the target gNB based on the SFN offset between the source gNB and the target gNB (i.e., the timing difference from the initial SFN boundary of the source gNB (e.g., SFN=0)) and then send the SFN timing of the target gNB to the target gNB. An exemplary buffering time of the first PDU in the PDU set in the source gNB is how long the first PDU has been buffered in the source gNB before being sent by the source gNB. In some scenarios, the last PDU in the downlink PDU set may arrive at the source gNB during the execution of the handover or after the handover is completed, and the source gNB may indicate that the buffering time of the last PDU in the PDU set at the source RAN node is zero.

[0154] In addition, regarding the special scenario where the last PDU in the downlink PDU set may arrive at the source gNB during the execution of the handover or after the handover is completed, in addition to the above solution, the source gNB may also only indicate the third information to implicitly indicate that the entire AN PSDB will be used for data transmission of the PDU set, or transmit the third information and explicitly indicate that the entire AN PSDB will be used for data transmission of the PDU set. For example, a bit may be added in the user plane protocol from the source gNB to the target gNB to indicate that the entire AN PSDB will be used for data transmission of the PDU set.

[0155] The target gNB will first calculate the passed AN PSDB of the PDU set based on the arrival time information about the last PDU in the PDU set arriving at the source gNB, and then calculate the remaining AN PSDB of the PDU set based on the passed AN PSDB and the total AN PSDB determined according to the third information. The calculation of the passed AN PSDB and the remaining AN PSDB has been illustrated above and will not be repeated in this article.

[0156] According to some other embodiments of the present application (hereinafter, scheme 1-3), the source gNB will calculate the passed AN PSDB and transmit the second information by including the third information and the passed AN PSDB. Regarding the passed AN PSDB, it can be calculated based on the arrival time information about the first PDU in the PDU set as illustrated in scheme 1-1, or calculated based on the arrival time information about the last PDU in the PDU set as illustrated in scheme 1-2, and will not be repeated herein.

[0157] Similarly, the source gNB will transmit the second information as illustrated in Scheme 1-1 and Scheme 1-2, which is also omitted in detail. As illustrated above, the target gNB will calculate the remaining AN PSDB of the PDU set based on the passed AN PSDB and the total AN PSDB determined based on the third information, which will not be repeated in this article.

[0158] According to some other embodiments of the present application (hereinafter, Scheme 1-4), the source gNB will calculate the remaining AN PSDB of the PDU set and transmit the second information by including the remaining AN PSDB of the PDU set. As illustrated above, the remaining AN PSDB is calculated based on the passed AN PSDB and the AN PSDB determined based on the first information. Similarly, with respect to the passed AN PSDB, it can be calculated based on the arrival time information about the first PDU in the PDU set as illustrated in Scheme 1-1, or calculated based on the arrival time information about the last PDU in the PDU set as illustrated in Scheme 1-2, and will not be repeated herein. In addition, the second information can be transmitted as illustrated in Scheme 1-1 or Scheme 1-2, and will not be repeated.

[0159] In addition, as described above, in some scenarios, the second information may come from the source RAN node and the UE respectively, for example, the source RAN node only transmits the third information to the target RAN node to indicate the AN PSDB. The arrival time of the first PDU or the arrival time of the last PDU or the AN PSDB that has been passed, etc. may be transmitted by the UE to the target RAN node. In some other scenarios, the source RAN node may transmit the arrival time of the first PDU or the arrival time of the last PDU or the AN PSDB that has been passed, etc. to the target RAN node. The target node may obtain the third information from another device other than the UE.

[0160] Scenario II

[0161] According to some embodiments of the present application, the wireless communication device that transmits the second information (ie, information associated with the AN PSDB of the PDU set) to the target RAN node is a remote device, such as a UE. However, the PDU set can only be an uplink PDU set.

[0162] Figure 6 is a flowchart illustrating an exemplary procedure of a method of supporting delay budget handling according to some other embodiments of the present application.

[0163] refer to Figure 6 According to some embodiments of the present application, in step 601, the UE may receive first information from the network side (e.g., from a source gNB or a CN node (e.g., AMF)), i.e., information indicating an AN PSDB of a PDU set. For example, the UE may receive an AN PSDB of a PDU set or receive a CN PSDB and a total PSDB associated with a PDU set. In the case where the UE receives the CN PSDB and the total PSDB, the UE may calculate or determine the AN PSDB by subtracting the CN PSDB from the total PSDB.

[0164] In response to the handover during the data transmission of the PDU set, the data transmission of the remaining PDUs in the PDU set will be performed by the target RAN node instead of the source RAN node. In some scenarios, the source RAN node may include all PDUs in the PDU set. In scenario II, the network side may request the UE to report the second information, i.e., the information associated with the AN PSDB of the PDU set, to the target in response to the success of the handover (e.g., via a PDCP header or MAC CE or PDCP control PDU or RRC signaling) in step 603; so that the target RAN node may perform the data transmission of the PDU set based on at least the second information in step 605 to achieve more accurate QoS management and scheduling. For example, the UE may transmit the second information after the handover is successful in step 603a (e.g., in the handover command in step 603b or after the handover). An exemplary handover command is RRCRecofiguration with synchronization.

[0165] Similarly, more specific embodiments are illustrated in view of different second information.

[0166] According to some embodiments of the present application (hereinafter, Scheme 2-1), according to Definition 1, the second information may indicate the arrival time information about the first PDU in the PDU set and the third information, the third information indicating the AN PSDB. In response to the success of the handover (for example, after the handover is completed and / or after the handover), the arrival time information about the first PDU in the PDU set and the third information may be transmitted to the target gNB in ​​the same or different messages and / or signaling. In some scenarios, as described above, the second information may indicate the arrival time information about the first PDU in the PDU set, and the target RAN node may obtain the third information in other ways (for example, from the source RAN node).

[0167] The arrival time information about the first PDU in the PDU set may be defined in various ways, which are the same as or similar to the arrival time information about the first PDU in the uplink PDU set as illustrated in scheme 1-1.

[0168] For example, the arrival time information about the first PDU in the PDU set may indicate at least one of the following: the absolute time when the BSR for the transmission of the last PDU in the PDU set is received from the UE; the absolute time when the last PDU reported by the UE arrives at the AS layer; the absolute time when the last PDU is generated in the application layer reported by the UE; SFN timing, which indicates the time when the BSR for the transmission of the last PDU in the PDU set is received from the UE; SFN timing, which indicates the time when the last PDU reported by the UE arrives at the AS; SFN timing, which indicates the time when the last PDU reported by the UE is generated in the application layer; or the buffering time of the last PDU in the PDU set at the UE. In the case where the last PDU in the PDU set arrives at the UE later than receiving the handover command or during the execution of the handover or after the handover is completed, the second information may indicate that the entire AN PSDB will be used for the data transmission of the PDU set (for example, through a bit in the PDCP header), or indicate that the buffering time of the last PDU in the PDU set at the UE is zero.

[0169] Similar to Scheme 1-1, the target gNB will first calculate the passed AN PSDB of the PDU based on the arrival time information about the first PDU in the PDU set, and then calculate the remaining AN PSDB of the PDU set based on the passed AN PSDB and the total AN PSDB determined according to the third information.

[0170] According to some other embodiments of the present application (hereinafter, Scheme 2-2), according to Definition 2, the second information may indicate the arrival time information about the last PDU in the PDU set and the third information, the third information indicating the AN PSDB. Similarly, the arrival time information about the last PDU in the PDU set and the third information may be transmitted to the target gNB in ​​the same or different messages and / or signaling. In some scenarios, as described above, the second information from the UE may indicate the arrival time information about the last PDU in the PDU set, and the target RAN node may obtain the third information in other ways (e.g., from the source RAN node).

[0171] The arrival time information about the last PDU in the PDU set may be defined in various ways. For example, similar to the arrival time information about the first PDU in the uplink PDU set, the arrival time information about the last PDU in the PDU set may indicate at least one of the following: the absolute time when the BSR for the transmission of the last PDU in the PDU set is received from the UE; the absolute time when the last PDU reported by the UE arrives at the AS layer; the absolute time when the last PDU is generated in the application layer reported by the UE; SFN timing, which indicates the time when the BSR for the transmission of the last PDU in the PDU set is received from the UE; SFN timing, which indicates the time when the last PDU reported by the UE arrives at the AS; SFN timing, which indicates the time when the last PDU reported by the UE is generated in the application layer; or the buffering time of the last PDU in the PDU set at the UE. In some scenarios, the last PDU in the uplink PDU set may arrive at the UE later than receiving the handover command or during the execution of the handover or after the handover is completed, and the UE may indicate that the buffering time of the last PDU in the PDU set at the source RAN node is zero.

[0172] In addition, regarding the special scenario that the last PDU in the downlink PDU set may arrive at the UE later than receiving the handover command or during the execution of the handover or after the handover is completed, in addition to the above solution, the UE may also only indicate the third information to implicitly indicate that the entire AN PSDB will be used for data transmission of the PDU set, or transmit the third information and explicitly indicate that the entire AN PSDB will be used for data transmission of the PDU set. For example, compared with the traditional header from the UE to the target gNB, a bit may be added in the PDCP header to indicate that the entire AN PSDB will be used for data transmission of the PDU set.

[0173] Similar to Scheme 1-1, the target gNB will first calculate the passed AN PSDB of the PDU set based on the arrival time information about the last PDU in the PDU set, and then calculate the remaining AN PSDB of the PDU set based on the passed AN PSDB and the total AN PSDB determined according to the third information.

[0174] According to some other embodiments of the present application (hereinafter, Scheme 2-3), the UE will calculate the passed AN PSDB and transmit the second information by including the third information and the passed AN PSDB. Regarding the passed AN PSDB, it can be calculated based on the arrival time information about the first PDU in the PDU set as illustrated in Scheme 2-1, or calculated based on the arrival time information about the last PDU in the PDU set as illustrated in Scheme 2-2, and will not be repeated herein. The target gNB will calculate the remaining AN PSDB of the PDU set based on the passed AN PSDB and the total AN PSDB determined based on the third information. In some scenarios, the second information from the UE may indicate the passed AN PSDB, and the target RAN node may obtain the third information in other ways (for example, from the source RAN node).

[0175] According to some other embodiments of the present application (hereinafter, Scheme 2-4), the UE will calculate the remaining AN PSDB of the PDU set and transmit the second information by including the remaining AN PSDB of the PDU set. The remaining AN PSDB is calculated based on the passed AN PSDB and the AN PSDB determined according to the first information. Similarly, regarding the passed AN PSDB, it can be calculated based on the arrival time information about the first PDU in the PDU set as illustrated in Scheme 2-1, or calculated based on the arrival time information about the last PDU in the PDU set as illustrated in Scheme 2-2, and will not be repeated herein.

[0176] In addition to the method, an embodiment of the present application also proposes a device that supports delay budget handling. Figure 7 is a block diagram of a device supporting delay budget handling according to some embodiments of the present application.

[0177] refer to Figure 7 , the device 700 (e.g., UE or source RAN node or target RAN node) may include at least one processor 702 and at least one transceiver 704. The transceiver 704 may include at least one separate receiving circuit system 706 and transmitting circuit system 708, or at least one integrated receiving circuit system 706 and transmitting circuit system 708. The at least one processor 702 may be a CPU, a DSP, a microprocessor, etc.

[0178] According to some embodiments of the present application, when the device 700 is a target RAN node (e.g., a target gNB), the processor is configured to: receive information associated with an AN PSDB of a PDU set in response to a switch of the UE from a source RAN node to a RAN node; and perform data transmission of the PDU set based at least on the information associated with the AN PSDB.

[0179] According to some other embodiments of the present application, when the device 700 is a wireless communication device rather than a target RAN node (for example, a source gNB or UE), the processor may be configured to: receive first information indicating an AN PSDB of a PDU set; and in response to a switching of the UE occurring during data transmission of the PDU set, transmit second information associated with the AN PSDB of the PDU set based at least on the first information indicating the AN PSDB.

[0180] In another example, Figure 8 A block diagram of an apparatus 800 supporting delay budget handling according to some other embodiments of the present application is illustrated.

[0181] like Figure 8 , apparatus 800 may include at least one non-transitory computer-readable medium 801, at least one receiving circuit system 802, at least one transmitting circuit system 804, and at least one processor 806, the at least one processor being coupled to the non-transitory computer-readable medium 801, the receiving circuit system 802, and the transmitting circuit system 804. Apparatus 800 may be a target RAN node or UE or a source RAN node configured to perform the method illustrated above, etc.

[0182] Although in this figure, elements such as at least one processor 806, transmission circuit system 804, and receiving circuit system 802 are described in singular form, plural forms are also contemplated unless it is explicitly stated that they are limited to the singular form. In some embodiments of the present application, the receiving circuit system 802 and the transmitting circuit system 804 can be combined into a single device, such as a transceiver. The processor 806 can be a CPU, a DSP, a microprocessor, etc. In a specific embodiment of the present application, the device 800 may further include an input device, a memory, and / or other components.

[0183] In some embodiments of the present application, the non-transitory computer-readable medium 801 may store computer-executable instructions thereon to cause the processor 806 to implement the method described above with respect to the target RAN node (e.g., target gNB). For example, when the computer-executable instructions are executed, the processor 806 interacts with the receiving circuit system 802 and the transmitting circuit system 804 to perform the steps described above with respect to the target RAN node.

[0184] In some other embodiments of the present application, the non-transitory computer-readable medium 801 may store thereon computer-executable instructions to cause the processor to implement the method described above with respect to the source RAN node or UE. For example, when the computer-executable instructions are executed, the processor 806 interacts with the receiving circuit system 802 and the transmitting circuit system 804 to perform the steps described above with respect to the source RAN node or UE.

[0185] The method according to the embodiment of the present application may also be implemented on a programmed processor. However, the controller, flow chart and module may also be implemented on a general or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit (e.g., a discrete element circuit, a programmable logic device), etc. In general, any device capable of implementing the flow chart shown in the figure may be used to implement the processor function of the present application. For example, an embodiment of the present application provides a device including a processor and a memory. Computer programmable instructions for implementing the method are stored in a memory, and the processor is configured to execute computer programmable instructions to implement the method. The method may be the method as described above or other methods according to the embodiment of the present application.

[0186] Alternative embodiments preferably implement the method according to the embodiment of the present application in a non-transitory computer-readable storage medium storing computer programmable instructions. The instructions are preferably executed by a computer executable component preferably integrated with a network security system. The non-transitory computer readable storage medium may be stored on any suitable computer readable medium, such as RAM, ROM, flash memory, EEPROM, optical storage device (CD or DVD), hard drive, floppy disk drive, or any suitable device. The computer executable component is preferably a processor, but the instructions may be executed alternatively or additionally by any suitable dedicated hardware device. For example, an embodiment of the present application provides a non-transitory computer readable storage medium having computer programmable instructions stored therein. The computer programmable instructions are configured to implement the method as described above or other methods according to the embodiment of the present application.

[0187] Although the present application has been described using its specific embodiments, it is apparent that many alternatives, modifications and variations are apparent to those skilled in the art. For example, the various components of the embodiments may be interchanged, added or replaced in other embodiments. In addition, not all elements of each figure are necessary for the operation of the disclosed embodiments. For example, those skilled in the art of the disclosed embodiments will be able to make and use the teachings of the present application by simply adopting the elements of the independent technical solutions. Therefore, the embodiments of the applications as set forth herein are intended to be illustrative, not restrictive. Various changes may be made without departing from the spirit and scope of the present application.

Claims

1. A radio access network RAN ​​node, comprising: Transceiver; as well as a processor coupled to the transceiver, wherein the processor is configured to cooperate with the transceiver to: receiving information associated with an access network AN PDU set delay budget PSDB AN PSDB of a set of protocol data units PDUs in response to a handover of a user equipment UE from a source RAN node to said RAN node; and Data transmission of the set of PDUs is performed based at least on the information associated with the AN PSDB.

2. The RAN node according to claim 1, wherein: The AN PSDB is the difference between the time when the first PDU in a downlink PDU set arrives at the RAN node and the time when the last PDU or all PDUs in the downlink PDU set are successfully delivered to the UE, or the difference between the time when the first PDU in an uplink PDU set is processed at the UE and the time when the last PDU or all PDUs in the uplink PDU set are successfully transmitted from the UE.

3. The RAN node according to claim 2, wherein: The information associated with the AN PSDB indicates arrival time information about the first PDU in the PDU set and AN PSDB information, the AN PSDB information indicating the AN PSDB, and the processor is configured to: calculating a remainder of the AN PSDB based on the arrival time information about the first PDU in the PDU set and the AN PSDB information; and The remaining portion of the AN PSDB is used for data transmission of the remaining PDUs in the PDU set.

4. The RAN node according to claim 1, wherein: The information associated with the AN PSDB indicates AN PSDB information and a passed portion of the AN PSDB, the AN PSDB information indicating the AN PSDB, and the processor is configured to: calculating a remaining portion of the ANPSDB based on the ANPSDB information and the passed portion of the ANPSDB; and The remaining portion of the AN PSDB is used for data transmission of the remaining PDUs in the PDU set.

5. The RAN node according to claim 1, wherein: The information associated with the AN PSDB indicates a remaining portion of the AN PSDB for the set of PDUs, and the processor is configured to: The remaining portion of the AN PSDB is used for data transmission of the remaining PDUs in the PDU set.

6. The RAN node according to claim 1, wherein: The information associated with the AN PSDB is received from the source RAN node during the handover via at least one of: Signaling of handover request; Signaling transmitted by sequence number SN status; a user plane protocol carried by a user plane General Packet Radio Service (GPRS) Tunneling Protocol (GTP-U) extension header; or Switch the source to the target transparent container in the relevant signaling.

7. The RAN node according to claim 1, wherein: In response to the success of the handover, the information associated with the AN PSDB is received from the UE via a Packet Data Convergence Protocol (PDCP) header or a Medium Access Control (MAC) Control Element (CE) or a PDCP Control PDU or a Radio Resource Control (RRC) signaling.

8. A wireless communication device, comprising: Transceiver; as well as a processor coupled to the transceiver, wherein the processor is configured to cooperate with the transceiver to: receiving first information indicating an access network AN PDU set delay budget PSDBAN PSDB of a protocol data unit PDU set; and In response to a handover of a user equipment UE occurring during data transmission of the PDU set, second information associated with the AN PSDB of the PDU set is transmitted based on at least the first information indicating the AN PSDB.

9. The wireless communication device according to claim 8, wherein: The AN PSDB is the difference between the time when the first PDU in a downlink PDU set arrives at the RAN node and the time when the last PDU or all PDUs in the downlink PDU set are successfully delivered to the UE, or the difference between the time when the first PDU in an uplink PDU set is processed at the UE and the time when the last PDU or all PDUs in the uplink PDU set are successfully transmitted from the UE.

10. The wireless communication device according to claim 9, wherein: The second information associated with the AN PSDB indicates arrival time information about the first PDU in the PDU set and third information, the third information indicating the AN PSDB.

11. The wireless communication device according to claim 9, wherein: The second information associated with the AN PSDB indicates third information and a passed portion of the AN PSDB, the third information indicating the AN PSDB, and the processor is configured to: The passed portion of the ANPSDB is calculated based on arrival time information about the first PDU in the PDU set.

12. The wireless communication device according to claim 9, wherein: The second information associated with the AN PSDB indicates a remaining portion of the AN PSDB for the set of PDUs, and the processor is configured to: calculating a passed portion of the ANPSDB based on arrival time information about the first PDU in the PDU set; and The remaining portion of the AN PSDB is calculated based on the passed portion of the AN PSDB and the first information indicative of the AN PSDB.

13. The wireless communication device according to claim 8, wherein: The wireless communication device is a source radio access network RAN ​​node of the UE, and the second information associated with the AN PSDB is transmitted during the handover via at least one of: Signaling of handover request; Signaling transmitted by sequence number SN status; a user plane protocol carried by a user plane General Packet Radio Service (GPRS) Tunneling Protocol (GTP-U) extension header; or Switch the source to the target transparent container in the relevant signaling.

14. A method comprising: receiving information associated with an access network AN PDU set delay budget PSDB AN PSDB of a set of protocol data units PDUs in response to a handover of a user equipment UE from a source RAN node to a RAN node; and Data transmission of the set of PDUs is performed based at least on the information associated with the AN PSDB.

15. A method comprising: Receiving first information indicating an access network AN PDU set delay budget PSDB ANPSDB of a set of protocol data units PDUs; and In response to a handover of a user equipment UE occurring during data transmission of the PDU set, second information associated with the AN PSDB of the PDU set is transmitted based on at least the first information indicating the AN PSDB.

Images