Method and system for releasing a pdu session

Abstract

The disclosure relates to a method and a UE for releasing a PDU session. The UE identifies that the UE is in a restricted service area. Upon identifying that the UE is in the restricted service area, the UE releases a PTI allocated by the UE, and performs a local release of a PDU session. In addition, the UE provides information related to the PDU session to the network based on a subsequent trigger of a registration procedure.

Description

Technical Field

[0001] This disclosure generally relates to the field of network communications, and more specifically, but not exclusively, to methods and apparatus for releasing packet data unit (PDU) sessions. Background Technology

[0002] 5G mobile communication technology defines a wide frequency band to enable high transmission rates and new services. It can be implemented not only in "sub-6GHz" bands such as 3.5GHz, but also in "above 6GHz" bands, known as millimeter wave (mmWave), including 28GHz and 39GHz. Furthermore, 6G mobile communication technology (referred to as "super 5G systems") is being considered in terahertz bands (e.g., the 95GHz to 3THz band), achieving transmission rates up to 50 times faster than 5G and ultra-low latency only one-tenth that of 5G.

[0003] In the early stages of 5G mobile communication technology development, to support services and meet the performance requirements associated with enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC), the following technologies have been continuously standardized: beamforming and massive MIMO for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves; dynamic operation supporting parametrics (e.g., operating multiple subcarrier spacings) to efficiently utilize millimeter wave resources and time slot formats; initial access technologies to support multi-beam transmission and broadband; the definition and operation of BWP (bandwidth portion); new channel coding methods such as LDPC (low-density parity check) codes for large data transmissions and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing for providing dedicated networks specifically for particular services.

[0004] Currently, discussions are underway regarding performance improvements and enhancements to the initial 5G mobile communication technology for services supported by 5G mobile communication technology. Physical layer standardization has been implemented for technologies such as V2X (Vehicle-to-Everything) which assists autonomous driving by transmitting vehicle location and status information to improve driver convenience, NR-U (New Radio-Unlicensed) which aims to ensure system operation in unlicensed frequency bands in compliance with various regulatory requirements, NR UE power saving, and non-terrestrial networks (NTN), i.e., direct satellite communication for UEs to provide coverage and positioning in areas where communication with terrestrial networks is not possible.

[0005] In addition, the following technologies in the air interface architecture / protocol have been continuously standardized: Industrial Internet of Things (IIoT) for supporting new services through interfacing and integration with other industries; IAB (Integrated Access and Backhaul) for providing nodes to extend network service areas by supporting wireless backhaul and access links in an integrated manner; mobility enhancements including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access (2-step RACH for NR) to simplify the random access process. The following technologies in the system architecture / services have also been continuously standardized: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies; and Mobile Edge Computing (MEC) based on UE location reception services.

[0006] With the commercialization of 5G mobile communication systems, the already exponentially growing number of connected devices will be linked to the communication network. Therefore, it is anticipated that there will be a need to enhance the functionality and performance of 5G mobile communication systems, as well as the integrated operation of connected devices. To this end, new research is planned related to extended reality (XR) technologies such as AR (Augmented Reality), VR (Virtual Reality), and MR (Mixed Reality), as well as new research related to 5G performance improvements and complexity reduction through the utilization of artificial intelligence (AI) and machine learning (ML), AI service support, meta-reality service support, and drone communication.

[0007] Furthermore, the development of such 5G mobile communication systems will serve as a foundation for the development of the following technologies: not only new waveforms for 6G mobile communication technologies covering the terahertz band, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas and large antennas, metamaterial lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technologies using OAM (orbital angular momentum) and RIS (reconfigurable smart surfaces), but also full-duplex technologies to improve the frequency efficiency of 6G mobile communication technologies and improve system networks, AI-based communication technologies that utilize satellites and AI (artificial intelligence) from the design stage to achieve system optimization and internalize end-to-end AI support functions, and next-generation distributed computing technologies that enable services at complexity levels exceeding the operational limits of UEs by utilizing ultra-high-performance communication and computing resources.

[0008] In mobile communications, when a user equipment (UE) is under Long Term Evolution (LTE) coverage or in a 5G system, a PDU session provides an end-to-end user plane connection between the UE and a specific data network (DN) through a User Plane Function (UPF). A PDU session supports one or more QoS flows.

[0009] Currently, existing systems do not handle the release of provided or old PDU sessions in restricted areas. For example, if a UE is located in an unlicensed / service-restricted area, the UE is not allowed to trigger any SM signaling to release the PDU session. Normally, when a UE is in a licensed or unrestricted area, the UE performs a local release of the PDU session and immediately notifies the network of the release. However, notifying the network leads to an unnecessary increase in signaling load on the network. For example, in emergencies such as earthquakes or natural disasters, an area can be considered a restricted area, often referred to as an unlicensed area. In this case, it is important to allow the terminal to trigger a registration process so that the network knows the terminal's location. Therefore, in emergencies, rescue personnel such as police and firefighters can reach the user. Thus, the UE is allowed to trigger signaling related to the registration process, but data transmission or reception is not permitted. Currently, when data transmission or reception is blocked, the application in the UE assumes there is a problem with the PDU session's connection to the data network via the UPF. Therefore, in the current UE implementation, the application layer triggers a PDU session reset process, i.e., a PDU session release and re-establishment process. Such a process from the UE can generate a large amount of signaling on the network. Therefore, it is necessary to avoid a large amount of signaling being generated on the network in emergency situations or in restricted areas. Furthermore, when a UE receives a trigger from the application layer to release a corresponding PDU session, the existing system does not provide any method for releasing the PDU session in service-restricted areas.

[0010] The information disclosed in this context is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission that the information constitutes prior art known to those skilled in the art or any form of implication. Summary of the Invention

[0011] Technical issues

[0012] This disclosure provides a method and apparatus for releasing a Packet Data Unit (PDU) session.

[0013] Solution

[0014] In one embodiment, this disclosure relates to a method for releasing a Protocol Data Unit (PDU) session. The method includes identifying that the UE is in a restricted service area. Upon identifying that the UE is in a restricted service area, the method includes releasing a Procedure Transaction Identifier (PTI) assigned by the UE and performing a local release of one or more PDU sessions within the restricted service area. Furthermore, the method includes providing information related to one or more PDU sessions to the network based on subsequent triggering of the registration process.

[0015] In one embodiment, this disclosure relates to a UE for releasing a Protocol Data Unit (PDU) session. The UE includes a processor and memory communicatively coupled to the processor. The memory stores processor-executable instructions that, when executed, cause the processor to release the PDU session. The processor is configured to recognize that the UE is in a restricted service area. Upon recognizing that the UE is in a restricted service area, the processor is configured to release a Procedure Transaction Identifier (PTI) assigned by the UE and perform a local release of one or more PDU sessions within the restricted service area. Furthermore, the processor is configured to provide information related to one or more PDU sessions to the network based on subsequent triggering of a registration process.

[0016] The above summary is illustrative only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent from the accompanying drawings and the following detailed description.

[0017] Beneficial effects of the invention

[0018] According to embodiments of this disclosure, the UE can release the PDU session even in a restricted service area. Attached Figure Description

[0019] The accompanying drawings, which comprise and form part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the principles disclosed. In the drawings, the leftmost numerals of the reference numerals identify the first drawing in which the reference numeral appears. The same numerals are used throughout the drawings to denote similar features and components. Some embodiments of systems and / or methods according to this subject matter will now be described by way of example only with reference to the accompanying drawings, in which:

[0020] Figure 1 An exemplary environment for releasing a PDU session according to some embodiments of this disclosure is shown;

[0021] Figure 2 Detailed block diagrams of a UE for releasing a PDU session according to some embodiments of the present disclosure are shown;

[0022] Figure 3a A sequence diagram for releasing a PDU session is shown according to some embodiments of the present disclosure;

[0023] Figure 3b A sequence diagram for releasing a PDU session is shown according to some embodiments of the present disclosure;

[0024] Figure 4 A flowchart illustrating an exemplary method for releasing a PDU session according to some embodiments of this disclosure is shown; and

[0025] Figure 5 A block diagram of an exemplary computer system for implementing embodiments consistent with this disclosure is shown.

[0026] Those skilled in the art will understand that any block diagram herein represents a conceptual view of an illustrative system embodying the principles of the subject matter. Similarly, any flowchart, schematic diagram, state transition diagram, pseudocode, etc., represents various processes that can be substantially represented on a computer-readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown. Detailed Implementation

[0027] In this document, the term "exemplary" is used to mean "as an example, instance, or illustration." Any embodiment or implementation of the subject matter described herein as "exemplary" is not necessarily to be construed as being more preferred or advantageous than other embodiments.

[0028] While this disclosure is susceptible to various modifications and alternatives, specific embodiments thereof have been shown by way of example and will be described in detail below. However, it should be understood that this disclosure is not intended to be limited to the forms disclosed, but rather, it is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

[0029] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a setup, apparatus, or method that includes a list of components or steps may include not only those components or steps but may also include other components or steps not expressly listed or inherent to the setup, apparatus, or method. In other words, one or more elements in a system or apparatus expressed by “comprising…” without further constraints do not exclude the presence of other elements or additional elements in the system or method.

[0030] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, so that a setup, apparatus, or method that includes a list of components or steps may include not only those components or steps but may also include other components or steps not expressly listed or inherent to the setup, apparatus, or method. In other words, one or more elements in a system or apparatus described by “comprising…” without further constraints do not exclude the presence of other elements or additional elements in the system or method.

[0031] In the following detailed description of embodiments of the present disclosure, reference is made to the accompanying drawings, which form a part of this document, illustrating specific embodiments in which the present disclosure may be practiced. These embodiments have been described in sufficient detail to enable those skilled in the art to practice the present disclosure, and it should be understood that other embodiments may be used and changes may be made without departing from the scope of the present disclosure. Therefore, the description below should not be considered limiting.

[0032] This disclosure relates to a method and a UE for releasing a PDU session. Typically, when a UE is located in a service-restricted area, and its application layer sends a trigger to release a PDU session, the UE is not permitted to send session management (SM) signaling to the network for releasing the PDU session in the service-restricted area. Therefore, this disclosure discloses the local release of a PDU session in a service-restricted area. Initially, when the UE's application layer decides to release a PDU session, the UE can check that it exists in a service-restricted area. When the UE's existence in a service-restricted area is identified, the UE performs the local release of the PDU session in the service-restricted area. When releasing the PDU session, the UE waits for a subsequent triggering of a NAS procedure within the UE to indicate the release of the PDU session to the network.

[0033] In another embodiment, when the UE is in a service-restricted area and the UE's application layer sends a trigger to release the PDU session, the UE waits to move from the service-restricted area to a serviceable area. Upon moving from the service-restricted area to the serviceable area, the UE releases the PDU session by triggering the PDU session release procedure. Therefore, this disclosure enables the release of PDU sessions in service-restricted areas and updates the state of the released PDU sessions. Thus, PDU sessions can be released locally without sending point-to-point signaling, helping the UE and network stay synchronized in terms of PDU session state.

[0034] Figure 1 An exemplary environment 100 for releasing a PDU session is illustrated. Environment 100 may include a UE 101 and a network 102. UE 101 may include, but is not limited to, a mobile phone, tablet, smartphone, laptop, desktop computer, personal computer (PC), notebook computer, etc. UE 101 communicates with network 102 to release the PDU session. Network 102 may be an Access Mobility Management Function (AFM) for managing connection and session-related information received from UE 101. Furthermore, UE 101 may include a processor 103, an I / O interface 104, and a memory 105. In some embodiments, memory 105 may be communicatively coupled to processor 103. Memory 105 stores instructions executed by processor 103 that, when executed, may cause UE 101 to release the PDU session, as disclosed in this disclosure.

[0035] In one embodiment, UE 101 can communicate via a communication network ( Figure 1(Not shown) communicates with a network. In one embodiment, the communication network may include, but is not limited to, direct interconnection, local area network (LAN), wide area network (WAN), controller area network (CAN), wireless network (e.g., using a wireless application protocol), the Internet, etc.

[0036] Typically, UE 101 can receive triggers from the application layer in UE 101 to release one or more PDU sessions. Upon receiving a trigger, UE 101 can identify that it exists in a service-restricted area. For example, a service-restricted area can be an area where UE 101 is not allowed to trigger any SM signaling. Service-restricted areas can include, but are not limited to, military operational areas, national security areas, and restricted areas. When UE 101 is identified as existing in a service-restricted area, i.e., UE 101 is in an unlicensed or non-licensed area, it acquires a Tracking Area Identity (TAI). Furthermore, upon identifying that UE 101 exists in a service-restricted area, UE 101 can locally release one or more PDU sessions within that area. UE 101 releases the assigned Procedure Transaction Identity (PTI) to locally release one or more PDU sessions. The PTI is an identifier assigned by UE 101 used to track and associate UE-requested ESM (EPS Session Management) procedures. UE 101 stores information related to the one or more released PDU sessions. Information associated with one or more PDU sessions may include, but is not limited to, identification details of one or more PDU session information element (IE) states for one or more PDU sessions. When releasing one or more PDU sessions, UE 101 may wait for the triggering of a subsequent Non-Access Stratum (NAS) procedure. NAS procedures may include, but are not limited to, registration procedures, service request procedures, etc. For example, a subsequent triggering of a NAS procedure occurs when UE 101 moves out of a registration area or when UE capabilities change. Those skilled in the art will understand that there may be one or more ways to trigger a NAS procedure. Upon receiving a subsequent triggering of a NAS procedure, UE 101 may use the PDU session state IE and information associated with one or more PDU sessions to provide an update to network 102 regarding the release of one or more PDU sessions. For example, considering that UE 101 is in a service-restricted area and receives a triggering of a NAS procedure such as a registration procedure or a service request procedure, UE 101 may include information related to the release of one or more PDU sessions and update the network that released one or more PDU sessions as part of the PDU session state IE.

[0037] In one embodiment, when UE 101 is in a service-restricted area and its application layer sends a trigger to release a PDU session, UE 101 waits to move from the service-restricted area to a serviceable area. A serviceable area is an area where UE 101 is allowed to trigger SM signaling. A serviceable area can also be referred to as a permitted area. In this case, UE 101 can detect that it has moved from a service-restricted area to a serviceable area. Once detected, UE 101 can release one or more PDU sessions by triggering a PDU session release procedure. The PDU session release procedure releases all resources associated with the PDU session. These resources may include, but are not limited to, IP addresses / prefixes allocated to the PDU session.

[0038] Figure 2 Detailed block diagrams of a UE for releasing a PDU session according to some embodiments of the present disclosure are shown.

[0039] This document describes in detail the data 107 in the memory 105 of the UE 101 and one or more modules 106.

[0040] In one implementation, one or more modules 106 may include, but are not limited to, trigger receiving module 201, identification module 202, PDU session release module 203, PDU session update module 204, and one or more other modules 205 associated with UE 101.

[0041] In one embodiment, the data 107 in memory 105 may include session release data 206, UE data 207, PDU session data 208, and other data 209 associated with UE 101.

[0042] In one embodiment, data 107 in memory 105 may be processed by one or more modules 106 in UE 101. In one embodiment, one or more modules 106 may be implemented as dedicated units, and when implemented in this way, the modules may be configured with the functions defined herein to create new hardware. As used herein, the term module may refer to application-specific integrated circuits (ASICs), electronic circuits, field-programmable gate arrays (FPGAs), programmable system-on-a-chip (PSoCs), combinational logic circuits, and / or other suitable components that provide the aforementioned functions.

[0043] One or more modules 106 and data 107 of this disclosure are used together to release a PDU session.

[0044] Session release data 206 may include messages from the application layer of UE 101 to release one or more PDU sessions.

[0045] UE data 207 includes data relating to the presence of UE 101 in a service-restricted area. For example, the data may be "1" when UE 101 is in a service-restricted area, and "0" when the UE is not in a service-restricted area. Those skilled in the art will recognize that data relating to the presence of the UE can be represented in any other form and is not limited to the examples described above.

[0046] PDU session data 208 may include information related to the identification details of one or more PDU sessions and information elements (IEs) of one or more PDU sessions.

[0047] Other data 209 may store data generated by modules used to perform various functions of UE 101, including temporary data and temporary files.

[0048] Trigger receiving module 201 can receive triggers from the application layer in UE 101 to release one or more PDU sessions. One or more PDU sessions provide end-to-end user plane connectivity between UE 101 and a specific data network (DN) via User Plane Function (UPF). Upon receiving a trigger, identification module 202 can scan areas and identify that UE 101 exists in a service-restricted area. When UE 101 is identified as existing in a service-restricted area, PDU session release module 203 can release one or more PDU sessions. Specifically, PDU session release module 203 can release PTIs allocated in UE 101 to locally release one or more PDU sessions. Furthermore, PDU session release module 203 stores information related to one or more PDU sessions in UE 101.

[0049] When one or more PDU sessions are released, the trigger receiving module 201 can further check and wait for a subsequent trigger / next trigger of the NAS process. For example, a subsequent trigger of the NAS process may occur when UE 101 moves out of the registration area, or when the UE's capabilities change. Those skilled in the art will understand that the NAS process can occur in any known existing method. Furthermore, upon receiving a subsequent trigger, in response to the subsequent trigger of the NAS process, the PDU session update module 204 provides the network 102 with a release update for one or more PDU sessions using the PDU session state IE and information associated with one or more PDU sessions. For example, consider... Figure 3a A sequence diagram is shown for updating PDU session releases in service-restricted areas. In one embodiment, Figure 3aThe sequence diagram includes UE 301, gNB 302, and network 303. Considering that UE 301 exists in a service-restricted area such as a military operations area, UE 301's application layer or modem layer triggers to release one or more PDU sessions. UE 301 releases the PTI and locally releases one or more PDU sessions, storing information associated with the one or more released PDU sessions in memory 105. The information associated with the one or more PDU sessions may include identification details of the one or more PDU sessions and the information element (IE) status of the one or more PDU sessions. When releasing one or more PDU sessions, UE 301 waits for a subsequent trigger of the NAS procedure from UE 301. The NAS procedure includes a registration procedure and a service request procedure. Upon receiving a subsequent trigger of the NAS procedure, UE 301 uses the PDU session state information element (IE) to update the release of one or more session PDUs to network 303 (such as AMF).

[0050] Figure 3b A sequence diagram is shown for releasing a PDU session in a serviceable area. In one embodiment, Figure 3b The sequence diagram includes UE 301, gNB 302, and network 303. For example, consider when UE 301 is in a service-restricted area, UE 301's application layer sends a trigger to release one or more PDU sessions. In this case, UE 301 waits to move from the service-restricted area to a serviceable area. When it detects that UE 301 has moved from the service-restricted area to a serviceable area, UE 301 releases one or more PDU sessions by triggering a PDU session release procedure. The PDU session release procedure releases resources such as IP addresses associated with one or more PDU sessions.

[0051] One or more modules 106 may also include other modules 205 to perform various other functions of UE 101. It is understood that such modules can be represented as a single module or a combination of different modules.

[0052] Figure 4 A flowchart illustrating an exemplary method for releasing a PDU session according to some embodiments of the present disclosure is shown.

[0053] like Figure 4 As shown, method 400 may include one or more boxes for executing a process in UE 101. Method 400 can be described in the general context of computer-executable instructions. Generally, computer-executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions that perform specific functions or implement specific abstract data types.

[0054] The order in which method 400 is described is not intended to be construed as limiting; any number of the described method boxes can be combined in any order to implement the method. Furthermore, individual boxes can be removed from the method without departing from the scope of the subject matter described herein. Moreover, the method can be implemented in any suitable hardware, software, firmware, or a combination thereof.

[0055] At box 401, trigger receiving module 201 receives a trigger from the application layer of UE 101 to release one or more PDU sessions.

[0056] At box 402, the identification module 202 identifies that UE 101 exists in a service-restricted area. UE 101 is unable to release SM signaling in the service-restricted area.

[0057] At box 403, the PDU session release module 203 releases one or more PDU sessions in the service-restricted area and stores information related to the one or more PDU sessions in UE 101. Specifically, the release of one or more PDU sessions includes releasing the PTIs allocated in the UE to release the one or more PDU sessions. The information related to the one or more PDU sessions may include status information and identification details of the one or more PDU sessions. The status of the one or more PDU sessions may be "inactive," meaning that the one or more PDU sessions have been deactivated.

[0058] In one embodiment, consider a scenario where UE 101 is located in a service-restricted area, and the application layer of UE 101 sends a trigger to release one or more PDU sessions. UE 101 awaits movement from the service-restricted area to a serviceable area. In this case, UE 101 can detect the movement. Once detected, one or more PDU sessions can be released by triggering a PDU session release procedure. The PDU session release procedure can release all resources associated with the PDU session. These resources may include, but are not limited to, the IP address / prefix assigned to the PDU session.

[0059] At box 404, the trigger receiving module 201 receives subsequent triggers of the NAS process from UE 101. The NAS process includes the registration process, service request process, etc.

[0060] At box 405, in response to a subsequent triggering of the NAS procedure, the PDU session update module 204 provides the network 102 with an update on the release of one or more PDU sessions, using the PDU session state IE and information associated with one or more PDU sessions.

[0061] Computing System

[0062] Figure 5 A block diagram of an exemplary computer system 500 for implementing embodiments consistent with this disclosure is shown. In one embodiment, computer system 500 may be a UE 101 configured to release a PDU session. Computer system 500 may include a central processing unit (“CPU” or “processor”) 502. Processor 502 may include at least one data processor for executing processes in a Virtual Storage Area Network. Processor 502 may include dedicated processing units such as an integrated system (bus) controller, a memory management control unit, a floating-point unit, a graphics processing unit, a digital signal processing unit, etc.

[0063] Processor 502 can communicate with one or more input / output (I / O) devices 509 and 510 via I / O interface 501. I / O interface 501 can employ communication protocols / methods such as, but not limited to, audio, analog, digital, mono, RCA, stereo, IEEE-1394, serial bus, Universal Serial Bus (USB), infrared, PS / 2, BNC, coaxial, component, composite, digital vision interface (DVI), high-definition multimedia interface (HDMI), RF antenna, S-video, VGA, IEEE 802.n / b / g / n / x, Bluetooth, cellular (e.g., Code Division Multiple Access (CDMA), High Speed ​​Packet Access (HSPA+), Global System for Mobile Communications (GSM), Long Term Evolution (LTE), WiMax, etc.).

[0064] Using I / O interface 501, computer system 500 can communicate with one or more I / O devices 509 and 510. For example, input device 509 can be an antenna, keyboard, mouse, joystick, (infrared) remote control, camera, card reader, fax machine, encryption device, biometric card reader, microphone, touchscreen, touchpad, trackball, stylus, scanner, storage device, transceiver, video device / source, etc. Output device 510 can be a printer, fax machine, video display (e.g., cathode ray tube (CRT), liquid crystal display (LCD), light-emitting diode (LED), plasma display panel (PDP), organic light-emitting diode display (OLED), etc.), audio speakers, etc.

[0065] Processor 502 may be configured to communicate with communication network 511 via network interface 503. Network interface 503 can communicate with communication network 511. Network interface 503 may employ connectivity protocols, including but not limited to direct connection, Ethernet (e.g., twisted pair 10 / 100 / 1000BaseT), Transmission Control Protocol / Internet Protocol (TCP / IP), Token Ring, IEEE 802.11a / b / g / n / x, etc. Communication network 511 may include, but is not limited to, direct interconnect, Local Area Network (LAN), Wide Area Network (WAN), Wireless Network (e.g., using Wireless Application Protocol), Internet, etc. By using network interface 503 and communication network 511, computer system 500 can communicate with the network to release PDU sessions. Network interface 503 can use connection protocols, including but not limited to direct connection, Ethernet (e.g., twisted pair 10 / 100 / 1000Base T), Transmission Control Protocol / Internet Protocol (TCP / IP), Token Ring, IEEE 802.11a / b / g / n / x, etc.

[0066] Communication networks 511 include, but are not limited to, direct interconnection, e-commerce networks, peer-to-peer (P2P) networks, local area networks (LANs), wide area networks (WANs), wireless networks (e.g., using Wireless Application Protocol), the Internet, Wi-Fi, etc. The first and second networks can be private or shared networks, representing a combination of different types of networks that communicate with each other using multiple protocols, such as Hypertext Transfer Protocol (HTTP), Transmission Control Protocol / Internet Protocol (TCP / IP), Wireless Application Protocol (WAP), etc. Furthermore, the first and second networks can include various network devices, including routers, bridges, servers, computing devices, storage devices, etc.

[0067] In some embodiments, the processor 502 may be arranged to communicate with the memory 505 (e.g., not in memory) via the storage interface 504. Figure 5 The storage interface 504 can communicate with the memory 505 (including but not limited to memory drives, removable disk drives, etc.) using the following connection protocols, such as Serial Advanced Technology Accessories (SATA), Integrated Drive Electronics (IDE), IEEE-1394, Universal Serial Bus (USB), Fibre Channel, Small Computer System Interface (SCSI), etc. The memory drive may also include magnetic drums, disk drives, magneto-optical drives, optical disc drives, redundant arrays of independent disks (RAID), solid-state storage devices, solid-state drives, etc.

[0068] Memory 505 may store a collection of program or database components, including but not limited to user interface 506, operating system 507, etc. In some embodiments, as described in this disclosure, computer system 500 may store user / application data 506, such as data, variables, records, etc. Such databases can be implemented as fault-tolerant, relational, scalable, and secure databases, such as... or

[0069] Operating system 507 facilitates resource management and operation of computer system 500. Examples of operating systems include, but are not limited to, the Apple Macintosh. X、 Similar to UNIX system distributions (e.g., Berkeley Software Distribution™ (BSD), FreeBSD™, NetBSD™, OpenBSD™, etc.), Linux distributions (e.g., Red Hat™, Ubuntu™, Kubuntu™, etc.), IBM™ OS / 2, Microsoft™ Windows™ (XP™, IBM™ / 7 / 8, 10, etc.), IOSTM, Android system OS, etc.

[0070] In some embodiments, computer system 500 may implement program components stored in web browser 508. Web browser 508 may be an hypertext viewing application, such as Microsoft IE, Google Chrome, Firefox, Apple Safari, etc. Secure web browsing can be provided using Hypertext Transfer Protocol Security (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), etc. Web browser 508 may use tools such as AJAX, DHTML, Adobe Flash, JavaScript, Java, Application Programming Interface (API), etc. In some embodiments, computer system 500 may implement program components stored in mail server. Mail server may be an Internet mail server, such as Microsoft Exchange, etc. Mail server may use tools such as ASP, ActiveX, ANSI C++ / C#, Microsoft .NET, Common Gateway Interface (CGI) scripts, Java, JavaScript, Perl, PHP, Python, WebObjects, etc. Mail server may utilize communication protocols such as Internet Message Access Protocol (IMAP), Message Passing Application Programming Interface (MAPI), Microsoft Exchange, Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), etc. In some embodiments, the computer system 500 may implement a program component for storing an email client. The email client may be an email viewing application, such as Apple Mail, Microsoft Entourage, Microsoft Outlook, Mozilla Thunderbird, etc.

[0071] Furthermore, embodiments consistent with this disclosure may be implemented using one or more computer-readable storage media. A computer-readable storage medium refers to any type of physical memory capable of storing processor-readable information or data. Therefore, a computer-readable storage medium may store instructions executable by one or more processors, including instructions that cause the processor to perform steps or stages consistent with the embodiments described herein. The term "computer-readable medium" should be understood to include tangible items and exclude carrier waves and transient signals, i.e., non-transient signals. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, non-volatile memory, hard disk drives, CD-ROMs, DVDs, flash drives, magnetic disks, and any other known physical storage media.

[0072] One embodiment of this disclosure provides a method for releasing a PDU session in a service-restricted area and updating the network upon the next trigger of a NAS procedure. This helps save signaling on the network in service-restricted areas designed not to receive repeated signaling.

[0073] Embodiments of this disclosure provide a method for locally releasing a PDU session without requiring peer signaling, and help the UE and network maintain PDU session state synchronization in emergency situations or in restricted areas such as military environments, or when signaling is reduced due to network load.

[0074] The described operations can be implemented using standard programming and / or engineering techniques as methods, systems, or artifacts to produce software, firmware, hardware, or any combination thereof. The described operations can be implemented as code that can be maintained in a "non-transitory computer-readable medium," wherein a processor can read and execute the code from the computer-readable medium. The processor is at least one of a microprocessor and a processor capable of processing and executing the query. Non-transitory computer-readable media can include media such as magnetic storage media (e.g., hard disk drives, floppy disks, magnetic tapes, etc.), optical disc storage (CD-ROM, DVD, optical discs, etc.), volatile and non-volatile storage devices (e.g., EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash memory, firmware, programmable logic, etc.). Furthermore, non-transitory computer-readable media can include all computer-readable media other than transient media. The code implementation of the described operations can also be implemented in hardware logic (e.g., integrated circuit chips, programmable gate arrays (PGAs), application-specific integrated circuits (ASICs), etc.).

[0075] "Article of manufacture" includes a non-transitory computer-readable medium and / or hardware logic in which code can be implemented. Encoding devices for implementing the code of the described embodiments of operation may include computer-readable media or hardware logic. Of course, those skilled in the art will recognize that various modifications can be made to this configuration without departing from the scope of the invention, and that the article of manufacture may include suitable information-carrying media known in the art.

[0076] The terms “one embodiment,” “embodiment,” “multiple embodiments,” “the embodiment,” “the multiple embodiments,” “one or more embodiments,” “some embodiments,” and “one embodiment” mean “one or more (but not all) embodiments of the invention,” unless otherwise expressly stated.

[0077] The terms “including,” “comprising,” “having,” and variations thereof mean “including, but not limited to,” unless otherwise expressly stated.

[0078] Unless otherwise expressly stated, the list of items does not imply that any or all of the items are mutually exclusive.

[0079] The terms “a,” “an,” and “the” mean “one or more” unless otherwise explicitly stated.

[0080] The description of an embodiment having multiple components that communicate with each other does not imply that all of these components are necessary. Rather, various optional components are described to illustrate various possible embodiments of the invention.

[0081] When a single device or article is described herein, it will be apparent that more than one device / article (whether or not they cooperate) may be used in place of the single device / article. Similarly, when more than one device or article (whether or not they cooperate) is described herein, it will be apparent that a single device / article may be used in place of more than one device / article, or that a different number of devices / articles may be used instead of the number of devices or programs shown. The functionality and / or features of a device may optionally be embodied by one or more other devices not explicitly described as having such functionality / features. Therefore, other embodiments of the invention do not necessarily need to include the device itself.

[0082] Figure 4 The operations shown illustrate certain events occurring in a specific order. In alternative embodiments, some operations may be performed, modified, or deleted in a different order. Furthermore, steps can be added to the logic described above, while still conforming to the embodiments described. Additionally, the operations described herein may occur sequentially, or some operations may be processed in parallel. Furthermore, operations may be executed by a single processing unit or by distributed processing units.

[0083] Finally, the language used in this specification is primarily for readability and pedagogical purposes and is not intended to be chosen to describe or limit the subject matter of this invention. Therefore, the scope of this invention is not limited by this detailed description, but rather by any claims published in the application herein. Accordingly, the disclosure of embodiments of this invention is intended to illustrate, rather than limit, the scope of the invention, which is set forth in the following claims.

[0084] While several aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The appended claims indicate the true scope and spirit, and the various aspects and embodiments disclosed herein are for illustrative purposes only and are not intended to be limiting.

Claims

1. A method for releasing a Protocol Data Unit (PDU) session in a wireless communication system, the method being performed by a User Equipment (UE) (101), comprising: Based on the Tracking Area Identifier (TAI), the system identifies that the UE is in a restricted service area. Identify one or more PDU sessions to be released; Delay the PDU session release process initiated with the network to release the one or more PDU sessions until the UE is no longer in the restricted service area; and When a UE is detected to have moved from a restricted service area to a serviceable area, the one or more PDU sessions are released by triggering a PDU session release procedure with the network.

2. The method according to claim 1, wherein, When the UE is in a restricted service area, the method further includes: Release the procedure transaction identifier (PTI) assigned by the UE; Perform local release of the PDU sessions within one or more PDU sessions in the restricted service area; and Based on subsequent triggers during the registration process, information related to the PDU session is provided to the network.

3. The method according to claim 2, in, Information related to the PDU session is provided using the PDU session state information element IE, and the information includes the state information of the PDU session.

4. The method according to claim 3, wherein, The status information indicates whether the PDU session corresponding to the status information is inactive.

5. The method according to claim 1, wherein, Whether a UE is in a restricted service area is identified based on its Tracking Area Identifier (TAI), which indicates an unauthorized or non-permitted area.

6. The method according to claim 1, further comprising: Receive a trigger from the application layer in the UE to release the one or more PDU sessions.

7. A user equipment (UE) (101) for releasing a Protocol Data Unit (PDU) session in a wireless communication system, the UE comprising: Processor (103); and A memory (105) communicatively coupled to the processor (103), wherein the memory (105) stores processor-executable instructions that, when executed, cause the processor (103) to: Based on the Tracking Area Identifier (TAI), the system identifies that the UE is in a restricted service area. Identify one or more PDU sessions to be released; Delay the PDU session release process initiated with the network to release the one or more PDU sessions until the UE is no longer in the restricted service area; and When a UE is detected to have moved from a restricted service area to a serviceable area, the one or more PDU sessions are released by triggering a PDU session release procedure with the network.

8. The UE according to claim 7, wherein, When the UE is in a restricted service area, the processor-executable instructions also cause the processor (103): Release the procedure transaction identifier (PTI) assigned by the UE; Perform local release of the PDU sessions within one or more PDU sessions in the restricted service area; and Based on subsequent triggers during the registration process, information related to the PDU session is provided to the network.

9. The UE according to claim 8, wherein, Information related to the PDU session is provided using the PDU session state information element IE, and the information includes the state information of the PDU session.

10. The UE according to claim 9, wherein, The status information indicates whether the PDU session corresponding to the status information is inactive.

11. The UE according to claim 7, wherein, Whether a UE is in a restricted service area is identified based on its Tracking Area Identifier (TAI), which indicates an unauthorized or non-permitted area.

12. The UE according to claim 7, wherein, The processor-executable instructions also cause the processor to: Receive a trigger from the application layer in the UE to release the one or more PDU sessions.

13. The UE according to claim 7, wherein, The restricted service area is the area where the UE is not allowed to trigger any session management signaling.

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