Method for direct switching application access between epdg and n3iwf no-3GPP access functions
By monitoring application activity status and directly switching between untrusted non-3GPP gateways during periods of low activity, the problem of interruption during non-3GPP access gateway handover between different 3GPP systems in existing technologies is solved, enabling continuous application operation and improving user experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-26
- Publication Date
- 2026-03-27
AI Technical Summary
In existing technologies, there are interruption and discontinuity issues when UEs switch between non-3GPP access gateways in different 3GPP systems. In particular, when switching from one untrusted non-3GPP access gateway to another, direct switching cannot be achieved, resulting in a degraded user experience.
By monitoring the activity status of applications, when an application is in a low-activity state, it directly switches between untrusted non-3GPP gateways, releases existing connections and establishes new connections, and adopts the 'disconnect first, connect later' or 'establish and release' approach to reduce downtime and achieve non-seamless handover.
Even with a slight and temporary drop in service quality, the application was able to continue running, reducing handover interruptions and improving the user experience.
Smart Images
Figure CN121753472A_ABST
Abstract
Description
Technical Field
[0001] This document generally describes methods and apparatus for operating in wireless communication systems, such as (but not limited to) wireless communication systems referred to as 3GPP systems as described in standard documents. Background Technology
[0002] With the integration of various 3GPP and non-3GPP technologies (such as 5G) and wireless LANs (such as Wi-Fi), mobile networks are becoming increasingly complex and diverse. Network operators have developed various gateways, such as Evolved Packet Data Gateways (ePDGs) and Non-3GPP Interoperability Functions (N3IWFs), to provide untrusted non-3GPP access to the 3GPP core network. The ePDG acts as the termination node for Internet Protocol Security (IPSec) tunnels to enable secure data exchange between UEs running applications connected via untrusted non-3GPP access networks (e.g., Wi-Fi) and Long Term Evolution (LTE) network systems (known as Evolved Packet System EPS). Similarly, the N3IWF, which also supports IPSec connectivity to the UE, is responsible for interoperability between UEs running applications connected via untrusted non-3GPP networks and 5G systems (5GS). Typically, applications running on non-3GPP networks will not consider switching to a 3GPP system once another 3GPP system becomes available, even if switching to a 3GPP system would be beneficial to the user experience.
[0003] Currently, 3GPP documents do not provide technologies for direct handover (i.e., without intra-3GPP or inter-3GPP handover) from a first non-3GPP access (e.g., ePDG) of a first 3GPP system to a second non-3GPP access (e.g., N3IWF) of a second 3GPP system. Figure 1 This is a graphical representation of the current situation described above.
[0004] Intra-3GPP handover between EPS core 110 (referred to as EPC) and 5GS core 120 (referred to as 5GC) can use the 101N26 interface, which provides seamless session continuity for single-registration mode UEs (e.g., as described in section 4.11.1 of 3GPP TS 23.502).
[0005] Alternatively, the intra-3GPP handover between EPS core 110 and 5GS core 120 can be a handover 102 that does not use the N26 interface (e.g., as described in section 4.11.2 of 3GPP TS 23.502).
[0006] Standardized intra-network handover procedures 103 and 104 have been established for handing over a UE from a first non-3GPP network gateway 130 (e.g., a gateway between a non-3GPP system and EPS) to EPC 110, and from a second non-3GPP network access 140 (i.e., a gateway between a non-3GPP system and 5GS) to 5GC 120. Further, 3GPP TS 23.502 section 4.11.3 outlines the handover procedure between EPS and 5GC-N3IWF, with subsections 4.11.3.1 describing handover procedures 105 and 108, and subsections 4.11.3.2 describing handover procedures 106 and 107. In this document, “access,” “access point,” and “gateway” are used to refer to the functionality of an untrusted non-3GPP to 3GPP interface, the physical means of implementing the functionality, and the effect of the functionality where appropriate.
[0007] Switching between different technologies for non-3GPP access can affect user equipment (such as...) Figure 1 This can cause problems for UE 150. For various reasons, the UE may be unable to access a second non-3GPP access (e.g., N3IWF). For example, when 5G is the preferred network, network congestion can prevent mobile devices from connecting to N3IWF. Summary of the Invention
[0008] The methods and network devices enable direct application switching between different untrusted non-3GPP gateways when the application is in a low-activity state (e.g., application-related traffic via the currently used non-3GPP access is below a predetermined threshold, and preferably, no application-related critical services are running). Although these methods are not seamless and lose existing context, handover interruptions are minimized, allowing the user's application to continue operating even with minor and transient degradation in service quality. Security context for the application can be re-established after the non-3GPP gateway switchover. Attached Figure Description
[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments, and these embodiments are explained together with the description.
[0010] Figure 1 It is a graphical illustration of currently available technologies for switching between different non-3GPP gateways.
[0011] Figure 2 This is a flowchart illustrating the actions performed by a user equipment (UE) according to an embodiment for switching applications between non-3GPP access functions to different 3GPP networks.
[0012] Figure 3A first scenario is illustrated for switching applications between non-3GPP access functions to different 3GPP networks, according to an embodiment.
[0013] Figure 4 A second scenario for switching applications between non-3GPP access functions, according to another embodiment, is shown.
[0014] Figure 5 A third scenario for switching non-3GPP access functions is shown (using intra-3GPP intermediate handover).
[0015] Figure 6 This is a flowchart of a method for directly switching non-3GPP access according to an embodiment.
[0016] Figure 7 This is a representation of a user equipment (UE) and a non-3GPP access configuration configured to enable switching to a non-3GPP gateway, according to an embodiment. Detailed Implementation
[0017] The methods and apparatus described in this section embody techniques related to direct handover between different untrusted non-3GPP access gateways (e.g., 130 and 140) on two different 3GPP networks (e.g., LTE and 5G). These methods and apparatus are also applicable to trusted non-3GPP gateways, such as trusted non-3GPP access points (TNAPs) and trusted WLANAAA proxies (TWAPs). To minimize disruption, the following embodiments detect low activity of an application using a non-3GPP access (e.g., ePDG or N3IWF) on one 3GPP network (e.g., LTE or 5G) and switch the application to another non-3GPP gateway (e.g., N3IWF or ePDG) on another 3GPP network (e.g., 5G or LTE) without interrupting the ongoing application. The handover is not performed seamlessly; that is, brief interruptions in data flow may occur. Direct handover of non-3GPP access does not employ intra-3GPP handover (such as...) Figure 1 Examples of 3GPP handovers include 102 and 103, inter-core 3GPP handovers (such as 101), and core-to-gateway handovers (such as 104 to 107). Direct handovers involve releasing an application's existing connection to a 3GPP network and establishing a new connection to another 3GPP network. Note that indirect handovers using intra-3GPP and inter-3GPP handovers can be seamless (i.e., performed without interrupting data flow).
[0018] Figure 2This is a flowchart illustrating the actions performed by a UE, according to an embodiment, for directly switching an application running on a non-3GPP radio access network between 3GPP networks. Initially, the UE connects application connection 201, which exchanges data using a first non-3GPP gateway, to a first 3GPP network (e.g., an LTE network or a 5G network). In other words, the application runs on the UE, which routes application-related data traffic to the 3GPP core network (EPC or 5GC) via a non-3GPP gateway (ePDG, N3IWF, TNAP, or TWAP).
[0019] The UE then assesses whether to switch to a second 3GPP network via a second non-3GPP access. For example, a switch from ePDG 130 to N3IWF 140 allows UE 150 to utilize 5GS features that positively impact software applications (such as access traffic steering, handover and separation ATSSS, network slicing, or reflective Quality of Service QoS). The advantage of using a particular 3GPP network for an application can be quantified as a priority value. For some applications, 5G networks may have a higher priority than LTE networks (e.g., due to the additional features mentioned above). However, when an application requires a more reliable but lower-capacity data stream under high mobility, a lower-volume LTE network may be more advantageous than a 5G network (and therefore have a higher associated priority). If the application has a priority value associated with the type of 3GPP network, UE 202's decision is based on a comparison of priority values corresponding to available 3GPP networks. In some examples, if the highest priority is higher than the priority value of the serving 3GPP network, the UE chooses to seek a connection to the 3GPP network among the available 3GPP networks associated with the highest priority value.
[0020] Further (the "yes" branch of 202), the UE detects whether an application is in a low-activity state by monitoring or inspecting various application-related aspects, such as access stratum (AS) connectivity status, user plane status, recent packet transmissions across non-3GPP gateways, and service status. An application's low-activity state can be based on low application-related traffic (e.g., traffic below a predetermined threshold during the last 3 seconds) and / or the absence of critical services with application-related activity (e.g., services that cannot be interrupted).
[0021] Monitoring applications connected to a first 3GPP core network via a first non-3GPP access point enables the identification of when an application is in a low-activity state. For example, monitoring application-related network traffic and usage patterns enables the detection or prediction of when no data flow is present or expected within an upcoming time interval (e.g., transmission via an IPSec tunnel). In another example, monitoring an application enables the detection of when application-related user plane resources are released or when the AS connection state is idle. In yet another example, monitoring an application enables the detection of when there are no active application-related user-aware sessions (e.g., no active voice calls based on IP Multimedia Subsystem (IMS) data connections).
[0022] When an application is detected to be in a low-activity state (the "Yes" branch of box 203), the UE switches the application 204 to the second non-3GPP gateway, as discussed further below. When the UE determines not to switch (the "No" branch of 202) or the application is not in a low-activity state (the "No" branch of 203), the UE keeps the application connected to the first 3GPP core network via the first non-3GPP access (skipping 204). The UE may periodically or when predetermined events (such as a different second 3GPP network becoming available) occur, repeating step 202 and potentially step 203.
[0023] When an application is in a low-activity state, switching the application from a connection to the first 3GPP core network via a first non-3GPP access point to a connection to the second 3GPP core network via a second non-3GPP gateway (i.e., step 204) can be implemented according to at least three scenarios: (1) a "break-before-make" scenario, (2) a "make-and-release" scenario, and (3) an intra-3GPP intermediate handover scenario. The first two scenarios are not seamless and use direct non-3GPP gateway type handover, while the latter is seamless and uses indirect non-3GPP gateway type handover.
[0024] Figure 3 , Figure 4 and Figure 5 Scenarios for switching applications between non-3GPP IP gateways to different 3GPP networks are illustrated. In these figures, time flows from the top to the bottom of the page, meaning that a first action (such as signal transmission) occurs before a second action indicated below the first action. These scenarios illustrate various embodiments of step 204 when a UE running an application using a non-3GPP network, such as a (trusted or untrusted) Wi-Fi network, has determined to switch to a non-3GPP access gateway (the "Yes" branch of step 202) and the application is in a low-activity state (the "Yes" branch of step 203).
[0025] Figure 3 A first scenario (“disconnect-before-connect”) for switching to a non-3GPP IP gateway for a different core network, according to an embodiment, is illustrated. UE 310 sends a 312 data network release request to a first non-3GPP access 320 currently used to connect an application to a first 3GPP core network. The first non-3GPP gateway 320 then acknowledges the data network release request by sending a 314 data network release response. After performing a local release 315 of communication resources used by the UE for communication via the first non-3GPP access 320, UE 310 exchanges a 316 message with a second non-3GPP access 330 for connecting the application to a second 3GPP core network. In this first scenario, UE 310 does not use the 3GPP core network 340 because the core network is connected via its respective gateway.
[0026] Figure 4 A second scenario (“Establishment and Release”) for switching to a non-3GPP gateway according to another embodiment is illustrated. In this scenario, the UE first exchanges message 416 with a second non-3GPP access 430 for connecting an application to a second 3GPP core network. The first non-3GPP gateway 420 then sends a data network release request 413 to the UE. The UE 410 acknowledges the data network release request by sending a data network release response 417. Note that in this case, the first 3GPP network (not the UE as in the first scenario) initiates the release of the connection with the UE running the application. The UE 410 then performs a local release 415 of the communication resources used by the UE to communicate with the first non-3GPP access. In this second scenario, the UE 410 does not use the 3GPP network 440 because the core network is connected via its respective gateway.
[0027] Figure 5 A third scenario is illustrated for handing over a non-3GPP gateway (using intra-3GPP intermediate handover). Unlike the first and second scenarios described above, in this third scenario, UE 510 employs the 3GPP core network 540 for non-3GPP access handover. UE 510 initially exchanges message 542 with the 3GPP core network (e.g., to initiate a handover request) to establish a connection with the first 3GPP core network via the first non-3GPP access 520. When it is determined that using the second 3GPP core network would be advantageous, UE 510 exchanges message 522 with the first non-3GPP access 520 to release the first data network connection. Then, UE 520 exchanges message 532 with the second non-3GPP access 530 to establish a second data network connection. UE 530 also exchanges message 544 with the 3GPP core network 540 to release the second data network connection.
[0028] Figure 6This is a flowchart of a method 600 for directly switching non-3GPP access according to an embodiment. Method 600 is performed by a wireless communication device (e.g., UE 310 or UE 410) running an application and communicating via a non-3GPP radio access network (e.g., a trusted or untrusted Wi-Fi network). Method 600 includes monitoring 610 for an application having a first connection to a first 3GPP core network via a first non-3GPP access (e.g., 320 or 420) to identify a low-activity state of the application. All of the above-described techniques for identifying a low-activity state can be applied individually or in combination.
[0029] Method 600 further includes, upon identifying a low-activity state of the application (i.e., the "yes" branch of 620), releasing 630 the first connection (i.e., communication resources reserved for communicating with the first access), and establishing 640 a second connection for the application to access the second 3GPP network via the second non-3GPP access. Establishing the second connection can be as follows: Figure 4 As shown, it occurs before the first connection is released, or as... Figure 3 This occurs after the first connection is released, as shown.
[0030] Figure 7 This is a structural representation of a wireless communication system 700 according to an embodiment, which includes a wireless communication device 710 (which can operate as a UE 310 or UE 410) and a wireless device 720 hosting non-3GPP gateways (320, 330, 420, 430) configured to enable direct handover between non-3GPP gateways.
[0031] The wireless communication device 710 includes an antenna connected to a radio frequency (RF) front-end 761, and at least one RF transceiver (such as an LTE transceiver 762, a 5G NR transceiver 763, or another transceiver 764) for communicating with the wireless communication device 720. The antenna and RF front-end 761 can be tuned to one or more frequency bands (e.g., subcarriers), as defined by the 3GPP LTE, 5G NR, and 6G communication standards and implemented by the respective transceivers. The wireless communication device 710 also includes one or more pre-encoders 765, one or more processors 766, and a computer-readable storage medium (CRM) 767. The processor 766 can be a single-core or multi-core processor, and the CRM 767 includes any suitable memory / storage device other than the propagating signal. For example, the memory / storage device may include random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), and / or flash memory that can be used to store direct gateway switching manager 768 and application 769 for implementing the various technologies described in this document. CCRM 767 stores instructions that can be executed by processor 766 to facilitate user plane communication, control plane signaling, and user interaction. Direct gateway switching manager 768, which can be implemented not only as software but also as hardware logic and / or circuitry, causes various steps and actions associated with switching application 769, which operates on a non-3GPP network between non-3GPP gateways to different 3GPP networks.
[0032] like Figure 7 The illustrated wireless device 720 provides non-3GPP gateway functionality. Wireless device 720 includes an antenna, an RF front-end 771, and an RF transceiver 772 (more transceivers may be present for different technologies, as shown for wireless communication device 710) for communicating with wireless communication device 710 and 3GPP network devices. The antenna and RF front-end 771 of wireless device 720 can be tuned to one or more frequency bands (e.g., subcarriers), for example, as defined by 3GPP LTE, 5G NR, and 6G communication standards and implemented by RF transceiver 772.
[0033] Wireless device 720 includes a processor 773 and a computer-readable storage medium (CRM) 774. Processor 773 may include a single-core or multi-core processor, and CRM 774 includes any suitable memory / storage device other than the propagating signal. For example, memory / storage may include random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), and / or flash memory. CRM 774 stores device data 775 that can be executed by processor 773 to enable wireless communication with wireless communication device 710 and with 3GPP network devices, including network scheduling data, radio resource management data, applications, and / or operating systems.
[0034] CRM 774 also stores a traffic monitor 776 and a handover manager 777, which enable the radio device 720 to perform various steps and actions associated with direct handover of non-3GPP access (such as non-3GPP access 778) with application 769. The radio device 720 also includes a core network interface 779, which may include standardized interfaces for exchanging user plane data and control plane data within a 3GPP network, such as Xn and / or X2 interfaces.
[0035] Wireless systems, such as Figure 7 The wireless system illustrated herein can implement various technologies related to direct non-3GPP gateway switching for applications running on non-3GPP networks.
[0036] The embodiments described in this section are referenced to the accompanying drawings. The same reference numerals in different drawings identify the same or similar elements. The detailed description does indeed exclude other embodiments within the scope of the appended claims. The embodiments are not limited to the described configurations but can be extended to other arrangements.
[0037] Throughout this section, references to "one embodiment" or "embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout the specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.
[0038] The numerical adjectives “first,” “second,” and “third” do not imply any order (they are not ordinal numbers), but are markers used to distinguish different instances of similar elements. Unless otherwise explicitly indicated, references to the singular (e.g., “a” or “a kind,” “the”) should include the plural.
[0039] Although features and elements of this embodiment are described in specific combinations in the embodiments, each feature or element may be used alone without other features and elements in the embodiments, or in various combinations with or without other features and elements disclosed herein. Methods or flowcharts may be implemented as computer programs, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a specially programmed computer or processor.
Claims
1. A method (600) performed by a wireless communication device running applications and communications on a non-3GPP radio access network, the method comprising: Monitoring (610) uses the application that exchanges data via a first connection to the first 3GPP core network through a first non-3GPP gateway to identify a low-activity state; as well as When the low activity state described in (620) is identified, Release (630) the first connection, and Establish (640) a second connection to the second 3GPP core network via a second non-3GPP gateway.
2. The method as described in claim 1, wherein, One of the first 3GPP core network and the second 3GPP core network is a Long Term Evolution (LTE) core network as defined in the 3GPP standard document, and one of the first non-3GPP gateway and the second non-3GPP gateway is an Evolved Packet Data Gateway (ePDG). The other of the first 3GPP core network and the second 3GPP core network is a fifth-generation 5G mobile network as defined in the 3GPP standard document, and the other of the first non-3GPP gateway and the second non-3GPP gateway is a non-3GPP interoperability function N3IWF.
3. The method as described in claim 1 or 2, wherein, The monitoring of the application includes tracking data traffic associated with the application via the first non-3GPP gateway, and the identification of the low activity state includes determining that the data traffic is below a predetermined threshold.
4. The method according to any one of claims 1 to 3, wherein, The identifier includes determining that no critical services related to the application are running.
5. The method according to any one of claims 1 to 4, wherein, The second non-3GPP gateway has a higher priority than the first non-3GPP gateway.
6. The method according to any one of claims 1 to 5, wherein, The release of the first connection begins before the establishment of the second connection.
7. The method according to any one of claims 1 to 5, wherein, The release of the first connection begins after the establishment of the second connection.
8. The method according to any one of claims 1 to 7, wherein, The time interval between the release of the first connection and the establishment of the second connection is less than 1 second.
9. The method according to any one of claims 1 to 8, wherein, The release of the first connection and the establishment of the second connection do not interrupt the application.
10. The method according to any one of claims 1 to 9, wherein, The identifier for the low-activity state includes detecting the release of user plane resources.
11. The method according to any one of claims 1 to 10, wherein, The low-activity state is identified by determining that there is no user-aware session with any activity related to the application.
12. The method of any one of claims 1 to 11, further comprising: After the second connection is established, the security context for the application is re-established.
13. The method according to any one of claims 1 to 12, wherein, At least one of the first connection and the second connection includes an Internet Protocol Security (IPsec) tunnel.
14. The method according to any one of claims 1 to 12, wherein, The non-3GPP radio access network is a wireless local area network (WLAN).
15. The method according to any one of claims 1 to 14, wherein, The monitoring in the application is triggered by a predetermined event.
16. A wireless communication device (310, 410, 710) comprising a transceiver (762, 763, 764), a processor (766), and a computer-readable storage medium (767), said computer-readable storage medium storing executable instructions (768) for the processor to perform any of the methods described in claims 1 to 17 using the transceiver.