5GSM congestion timer processing method and user equipment
By stopping and starting the corresponding congestion timer according to the received 5GSM message type in the 5GSM system, the complex problem of timer management in the prior art is solved, and more stable and efficient system operations are achieved.
Patent Information
- Application Number
- CN202111134593.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2021-09-14
- Filing Date
- 2021-09-27
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2041-09-27
AI Technical Summary
In 5G mobile communication systems, the prior art fails to clarify how to stop S-NSSAI-based congestion timers, especially when receiving different types of 5GSM messages, resulting in complex timer management and lack of standardized processing flows.
It is recommended that the user equipment (UE) stop the backoff timer applied to all PLMNs and registered PLMNs when receiving a specific type of 5GSM message, and start a new timer based on the timer value carried in the new 5GSM message.
Through standardized processing flow, the UE can effectively manage and stop the running congestion timer, ensuring the correct application and switching of the timer in different scenarios, improving the stability and efficiency of the system.
Smart Images
Figure CN114302447B_ABST
Abstract
Description
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] This application claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 63 / 089,067, filed on October 8, 2020, and entitled “Handling of Stopping 5GSM Congestion Timers,” the subject matter of which is incorporated herein by reference. Technical Field
[0003] The disclosed embodiments relate generally to wireless communications, and more particularly to methods for supporting the processing of 5G session management (5GSM) congestion timers in next generation 5G mobile communication systems. Background Art
[0004] Wireless communication networks have grown exponentially over the years. Long-Term Evolution (LTE) systems offer high peak data rates, low latency, improved system capacity, and low operating costs due to simplified network architecture. LTE systems, also known as 4G systems, also provide seamless integration with older wireless networks such as GSM, CDMA, and Universal Mobile Telecommunication System (UMTS). In LTE systems, the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) includes multiple evolved Node-Bs (eNodeB / eNB) that communicate with multiple mobile stations (called User Equipment (UE)). The 3rd Generation Partner Project (3GPP) network typically includes a mix of 2G / 3G / 4G systems. As network design is optimized, many improvements have been developed in the evolution of various standards. The Next Generation Mobile Network (NGMN) committee has decided to focus future NGMN activities on defining the end-to-end requirements for 5G New Radio (NR) systems.
[0005] In 5GS, a congestion control mechanism based on Single-Network Slice Selection Assistance Information (S-NSSAI) is introduced. When one or more S-NSSAI congestion criteria are met, the network can detect and start performing S-NSSAI-based congestion control. The network will provide a "5GSM Congestion Retry Indicator" to indicate whether the corresponding back-off (BO) timer is applied to all public land mobile networks (PLMNs) or only to registered PLMNs. However, the "5GSM Congestion Retry Indicator" is an optional information element (IE). When 1) a timer value and a "5GSM Congestion Retry Indicator" are provided, 2) only a timer value is provided, 3) neither a timer value nor a "5GSM Congestion Retry Indicator" is provided, and 4) only a "5GSM Congestion Retry Indicator" is provided, it is not defined which or which running back-off timers should be stopped. Furthermore, it is not defined how the UE should stop the running S-NSSAI based congestion timer when the UE receives a network requested PDU Session procedure.
[0006] Find a solution. Summary of the invention
[0007] In 5GS, based on the 5GSM congestion retry indicator, the S-NSSAI based BO timer (T3584 / T3585) can be applied to the registered PLMN or all PLMNs. For a specific PDU session, the corresponding BO timer applied to the registered PLMN and the BO timer applied to all PLMNs can run simultaneously. It is recommended that the UE stop the BO timer applied to all PLMNs and the BO timer applied to the registered PLMN (if running) in all the following scenarios: 1) receiving a PDU session release command without a BO timer, 2) receiving a PDU session release command with 5GSM cause #39, 3) receiving a PDU session modification command, 4) receiving a 5GSM message with a 5GSM congestion control BO timer value, and 5) receiving a PDU session authentication command.
[0008] In one embodiment, a UE receives a 5GSM message in a mobile communication network. The UE registers to a PLMN. The UE determines whether a BO timer is running. The running BO timer applies to all PLMNs or to the registered PLMN. The UE stops the running BO timer in response to a 5GSM message, wherein the 5GSM message is one of a PDU session release command without a backoff timer, a PDU session release command with a 5GSM cause #39, a PDU session modification command, a PDU session authentication command, and a 5GSM message with a 5GSM congestion control backoff timer value. After the running BO timer stops, the UE starts a new BO timer according to the 5GSM message providing the BO timer with the network.
[0009] In another embodiment, a UE receives a first 5GSM message in a mobile communication network. The UE registers to a first PLMN. The UE starts a first BO timer according to a first BO timer value carried in the first 5GSM message. The first BO timer is applied to a first PLMN type. The UE receives a second 5GSM message through the UE and stops the first BO timer in response. The UE starts a new BO timer according to a second BO timer value carried in the second 5GSM message. The new BO timer is applied to a second PLMN type, and the first PLMN type and the second PLMN type are different.
[0010] Other embodiments and advantages are described in the detailed description that follows. This summary is not intended to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings illustrate embodiments of the present invention, wherein like numerals refer to like parts.
[0012] Figure 1 An exemplary 5G NR network supporting processing of a 5GSM congestion timer according to one novel aspect is illustrated.
[0013] Figure 2 A simplified block diagram of a wireless device according to an embodiment of the present invention is illustrated.
[0014] Figure 3 The 5GSM Congestion Retry Indicator Information Element IE is illustrated.
[0015] Figure 4 A method of handling a backoff timer under S-NSSAI based congestion control when a 5GSM message is received from the network is illustrated.
[0016] Figure 5 A first embodiment of stopping an existing BO timer based on a later received 5GSM message according to one novel aspect is shown.
[0017] Figure 6 A second embodiment of stopping an existing BO timer based on a later received 5GSM message according to one novel aspect is shown.
[0018] Figure 7 is a flow chart of a method for handling backoff timers under S-NSSAI based congestion control when receiving a 5GSM message according to one novel aspect.
[0019] Figure 8 is a flow chart of another method for handling backoff timers under S-NSSAI based congestion control when receiving a 5GSM message according to one novel aspect. DETAILED DESCRIPTION
[0020] Reference will now be made in detail to some embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0021] Figure 1 An exemplary 5G NR network 100 supporting the processing of a 5GSM congestion timer according to one novel aspect is illustrated. The 5G / NR network 100 includes an application server 111 that provides various services by communicating with a plurality of UEs including a UE 114. Figure 1 In the example of , the application server 111 is part of the Core Network (CN) 110. UE 114 and its serving base station BS 115 are part of the Radio Access Network (RAN) 120. RAN 120 provides radio access for UE 114 via Radio Access Technology (RAT). The application server 111 communicates with UE 114 via User Plane Function (UPF) 116 and BS 115. The Access and Mobility Management Function (AMF) 117 communicates with BS 115, Session Management Function (SMF) 118 and UPF 116 for access and mobility management of wireless access devices in the 5G / NR network 100. Figure 1In the example of , AMF 117, SMF 118 and UPF 116 also belong to CN 110. UE 114 can be equipped with a Radio Frequency (RF) transceiver or multiple RF transceivers for different application services through different RAT / CN. UE 114 can be a smartphone, a wearable device, an Internet of Things (IoT) device, a tablet computer, etc.
[0022] In 5GS, a congestion control mechanism based on S-NSSAI is introduced. On the UE side, the 5GS session management timer T3584 for congestion control based on S-NSSAI is started and stopped on the basis of each S-NSSAI, Data Network Name (DNN) and PLMN, and the 5GS session management timer T3585 for congestion control based on S-NSSAI is started and stopped on the basis of each S-NSSAI and PLMN. As shown in 140, if the 5GSM message includes a 5GSM congestion retry indicator IE set to "Apply backoff timer in all PLMNs", the UE applies timer T3584 / T3585 to all PLMNs. Otherwise, the UE applies timer T3584 / T3585 for the registered PLMN.
[0023] However, "5GSM Congestion Retry Indicator" is an optional IE. It is not defined which or which running back-off timers should be stopped when 1) a timer value and "5GSM Congestion Retry Indication" are provided, 2) only a timer value is provided, 3) neither a timer value nor a "5GSM Congestion Retry Indication" is provided, and 4) only a "5GSM Congestion Retry Indication" is provided. In addition, it is not defined how the UE should stop the running S-NSSAI based congestion timer when the UE receives a network requested PDU session process. According to a novel aspect, it is recommended that the UE stop the BO timer (if running) applied to all PLMNs and the BO timer (if running) applied to the registered PLMN in all of the following cases (as shown in 130): 1) receiving a PDU session release command without a BO timer, 2) receiving a PDU session release command with 5GSM cause #39, 3) receiving a PDU session modification command, 4) receiving a 5GSM message with a 5GSM congestion control BO timer value, and 5) receiving a PDU session authentication command from the network.
[0024] Figure 2A simplified block diagram of a wireless device (e.g., UE 201 and network entity 211) according to an embodiment of the present invention is shown. The network entity 211 can be a base station combined with an AMF. The network entity 211 has an antenna 215 for sending and receiving radio signals. The RF transceiver 214 is coupled to the antenna 215, receives RF signals from the antenna 215, converts them into baseband signals and sends the baseband signals to the processor 213. The RF transceiver 214 also converts the baseband signals received from the processor 213 into RF signals and sends them to the antenna 215. The processor 213 processes the received baseband signals and calls different functional modules to perform features in the network entity 211. The memory 212 includes volatile computer-readable storage media and non-volatile computer-readable storage media, storing program instructions and data 220 to control the operation of the network entity 211. In Figure 2 In the example of , the network entity 211 also includes a set of control function modules and circuits 290. The PDU session processing circuit 231 processes the PDU session establishment, modification, release, and authentication and authorization process. The congestion control processing circuit 232 processes the backoff timer for congestion control. The configuration and control circuit 233 provides different parameters to configure and control the UE 201.
[0025] Similarly, UE 201 has a memory 202, a processor 203, and an RF transceiver 204. The RF transceiver 204 is coupled to an antenna 205, receives RF signals from the antenna 205, converts them to baseband signals, and sends the baseband signals to the processor 203. The RF transceiver 204 also converts the baseband signals received from the processor 203, converts them to RF signals, and sends them to the antenna 205. The processor 203 processes the received baseband signals and calls different functional modules and circuits to perform features in the UE 201. The memory 202 includes volatile computer-readable storage media and non-volatile computer-readable storage media, and stores program instructions and data 210 executed by the processor 203 to control the operation of the UE 201. Suitable processors include, for example, dedicated processors, digital signal processors (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) and other types of integrated circuits (IC). A processor associated with software can be used to implement and configure features of UE 201.
[0026] UE 201 also includes a set of functional modules and control circuits to perform the functional tasks of UE 201. The protocol stack 260 includes a non-access layer (NAS) layer to communicate with the AMF and / or SMF in the core network, a radio resource control (RRC) layer for high-level configuration and control, a packet data convergence protocol / radio link control (PDCP / RLC) layer, a media access control (MAC) layer, and a physical (PHY) layer. The system modules and circuits 270 can be implemented and configured by software, firmware, hardware, and / or a combination thereof. The functional modules and circuits cooperate with each other when executed by the processor 203 via program instructions contained in the memory 202 to allow UE 201 to perform embodiments and functional tasks and features in the mobile communication network. In one example, the PDU session processing circuit 221 handles PDU session establishment, modification, release, and authentication and authorization processes. The congestion control processing circuit 222 processes a back-off timer for congestion control. The configuration and control circuit 223 processes the configuration and control of the UE 201 .
[0027] Figure 3 The 5GSM congestion retry indicator information element IE 300 is illustrated. In 5GS, a congestion control mechanism based on S-NSSAI is introduced. On the UE side, the 5GS session management timer T3584 for congestion control based on S-NSSAI is started and stopped on the basis of each S-NSSAI, DNN and PLMN, and the 5GS session management timer T3585 for congestion control based on S-NSSAI is started and stopped on the basis of each S-NSSAI and PLMN. The purpose of the retry indicator information element is to indicate the conditions under which the UE is allowed to retry the session management process corresponding to the 5GS session management process rejected by the network in the current PLMN or an equivalent PLMN of the same DNN. The purpose of the 5GSM congestion retry indication information element is to indicate whether the backoff timer is applied to the registered PLMN or all PLMNs. Specifically, the network will provide a "5GSM congestion retry indicator", such as an ABO bit, to indicate whether the corresponding BO timer is applied to all PLMNs or registered PLMNs. However, the "5GSM congestion retry indicator" is an optional IE. The network may or may not provide a BO timer value and / or a corresponding 5GSM congestion retry indicator.
[0028] In the UE, the 5GS session management timer T3584 for S-NSSAI based congestion control is started and stopped on a per S-NSSAI, DNN and PLMN basis. If the 5GSM Congestion Retry Indicator IE set to "Apply backoff timer in all PLMNs" is included in a 5GSM message with 5GSM cause value #67 "Insufficient resources for specific slices and DNNs", the UE applies timer T3584 for all PLMNs. Otherwise, the UE applies timer T3584 for the registered PLMN. If timer T3584 applies to all PLMNs, timer T3584 is started when the UE is registered in the VPLMN and the S-NSSAI is provided by the UE during PDU session establishment, and timer T3584 is associated with the [mapped S-NSSAI, DNN] combination of the PDU session.
[0029] In the UE, the 5GS session management timer T3585 for S-NSSAI based congestion control is started and stopped on a per S-NSSAI and PLMN basis. If the 5GSM Congestion Retry Indicator IE set to "Apply backoff timer in all PLMNs" is included in a 5GSM message with 5GSM cause value #69 "Insufficient resources for a particular slice", the UE applies timer T3585 for all PLMNs. Otherwise, the UE applies timer T3585 for the registered PLMN. If timer T3585 applies to all PLMNs, timer T3585 is started when the UE is registered in the VPLMN and the S-NSSAI is provided by the UE during PDU session establishment, and timer T3585 is associated with the mapped S-NSSAI of the PDU session.
[0030] Figure 4A method for handling a backoff timer under S-NSSAI based congestion control when a 5GSM message is received from the network is illustrated, with or without a BO timer value and / or a 5GSM congestion retry indicator. In 5G / NR, a Protocol Data Unit (PDU) session defines an association between a UE 401 and a data network 402 that provides a PDU connection service. Each PDU session has information including an SSC mode, a service NSSAI, a DNN, a PDU session type, an access type, a PDU address, and a PDU session ID (PSI). In step 411, the UE 401 establishes one or more PDU sessions with the network. In step 421, in certain scenarios of congestion control, the UE 401 starts a timer T3585 or T3584 for S-NSSAI based congestion control on a per S-NSSAI, PLMN (and DNN) basis. The network will provide a “5GSM Congestion Retry Indicator” to indicate whether the corresponding BO timer applies to all PLMNs or to the registered PLMN.
[0031] In step 431, UE 401 receives a 5GSM message from the network, which triggers the processing of congestion control and BO timer control. UE 401 may receive one of the following 5GSM messages: 1) receiving a PDU session release command without a BO timer (431a), 2) receiving a PDU session release command with a 5GSM cause #39 (431b), 3) receiving a PDU session modification command (431c), 4) receiving a 5GSM message with a 5GSM congestion control BO timer value (431d), and 5) receiving a PDU session authentication command (431e). This 5GSM message triggers the processing of an existing BO timer and the start of a new BO timer. Note that for a specific PDU session, the corresponding BO timer applied to the registered PLMN and the BO timer applied to all PLMNs may run simultaneously (e.g., in step 421). In one novel aspect, in step 441, if operating in all the above scenarios, the UE 401 stops the BO timer applied to all PLMNs and the BO timer applied to the registered PLMN before a new BO timer is started.
[0032] The 5GSM message may not include a BO timer value or a "5GSM congestion retry indicator". In the first example, when both a timer value and a "5GSM congestion retry indicator" are provided in the 5GSM message, the UE stops the existing running timers (if any), including the BO timer applied to all PLMNs and the BO timer applied to the registered PLMN, before starting a new BO timer. In the second example, when only a timer value is provided in the 5GSM message (but no "5GSM congestion retry indicator"), the UE stops the existing running timers (if any), including the BO timer applied to all PLMNs and the BO timer applied to the registered PLMN, before starting a new BO timer. In the third example, when neither a timer value nor a "5GSM congestion retry indicator" is provided in the 5GSM message (such as a PDU session release command), the UE stops the existing running timers (if any), including the BO timer applied to all PLMNs and the BO timer applied to the registered PLMN. In the fourth example, when only a 5GSM congestion retry indicator (but no "timer value") is provided in the 5GSM message, the UE stops the existing running timers (if any), including both the BO timer applied to all PLMNs and the BO timer applied to the registered PLMN, before starting a new BO timer.
[0033] Figure 5A first embodiment of stopping an existing BO timer based on a later received 5GSM message according to a novel aspect is shown. In step 511, UE 501 establishes a first PDU session 1 with network 502 having parameters PSI=1, DNN1 and in S-NSSAI1. In step 512, UE 501 establishes a second PDU session 2 with a network having parameters PSI=2, DNN2 and in the same S-NSSAI1. In step 521, UE 501 sends a PDU session modification request message to add a new QoS flow for PDU session 1. In step 522, due to slice congestion, the network rejects the request and sends a PDU session modification reject message to UE 501. The reject message carries 5GSM cause #69, BO timer value and ABO=all PLMNs. In response to the reject message, in step 523, UE 501 starts a BO timer (e.g., T3585) associated with S-NSSAI1 applied to all PLMNs. In step 531, the network releases PDU Session 2 by sending a PDU Session Release Command. The release message carries 5GSM cause #69, BO timer value and ABO=RPLMN (registered PLMN). In step 532, UE 501 sends a PDU Session Release Complete message to the network. In addition, in response to the PDU Session Release Command, UE 501 needs to start another new BO timer (e.g., T3585) associated with S-NSSAI1 applied to RPLMN.
[0034] The PDU Session Release Command is a second 5GSM message for PDU Session 2 in the same S-NSSAI1, which triggers S-NSSAI based congestion control and BO timer processing. Before starting a new BO timer, in step 541, UE 501 stops the running BO timer applied to all PLMNs. In step 542, UE 501 starts a new BO timer (e.g., according to the BO timer value) based on the 5GSM message received in step 531 and applies it to RPLMN. In step 551, UE 501 moves to another new PLMN. Since the new BO timer is only applied to RPLMN, it is not applied to the new PLMN. Therefore, in step 552, UE 501 is allowed to resend a PDU Session Modification Request message to the network (adding a new QoS flow for PDU Session 1, as in step 521). In step 553, UE 501 receives a PDU Session Modification Command message from the network. In step 554, UE 501 sends a PDU Session Modification Complete message to the network.
[0035] Note that before UE 501 receives the 5GSM message in step 531, UE 501 already has an existing BO timer associated with S-NSSAI1 running, and the running BO timer applies to all PLMNs. After receiving the 5GSM message in step 531, UE 501 stops the running BO timer, regardless of whether the 5GSM message carries a new BO timer value and a "5GSM congestion retry indicator". For example, when the running BO timer is used for all PLMNs and the new BO timer is used for RPLMN (different PLMN type), the running BO timer needs to be stopped before the new BO timer is started. In addition, if two BO timers are running and both BO timers apply to all PLMNs and RPLMN, both BO timers need to be stopped. Also note that although Figure 5 The method is for 5GSM reason #69 and BO timer T3585, but the same method can be applied to 5GSM reason #67 and BO timer T3584.
[0036] Figure 6 A second embodiment of stopping an existing BO timer based on a later received 5GSM message according to a novel aspect is shown. In step 611, UE 601 registers to a first PLMN (VPLMN1). In step 612, UE 601 establishes PDU Session 1 with the network with parameters PSI=1, DNN1 and in S-NSSAI1. In step 613, UE 601 sends a PDU Session Modification Request message to add a new QoS flow for PDU Session 1. In step 614, due to slice congestion, the network rejects the request and sends a PDU Session Modification Reject message to UE 601. The reject message carries 5GSM cause #69, BO timer value and ABO=RPLMN. In response to the reject message, in step 615, UE 601 starts a BO timer (e.g., T3585) associated with S-NSSAI1 applied to RPLMN (VPLMN1). In step 621, UE 601 registers to another PLMN (VPLMN2). Because the BO timer is only applied to VPLMN1, in step 622, UE 601 is allowed to send a second PDU session modification request message to add a new QoS flow for PDU session 1. In step 623, due to slice congestion, the network rejects the request and sends a second PDU session modification reject message to UE 601. The second PDU session modification reject message carries 5GSM cause #69, BO timer value and ABO=RPLMN. In response to the reject message, UE 601 needs to start a new BO timer (e.g., T3585) associated with S-NSSAI1 applied to RPLMN (VPLMN2).
[0037] The second PDU session modification reject message is for PDU session 1 in the same S-NSSAI1, which triggers S-NSSAI based congestion control and BO timer processing. Before starting a new BO timer, in step 641, UE 601 stops the running BO timer applied to VPLMN1. In step 642, UE 601 starts a new BO timer (e.g., according to the BO timer value) based on the 5GSM message received in step 623 and applies it to RPLMN (VPLMN2). In step 651, UE 601 moves back to VPLMN1. Since the new BO timer is only applied to VPLMN2 and not to VPLMN1. Therefore, in step 652, UE 601 is allowed to resend the PDU session modification request message to the network (adding a new QoS flow for PDU session 1, as in step 613). In step 653, UE 601 receives a PDU session modification command message from the network. In step 654, UE 601 sends a PDU session modification complete message to the network.
[0038] Note that before UE 601 receives the 5GSM message in step 623, UE 601 already has an existing BO timer associated with S-NSSAI1 running, and the running BO timer is applied to VPLMN1. After receiving the 5GSM message in step 623, UE 601 stops the running BO timer, regardless of whether the 5GSM message carries a new BO timer value and a "5GSM congestion retry indicator". For example, when the running BO timer is for VPLMN1 and the new BO timer is for VPLMN2 (different PLMN but same RPLMN type), the running BO timer needs to be stopped before the new BO timer is started. In addition, if two BO timers are running and both BO timers are applied to all PLMNs and RPLMNs, both BO timers need to be stopped. Also note that although Figure 6 The method is for 5GSM reason #69 and BO timer T3585, but the same method can be applied to 5GSM reason #67 and BO timer T3584.
[0039] Figure 7The present invention is a flowchart of a method for processing a backoff timer under S-NSSAI-based congestion control when receiving a 5GSM message according to a novel aspect. In step 701, the UE receives a 5GSM message in a mobile communication network. The UE is registered to a PLMN. In step 702, the UE determines whether a BO timer is running, wherein the running BO timer is applied to all PLMNs or to the registered PLMN. In step 703, the UE stops the running BO timer in response to a 5GSM message, wherein the 5GSM message belongs to one of a PDU session release command without a backoff timer, a PDU session release command with 5GSM cause #39, a PDU session modification command, a PDU session authentication command, and a 5GSM message with a 5GSM congestion control backoff timer value. In step 704, after the running BO timer stops, the UE starts a new BO timer according to the 5GSM message in which the network provides the BO timer.
[0040] Figure 8 801 is a flowchart of another method for handling a backoff timer under S-NSSAI based congestion control with or without a BO timer value and / or a 5GSM congestion retry indicator according to a novel aspect. In step 801, a UE receives a first 5GSM message in a mobile communication network. The UE is registered to a first PLMN. In step 802, the UE starts a first BO timer based on a first BO timer value carried in the first 5GSM message. The first BO timer is applied to a first PLMN type. In step 803, the UE receives a second 5GSM message by the UE and stops the first BO timer in response. In step 804, the UE starts a new BO timer based on a second BO timer value carried in the second 5GSM message. The new BO timer is applied to a second PLMN type, and the first PLMN type and the second PLMN type are different.
[0041] Although the present invention has been described in conjunction with certain specific embodiments for teaching purposes, the present invention is not limited thereto. Therefore, various modifications, adaptations and combinations of the various features of the described embodiments may be practiced without departing from the scope of the present invention as set forth in the claims.
Claims
1. A method for processing a 5G session management congestion timer, comprising: receiving, by a user equipment in a mobile communications network, a 5G session management message, wherein the user equipment is registered to a public land mobile network; determining whether a back-off timer is running, wherein the running back-off timer applies to all public land mobile networks or applies to a registered public land mobile network; In response to the 5G session management message, stop the running back-off timer; as well as After the running back-off timer stops, starting the new back-off timer according to a 5G session management message in which the network provides a new back-off timer, wherein the new back-off timer and the running back-off timer correspond to different public land mobile network types.
2. The method according to claim 1, characterized in that The 5G session management message includes a 5G session management congestion retry indicator.
3. The method according to claim 2, characterized in that The 5G session management congestion retry indicator indicates that the new back-off timer applies to all public land mobile networks or to the registered public land mobile network.
4. The method according to claim 1, characterized in that The running back-off timer and the new back-off timer are associated with the single network slice selection assistance information, or are associated with the same combination of the single network slice selection assistance information and the data network name.
5. The method according to claim 1, characterized in that When the 5G session management message does not include a 5G session management congestion retry indicator, the user equipment stops the running back-off timer.
6. A user equipment for 5G session management congestion timer processing, comprising: a transceiver for receiving a 5G session management message in a mobile communications network, wherein the user equipment is registered to a public land mobile network; a congestion control processing circuit configured to determine whether a back-off timer is running, wherein the running back-off timer applies to all public land mobile networks or applies to registered public land mobile networks, wherein The congestion control processing circuit stops the running back-off timer in response to the 5G session management message; as well as A new back-off timer is used to start after the running back-off timer stops according to a 5G session management message of the new back-off timer provided by the network, wherein the new back-off timer and the running back-off timer correspond to different public land mobile network types.
7. The user equipment according to claim 6, characterized in that The 5G session management message includes a 5G session management congestion retry indicator.
8. The user equipment according to claim 7, characterized in that The 5G session management congestion retry indicator indicates that the new back-off timer is applied to all public land mobile networks or to the registered public land mobile network.
9. The user equipment according to claim 6, characterized in that The running back-off timer and the new back-off timer are associated with the single network slice selection assistance information, or are associated with the same combination of the single network slice selection assistance information and the data network name.
10. The user equipment according to claim 6, characterized in that When the 5G session management message does not include a 5G session management congestion retry indicator, the user equipment stops the running back-off timer.
11. A method for processing a 5G session management congestion timer, comprising: receiving, by a user equipment in a mobile communications network, a first 5G session management message, wherein the user equipment is registered to a first public land mobile network; Starting a first back-off timer based on a first back-off timer value carried in the first 5G session management message, wherein the first back-off timer is applied to a first public land mobile network type; receiving, by the user equipment, a second 5G session management message and stopping the first backoff timer in response; as well as A new back-off timer is started based on a second back-off timer value carried in a second 5G session management message, wherein the new back-off timer is applied to a second public land mobile network type, wherein the first public land mobile network type and the second public land mobile network type are different, and the second 5G session management message carries a 5G session management congestion retry indicator indicating the second public land mobile network type.
12. The method according to claim 11, characterized in that The second 5G session management message is one of a protocol data unit session release command and a protocol data unit session modification rejection.
13. The method according to claim 11, characterized in that The second 5G session management message does not include a 5G session management congestion retry indicator.
14. The method according to claim 11, characterized in that The first public land mobile network type is all public land mobile networks and the second public land mobile network type is registered public land mobile networks, or the first public land mobile network type is registered public land mobile networks and the second public land mobile network type is all public land mobile networks.
15. The method according to claim 11, characterized in that When the user equipment receives the second 5G session management message, the user equipment is registered to the second public land mobile network.
16. A non-volatile computer-readable storage medium storing program instructions and data, which, when executed by a processor of a user device for 5G session management congestion timer processing, enables the user device to perform the operations described in any one of the methods of claims 1-5 and 11-15 above.