Mobility between gateway devices in non-3GPP access

Abstract

Example embodiments of the present disclosure relate to a device, method, apparatus and computer readable storage medium for status notification of an access network for time-sensitive communication. In an example embodiment, a terminal device determines a target access device via which the terminal device communicates with a target gateway device. Further, the terminal device sends a message to the source gateway device indicating a handover from the source access device to the target access device, with which the terminal device communicates via the source access device. Further, the terminal device communicates with the target gateway device based on the same context associated with the terminal device when communicating with the source gateway device.

Description

Technical Field

[0001] Example embodiments of the present disclosure relate generally to the field of communications, and in particular to devices, methods, apparatuses, and computer-readable storage media for mobility between gateway devices in non-3rd Generation Partnership Project (non-3GPP) access. Background Art

[0002] The 3GPP Release 15 architecture supports access to the 5G system using the fifth generation (5G) New Radio (NR) as well as via non-3GPP access networks. The Non-3GPP Interworking Function (N3IWF) has been defined as part of the untrusted non-3GPP access. Both 5G NR and non-3GPP access interface to the 5G Core Network (5GC) using the same user plane interface (N3) and control plane interface (N2), with the N3IWF terminating the N2 and N3 interfaces.

[0003] In addition, the 3GPP Release 16 architecture supports the integration of wireless local area network (WLAN) systems into the 5G architecture using a trusted model. WLAN access is deployed and managed by 5G mobile operators or third parties trusted by 5G mobile operators. After registration in the 5G system, WLAN access is trusted by both 5GC and 5G terminals. The Trusted WLAN Access Network (TNAN) consists of two types of network functions, namely the Trusted WLAN Access Point (TNAP) to which the User Equipment (UE) is connected, and the Trusted WLAN Gateway Function (TNGF) that opens the N2 or N3 interface and enables the UE to connect to the 5GC through WLAN access technology. Summary of the invention

[0004] In general, example embodiments of the present disclosure provide devices, methods, apparatuses, and computer-readable storage media for mobility between gateway devices in non-3GPP accesses.

[0005] In a first aspect, a method is provided. In the method, a terminal device determines a target access device, and the terminal device communicates with a target gateway device via the target access device. In addition, the terminal device sends a message indicating a switch from the source access device to the target access device to a source gateway device, and the terminal device communicates with the source gateway device via the source access device. In addition, the terminal device communicates with the target gateway device based on the same context associated with the terminal device as when communicating with the source gateway device.

[0006] In a second aspect, a method is provided. In the method, a target access device receives a request from a terminal device to associate with the target access device, the request indicating a switch from a source access device to a target access device. In addition, the target access device sends a response to the request to the terminal device. In addition, the target access device sends an indication indicating the switch to a target gateway device, and the terminal device communicates with the target gateway device via the target access device.

[0007] In a third aspect, a method is provided. In the method, a source gateway device receives a message from a terminal device indicating a switch from a source access device to a target access device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. Then, the source gateway device determines the need for a change from the source gateway device to the target gateway device based on the message. In addition, the source gateway device receives a request for a context associated with the terminal device from the target gateway device. In addition, the source gateway device sends the context to the target gateway device.

[0008] In a fourth aspect, a method is provided. In the method, a target gateway device receives an indication from a target access device indicating a handover of a terminal device from a source access device to a target access device, the terminal device communicates with the target gateway device via the target access device, and the terminal device communicates with the source gateway device via the source access device. In addition, the target gateway device sends a request for a context associated with the terminal device to the source gateway device. Then, the target gateway device receives the context from the source gateway device. In addition, the target gateway device communicates with the terminal device based on the context.

[0009] In a fifth aspect, a method is provided. In the method, a source gateway device receives a first message from a terminal device indicating a switch from a source access device to a target access device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. Then, the source gateway device determines the need to change from the source gateway device to the target gateway device based on the first message. In addition, the source gateway device sends a second message indicating the switch to the core network device. In addition, the source gateway device receives a command for the switch from the core network device.

[0010] In a sixth aspect, a method is provided. In the method, a target gateway device receives a request for a handover of a terminal device from a source access device to a target access device from a core network device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. Then, the target gateway device receives an indication of the handover from the target access device. Then, the target gateway device sends a confirmation of the request to the core network device. In addition, the target gateway device communicates with the terminal device based on a context associated with the terminal device that is the same as when the source gateway device and the terminal device communicate.

[0011] In a seventh aspect, a method is provided. In the method, a core network device receives a message from a source gateway device indicating a handover of a terminal device from a source access device to a target access device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. In addition, the core network device determines the target gateway device based on the message. Then, the core network device sends a request for the handover to the target gateway device. In addition, the core network device receives a confirmation of the request from the target gateway device.

[0012] In an eighth aspect, a terminal device is provided, the terminal device comprising at least one processor and at least one memory comprising computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: determine a target access device, the terminal device communicates with a target gateway device via the target access device. In addition, the terminal device is caused to send a message indicating a switch from a source access device to a target access device to a source gateway device, the terminal device communicates with the source gateway device via the source access device. In addition, the terminal device is caused to communicate with the target gateway device based on the same context associated with the terminal device as when communicating with the source gateway device.

[0013] In a ninth aspect, a target access device is provided, the target access device comprising at least one processor and at least one memory comprising computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, cause the target access device to: receive a request from a terminal device to associate with the target access device, the request indicating a switch from a source access device to a target access device. In addition, the target access device is caused to send a response to the request to the terminal device. In addition, the target access device is caused to send an indication indicating the switch to a target gateway device, and the terminal device communicates with the target gateway device via the target access device.

[0014] In a tenth aspect, a source gateway device is provided, the source gateway device comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, enable the source gateway device to: receive a message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. Then, the source gateway device is caused to determine the need for a change from the source gateway device to the target gateway device based on the message. In addition, the source gateway device is caused to receive a request for a context associated with the terminal device from the target gateway device. In addition, the source gateway device is caused to send the context to the target gateway device.

[0015] In the eleventh aspect, a target gateway device is provided, the target gateway device comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, enable the target gateway device to: receive an indication indicating the switching of the terminal device from the source access device to the target access device from the target access device, the terminal device communicates with the target gateway device via the target access device, and the terminal device communicates with the source gateway device via the source access device. In addition, the target gateway device is caused to send a request for a context associated with the terminal device to the source gateway device. Then, the target gateway device is caused to receive the context from the source gateway device. In addition, the target gateway device is caused to communicate with the terminal device based on the context.

[0016] In the twelfth aspect, a source gateway device is provided, the source gateway device comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, enable the source gateway device to: receive a first message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. Then, the source gateway device is caused to determine the need for a change from the source gateway device to the target gateway device based on the first message. In addition, the source gateway device is caused to send a second message indicating the switch to a core network device. In addition, the source gateway device is caused to receive a command for the switch from the core network device.

[0017] In the thirteenth aspect, a target gateway device is provided, the target gateway device comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, enable the target gateway device to: receive a request for switching of a terminal device from a source access device to a target access device from a core network device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. Then, the target gateway device is caused to receive an indication indicating the switching from the target access device. Then, the target gateway device is caused to send a confirmation of the request to the core network device. In addition, the target gateway device is caused to communicate with the terminal device based on the same context associated with the terminal device as when the source gateway device and the terminal device communicate.

[0018] In a fourteenth aspect, a core network device is provided, the core network device comprising at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, enable the core network device to: receive a message from a source gateway device indicating the switching of a terminal device from a source access device to a target access device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device. In addition, the core network device is caused to determine the target gateway device based on the message. Then, the core network device is caused to send a request for the switching to the target gateway device. In addition, the core network device is caused to receive a confirmation of the request from the target gateway device.

[0019] In a fifteenth aspect, an apparatus is provided, the apparatus comprising means for performing a method according to one of the first to seventh aspects.

[0020] In a sixteenth aspect, a computer-readable storage medium is provided, the computer-readable storage medium comprising program instructions stored thereon, wherein when the instructions are executed by a processor of a device, the device executes a method according to one of the first to seventh aspects.

[0021] It should be understood that the invention summary is not intended to identify the key or essential features of the exemplary embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0023] Figure 1A A 3GPP protocol stack for an untrusted non-3GPP access network is shown;

[0024] Figure 1B shows a 3GPP protocol stack for a trusted non-3GPP access network;

[0025] Figure 2 An example environment is shown in which embodiments of the present disclosure may be implemented;

[0026] Figure 3 shows a signaling flow between devices in an Xn-based handover scenario according to some example embodiments of the present disclosure;

[0027] Figure 4 shows a signaling flow between devices in an N2-based handover scenario according to some example embodiments of the present disclosure;

[0028] Figure 5 An example process of UE registering with 5GC in an Xn-based handover scenario according to some example embodiments of the present disclosure is shown;

[0029] Figure 6 An example process of UE registering with 5GC in a N2-based handover scenario according to some example embodiments of the present disclosure is shown;

[0030] Figure 7 A flowchart showing an example method for a terminal device according to some example embodiments of the present disclosure is shown;

[0031] Figure 8 A flowchart illustrating an example method for a target access device according to some example embodiments of the present disclosure is shown;

[0032] Fig. 9 A flowchart illustrating an example method for a source gateway device according to some example embodiments of the present disclosure is shown;

[0033] Fig.10 A flowchart illustrating an example method for a target gateway device according to some example embodiments of the present disclosure is shown;

[0034] Fig.11 A flowchart illustrating an example method for a source gateway device according to some other example embodiments of the present disclosure;

[0035] Fig.12 A flowchart illustrating an example method for a target gateway device according to some other example embodiments of the present disclosure is shown;

[0036] Fig.13 A flowchart illustrating an example method for a core network device according to some example embodiments of the present disclosure; and

[0037] Fig.14 A simplified block diagram of a device suitable for implementing an example embodiment of the present disclosure is shown.

[0038] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0039] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these example embodiments are described only for illustrative purposes and to help those skilled in the art understand and implement the present disclosure without any limitation to the scope of the present disclosure. The disclosure described herein can be implemented in various ways different from the ways described below.

[0040] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0041] As used herein, the term "access device" refers to a device via which services can be provided to terminal devices in a cellular communication network. Examples of access devices include relays, access points (APs), transmission points (TRPs), node Bs (NodeBs or NBs), evolved NodeBs (eNodeBs or eNBs), new radio (NR) NodeBs (gNBs), remote radio units (RRUs), radio heads (RHs), remote radio heads (RRHs), low-power nodes (such as femto, pico), etc. For the purpose of discussion, some example embodiments will be described using a base station as an example of an access device.

[0042] As used herein, the term "terminal device" refers to any device capable of wireless communication with each other or with an access device. Communication may involve sending and / or receiving wireless signals using electromagnetic signals, radio waves, infrared signals, and / or other types of signals suitable for transmitting information in the air. Examples of terminal devices may include user equipment (UE). In some example embodiments, the UE may be configured to send and / or receive information without direct human interaction. For example, the UE may send information to a base station according to a predetermined schedule, when triggered by an internal or external event, or in response to a request from the network side.

[0043] As used herein, in some example embodiments, the term "core network device" refers to a device that can communicate with an access device and provide services to a terminal device in the core network. Examples of core network devices may include user plane functions (UPFs), application servers, mobile switching centers (MSCs), MMEs, operations and management (O&M) nodes, operations support system (OSS) nodes, self-organizing network (SON) nodes, positioning nodes such as enhanced serving mobile location centers (E-SMLCs), mobile data terminals (MDTs), common control network functions (CCNFs), access and mobility management functions (AMFs), session management functions (SMFs), and policy control functions (PCFs).

[0044] As used herein, in some example embodiments, the term "gateway device" refers to a device for communicating with an access device (such as an AP) and a core network device (such as an AMF) for non-3GPP access. For example, the gateway device may include a TNGF and / or a N3IWF.

[0045] As used herein, the term "circuitry" may refer to one or more or all of the following:

[0046] (a) hardware circuit implementation only (such as implementation only in analog and / or digital circuitry), and

[0047] (b) a combination of hardware circuitry and software such as (where applicable):

[0048] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0049] (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions, and

[0050] (c) Hardware circuits and / or processor(s), such as microprocessor(s) or portions of microprocessor(s), that require software (e.g., firmware) to operate, but where the software may not be present, the software may be absent.

[0051] This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or process and its accompanying software and / or firmware. For example, and if applicable to a particular claim element, the term circuitry also covers a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular base station, or other computing or base station.

[0052] As used herein, the singular forms "a", "an", and "the" shall also include the plural forms unless the context clearly indicates otherwise. The term "including" and its variations shall be understood as open terms, meaning "including but not limited to." The term "based on" shall be understood as "based at least in part on." The terms "one embodiment" and "an embodiment" shall be understood as "at least one embodiment." The term "another embodiment" shall be understood as "at least one other embodiment." Additional explicit and implicit definitions may be included below.

[0053] As mentioned above, the 3GPP Release 15 architecture supports access to the 5G system using the fifth generation (5G) New Radio (NR) and via non-3GPP access networks. The non-3GPP interworking function (N3IWF) has been defined as part of the untrusted non-3GPP access. Both 5GNR and non-3GPP access use the same user plane interface (N3) and control plane interface (N2) to interface to the 5G core network (5GC), where the N3IWF terminates the N2 and N3 interfaces. Figure 1A The 3GPP protocol stack for an untrusted non-3GPP access network is shown in FIG.

[0054] In addition, the 3GPP Release 16 architecture supports the integration of wireless local area network (WLAN) systems into the 5G architecture using a trusted model. In this case, WLAN access is deployed and managed by the 5G mobile operator or a third party trusted by the 5G mobile operator. After registration in the 5G system, WLAN access is trusted by both 5GC and 5G terminals. The Trusted WLAN Access Network (TNAN) consists of two types of network functions, namely the Trusted WLAN Access Point (TNAP) to which the user equipment (UE) is connected, and the Trusted WLAN Gateway Function (TNGF) that opens the N2 or N3 interface and enables the UE to connect to the 5GC through WLAN access technology. Figure 1B The 3GPP protocol stack for a trusted non-3GPP access network is shown in . TNGF is part of the core network from a wireless fidelity (WiFi) / WLAN perspective, but from a 3GPP perspective, it is part of the access network.

[0055] When Internet Protocol Security (IPsec) is deployed for the connection between the UE and the 5GC, link layer security on the WLAN link is not required. Therefore, the untrusted non-3GPP access does not mandate access authentication for Wireless Fidelity (Wi-Fi) Protected Access (WPA) 2 / 3 Enterprise mode, and only uses the 5G Extensible Authentication Protocol (EAP) authentication method to establish a security association for the IPsec tunnel based on Internet Key Exchange (IKE)-v2.

[0056] However, most public WLAN access networks simultaneously offer a secure access mode based on WPA 2 / 3 Enterprise, where the UE is automatically connected through the Subscriber Identity Module (SIM) / Authentication and Key Agreement (AKA) credentials. Global roaming of such secure public WLAN access is currently being widely deployed through the OpenRoaming project of the Wireless Broadband Alliance (WBA), which reduces the operational overhead of becoming a partner of a global roaming alliance. The WLAN technology deployed in the OpenRoaming network is the same technology that mobile operators use in their own trusted WLAN access networks. With this convergence of access technologies, it becomes feasible for mobile operators to establish global WLAN roaming capabilities for their subscribers by leveraging OpenRoaming technology and the need for seamless mobility across all WLAN accesses due to compatible security levels. Mobile operators can even signal a single global mobility domain through a virtual WLAN access network to indicate the same service set identity (SSID) and mobility domain across multiple WLAN access providers.

[0057] Even though this deployment scenario is not formally consistent with trusted WLAN access, it can deploy the access procedures defined for trusted WLAN access and provide an extended coverage access infrastructure consisting of several access networks belonging to different access providers, each of which is connected to the 5GC through a dedicated N3IWF. In this case, the N3IWF behaves exactly like the TNGF and can establish wide-area WLAN access across multiple WLAN access domains under the control of the 5G mobile network operator.

[0058] Therefore, the development of WLAN roaming makes it possible to support fully automatic network access in a wider area. It is hoped that the 5G service can be connected seamlessly without interruption when changing WLAN access. Deploying the same SSID / Extended Service Set (ESS) across multiple WLAN accesses can indicate seamless connection to IP services to the UE, but the operational establishment of WLAN access may require the deployment of multiple instances of TNGF or N3IWF to serve different adjacent WLAN access areas.

[0059] When WLAN access will be connected to 5GC through different TNGFs or N3IWFs, the current 3GPP architecture for integrating Wi-Fi with 5GC only allows for sporadic coverage without mobility support between adjacent Wi-Fi access areas. Each Wi-Fi access network defined by TNGF or N3IWF currently establishes an independent access area, and when the UE moves between them, it needs to fully re-authenticate, re-authorize, and re-establish the IPsec tunnel. Currently, no mobility support is available for transitions between different TNGFs or N3IWFs.

[0060] The need to re-establish IPsec tunnels when changing TNGF or N3IWF disrupts seamless connectivity for 5G services, even in cases where a WLAN transition within the same SSID / ESS would indicate uninterrupted access to IP services to the UE. Due to the re-establishment of IPsec, the IP connectivity at the UE is disrupted and a full reconnection is required to restore IP connectivity to the 5G services. Therefore, it is desirable to be able to maintain security associations and IPsec tunnels when changing tunnel endpoints from one TNGF or N3IWF to another TNGF / N3IWF.

[0061] In one aspect, some exemplary embodiments of the present disclosure provide a solution for mobility between gateway devices in non-3GPP access in an Xn-based handover scenario. For example, the target access device may be a target AP, and the source gateway device or the target gateway device may be a TNGF or a N3IWF.

[0062] In this scheme, the terminal device determines the target access device, and the terminal device communicates with the target gateway device via the target access device. Then, the terminal device sends a message indicating the switch from the source access device to the target access device to the source gateway device, and the terminal device communicates with the source gateway device via the source access device. In addition, the terminal device sends a request indicating the switch associated with the target access device to the target access device. Then, the target access device sends a response to the request to the terminal device, and sends an indication indicating the switch to the target gateway device. The target gateway device sends a request for a context associated with the terminal device to the source gateway device. Then, the source gateway device sends the context to the target gateway device. The terminal device communicates with the target gateway device based on the same context associated with the terminal device and when communicating with the source gateway device.

[0063] On the other hand, some exemplary embodiments of the present disclosure provide a solution for mobility between gateway devices in non-3GPP access in N2-based handover scenarios. For example, the target access device may be a target AP, and the source gateway device or the target gateway device may be a TNGF or N3IWF, and the core network device may be an AMF.

[0064] In this scheme, the terminal device determines the target access device, and the terminal device communicates with the target gateway device via the target access device. Then, the terminal device sends a first message indicating the switch from the source access device to the target access device to the source gateway device, and the terminal device communicates with the source gateway device via the source access device. Then, the source gateway device sends a second message indicating the switch to the core network device. The core network device determines the target gateway device based on the second message, and then sends a request for the switch to the target gateway device. In addition, the terminal device sends a request indicating the switch associated with the target access device to the target access device. Then, the target access device sends a response to the request to the terminal device, and sends an indication indicating the switch to the target gateway device. The target gateway device sends a confirmation of the request to the core network device. Then, the target gateway device communicates with the terminal device based on the same context associated with the terminal device as when the source gateway device and the terminal device communicate.

[0065] These solutions facilitate flexible and efficient handover between gateway devices in non-3GPP access in both Xn-based handover scenarios and N2-based handover scenarios. Therefore, when changing WLAN access, you can seamlessly connect to 5G services without interruption. Therefore, the user experience can be significantly improved.

[0066] Figure 2 An example environment 200 is shown in which embodiments of the present disclosure may be implemented.

[0067] As shown, environment 200 as part of a communication network includes terminal device 201 and access device (referred to as source access device) 203. Environment 200 also includes gateway device (referred to as source gateway device) 205. For example, terminal device 201 can communicate with source gateway device 205 via source access device 203.

[0068] The environment 200 also includes another access device (referred to as a target access device) 207 and another gateway device (referred to as a target gateway device) 209. As shown in the figure, the target access device 207 acts as an intermediary between the terminal device 201 and the target gateway device 209.

[0069] Environment 200 also includes core network device 211. Source gateway device 205 and target gateway device 209 may be directly or indirectly connected to core network device 211 via one or more other devices or functions. Similarly, the connection between source access device 203 and source gateway device 205 and the connection between target access device 207 and target gateway device 209 may be direct or indirect.

[0070] In some embodiments, source gateway device 205 and target gateway device 209 may communicate directly or indirectly via one or more other devices or functions.

[0071] In some example embodiments, source gateway device 205 may be physically integrated into source access device 203, and, for example, implemented as a function or entity physically integrated into source access device 203. In this case, source gateway device 205 may communicate with source access device 203 via internal wiring. Likewise, in some example embodiments, target gateway device 209 may be physically integrated into target access device 207, and, for example, implemented as a function or entity physically integrated into target access device 207. In this case, target gateway device 209 may communicate with target access device 207 via internal wiring.

[0072] Communications between individual devices or functions in environment 200 may follow any suitable communication standard or protocol already in existence or to be developed in the future. The scope of the present disclosure is not limited in this regard.

[0073] It should be understood that the devices or functions shown in environment 200 are for illustrative purposes only and do not represent any limitation. Environment 200 may include any other suitable devices, elements or functions for providing communication. For example, one or more intermediaries may exist between source access device 203 and source gateway device 205 and / or between source gateway device 205 and core network device 211.

[0074] The following will refer to Figure 3-Figure 4 High-level interactions between devices and functions in environment 200 are discussed.

[0075] Figure 3 FIG. 4 shows a signaling flow between devices in an Xn-based handover scenario according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to FIG. Figure 2 Describe the signaling flow 300. For example, the terminal device 201 can be implemented by a UE, the target access device 207 can be implemented by an AP, the source gateway device 205 can be implemented by a TNGF or a N3IWF, and the target gateway device 209 can be implemented by a TNGF or a N3IWF.

[0076] like Figure 3As shown, the terminal device 201 determines (305) the target access device 207, and the terminal device 201 communicates with the target gateway device 209 via the target access device. In some example embodiments, the terminal device 201 can perform WLAN measurements to provide better guidance to find candidate access devices that provide the required connection. When the terminal device 201 determines that the current WLAN radio link no longer provides the required level of service based on an internal policy, it can scan the environment and select the best target access device for seamless switching to maintain the required quality of service. For example, the terminal device 201 can check and verify that the target access device 207 indicates the same SSID and the final homogeneous extended service set identifier (HESSID) when provided. For example, if the terminal device 201 determines that the performance at multiple candidate access devices including the target access device 209 is better than the source access device 205, it can determine the target access device 209 from the multiple candidate access devices.

[0077] The terminal device 201 then sends (310) a message to the source gateway device 205 indicating a switch from the source access device 203 to the target access device 207. For example, the message may include at least one of the following: an identifier of the terminal device 201 and an identifier of the target access device 207. For example, the identifier may include a media access control (MAC) address. Alternatively or additionally, without any limitation on the scope of the present disclosure, the identifier may include other types of identifiers for identification. The source gateway device 205 then determines (315) that a change from the source gateway device 205 to the target gateway device 209 is required based on the message. For example, the source gateway device 205 may determine the target gateway device 209 based on the identifier of the target access device 207. It should be understood that the source gateway device 205 may determine the target gateway device 207 in other ways without any limitation on the scope of the present disclosure.

[0078] In some example embodiments, terminal device 201 sends (320) a request to associate with target access device 207 to target access device 207. For example, the request may indicate a switch from source access device 203 to target access device 207. For example, the request may include an identifier of source access device 203. Target access device 207 sends (325) a response to the request to terminal device 210. Target access device 207 then sends (330) an indication indicating the switch to target gateway device 209. For example, the indication may include at least one of: an identifier of terminal device 201, an identifier of source access device 203, and an identifier of target access device 207.

[0079] Then, in some example embodiments, the target gateway device 209 may determine the source gateway device 205 based on the identifier of the source access device 203 included in the indication. In this case, each TNGF including the source gateway device 205 may register its Xn address with the network repository function (NRF) using the MAC address list of the access device it serves, using, for example, the Nnrf_NFManagement_NFRegister operation defined in 3GPP Technical Specification (TS) 23.502. Therefore, the target gateway device 209 may be configured with a list of access devices served by the adjacent TNGF. The target gateway device 209 may then search a public database, such as NRF. For example, the target gateway device 209 may discover the source gateway device 205 by issuing, for example, the Nnrf_NFDiscovery_Request operation defined in 3GPP TS23.502 (providing the identifier of the source access device 203 as an input parameter). It should be understood that, without any limitation to the scope of the present disclosure, the target gateway device 209 may determine the source gateway device 205 in other ways.

[0080] like Figure 3 As shown, the target gateway device 209 sends (335) a request for a context associated with the terminal device 201 to the source gateway device 205. In some example embodiments, the context may include security information for communication with the terminal device 201 at the target access device 207. For example, the context may include a key for communication with the terminal device 201. For example, the context may include an EAP re-authentication Rook key (Rrk). Alternatively or additionally, the context may include parameters associated with the Internet Protocol security of the target gateway device 209. For example, the context may include IPSec related parameters, such as a security parameter index SPI, a security association (SA) list, a service filter per SA, and / or an IPSec sequence number per SA. As another example, the context may include 3GPP key material received from the 5GC.

[0081] In some example embodiments, the request for the context may include at least one of: an identifier of the terminal device 201, an identifier of the source access device 203, an identifier of the target access device 207, and an Internet Protocol address of the target gateway device 209. In response, the source gateway device 205 sends (340) the context to the target gateway device 209. For example, when the terminal device 201 joins the target access device 207, the terminal device may issue relevant EAP signaling to the target gateway device 209 using an EAP reauthentication protocol, which is relayed by the target access device 207. The target gateway device 209 may then reuse the information received in the context (e.g., EAP Rrk) to derive a new working key (such as a new PMK) for WLAN security through an EAP reauthentication process, while the IPSec SA security parameters may remain unchanged, associated with a previous PMK determined when the UE last connected to the network (e.g., when the UE registered).

[0082] Afterwards, some IEEE security processes may be performed. For example, these processes may include subsequent EAP message exchanges, and 4-way handshakes to establish various keys required for secure WLAN communication. The terminal device 110 then communicates with the target gateway device 209 based on the same context associated with the terminal device 201 as when communicating with the source gateway device 205 (345). For example, the terminal device 201 may then begin to use the target access device 207 to send uplink (UL) traffic. The target TNGF 507 may start an IPSec state machine. For example, the IPsec endpoint may then be enabled.

[0083] In addition, the source gateway device 205 may receive an indication of resource release. Then, the source gateway device 205 may release resources used for communication with the terminal device 201 by at least disabling the Internet Protocol Security endpoint.

[0084] In this way, flexible and efficient handover can be achieved between gateway devices of non-3GPP access in Xn-based handover scenarios. Therefore, seamless connection to 5G services without interruption is allowed when changing WLAN access. Therefore, user experience can be significantly improved.

[0085] Figure 4 FIG. 4 shows a signaling flow between devices in a N2-based handover scenario according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to Figure 2Describe the signaling flow 400. For example, the terminal device 201 can be implemented by a UE, the target access device 207 can be implemented by an AP, the source gateway device 205 can be implemented by a TNGF or N3IWF, the target gateway device 209 can be implemented by a TNGF or N3IWF, and the core network device 211 can be implemented by an AMF.

[0086] like Figure 4 As shown, the terminal device 201 determines (405) the target access device 207, and the terminal device 201 communicates with the target gateway device 209 via the target access device 207. The terminal device 201 can communicate with the reference Figure 3 The target access device 207 is determined in a similar manner as described above.

[0087] The terminal device 201 then sends (410) a message (also referred to as a first message) to the source gateway device 205 indicating a switch from the source access device 203 to the target access device 207. For example, the first message may include at least one of the following: an identifier of the terminal device 201 and an identifier of the target access device 207. For example, the identifier may include a media access control (MAC) address. Alternatively or additionally, without any limitation on the scope of the present disclosure, the identifier may include other types of identifiers for identification. The source gateway device 205 then determines (415) that a change from the source gateway device 205 to the target gateway device 209 is required based on the first message. For example, the source gateway device 205 may determine the target gateway device 209 based on the identifier of the target access device 207 included in the first message. Similarly, the source gateway device 205 may be configured with a list of access devices served by neighboring TNGFs or N3IWFs. The source gateway device 205 may then search a public database, such as a network repository function (NRF). For example, the source gateway device 205 can discover the target gateway device 209 by issuing, for example, an Nnrf_NFDiscovery_Request operation defined in 3GPP TS23.502 (providing the identifier of the target access device 207 as an input parameter). It should be understood that without any limitation on the scope of the present disclosure, the source gateway device 205 can determine the target gateway device 207 in other ways.

[0088] like Figure 4As shown, the source gateway device 205 sends (420) another message (also referred to as a second message) to the core network device 211 indicating the handover. In some example embodiments, the second message may include at least one of the following: an identifier of the target access device 207, an identifier of the target gateway device 209, a context associated with Internet Protocol security, and a context associated with authentication protocol security (such as EAP security). For example, the second message may include an Rrk that is used to establish a WLAN security context during EAP reauthentication to avoid the need to perform a full EAP authentication process with the 5GC.

[0089] Then, the core network device 211 determines (425) the target gateway device 209 based on the second message. For example, the core network device 211 may determine the target gateway device 209 based on the identifier of the target access device 207 included in the second message. In addition, based on the second message, the core network device 211 may also perform preparations for switching. For example, the core network device 211 may interact with the SMF and the UPF for switching. For example, a transparent 5G access network (AN) to 5G AN container may include TNGF related information.

[0090] Then, the core network device 211 sends (430) a request for the handover to the target gateway device 209. For example, the request may include at least one of the following: an identifier of the target gateway device 209, a context associated with Internet Protocol security, and a context associated with authentication protocol security. For example, the request may contain TNGF related information included in the second message. Therefore, the context associated with the terminal device 201 can be obtained by the target gateway device 209 based on a request from the core network device 211 for future communications with the terminal device 201. In some example embodiments, the context associated with the terminal device 201 may include security information for communication with the terminal device 201 at the target access device 207. For example, the context may include a key for communication with the terminal device 201. For example, the context may include an EAP re-authentication Rook key (Rrk). Alternatively or additionally, the context may include parameters associated with the Internet Protocol security of the target gateway device 209. For example, the context may include IPSec related parameters such as a security parameter index SPI, a security association (SA) list, a service filter per SA, and / or an IPSec sequence number per SA. As another example, the context may include 3GPP key material received from the 5GC.

[0091] In some example embodiments, the terminal device 201 may send a request to the target access device 207 to associate with the target access device 207. For example, the request may indicate a switch from the source access device 203 to the target access device 207. For example, the request may include an identifier of the source access device 203. The target access device 207 may send a response to the request to the terminal device 210. The target access device 207 then sends (435) an indication indicating the switch to the target gateway device 209. For example, the indication may include at least one of the following: an identifier of the terminal device 201, an identifier of the source access device 203, and an identifier of the target access device 207. Then, in response to the request for the switch from the core network device 211, the target gateway device 209 sends (440) a confirmation of the request to the core network device 211.

[0092] In some example embodiments, core network device 211 may send (445) a command for switching to source gateway device 205. For example, the command may instruct source gateway device 205 to release resources for communication with terminal device 201 by at least disabling the Internet Protocol security endpoint. In response to the command, source gateway device 205 may disabling the Internet Protocol security endpoint.

[0093] Then, in some example embodiments, an IEEE security EAP reauthentication process may be performed. After the target gateway device 209 has received the first AAA message corresponding to the IEEE security EAP reauthentication process and the transparent 5G AN to 5G AN container with the EAP security context (Rrk), the target gateway device 209 may continue with the remaining messages of the EAP reauthentication process. In addition, the IEEE security process may be performed through a 4-way handshake to establish a working key at the terminal device 201 and the target access device 207. When the reassociation and link security establishment are completed, the terminal device 201 may start sending uplink traffic, which may be processed by the target gateway device 209 based on the IPSec security context received through the N2 interface. Then, as Figure 4 As shown, the target gateway device 209 communicates with the terminal device 201 based on the same context associated with the terminal device 201 as when the source gateway device 205 and the terminal device 201 communicate (450).

[0094] In this way, flexible and efficient handover can be achieved between gateway devices of non-3GPP access in N2-based handover scenarios. Therefore, seamless connection to 5G services without interruption is allowed when changing WLAN access. Therefore, user experience can be significantly improved.

[0095] Figure 5FIG. 1 shows an example process of a UE registering with a 5GC in an Xn-based handover scenario according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to FIG. Figure 2 Describe process 500. For example, in this case, terminal device 201 can be implemented by UE 501, target access device 207 can be implemented by target AP 503, source gateway device 205 can be implemented by source TNGF 505, target gateway device 209 can be implemented by target TNGF 507, and core network device 211 can be implemented by AMF509.

[0096] like Figure 5 As shown, at 510, UE 501 decides to make a transition to target AP 503. At 511, after making the handover (HO) decision, UE 501 notifies the source TNGF 505 of its selected target AP 503. In this case, a message indicating the handover including the UE MAC address and the target AP MAC address is sent by UE 501 to the source TNGF 505. At 512-514, UE 501 issues a reassociation with the target AP 503 (providing the source AP MAC address).

[0097] Then, at 516, the target AP 503 issues a HO indication to the target TNGF 507, providing the UE MAC address and the source and target AP MAC addresses. At 518, the target TNGF 507 determines the source TNGF 505 based on the source AP MAC address. For example, the determination may use a target TNGF discovery that uses NRF, where the target TNGF discovery uses the target AP and SSID as search criteria. At 520, the target TNGF 507 issues an Xn UE context request that provides the UE MAC address and the source and target AP MAC addresses, as well as an address for receiving DL traffic (which is not delivered to the UE 501 and is forwarded to the target TNGF 507), such as the Internet Protocol address of the target TNGF 507. In response, the source TNGF 505 stops its IPSec state machine and, at 522, provides the UE context in an Xn UE context response. For example, the UE context may include a reference to the UE MAC address and the source and target AP MAC addresses. Figure 3At 524-526, when UE 501 joins target AP 503, the UE issues relevant EAP signaling to target TNGF 507 using the EAP reauthentication protocol, which is relayed by target AP 503. At 528, target TNGF 507 reuses the information received at 522 (e.g., EAP Rrk) to derive a new working key (such as a new PMK) for WLAN security through the EAP reauthentication process, while the IPSec SA security parameters remain unchanged, related to the previous PMK determined when the UE was most recently connected to the network (e.g., when the UE registered).

[0098] At 530-534, IEEE security procedures are performed, including subsequent EAP message exchanges, and 4-way handshakes to establish various keys required for secure WLAN communications. At 536-538, UE 501 begins to use target AP 503 to send uplink (UL) traffic. The target TNGF 507 starts the IPSec state machine using information received, for example, at step 522. At 540, the target TNGF 507 sends an Xn HO success to the source TNGF 505 to indicate the success of the HO and request the actual forwarding of the DL data stored at the source TNGF 505. At 542, the DL data stored at the source TNGF 505 is forwarded to the target TNGF 507. At 544, the target TNGF 507 sends an N2 path switching request to the AMF 509. The target TNGF 507 notifies the 5GC that the UE 501 has moved to the target AP 503 and provides a list of PDU sessions to be switched. The tunnel information of each PDU session to be switched is included in the N2 SM information and points to the target TNGF 507. At 546, the session update process is performed. At 548, an N2 path switch request is sent to the target TNGF 507. At 550, an indication for releasing resources is sent to the source TNGF 505.

[0099] As mentioned above Figure 3 All operations and features described are also applicable to the signaling flow 500 and have similar effects. For simplicity, the details will be omitted.

[0100] Figure 6 FIG. 1 shows an example process of a UE registering with a 5GC in an Xn-based handover scenario according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to FIG. Figure 2Describe process 600. For example, in this case, terminal device 201 can be implemented by UE 601, target access device 207 can be implemented by target AP 603, source gateway device 205 can be implemented by source TNGF 605, target gateway device 209 can be implemented by target TNGF 606, and core network device 211 can be implemented by AMF 607.

[0101] like Figure 6 As shown, at 610, UE 601 decides to make a transition to target AP 603. At 611, after making the HO decision, UE 601 notifies the source TNGF 605 of its selected target AP 603. In this case, a message indicating the handover decision from UE 601 is sent by UE 601 to the source TNGF 605, the message including the UE MAC address and the target AP MAC address. At 612-613, UE 601 issues a reassociation with target AP 603 (providing the source AP MAC address). Then, at 614, the target AP 603 issues a HO indication to the target TNGF 606, providing the UE MAC address and the source and target AP MAC addresses.

[0102] In addition, as triggered by the HO indication at 611, 615, and 612, the source TNGF 605 determines that a TNGF change is required. For example, the source TNGF 605 can determine the target TNGF 606 based on the target AP MAC address. At 617, the source TNGF 605 sends an N2 HO Required message to the AMF 607. The message may include TNGF service continuity information, such as an identifier of the target TNGF 606 to indicate the target TNGF 606, and may also include an IPSec context and a TNGF EAP security context, in particular, a reauthentication root key (Rrk) for establishing a WLAN security context when the target AP EAP is reauthenticated to avoid the need to perform a full EAP authentication process with the 5GC via the authentication server function (AUSF). At 618, the AMF 607 determines the target TNGF 606 based on the target AP MAC address. At 620, the AMF 607 performs HO preparation. For example, interactions with the SMF 608 and the UPF 609 are performed. At 622, AMF 607 sends a HO request to the target TNGF 606, where the transparent 5G AN to 5G AN container contains the TNGF service continuity information included in the N2 HO Required message. At 624, the target TNGF 606 responds with a HO Request Ack.

[0103] Then, at 626, a HO command is sent to the source TNGF 605. After receiving the handover command, the source TNGF 605 disables the original IPSec endpoint. At 628-630, the IEEE security EAP reauthentication process is performed. After the target TNGF 606 receives the first AAA message transfer corresponding to the IEEE security EAP reauthentication process and the transparent 5G AN to 5G AN container with the TNGF EAP security context (Rrk), the target TNGF 606 continues the remaining messages of the EAP reauthentication process. At 632, the IEEE security process is performed through a 4-way handshake to establish working keys at the UE 601 and the target AP 603. At 634-636, when the reassociation and link security establishment are completed, the UE 601 starts sending UL traffic, which can be processed by the target TNGF 606 based on the IPSec security context received through N2. At 638, an N2 HO Notification message is sent by the target TNGF 606 as defined in 3GPP TS 38.413. At 640, the HO Execution phase is performed. This phase includes interactions with the SMF 608 and the UPF 609. At 642, the AMF 607 sends a UE Context Release Command message to the source TNGF 605. The source TNGF 605 then releases resources and then sends a UE Context Release Complete message to the AMF 607 at 644.

[0104] As mentioned above Figure 4 All operations and features described are also applicable to process 600 and have similar effects. For simplicity, details will be omitted.

[0105] Figure 7 1 shows a flowchart of an example method for a terminal device according to some example embodiments of the present disclosure. The method 700 may be performed in a manner such as Figure 2 For the purpose of discussion, reference will be made to the terminal device 201. Figure 2 Method 700 is described.

[0106] At block 710, the terminal device 201 determines a target access device 207, via which the terminal device 201 communicates with the target gateway device 209. At block 720, the terminal device 201 sends a message indicating a switch from the source access device 203 to the target access device 207 to the source gateway device 205, via which the terminal device 201 communicates with the source gateway device 205. At block 730, the terminal device 201 communicates with the target gateway device 209 based on the same context associated with the terminal device 201 as when communicating with the source gateway device 205.

[0107] In some example embodiments, the context may include at least one of: security information for communication with the terminal device 201 at the target access device 207 ; and parameters associated with Internet Protocol security of the target gateway device 209 .

[0108] In some example embodiments, the message may include at least one of: an identifier of the terminal device 201 ; and an identifier of the target access device 207 .

[0109] In some example embodiments, the terminal device 201 may send a request to the target access device 207 for associating with the target access device 207 , the request including an identifier of the source access device 203 ; and receive a response to the request from the target access device 207 .

[0110] Those skilled in the art will appreciate that the above reference Figure 3-Figure 6 All operations and features described are also applicable to method 700 and have similar effects.

[0111] Figure 8 800 is a flowchart showing an example method for target access device 207 according to some example embodiments of the present disclosure. Figure 2 The target access device 207 is shown as being implemented. For the purpose of discussion, reference will be made to Figure 2 Method 800 is described.

[0112] At block 810, the target access device 207 receives a request from the terminal device 201 to associate with the target access device 207, the request indicating a switch from the source access device 205 to the target access device 207. At block 820, the target access device 207 sends a response to the request to the terminal device 201. At block 830, the target access device 207 sends an indication indicating the switch to the target gateway device 209, and the terminal device 201 communicates with the target gateway device 209 via the target access device 207.

[0113] In some example embodiments, the request may include an identifier of the source access device 203 .

[0114] In some example embodiments, the indication may include at least one of: an identifier of the terminal device 201 ; an identifier of the source access device 203 ; and an identifier of the target access device 207 .

[0115] Those skilled in the art will appreciate that the above reference Figure 3-Figure 6 All operations and features described are also applicable to method 800 and have similar effects.

[0116] Fig. 9900 is a flowchart of an example method for a source gateway device according to some example embodiments of the present disclosure. Figure 2 The source gateway device 205 is shown as being implemented. For the purpose of discussion, reference will be made to Figure 2 Method 900 is described.

[0117] At box 910, source gateway device 205 receives a message indicating a switch from source access device 203 to target access device 207 from terminal device 201, terminal device 201 communicates with source gateway device 205 via source access device 203, and terminal device 201 communicates with target gateway device 209 via target access device 207. At box 920, source gateway device 205 determines that a change from source gateway device to target gateway device is required based on the message. At box 930, source gateway device 205 receives a request for a context associated with terminal device 201 from target gateway device 209. At box 940, source gateway device 205 sends the context to target gateway device 209.

[0118] In some example embodiments, the message may include at least one of: an identifier of the terminal device 201 ; and an identifier of the target access device 207 .

[0119] In some example embodiments, the request may include at least one of: an identifier of the terminal device 201 ; an identifier of the source access device; an identifier of the target access device 207 ; and an Internet Protocol address of the target gateway device 209 .

[0120] In some example embodiments, the context may include at least one of: security information for communication with the terminal device 201 at the target access device 207 ; and parameters associated with Internet Protocol security of the target gateway device 209 .

[0121] In some example embodiments, source gateway device 205 may free up resources for communication with terminal device 201 by at least disabling an Internet Protocol security endpoint.

[0122] Those skilled in the art will appreciate that the above reference Figure 3 and Figure 5 All operations and features described are also applicable to method 900 and have similar effects.

[0123] Fig.10 1 shows a flowchart of an example method for the target gateway device 209 according to some example embodiments of the present disclosure. The method 1000 may be performed in the following manner: Figure 2 The target gateway device 209 is shown as being implemented. For the purpose of discussion, reference will be made to Figure 2 Method 1000 is described.

[0124] At block 1010, the target gateway device 209 receives an indication of a handover of the terminal device 210 from the source access device 203 to the target access device 217 from the target access device 207, the terminal device 201 communicates with the target gateway device 209 via the target access device 207, and the terminal device communicates with the source gateway device 205 via the source access device 203. At block 1020, the target gateway device 209 sends a request for a context associated with the terminal device 201 to the source gateway device 205. At block 1030, the target gateway device 209 receives the context from the source gateway device 205. At block 1040, the target gateway device 209 communicates with the terminal device 201 based on the context.

[0125] In some example embodiments, the indication may include at least one of: an identifier of the terminal device 201 ; an identifier of the source access device; and an identifier of the target access device 207 .

[0126] In some example embodiments, target gateway device 209 may determine source gateway device 205 based on an identifier of the source access device included in the indication.

[0127] In some example embodiments, the request may include at least one of: an identifier of the terminal device 201 ; an identifier of the source access device; an identifier of the target access device 207 ; and an Internet Protocol address of the target gateway device 209 .

[0128] In some example embodiments, the context may include at least one of: security information for communication with the terminal device 201 at the target access device 207 ; and parameters associated with Internet Protocol security of the target gateway device 209 .

[0129] Those skilled in the art will appreciate that the above reference Figure 3 and Figure 5 All operations and features described are also applicable to method 1000 and have similar effects.

[0130] Fig.11 FIG. 1100 is a flowchart of an example method for a source gateway device according to some other example embodiments of the present disclosure. Figure 2 The source gateway device 205 is shown as being implemented. For the purpose of discussion, reference will be made to Figure 2 Method 1100 is described.

[0131] At block 1110, source gateway device 205 receives a first message from terminal device 201 indicating a switch from source access device 203 to target access device 207. At block 1120, source gateway device 205 determines that a change from source gateway device to target gateway device is required based on the first message. At block 1130, source gateway device 205 sends a second message indicating the switch to core network device 211. At block 1140, source gateway device 205 receives a command for the switch from core network device 211.

[0132] In some example embodiments, source gateway device 205 may, in response to the command, release resources used for communication with terminal device 201 by at least disabling the Internet Protocol security endpoint.

[0133] In some example embodiments, the first message may include at least one of: an identifier of the terminal device 201 ; and an identifier of the target access device 207 .

[0134] In some example embodiments, source gateway device 205 may determine target gateway device 209 based on an identifier of target access device 207 .

[0135] In some example embodiments, the second message may include at least one of: an identifier of the target access device 207; an identifier of the target gateway device 209; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0136] Those skilled in the art will appreciate that the above reference Figure 4 and Figure 6 All operations and features described are also applicable to method 1100 and have similar effects.

[0137] Fig.12 FIG. 12 is a flowchart showing an example method for the target gateway device 209 according to some other example embodiments of the present disclosure. The method 1200 may be performed in a manner such as Figure 2 The target gateway device 209 is shown as being implemented. For the purpose of discussion, reference will be made to Figure 2 Describe method 1200.

[0138] At block 1210, the target gateway device 209 receives a request for handover of the terminal device 201 from the source access device 203 to the target access device 207 from the core network device 211, the terminal device 201 communicates with the source gateway device 205 via the source access device 203, and the terminal device 201 communicates with the target gateway device 209 via the target access device 207. At block 1220, the target gateway device 209 receives an indication indicating the handover from the target access device 207. At block 1230, the target gateway device 209 sends a confirmation of the request to the core network device 211. At block 1240, the target gateway device 209 communicates with the terminal device 201 based on the same context associated with the terminal device 201 as when the source gateway device 205 and the terminal device 201 communicate.

[0139] In some example embodiments, the request may include at least one of: an identifier of the target gateway device 209; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0140] In some example embodiments, the indication may include at least one of: an identifier of the terminal device 201 ; an identifier of the source access device; and an identifier of the target access device 207 .

[0141] In some example embodiments, the context may include at least one of: security information for communication with the terminal device 201 at the target access device 207 ; and parameters associated with Internet Protocol security of the target gateway device 209 .

[0142] Those skilled in the art will appreciate that the above reference Figure 4 and Figure 6 All operations and features described are also applicable to method 1200 and have similar effects.

[0143] Fig.13 1 shows a flowchart of an example method for a core network device 211 according to some example embodiments of the present disclosure. The method 1300 may be performed in a Figure 2 For the purpose of discussion, reference will be made to Figure 2 Describe method 1300.

[0144] At block 1310, the core network device 211 receives a second message from the source gateway device 205 indicating the handover of the terminal device 201 from the source access device 203 to the target access device 207, the terminal device 201 communicates with the source gateway device 205 via the source access device 203, and the terminal device 201 communicates with the target gateway device 209 via the target access device 207. At block 1320, the core network device 211 determines the target gateway device 209 based on the second message. At block 1330, the core network device 211 sends a request for the handover to the target gateway device 209. At block 1340, the core network device 211 receives a confirmation of the request from the target gateway device 209.

[0145] In some example embodiments, the second message may include at least one of: an identifier of the target access device 207; an identifier of the target gateway device 209; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0146] In some example embodiments, the request may include at least one of: an identifier of the target gateway device 209; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0147] In some example embodiments, the core network device 211 may perform preparation for the handover based on the second message.

[0148] In some example embodiments, the core network device 211 may send a command for the switch to the source gateway device 205 , where the command is used to release resources used for communication with the terminal device 201 by at least disabling the Internet Protocol security endpoint.

[0149] Those skilled in the art will appreciate that the above reference Figure 4 and Figure 6 All operations and features described are also applicable to method 1300 and have similar effects.

[0150] Fig.14 1 is a simplified block diagram of a device 1400 suitable for implementing an example embodiment of the present disclosure. The device 1400 may be configured as follows: Figure 2 The terminal device 201, source gateway device 205, target access device 207, target gateway device 209 and core network device 211 are shown as being implemented, or are implemented as a part of these devices.

[0151] As shown, the device 1400 includes a processor 1410, a memory 1420 coupled to the processor 1410, a communication module 1430 coupled to the processor 1410, and a communication interface (not shown) coupled to the communication module 1430. The memory 1420 stores at least a program 1440. The communication module 1430 is used for bidirectional communication, for example, via multiple antennas. The communication interface can represent any interface necessary for communication.

[0152] Assume that program 1440 includes program instructions that, when executed by associated processor 1410, enable device 1400 to operate in accordance with example embodiments of the present disclosure, as referred to herein. Figure 2-Figure 6 The example embodiments herein may be implemented by computer software executable by a processor 1410 of the device 1400, or by hardware, or by a combination of software and hardware. The processor 1410 may be configured to implement various example embodiments of the present disclosure.

[0153] Memory 1420 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, such as non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory, as non-limiting examples. Although only one memory 1420 is shown in device 1400, multiple physically distinct memory modules may be present in device 1400. Processor 1410 may be of any type suitable for a local technology network and may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture, as non-limiting examples. Device 1400 may have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock that synchronizes a main processor.

[0154] When the device 1400 acts as the terminal device 201 or a part of the terminal device 201, the processor 1410 and the communication module 1430 can cooperate to implement the above reference Figure 7 When the device 1400 acts as a target access device 207 or a part of the target access device 207, the processor 1410 and the communication module 1430 can cooperate to implement the above reference Figure 8 When the device 1400 acts as a source gateway device 205 or a part of the source gateway device 205, the processor 1410 and the communication module 1430 can cooperate to implement the above reference Fig. 9 and Fig.11When the device 1400 acts as a target gateway device 209 or a part of the target gateway device 209, the processor 1410 and the communication module 1430 can cooperate to implement the above reference Fig.10 and Fig.12 When the device 1400 acts as a core network device 211 or a part of the core network device 211, the processor 1410 and the communication module 1430 can cooperate to implement the method 1000 or 1200 as described above. Fig.13 The method 1300 is described above. Figure 2-Figure 13 All operations and features described are also applicable to the device 1400 and have similar effects. For simplicity, the details will be omitted.

[0155] In general, various example embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device. Although various aspects of the example embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other illustrations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0156] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer executable instructions, such as those included in a program module, which are executed in a device on a target real or virtual processor to perform the above referenced Figure 7-Figure 13 Any of the methods 700-1300 described. Typically, a program module includes a routine, program, library, object, class, component, data structure, etc. that performs a specific task or implements a specific abstract data type. In various example embodiments, the functions of the program modules can be combined or split between program modules as needed. The machine executable instructions of the program modules can be executed in a local or distributed device. In a distributed device, the program modules can be located in both local and remote storage media.

[0157] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code, when executed by the processor or controller, enables the function / operation specified in the flow chart and / or block diagram to be realized. The program code can be executed completely on the machine, partially on the machine, executed as an independent software package, partially on the machine and partially on a remote machine, or completely on a remote computer or server.

[0158] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals and computer-readable media.

[0159] Computer readable medium can be computer readable signal medium or computer readable storage medium.Computer readable medium can include but not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, device or equipment or any suitable combination of the foregoing.More specific examples of computer readable storage medium will include electrical connection with one or more wires, portable computer floppy disk, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), digital versatile disk (DVD), optical storage device, magnetic storage device or any suitable combination of the foregoing.

[0160] In addition, although the operations are described in a specific order, this should not be understood as requiring such operations to be performed in the specific order shown or in sequence, or requiring the execution of all the operations shown to obtain the desired result. In some cases, multitasking and parallel processing can be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be interpreted as limitations on the scope of the present disclosure, but can be interpreted as descriptions of features peculiar to specific example embodiments. Certain features described in the context of separate example embodiments may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple example embodiments individually or in any suitable sub-combination.

[0161] Although the disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0162] Various example embodiments of these techniques have been described. In addition to or as an alternative to the above, the following examples are described. Features described in any of the following examples can be used with any of the other examples described herein.

[0163] In some aspects, a method includes: at a terminal device, determining a target access device, the terminal device communicating with a target gateway device via the target access device; sending a message indicating a switch from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device; and communicating with the target gateway device based on the same context associated with the terminal device as when communicating with the source gateway device.

[0164] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0165] In some example embodiments, the message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0166] In some example embodiments, the method further includes sending a request to the target access device to associate with the target access device, the request including an identifier of the source access device; and receiving a response to the request from the target access device.

[0167] In some aspects, a method includes: receiving, at a target access device, a request from a terminal device to associate with the target access device, the request indicating a switch from a source access device to the target access device; sending a response to the request to the terminal device; and sending an indication indicating the switch to a target gateway device, the terminal device communicating with the target gateway device via the target access device.

[0168] In some example embodiments, the request includes an identifier of the source access device.

[0169] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0170] In some aspects, a method includes: at a source gateway device, receiving a message from a terminal device indicating a switch from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; determining based on the message that a change from the source gateway device to the target gateway device is required; receiving a request for a context associated with the terminal device from the target gateway device; and sending the context to the target gateway device.

[0171] In some example embodiments, the message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0172] In some example embodiments, the request includes at least one of: an identifier of the terminal device; an identifier of the source access device; an identifier of the target access device; and an Internet Protocol address of the target gateway device.

[0173] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0174] In some example embodiments, the method further comprises releasing resources for communication with the terminal device by disabling at least the Internet Protocol Security endpoint.

[0175] In some aspects, a method includes: at a target gateway device, receiving an indication from a target access device indicating a switch of a terminal device from a source access device to a target access device, the terminal device communicating with a target gateway device via the target access device, and the terminal device communicating with a source gateway device via the source access device; sending a request for a context associated with the terminal device to the source gateway device; receiving the context from the source gateway device; and communicating with the terminal device based on the context.

[0176] In some example embodiments, the indication includes at least one of: an identifier of the terminal device; an identifier of the source access device.

[0177] In some example embodiments, the method further comprises determining a source gateway device based on an identifier of a source access device included in the indication.

[0178] In some example embodiments, the request includes at least one of: an identifier of the terminal device; an identifier of the source access device; an identifier of the target access device; and an Internet Protocol address of the target gateway device.

[0179] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0180] In some aspects, a method includes: at a source gateway device, receiving a first message from a terminal device indicating a switch from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; determining that a change from the source gateway device to the target gateway device is required based on the first message; sending a second message indicating the switch to a core network device; and receiving a command for the switch from the core network device.

[0181] In some example embodiments, the method further comprises, in response to the command, releasing resources for communication with the terminal device by disabling at least the Internet Protocol Security endpoint.

[0182] In some example embodiments, the first message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0183] In some example embodiments, the method further comprises determining a target gateway device based on an identifier of the target access device.

[0184] In some example embodiments, the second message includes at least one of: an identifier of a target access device; an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0185] In some aspects, a method includes: at a target gateway device, receiving a request from a core network device for switching of a terminal device from a source access device to a target access device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with a target gateway device via the target access device; receiving an indication indicating the switching from the target access device; sending a confirmation of the request to the core network device; and communicating with the terminal device based on a context associated with the terminal device that is the same as when the source gateway device and the terminal device communicate.

[0186] In some example embodiments, the request includes at least one of: an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0187] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0188] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0189] In some aspects, a method includes: at a core network device, receiving a second message from a source gateway device indicating a switch of a terminal device from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with a target gateway device via the target access device; determining a target gateway device based on the second message; sending a request for the switch to the target gateway device; and receiving a confirmation of the request from the target gateway device.

[0190] In some example embodiments, the second message includes at least one of: an identifier of a target access device; an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0191] In some example embodiments, the request includes at least one of: an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0192] In some example embodiments, the method further comprises performing preparation for the handover based on the second message.

[0193] In some example embodiments, the method further comprises: sending a command for the switch to the source gateway device, the command being used to release resources for communication with the terminal device by at least disabling an Internet Protocol security endpoint.

[0194] In some aspects, a terminal device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the terminal device to: determine a target access device, via which the terminal device communicates with a target gateway device; send a message to a source gateway device indicating a switch from a source access device to a target access device, via which the terminal device communicates with the source gateway device; and communicate with the target gateway device based on the same context associated with the terminal device as when communicating with the source gateway device.

[0195] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0196] In some example embodiments, the message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0197] In some example embodiments, the terminal device is further caused to: send a request to the target access device to associate with the target access device, the request including an identifier of the source access device; and receive a response to the request from the target access device.

[0198] In some aspects, a target access device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the target access device to: receive a request from a terminal device to associate with the target access device, the request indicating a switch from a source access device to a target access device; send a response to the request to the terminal device; and send an indication indicating the switch to a target gateway device, the terminal device communicating with the target gateway device via the target access device.

[0199] In some example embodiments, the request includes an identifier of the source access device.

[0200] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0201] In some aspects, a source gateway device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the source gateway device to: receive a message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; determine based on the message that a change from the source gateway device to the target gateway device is required; receive a request for a context associated with the terminal device from the target gateway device; and send the context to the target gateway device.

[0202] In some example embodiments, the message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0203] In some example embodiments, the request includes at least one of: an identifier of the terminal device; an identifier of the source access device; an identifier of the target access device; and an Internet Protocol address of the target gateway device.

[0204] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0205] In some example embodiments, the source gateway device is further caused to release resources used for communications with the terminal device by disabling at least the Internet Protocol Security endpoint.

[0206] In some aspects, a target gateway device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the target gateway device to: receive an indication from a target access device indicating a switch of a terminal device from a source access device to a target access device, the terminal device communicates with the target gateway device via the target access device, and the terminal device communicates with the source gateway device via the source access device; send a request for a context associated with the terminal device to the source gateway device; receive the context from the source gateway device; and communicate with the terminal device based on the context.

[0207] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0208] In some example embodiments, the target gateway device is further caused to determine the source gateway device based on an identifier of the source access device included in the indication.

[0209] In some example embodiments, the request includes at least one of: an identifier of the terminal device; an identifier of the source access device; an identifier of the target access device; and an Internet Protocol address of the target gateway device.

[0210] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0211] In some aspects, a source gateway device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the source gateway device to: receive a first message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with the target gateway device via the target access device; determine based on the first message that a change from the source gateway device to the target gateway device is required; send a second message indicating the switch to a core network device; and receive a command for the switch from the core network device.

[0212] In some example embodiments, the source gateway device is further caused to, in response to the command, release resources used for communications with the terminal device by disabling at least the Internet Protocol Security endpoint.

[0213] In some example embodiments, the first message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0214] In some example embodiments, the source gateway device is further caused to determine the target gateway device based on an identifier of the target access device.

[0215] In some example embodiments, the second message includes at least one of: an identifier of a target access device; an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0216] In some aspects, a target gateway device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the target gateway device to: receive a request from a core network device for switching of a terminal device from a source access device to a target access device, the terminal device communicates with a source gateway device via the source access device, and the terminal device communicates with a target gateway device via the target access device; receive an indication indicating the switching from the target access device; send a confirmation of the request to the core network device; and communicate with the terminal device based on a context associated with the terminal device that is the same as when the source gateway device and the terminal device communicate.

[0217] In some example embodiments, the request includes at least one of: an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0218] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0219] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0220] In some aspects, a core network device comprises: at least one processor; and at least one memory comprising computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the core network device to: receive a second message from a source gateway device indicating a switch of a terminal device from a source access device to a target access device, the terminal device communicates with the source gateway device via the source access device, and the terminal device communicates with a target gateway device via the target access device; determine a target gateway device based on the second message; send a request for the switch to the target gateway device; and receive a confirmation of the request from the target gateway device.

[0221] In some example embodiments, the second message includes at least one of: an identifier of a target access device; an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0222] In some example embodiments, the request includes at least one of: an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0223] In some example embodiments, the core network device is further caused to: perform preparation for the handover based on the second message.

[0224] In some example embodiments, the core network device is further caused to: send a command for the switch to the source gateway device, the command being used to release resources for communication with the terminal device by at least disabling an Internet Protocol security endpoint.

[0225] In some aspects, an apparatus includes: a component for determining a target access device, via which a terminal device communicates with a target gateway device; a component for sending a message indicating a switch from a source access device to a target access device, via which the terminal device communicates with the source gateway device; and a component for communicating with the target gateway device based on the same context associated with the terminal device as when communicating with the source gateway device.

[0226] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0227] In some example embodiments, the message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0228] In some example embodiments, the apparatus further comprises: means for sending a request to the target access device to associate with the target access device, the request comprising an identifier of the source access device; and means for receiving a response to the request from the target access device.

[0229] In some aspects, an apparatus includes: a component for receiving a request from a terminal device to associate with a target access device, the request indicating a switch from a source access device to a target access device; a component for sending a response to the request to the terminal device; and a component for sending an indication indicating the switch to a target gateway device, the terminal device communicating with the target gateway device via the target access device.

[0230] In some example embodiments, the request includes an identifier of the source access device.

[0231] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0232] In some aspects, an apparatus includes: a component for receiving a message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with a target gateway device via the target access device; a component for determining that a change from the source gateway device to the target gateway device is required based on the message; a component for receiving a request for a context associated with the terminal device from the target gateway device; and a component for sending the context to the target gateway device.

[0233] In some example embodiments, the message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0234] In some example embodiments, the request includes at least one of: an identifier of the terminal device; an identifier of the source access device; an identifier of the target access device; and an Internet Protocol address of the target gateway device.

[0235] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0236] In some example embodiments, the apparatus further comprises means for releasing resources for communication with the terminal device by disabling at least the Internet Protocol Security endpoint.

[0237] In some aspects, an apparatus includes: a component for receiving an indication from a target access device indicating a switch of a terminal device from a source access device to a target access device, the terminal device communicating with a target gateway device via the target access device, and the terminal device communicating with a source gateway device via the source access device; a component for sending a request for a context associated with the terminal device to the source gateway device; a component for receiving the context from the source gateway device; and a component for communicating with the terminal device based on the context.

[0238] In some example embodiments, the indication includes at least one of: an identifier of the terminal device; an identifier of the source access device.

[0239] In some example embodiments, the apparatus further comprises means for determining a source gateway device based on an identifier of the source access device included in the indication.

[0240] In some example embodiments, the request includes at least one of: an identifier of the terminal device; an identifier of the source access device; an identifier of the target access device; and an Internet Protocol address of the target gateway device.

[0241] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0242] In some aspects, an apparatus includes: a component for receiving a first message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with a target gateway device via the target access device; a component for determining a change required from the source gateway device to the target gateway device based on the first message; a component for sending a second message indicating the switch to a core network device; and a component for receiving a command for the switch from the core network device.

[0243] In some example embodiments, the apparatus further comprises means for releasing resources for communication with the terminal device by disabling at least an Internet Protocol security endpoint in response to the command.

[0244] In some example embodiments, the first message includes at least one of: an identifier of the terminal device; and an identifier of the target access device.

[0245] In some example embodiments, the apparatus further comprises means for determining a target gateway device based on an identifier of the target access device.

[0246] In some example embodiments, the second message includes at least one of: an identifier of a target access device; an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0247] In some aspects, an apparatus includes: a component for receiving a request for switching of a terminal device from a source access device to a target access device from a core network device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with a target gateway device via the target access device; a component for receiving an indication indicating the switching from the target access device; a component for sending a confirmation of the request to the core network device; and a component for communicating with the terminal device based on a context associated with the terminal device that is the same as when the source gateway device and the terminal device communicate.

[0248] In some example embodiments, the request includes at least one of: an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0249] In some example embodiments, the indication includes at least one of: an identifier of a terminal device; an identifier of a source access device; and an identifier of a target access device.

[0250] In some example embodiments, the context includes at least one of: security information for communications with the terminal device at the target access device; and parameters associated with Internet Protocol Security of the target gateway device.

[0251] In some aspects, an apparatus includes: a component for receiving a second message from a source gateway device indicating a switch of a terminal device from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; a component for determining a target gateway device based on the second message; a component for sending a request for the switch to the target gateway device; and a component for receiving a confirmation of the request from the target gateway device.

[0252] In some example embodiments, the second message includes at least one of: an identifier of a target access device; an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0253] In some example embodiments, the request includes at least one of: an identifier of a target gateway device; a context associated with Internet Protocol security; and a context associated with Authentication Protocol security.

[0254] In some example embodiments, the method further comprises performing preparation for the handover based on the second message.

[0255] In some example embodiments, the apparatus further comprises: means for sending a command for the switching to the source gateway device, the command being used to release resources for communication with the terminal device by at least disabling an Internet Protocol security endpoint.

[0256] In some aspects, a computer-readable storage medium includes program instructions stored thereon, which when executed by a processor of a device causes the device to perform methods according to some example embodiments of the present disclosure.

Claims

1. A terminal device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: Determine a target access device, the terminal device communicates with a target gateway device via the target access device; Sending a message indicating switching from the source access device to the target access device to the source gateway device, the terminal device communicating with the source gateway device via the source access device; and The target gateway device is communicated with based on the same context associated with the terminal device as when communicating with the source gateway device.

2. The terminal device according to claim 1, wherein the context comprises at least one of the following: security information for communication with the terminal device at the target access device; and Parameters associated with Internet Protocol Security of the target gateway device.

3. The terminal device according to claim 1 or 2, wherein the message comprises at least one of the following: An identifier of the terminal device; and The identifier of the target access device.

4. The terminal device according to any one of claims 1 to 3, wherein the terminal device is further configured to: sending a request to the target access device to associate with the target access device, the request including an identifier of the source access device; and A response to the request is received from the target access device.

5. A target access device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the target access device to: receiving, from a terminal device, a request to associate with the target access device, the request indicating a switch from a source access device to the target access device; sending a response to the request to the terminal device; as well as An indication indicating the switching is sent to a target gateway device, and the terminal device communicates with the target gateway device via the target access device.

6. The target access device of claim 5, wherein the request includes an identifier of the source access device.

7. The target access device according to claim 6, wherein the indication comprises at least one of the following: An identifier of the terminal device; the identifier of the source access device; and The identifier of the target access device.

8. A source gateway device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the source gateway device to: receiving a message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; determining based on the message that a change from the source gateway device to a target gateway device is required; receiving, from the target gateway device, a request for a context associated with the terminal device; as well as The context is sent to the target gateway device.

9. The source gateway device according to claim 8, wherein the message comprises at least one of the following: An identifier of the terminal device; and The identifier of the target access device.

10. The source gateway device according to claim 8 or 9, wherein the request comprises at least one of the following: the identifier of the terminal device; An identifier of the source access device; The identifier of the target access device; and The Internet Protocol address of the target gateway device.

11. The source gateway device according to any one of claims 8 to 10, wherein the context comprises at least one of the following: security information for communication with the terminal device at the target access device; and Parameters associated with Internet Protocol Security of the target gateway device.

12. The source gateway device according to any one of claims 8 to 11, wherein the source gateway device is further configured to: Resources used for communication with the terminal device are freed by disabling at least an Internet Protocol security endpoint.

13. A target gateway device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the target gateway device to: Receiving, from a target access device, an indication of switching of a terminal device from a source access device to the target access device, the terminal device communicating with the target gateway device via the target access device, and the terminal device communicating with the source gateway device via the source access device; sending a request for a context associated with the terminal device to the source gateway device; receiving the context from the source gateway device; as well as Communicate with the terminal device based on the context.

14. The target gateway device according to claim 13, wherein the indication comprises at least one of the following: An identifier of the terminal device; An identifier of the source access device; and The identifier of the target access device.

15. The target gateway device according to claim 14, wherein the target gateway device is further configured to: The source gateway device is determined based on the identifier of the source access device included in the indication.

16. The target gateway device according to claim 14 or 15, wherein the request comprises at least one of the following: the identifier of the terminal device; the identifier of the source access device; The identifier of the target access device; and The Internet Protocol address of the target gateway device.

17. The target gateway device according to any one of claims 13 to 16, wherein the context comprises at least one of the following: security information for communication with the terminal device at the target access device; and Parameters associated with Internet Protocol Security of the target gateway device.

18. A source gateway device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the source gateway device to: receiving a first message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; Based on the first message, determining that a change from the source gateway device to the target gateway device is required; Sending a second message indicating the switching to the core network device; as well as A command for the switching is received from the core network device.

19. The source gateway device according to claim 18, wherein the source gateway device is further caused to: In response to the command, resources used for communication with the terminal device are released by at least disabling an Internet Protocol security endpoint.

20. The source gateway device according to claim 18 or 19, wherein the first message includes at least one of the following: An identifier of the terminal device; and The identifier of the target access device.

21. The source gateway device according to claim 20, wherein the source gateway device is further caused to: The target gateway device is determined based on the identifier of the target access device.

22. The source gateway device according to claim 20 or 21, wherein the second message comprises at least one of the following: the identifier of the target access device; An identifier of the target gateway device; context associated with Internet Protocol Security; as well as A context associated with authentication protocol security.

23. A target gateway device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the target gateway device to: Receiving, from a core network device, a request for handover of a terminal device from a source access device to a target access device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; receiving an indication indicating the switching from the target access device; Sending a confirmation of the request to the core network device; as well as Communicating with the terminal device based on the same context associated with the terminal device as when communicating with the source gateway device.

24. The target gateway device according to claim 23, wherein the request comprises at least one of the following: An identifier of the target gateway device; context related to Internet Protocol Security; and A context associated with authentication protocol security.

25. The target gateway device according to claim 23 or 24, wherein the indication comprises at least one of the following: An identifier of the terminal device; An identifier of the source access device; and The identifier of the target access device.

26. The target gateway device according to any one of claims 23 to 25, wherein the context comprises at least one of the following: security information for communication with the terminal device at the target access device; and Parameters associated with Internet Protocol Security of the target gateway device.

27. A core network device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the core network device to: receiving, from a source gateway device, a second message indicating switching of a terminal device from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; determining the target gateway device based on the second message; Sending a request for the switching to the target gateway device; as well as An acknowledgement of the request is received from the target gateway device.

28. The core network device according to claim 27, wherein the second message includes at least one of the following: An identifier of the target access device; An identifier of the target gateway device; context related to Internet Protocol Security; and A context associated with authentication protocol security.

29. The core network device according to claim 28, wherein the request comprises at least one of the following: An identifier of the target gateway device; context related to Internet Protocol Security; and A context associated with authentication protocol security.

30. The core network device according to any one of claims 27 to 29, wherein the core network device is further configured to: Preparation for the handover is performed based on the second message.

31. The core network device according to any one of claims 27 to 30, wherein the core network device is further configured to: A command for the switching is sent to the source gateway device, the command being used to release resources used for communication with the terminal device by at least disabling an Internet Protocol security endpoint.

32. A method comprising: At the terminal device, Determine a target access device, the terminal device communicates with a target gateway device via the target access device; Sending a message indicating switching from the source access device to the target access device to the source gateway device, the terminal device communicating with the source gateway device via the source access device; and The target gateway device is communicated with based on the same context associated with the terminal device as when communicating with the source gateway device.

33. A method comprising: At the target access device, receiving, from a terminal device, a request to associate with the target access device, the request indicating a switch from a source access device to the target access device; sending a response to the request to the terminal device; as well as An indication indicating the switching is sent to a target gateway device, and the terminal device communicates with the target gateway device via the target access device.

34. A method comprising: At the source gateway device, receiving a message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; Based on the message, determining that a change from the source gateway device to a target gateway device is required; receiving, from the target gateway device, a request for a context associated with the terminal device; as well as The context is sent to the target gateway device.

35. A method comprising: At the target gateway device, Receiving, from a target access device, an indication of switching of a terminal device from a source access device to the target access device, the terminal device communicating with the target gateway device via the target access device, and the terminal device communicating with the source gateway device via the source access device; sending a request for a context associated with the terminal device to the source gateway device; receiving the context from the source gateway device; as well as Communicate with the terminal device based on the context.

36. A method comprising: At the source gateway device, receiving a first message indicating a switch from a source access device to a target access device from a terminal device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; Based on the first message, determining that a change from the source gateway device to the target gateway device is required; Sending a second message indicating the switching to the core network device; as well as A command for the switching is received from the core network device.

37. A method comprising: At the target gateway device, Receiving, from a core network device, a request for handover of a terminal device from a source access device to a target access device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; receiving an indication indicating the switching from the target access device; Sending a confirmation of the request to the core network device; as well as Communicating with the terminal device based on the same context associated with the terminal device as when communicating with the source gateway device.

38. A method comprising: At the core network equipment, receiving, from a source gateway device, a second message indicating switching of a terminal device from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, and the terminal device communicating with the target gateway device via the target access device; determining the target gateway device based on the second message; Sending a request for the switching to the target gateway device; as well as An acknowledgement of the request is received from the target gateway device.

39. An apparatus comprising: A component for determining a target access device, via which the terminal device communicates with the target gateway device; a component for sending a message indicating a switch from a source access device to the target access device to a source gateway device, the terminal device communicating with the source gateway device via the source access device; as well as Means for communicating with the target gateway device based on the same context associated with the terminal device as when communicating with the source gateway device.

40. An apparatus comprising: means for receiving, from a terminal device, a request to associate with a target access device, the request indicating a switch from a source access device to the target access device; means for sending a response to the request to the terminal device; as well as A component used to send an indication of the switching to a target gateway device, wherein the terminal device communicates with the target gateway device via the target access device.

41. An apparatus comprising: means for receiving a message indicating a handover from a source access device to a target access device from a terminal device, the terminal device communicating with a source gateway device via the source access device, the terminal device communicating with a target gateway device via the target access device; means for determining, based on the message, that a change from the source gateway device to a target gateway device is required; means for receiving, from the target gateway device, a request for a context associated with the terminal device; as well as Means for sending the context to the target gateway device.

42. An apparatus comprising: A component for receiving an indication from a target access device indicating a handover of a terminal device from a source access device to the target access device, the terminal device communicating with a target gateway device via the target access device, the terminal device communicating with a source gateway device via the source access device; means for sending a request to the source gateway device for a context associated with the terminal device; means for receiving said context from said source gateway device; as well as Means for communicating with the terminal device based on the context.

43. An apparatus comprising: a component for receiving a first message indicating a handover from a source access device to a target access device from a terminal device, the terminal device communicating with a source gateway device via the source access device, the terminal device communicating with a target gateway device via the target access device; means for determining, based on the first message, that a change from the source gateway device to the target gateway device is required; A component for sending a second message indicating the switching to a core network device; as well as A component for receiving a command for the switching from the core network device.

44. An apparatus comprising: A component for receiving a request for handover of a terminal device from a source access device to a target access device from a core network device, the terminal device communicating with a source gateway device via the source access device, and the terminal device communicating with a target gateway device via the target access device; means for receiving an indication from the target access device indicating the switching; A component for sending a confirmation of the request to the core network device; as well as Means for communicating with the terminal device based on the same context associated with the terminal device as when communicating with the source gateway device.

45. An apparatus comprising: a component for receiving, from a source gateway device, a second message indicating a handover of a terminal device from a source access device to a target access device, the terminal device communicating with the source gateway device via the source access device, the terminal device communicating with the target gateway device via the target access device; means for determining said target gateway device based on said second message; A component for sending a request for the switching to the target gateway device; as well as Means for receiving an acknowledgement of the request from the target gateway device.

46. ​​A computer-readable storage medium comprising program instructions stored thereon, which instructions, when executed by a processor of a device, cause the device to perform the method according to any one of claims 32 to 38.

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