HK1249333B - Device, system and method of hplmn preferred epdg selection in roaming scenarios - Google Patents

Description

Device, system and method for selecting EPDG that prioritizes HPLMN in roaming scenarios

Priority Declaration

This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 62/163,218, filed on May 18, 2015, entitled “HPLMN PREFERRED EPDG SELECTION IN ROAMING SCENARIOS,” which is incorporated herein by reference in its entirety.

Technical Field

Embodiments relate to wireless access networks. Some embodiments relate to connectivity scenarios in cellular networks including 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) networks and LTE-Advanced (LTE-A) networks, as well as fourth generation (4G) networks and fifth generation (5G) networks.

Background Art

The use of personal communication devices has grown by leaps and bounds over the past two decades. The penetration of mobile devices (user equipment or UE) in modern society continues to drive the demand for a wide variety of networked devices in many different environments. The use of networked devices using 3GPP LTE systems has increased in all areas of home and work life. Because existing devices and networks are sometimes confusing, providing appropriate communication capabilities for specific users and UEs can be very complex. This may be especially true in cases where UEs frequently roam from their home network. In such situations, even if the UE wishes to use the resources and policies of the Home Public Land Mobile Network (HPLMN), the UE may be restricted to using the resources and policies of the Visited Public Land Mobile Network (VPLMN). This can be particularly problematic in situations where there are untrusted connectivity scenarios in the VPLMN (e.g., accessing the 3GPP LTE system using an untrusted Wireless Local Area Network (WLAN)).

It may therefore be desirable to provide the UE with the ability to use alternative connectivity preferences in roaming scenarios.

Summary of the Invention

In one aspect, the present disclosure provides a device of a user equipment (UE). The device includes: a transceiver configured to communicate with a 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) network through an access point (AP) of a non-secured network; and a processing circuit configured to: when the UE is roaming to a visited public land mobile network (VPLMN) and attempting to connect to the AP, obtain enhanced packet data gateway (ePDG) selection information, the ePDG selection information indicating whether to attempt to connect to a home public land mobile network (HPLMN) ePDG (HePDG) or a VPLMN ePDG (VePDG); configure the transceiver to connect to the one of the HePDG and the VePDG indicated by the ePDG selection information; and configure the transceiver to obtain the ePDG selection information through the AP using a wireless local area network (WLAN) access network query protocol (ANQP), wherein: the ANQP query includes an Info ID field, the Info ID field indicates whether to attempt to connect to the home public land mobile network (HPLMN) ePDG (HePDG) or the VPLMN ePDG (VePDG). The ID field indicates that the ANQP response to the UE will use a universal container, which includes: a version field indicating the version of the universal container; a header length field defining the number of octets following the length of the header length field; and a payload field including multiple information element identifiers IEI; and the ANQP response includes a list of public land mobile network PLMN identifiers supported by the WLAN network and which operators support S2b and are deployed with one or more ePDGs.

Other aspects of the present disclosure provide apparatuses, methods, devices, and computer-readable storage media associated with or corresponding to the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals with different letter suffixes may represent different instances of similar components. The accompanying drawings generally illustrate various embodiments discussed in this document by way of example and not limitation.

FIG1 is a functional diagram of a 3GPP network according to some embodiments.

FIG2 is a block diagram of a 3GPP device according to some embodiments.

FIG3 illustrates home operator preference according to some embodiments.

FIG4 illustrates a general WLAN container structure according to some embodiments.

FIG5 illustrates a flow diagram of enhanced packet data gateway (ePDG) selection according to some embodiments.

DETAILED DESCRIPTION

The following description and accompanying drawings sufficiently illustrate the specific embodiments to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, processing, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. The embodiments set forth in the claims encompass all available equivalents of those claims.

Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless mobile devices. Wireless communication system standards and protocols may include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE); the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, commonly known in the industry as Worldwide Interoperability for Microwave Access (WiMAX); and the IEEE 802.11 standard, commonly known in the industry as Wi-Fi.

Figure 1 is a functional diagram of a 3GPP network according to some embodiments. The network may include a radio access network (RAN) (e.g., as shown, E-UTRAN or Evolved Universal Terrestrial Radio Access Network) 101 and a core network 120 (e.g., shown as an Evolved Packet Core (EPC)) coupled together via an S1 interface 115. For convenience and brevity, only the core network 120 and a portion of the RAN 101 are shown.

The core network 120 includes a mobility management entity (MME) 122, a serving gateway (serving GW) 124, and a packet data network gateway (PDN GW) 126. The RAN 101 includes an evolved Node B (eNB) 104 (which can operate as a base station) to communicate with a user equipment (UE) 102. The eNB 104 can include a macro eNB and a low power (LP) eNB. The LP eNB 104 can be an access point configured to communicate with the UE 102 via IEEE 802.11. An access point controller (APC) can be arranged between the AP 104 and the ePDG 132, 162.

The MME 122 is similar in functionality to the control plane of a traditional Serving GPRS Support Node (SGSN). The MME 122 manages mobility aspects of access, such as gateway selection during the UE's initial attachment and when performing intra-LTE handovers, tracking area list management, paging and marking procedures, bearer activation/deactivation, user authentication, and the generation and allocation of temporary identities to the UE. The MME 122 also determines the UE's authorization to use the service provider's PLMN and enforces UE roaming restrictions. The MME 122 can be connected to a Home Subscriber Server (HSS) 128, which contains user-related and subscription-related information. The HSS 128 can support mobility management, call and session establishment support, user authentication, and access authorization.

The Serving GW 124 may terminate the interface toward the RAN 101 and route traffic packets (e.g., data packets or voice packets) between the RAN 101 and the core network 120. Furthermore, the Serving GW 124 may be a local mobility anchor point for inter-eNB handovers and may also provide an anchor for inter-3GPP mobility. Other responsibilities of the Serving GW 124 may include lawful interception, charging, and some policy enforcement. The Serving GW 124 and the MME 122 may be implemented in one physical node or in separate physical nodes.

The PDN GW 126 can terminate the SGi interface towards the packet data network (PDN). The PDN GW 126 can route traffic packets between the EPC 120 and external PDNs and can be a key node for policy enforcement and charging data collection. The PDN GW 126 can also provide an anchor point for mobility with non-LTE access. The external PDN can be any kind of IP network as well as an IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the Serving GW 124 can be implemented in one physical node or in separate physical nodes.

The eNB 104 (macro and micro eNBs) terminates the air interface protocol and can be the first point of contact for the UE 102. The eNB 104 can communicate with the UE 102 in both normal coverage mode and one or more enhanced coverage modes. In some embodiments, the eNB 104 can implement various logical functions for the RAN 101, including but not limited to RNC (Radio Network Controller) functions such as radio bearer management, uplink and downlink dynamic radio resource management and traffic packet scheduling, and mobility management. According to some embodiments, the UE 102 can be configured to communicate with the eNB 104 via orthogonal multiple access (OMA) communications (e.g., time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), SC-FDMA) or other communication signals over a multi-carrier communication channel according to an appropriate communication technology. OFDM signals can include multiple orthogonal subcarriers. According to some embodiments, the UE 102 can be configured to communicate via non-orthogonal multiple access (NOMA) signals.

The S1 interface 115 may separate the RAN 101 and the EPC 120. The S1 interface 115 may be divided into two parts: S1-U, which carries traffic packets between the eNB 104 and the Serving GW 124, and S1-MME, which is the signaling interface between the eNB 104 and the MME 122.

For cellular networks, LP cells are typically used to extend coverage to indoor areas where outdoor signals don't reach well, or to increase network capacity in areas with high phone usage, such as train stations. The term low-power (LP) eNB, as used herein, refers to any suitable lower-power eNB used to implement narrower cells (narrower than macrocells), such as femtocells, picocells, or microcells. Femtocell eNBs are typically provided by mobile network operators to their residential or enterprise customers. Femtocells are typically the size of a residential gateway or smaller and are typically connected to a user's broadband line. Once connected, a femtocell connects to the mobile operator's mobile network and provides additional coverage for residential femtocells, typically with a range of 30 to 50 meters. Thus, an LP eNB can be a femtocell eNB because it is coupled through a PDN GW 126. Similarly, a picocell is a wireless communication system that typically covers a small area, such as within a building (office, shopping mall, train station, etc.) or, more recently, on an airplane. A picocell eNB can generally be connected to another eNB (e.g., a macro eNB) via its base station controller (BSC) functionality via an X2 link. Thus, a low-end eNB can be implemented using a picocell eNB because it is coupled to the macro eNB via the X2 interface. A picocell eNB or other low-end eNB can include some or all of the functionality of a macro eNB. In some cases, this may be referred to as an access point base station or enterprise femtocell.

Figure 1 also includes a policy and charging control (PCC) architecture. The PCC architecture may include, among other things: application functions (AFs) 144, 154; policy and charging rules functions (PCRFs) 146, 156; a policy and control enforcement function (PCEF 140) 140; a subscription profile repository (SPR) 152 that may store user policy and charging control subscription information; a bearer binding and event reporting function (BBERF) 142; an online charging system (OCS) 158 and an offline charging system (OFCS) 148; an authentication, authorization, and accounting (AAA) server (not shown) that may process UE requests for access to computer resources and provide authentication services; and an access network discovery and selection function (ANDSF) server 134 that may provide the UE with discovery information about connectivity to 3GPP and non-3GPP access networks (e.g., Wi-Fi) owned by the UE's operator or with which the UE's operator has a roaming agreement.

The ANDSF server 134 can assist the UE in discovering non-3GPP access networks such as WiFi networks in the vicinity of the UE and provide rules to prioritize and manage connections to non-3GPP access networks. The ANDSF server 134 can provide policies and preferences using one or more ANDSF policies to help achieve efficient use of the authorized bandwidth by offloading traffic flows to and from the UE via WLAN or other networks (rather than by using 3GPP or other cellular wireless networks). The ANDSF server 134 may have defined mechanisms that enable the UE to determine which access technology is preferred for connection and/or for specific IP traffic in specific circumstances (for example, by using Inter-System Mobility Policy (ISMP) and/or Inter-System Routing Policy (ISRP)). The ANDSF client can run on the UE and interact with the ANDSF server 134 using the Open Mobile Alliance Device Management (OMA-DM) protocol over the S14 interface. ANDSF information may be provided in a query-response, where the request may include the UE's location and capabilities (e.g., supported interfaces), and the response may include the type of access (e.g., WiFi, WiMax), the RAN ID (e.g., the SSID of an available WLAN), and technology-specific information such as one or more carrier frequencies. ANDSF server 134 may be implemented within EPC 120 and connected to access point controller (APC) 136.

Different functions may be provided in various servers and modules deployed throughout the RAN 101. PCEF 140 may be located in the VPLMN 110. Policy and charging rules may be sent from the home network PCRF (HPCRF) 156 to the visited network PCRF (VPCRF) 146 via the S9 interface. The rules may then be sent to the visited network PCEF 140 via the Gx interface and to the visited network BBERF 142 via the Gxx interface. The visited network PCEF 140 may be connected to the visited network OFCS 148 and to the home network OCS 158 via the Gy interface.

As shown, the PCRFs 146, 156 may include an HPCRF 156 and a VPCRF 146. The PCRFs 146, 156 may provide policy and charging rules for implementation to the PCEF 140. The PCRFs 146, 156 may also compare the rules to UE subscription information to ensure compliance.

In some embodiments, the PCRF 146, 156 may obtain information from the AF 144, 154, the SPR 152, and the PCEF 140. More specifically, in some embodiments, when the UE is attached to the RAN 101 and parameter negotiation is performed, the AF 144, 154 may provide the UE with service information. If the service information is consistent with the PCRF policy, the PCRF 146, 156 may accept the negotiation; otherwise, the PCRF 146, 156 may reject the negotiation and provide the AF 144, 154 with service parameters acceptable to the PCRF 146, 156, which may then return the acceptable parameters to the UE.

Similarly, in some embodiments, PCEF 140 can provide RAN information related to bearers to PCRFs 146, 156. PCEF 140 can formulate PCRF policies and charging rules for service data flows on the bearer plane. After the bearer is established, PCEF 140 can control the service flow based on the PCRF rules, depending on the UE's QoS. PCEF 140 can also implement online and/or offline charging based on the PCRF charging rules. PCEF 140 can communicate with OCS 158 for online charging and OFCS 148 for offline charging to obtain charging information, respectively. PCEF 140 can be located within Serving GW 124, PDN GW 126, or Evolved Packet Data Gateway (ePDG) 132.

BBERF 142 may be located in serving GW 124, another PDN GW (not shown), or ePDG 132. The gateway may depend on whether UE 102 accesses RAN 101 via E-UTRAN 101 (serving GW 124), a trusted non-3GPP network (another PDN GW), or an untrusted non-3GPP access system (ePDG 132). ePDG 132 may protect data transmission between UE 102 and the EPC using untrusted non-3GPP access by acting as a termination node for the IPsec tunnel established with UE 102. An example of untrusted access may be a connection via a public WiFi hotspot or other network connection that a network operator may consider untrusted from a security perspective. ePDG 132 may map the IPsec tunnel to a General Packet Radio Service (GPRS) Tunneling Protocol (GTP) or Proxy Mobile IPv6 (PMIP) tunnel that terminates at PDN GW 126. Note that while only a single gateway of each is shown, there may be multiple of each of one or more different gateways, such as ePDG 132. Furthermore, the elements shown, such as EPC 120, ePDG 132, E-UTRAN 101, etc., may be present in each of VPLMN 110 and HPLMN 150.

FIG2 is a functional diagram of a 3GPP device according to some embodiments. The device may be, for example, a UE or an eNB. In some embodiments, the eNB may be a fixed, non-mobile device. 3GPP device 200 may include physical layer circuitry 202 for transmitting and receiving signals using one or more antennas 201. 3GPP device 200 may also include medium access control (MAC) layer circuitry 204 for controlling access to a wireless medium. 3GPP device 200 may also include processing circuitry 206 and memory 208 configured to perform the operations described herein.

In some embodiments, the mobile device or other device described herein may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, an internet tablet, a wireless phone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a sensor, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that can wirelessly receive and/or send information. In some embodiments, the mobile device or other device may be a UE 102 or eNB 104 configured to operate according to 3GPP standards. In some embodiments, the mobile device or other device may be configured to operate according to other protocols or standards, including IEEE 802.11 or other IEEE standards. In some embodiments, the mobile device or other device may include one or more of the following: a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device components. The display may be an LCD screen including a touch screen.

Antenna 201 may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, antennas 201 may be effectively separated to exploit possible spatial diversity and different channel characteristics.

Although the 3GPP device 200 is shown as having several separate functional elements, one or more of these functional elements may be combined and may be implemented by a combination of software-configured elements (e.g., a processing element including a digital signal processor (DSP)) and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and combinations of various hardware and logic circuits for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes running on one or more processing elements.

Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transient mechanism for storing information in a machine (e.g., computer) readable form. For example, a computer-readable storage device may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium, an optical storage medium, a flash memory device, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

The term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database and/or associated caches and servers) configured to store one or more instructions. The term "machine-readable medium" may include any medium capable of storing, encoding, or carrying instructions for execution by the 3GPP device 200 and causing it to perform any one or more of the techniques of the present disclosure, or capable of storing, encoding, or carrying data structures used by or associated with such instructions. The term "transmission medium" should be understood to include any intangible medium capable of storing, encoding, or carrying instructions for execution, and includes digital or analog communication signals or other intangible media that facilitate the communication of such software.

As described above, even if the UE desires to use HPLMN resources and policies, the delivery of appropriate communication capabilities for a particular UE may be limited to the use of VPLMN resources and policies. In some embodiments, greater flexibility may be required to support optional connectivity preferences for the UE when roaming from the UE's home network. To this end, work has recently been underway on IR.51, which defines an IP Multimedia Subsystem (IMS) profile for voice, video, and Short Message Service (SMS) over Wi-Fi based on 3GPP specifications, and uses 3GPP specifications for ePDG selection in untrusted S2b (PGW-ePDG) connectivity scenarios. In other words, a minimum mandatory set of features defined in the 3GPP specifications can be identified that the UE and network must implement to ensure interoperable, high-quality IMS-based telephony and conversational video services over Wi-Fi access networks.

In some embodiments, when a UE roams from an HPLMN to a VPLMN, the UE may access the network using an unsecured WiFi connection via an AP. An IPSec tunnel may be established between the UE and the ePDG. Specifically, the UE may typically first attempt to connect to one of the VPLMN ePDGs. If this connection is unsuccessful or not authenticated, the UE may then attempt to connect to one of the HPLMN ePDGs. However, in some Voice-over-WiFi (VoWiFi) deployment scenarios where one or more HPLMN ePDGs are reachable and available, the UE may wish to initially connect to one of the HPLMN ePDGs. Such deployment scenarios include when the visited network has not yet deployed VoWiFi services or when sufficient interoperability testing has not been performed to ensure proper functioning of VoWiFi services in the visited network. Furthermore, even if the VPLMN is capable of providing the requested service (e.g., VoWiFi), if there is no roaming agreement between the home network operator and the visited network operator (wherein the roaming agreement defines how the visiting UE can access desired services in its home network through the visited network), the UE may wish to connect to one of the HPLMN ePDGs.

In current 3GPP specifications, when a UE is in the HPLMN, it can connect to the ePDG corresponding to the home operator; however, there is currently no mechanism that allows the UE to select the HPLMN ePDG in roaming scenarios involving a visiting operator. In roaming scenarios, the UE may typically use VPLMN resources instead. Therefore, in roaming scenarios, even when HPLMN policies are required, VPLMN policies are generally preferred to support handovers that break the PDN connection locally.

To overcome this problem, in some embodiments, the selection of an HPLMN-based ePDG may depend on a pre-configured HPLMN preference or a dynamic policy available from the UE's home operator, for example, via one or more ANDSF Management Objects (MOs). The HPLMN preference may have a higher priority than the VPLMN preference, and the HPLMN preference may only be used in specific circumstances rather than as a hard default configuration.

Therefore, some embodiments relate to mechanisms for selectively connecting a UE to an HPLMN ePDG in roaming scenarios based on home/visited operator preferences. The following describes in more detail how a UE can obtain an HPLMN ePDG address and connect to the HPLMN ePDG. In some embodiments, this may also apply to situations involving lawful interception and emergency scenarios, in each of which different routing may occur than under normal communication conditions.

When a UE accesses a 3GPP network via an AP of a non-secured network while roaming, the UE can obtain a list of reachable ePDGs from the AP and can make a decision based on this list. In some cases, the UE can select an HPLMN ePDG, for example, if it is reachable by the APC. In some embodiments, the UE can store a pre-configured configuration or other static configuration to select an HPLMN ePDG. This configuration can be stored in a configuration file in a removable or non-removable memory of the UE (e.g., a Universal Integrated Circuit Card (UICC) or other non-volatile memory in the UE).

One or more ANDSF MOs may also be pre-configured in the UE, in the same or different memory as the storage configuration file. The ANDSF MO may be a configuration parameter in a hierarchical device management structure that includes network selection rules. The ANDSF MO may be constructed in an extensible markup language (XML) format and may be pulled from or pushed to the UE. Information about the UE and appropriate ePDG connection information may be transmitted to and stored by the ANDSF server. In some embodiments, the UE may alternatively or additionally be configured to identify an access network and establish a connection with one or more RATs of the access network based on the relative priority of the RATs depending on the network selection rules.

In some embodiments, the UE may use one or more WLAN Access Network Query Protocol (ANQP) mechanisms to select an HPLMN ePDG. ANQP is a query and response protocol that defines the services provided by an AP, and ANQP can be used to discover domain names, accessible roaming partners, supported credential types and authentication methods, IP address type availability, and other information for network selection. By using the ANQP method, the UE may be able to obtain a list of PLMN identifiers supported by the WLAN network. Additional information may be provided as part of the ANQP method to indicate which operators support S2b and have one or more ePDGs deployed. The UE may be able to use this mechanism to prioritize the HPLMN or an equivalent HPLMN-based ePDG (also referred to herein as an HPLMN ePDG or HePDG).

In some embodiments, the UE may use ANDSF rules to select the HPLMN ePDG. In these embodiments, the UE may obtain the home operator preference from a policy server such as the Home ANDSF (HANDSF). When the UE is roaming, the HANDSF may be able to indicate to the UE whether the UE should connect to the HPLMN ePDG. The various roaming scenarios defined by ANDSF rules may include, for example, whether to connect to the HPLMN ePDG when the UE roams to a specific VPLMN or a specific set of VPLMNs. ANDSF rules may take into account information based on roaming agreements.

In some embodiments, where dynamic rules (obtained via ANDSF or ANQP) are not available, static or pre-configured rules may be used. In some embodiments, the HPLMN ePDG may be selected by the UE using RAN rules. Whether or not to use RAN rules may depend on whether ANDSF rules are stored in the UE. In some embodiments, there may be a priority such that when both RAN rules and ANDSF rules are present in the UE, ANDSF rules may be used. In some embodiments, ANDSF rules may be used when there is a conflict between ANDSF rules and RAN rules. In some embodiments where there are no ANDSF rules, and if the UE is using RAN rules from a VPLMN, the UE may use static or pre-configured HPLMN configuration (if available). The UE may store RAN rules in the same or different memory as the configuration file.

Thus, the various embodiments described above may allow the UE's home operator to take different actions when the UE is roaming based on pre-configured or dynamic policies and preferences available from the home operator. In some embodiments, the home operator may prioritize connecting the UE to an HPLMN ePDG, in which case the UE may connect to the HPLMN ePDG. In some embodiments, the home operator may prioritize connecting the UE to a VPLMN ePDG, in which case the home operator may provide a list of VPLMNs to which the UE can connect to the VPLMN ePDG. In some embodiments, if pre-configured or dynamic policies/preferences are not available from the home operator, the UE may follow the VPLMN policy and select an ePDG accordingly.

The information pre-configured in the UE by the home operator can be statically provided in the UE, in a configuration file in the UICC, or in a non-volatile storage device in the UE. In some embodiments, this information can alternatively or additionally be obtained in a management object such as an ANDSF MO. The configuration in the UE can be updated by the operator using an over-the-air server and remote file management capabilities. The configuration can be updated periodically or when a predetermined event occurs, for example, a change in the configuration by the home operator, including a change in the roaming agreement of the home operator or the UE moving to a new VPLMN or accessing a different WLAN or using a different RAT.

The preconfigured information may include, among others, one or more preferences of home operators in roaming scenarios, a list of preferred PLMN-specific fully qualified domain names (FQDNs), and a list of VPLMNs where a VPLMN policy is preferred over the home operator policy.

More specifically, the home operator in a roaming scenario may be an indication from the home operator that the HPLMN prefers the UE to use the HPLMN ePDG in a roaming scenario. If there is such an indication in the UE, the UE may prioritize the HPLMN ePDG over the VPLMN ePDG.

The list of preferred PLMN-specific FQDNs provided by the home operator may contain, for each PLMN, a list of FQDNs that the UE may select to connect to the ePDG. If the HPLMN ePDG is preferred, the UE may select an appropriate PLMN and FQDN from this list that is suitable for the UE. When the UE is not connected to any PLMN over any RAT, the UE may use the default PLMN.

The UE may also include a list of VPLMNs for which VPLMN policies are preferred over the home operator policies. When roaming into such a VPLMN, the UE may select an ePDG that connects to the VPLMN ePDG instead of the HPLMN ePDG. If the connection to the VPLMN ePDG fails, the HPLMN policies may be applied instead, and the UE may then connect to the HPLMN ePDG.

Figure 3 illustrates home operator preference according to some embodiments. More specifically, Figure 3 illustrates home operator preference being delivered to a UE using ANDSFMO.

In roaming scenarios, an ANDSF server can be used to provide updates and other information for ePDG selection. The ANDSF server can organize device configuration data in a hierarchical management tree consisting of at least one node and at least one leaf. ANDSF information can be provided during tunnel establishment to determine the home operator preference to connect to the appropriate ePDG. The tree structure can contain various branches with one or more nodes and leaves, including a HomeNetworkPreference node 302, an S2bConnectivityPreference node 304, an HPLMN_ePDG_Preference flag 306, a PreferredFQDN node 308, a Service Provider leaf 310, an FQDN leaf 312, a Priority leaf 314, a Default_FQDN leaf 316, and a Visited_ePDG_SPL list 318. Thus, the ANDSF MO may contain Home Network Preference Data, S2b Connectivity Preference Data, HPLMN_ePDG_Preference Flag, Preferred FQDN Data, Service Provider Data, FQDN Data, Priority Data, Default_FQDN Data and Visited_ePDG_SPL List.

Specifically, in some embodiments, the home network preference node 302 may provide a home operator preference. The home network preference node 302 may have multiple nodes and leaves attached to it. The S2b connectivity preference node 304 may be connected to the home network preference node 302 and may indicate the home operator preference for S2b connectivity and ePDG selection in various scenarios. The PDN GW may connect to the ePDG using an S2b interface for untrusted access. For example, the S2b connectivity preference node 304 may be defined within the XML format of the MO as: <X>/HomeNetworkPreference?/<X>/S2bConnectivityPreference.

The S2b connectivity preference node 304 may connect to other nodes and leaves. One such leaf may be the HPLMN_ePDG_Preference Flag 306, which may be set to 1 or reset to 0. In response to the HPLMN_ePDG_Preference Flag 306 being set (to 1), the UE may determine that the home operator prefers to connect the UE to the HPLMN ePDG in a roaming scenario.

A default_FQDN leaf 316 may also be connected to the S2b connectivity preference node 304. The default_FQDN leaf 316 may indicate the FQDN to use if the UE is not connected to any PLMN for any access technology.

The visited_ePDG_SPL list 318 may also be connected to the S2b connectivity preference node 304. The visited_ePDG_SPL list 318 may contain a list of visited service providers of the operator. When the UE roams to any PLMN in the visited service provider list, the UE may connect to the ePDG of the visited PLMN.

The preferred FQDN node 308 may also be connected to the S2b connectivity preference node 304. The preferred FQDN node 308 may provide a list of preferred FQDNs that are preferred by the HPLMN for different PLMNs. The UE may use this list to construct an FQDN based on the PLMN to which the UE is connected. The preferred FQDN node 308 may be connected to a service provider leaf 310, an FQDN leaf 312, and a priority leaf 314. The service provider leaf 310 may provide the PLMN identifier of the access operator. The FQDN leaf 312 may use a DNS-based mechanism to provide an FQDN that may be used to obtain the IP address of the desired ePDG. The UE may connect to this ePDG in a roaming scenario. The priority leaf 314 may indicate the priority order of the PLMNs in the list. Thus, if there are multiple VPLMNs to which the UE can roam in a given area, the priority leaf 314 may indicate the priority of using the VPLMNs. For example, the priority leaf 314 may be defined within the XML format of the MO as: <X>/HomeNetworkPreference? /<X>/S2bConnectivityPreference/<X>/PreferredFQDNs/<X>/Priority.

In addition to or instead of using ANDSF (or ANQP) provided updates for ePDG selection in roaming scenarios, updates can be based on RAN rules. In some embodiments, updates can be prioritized so that if both ANDSF and RAN rules exist, ANDSF rules can be used to obtain these updates. In such embodiments, in the absence of ANDSF rules, if the UE is using RAN rules from the VPLMN, the UE can use a static or pre-configured HPLMN configuration (if one is available in the roaming scenario) and apply the HPLMN configuration to ePDG selection.

In some embodiments, the UE may use the information returned as part of the ANQP query to determine which ePDG to connect to. When the UE queries the AP using ANQP, the UE may receive a description of available services without having to commit to the network. The ANQP query may include an Info ID field, which may indicate that the response to the UE is to use a generic container. A generic WLAN container may be defined in which the UE can request a set of parameters and information about connectivity options supported over the S2b interface. The generic WLAN container may contain information that allows a WLAN access network to connect to the 3GPP Enhanced Packet Core (EPC), including information such as that defined by the ANDSF.

4 illustrates a generic WLAN container structure according to some embodiments. The generic WLAN container 400 may include a version field 402, a header length field 404, and a payload field 406 containing a plurality of information element identifiers (IEIs).

The generic WLAN container 400 can have several different versions. Therefore, the version field 402 can define the version of the generic WLAN container. The version field 402 can be defined using a field having a length of a single octet. For example, version 1 of the generic WLAN container can be defined by 00000000, with other versions defined similarly. Unused values can be reserved for future use (which can also serve a dual purpose). Therefore, unused values can be used to indicate the version number and other information unrelated to the version number.

The header length field 404 may include a field with a length of 2 octets. The header length field 404 may define the number of octets following the header length in the generic WLAN container 400. Thus, the header length field 404 may indicate the length of the payload field 406.

The payload field 406 may be a generic container, the contents of which are defined in 3GPP specifications (particularly technical specification 23.234).Each IEI in the payload field 406 may define the associated information element content. Using the above-mentioned home operator preference as an example, an IEI of 00000001 may indicate that the IE provides HPLMN_ePDG_Preference; an IEI of 00000002 may indicate that the IE provides a default_FQDN; an IEI of 00000003 may indicate that the IE provides the number of preferred FQDNs; an IEI of 00000004 may indicate that the IE provides the length of a sub-container for the number of preferred FQDNs, where each entry in the sub-container may contain a PLMN-ID, an FQDN, and a priority; an IEI of 00000005 may indicate that the IE provides the number of preferred access service providers; an IEI of 00000006 may indicate that the IE provides the length of a sub-container for the number of preferred access service providers, where each entry in the sub-container may contain a PLMN-ID and a priority; IEIs of 00000007 to 11111111 may be reserved for future use. For each IEI, the first octet may be the IE identifier, followed by the length of the IEI, and then any other IEI-specific fields.

FIG5 shows a flow chart of ePDG selection according to some embodiments. As mentioned above, the operations shown in FIG5 may also be applied to emergency service scenarios. The method shown in FIG5 may be used by the UE shown in FIG1 or FIG2, for example.

At operation 500, the UE may obtain information indicating which ePDG to select. In some embodiments, static or pre-configured information in a configuration file stored in the UE's memory may be used. In some embodiments, dynamic information obtained over the air (e.g., when accessing a WLAN network) from a home operator may be used. In some embodiments, both dynamic and static information are available to the UE, in which case the dynamic information (which may be the most recent) may take precedence over the static information and, therefore, be used in place of the static information.

If dynamic information is used, the UE may attempt to obtain ANDSF information. If successful, the UE may use the ANDSF information. If the ANDSF information cannot be accessed, or if the ANDSF information is unavailable for other reasons, the UE may attempt to obtain selection information using ANQP. If the selection information can be obtained using ANQP, the UE may apply the selection information obtained using ANQP. If the UE cannot obtain dynamic information, or if the UE uses RAN rules, the UE may instead apply static or pre-configured selection information.

Therefore, a configuration file can be configured to store rules for ePDG selection. The configuration file can store information including selection rules and a list of ePDGs. In some embodiments, these rules can indicate the priority of different types of ePDG connections based on, for example, the specific network or RAT implemented or included in the network. The rules stored by the configuration file can be obtained in various ways. In some embodiments, the configuration file can store preconfigured rules. For example, the rules stored by the configuration file can be stored during the manufacture or initial programming of the UE. In some embodiments, the configuration file can be configured to synchronize the rules with network components. For example, the configuration file and the ANDSF server can synchronize at least a portion of the MO stored by the UE so that the UE has the same version as the visiting or home ANDSF server. The configuration file can store the rules by storing at least a portion of the MO. In some embodiments, the MO can be synchronized with the ANDSF server when the UE is activated. In some embodiments, the MO can be synchronized dynamically so that the configuration file stores the latest version of the MO. For example, the ANDSF server can send a message to the UE indicating that the MO has been changed or updated, and the UE can connect to the ANDSF server to synchronize the MO. In some embodiments, only the portion of the MO that has been modified is sent to the UE to save bandwidth and/or the MO may be updated over an alternative network connection (eg, over a Wi-Fi RAN or WiMAX RAN).

The configuration file can obtain rules and/or store the rules in the MO. For example, the rules can be obtained and/or stored in a structure that includes an ANDSF MO. In some embodiments, the MO can be compatible with Open Mobile Alliance (OMA) Device Management (DM). In some embodiments, the rules and/or policies in the MO can be stored or indicated in an extensible markup language (XML) format. In some embodiments, the ANDSF MO includes preferences in XML format. For example, policies and preferences can be organized in a branch and leaf structure formatted according to XML. Preferences can be included in one or more of ISMP and ISRP.

At operation 502, the UE may determine whether it is roaming. For example, the UE may determine based on location whether it is roaming, ie, outside its home network and using resources from another operator's network.

Regardless of whether dynamic or static information is used, the information obtained may include a preferred FQDN list. This information is used at operation 504, where the UE may determine whether it is attached to the PLMN specified by the service provider in the preferred FQDN list. If multiple PLMNs are available, the UE may use the preferred FQDN list to select the highest priority PLMN to attach to.

If the UE determines at operation 504 that it is attached to a PLMN specified by the service provider in the preferred FQDN list, then at operation 506, the UE may determine the FQDN corresponding to the highest priority PLMN. The UE may then use a Domain Name System (DNS) mechanism to obtain the IP address of the ePDG of the highest priority PLMN. The UE may then connect to the ePDG of the highest priority PLMN.

When the UE is roaming in a visited service provider network, the UE may determine whether the HPLMN has indicated that the UE should use the ePDG (VePDG) corresponding to the visited service provider at operation 508. The UE may make this determination based on whether HPLMN_ePDG_Preference is set to 0 as determined using the acquired information.

If the UE determines that it will use the VePDG at operation 508 , the UE may create an FQDN based on the VPLMN. The UE may then connect to the VePDG at operation 510 using the created FQDN.

If the UE determines that it cannot connect to any PLMN, the UE may extract a default FQDN from the acquired information. The default FQDN may correspond to a specific PLMN. The UE may then use the default FQDN at operation 516 to connect to the ePDG corresponding to the specific PLMN.

If the UE determines at operation 508 that the HPLMN has indicated that the UE should not use VePDG, i.e., HPLMN_ePDG_Preference is set to 1, the UE may connect to the ePDG corresponding to the FQDN of the home operator (HePDG) at operation 518. Similarly, if the UE is not roaming but is in the HPLMN, the UE may connect to the ePDG corresponding to the FQDN of the home operator. In addition, the UE may detect a failure in operation 504, 510, or 514, and if so, the UE may jump directly to step 5.

Although not shown in FIG5 , in some embodiments, whether an ePDG supports emergency services may be a factor in determining whether to select the ePDG. For example, if the ePDG selected according to the described operations supports emergency services, then the ePDG may be selected. In some embodiments, the ePDG may be selected based on the emergency FQDN.

In some embodiments, the UE may prioritize ePDG selection information obtained from different sources to resolve conflicts. For example, the UE may have ePDG selection information in memory (UICC, ME memory, etc.) and in an ANDSF MO. In one such embodiment, the information in memory may take precedence over the ANDSF MO information.

Therefore, in some embodiments, in a first operation, if a HePDG identifier is configured in the UE, the UE may select the HePDG using the configured IP address. Alternatively, the UE may use the configured FQDN to perform a DNS query to obtain the IP address(es) of the ePDG(s) in the HPLMN.

In the second operation, if the HePDG identity is not configured in the UE, the UE is attached to the PLMN and the PLMN is found in the ePDG selection information in the UE. The UE can select the ePDG (VePDG) of the PLMN. Otherwise, the UE can select the ePDG of the default PLMN.

In the third operation, if the HePDG identifier is not configured in the UE and the UE is not attached to a PLMN, the UE may select the HePDG. If the HPLMN FQDN is stored in the UE, the UE may construct the HePDG FQDN based on the stored information. Otherwise, the UE may construct the operator identifier FQDN based on the HPLMN's operator PLMN ID and then perform a DNS query to obtain the ePDG IP address.

Various examples of the present disclosure are provided below. These examples are not intended to limit the disclosure herein in any way. In Example 1, an apparatus of a user equipment (UE) may include: a transceiver arranged to communicate with a 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) network via an access point (AP) of a non-secured network; and a processing circuit arranged to: when the UE is roaming to a visited public land mobile network (VPLMN) and attempting to connect to the AP, obtain enhanced packet data gateway (ePDG) selection information indicating whether to attempt to connect to a home public land mobile network (HPLMN) ePDG (HePDG) or a VPLMN ePDG (VePDG); and configure the transceiver to connect to the one of the HePDG and the VePDG indicated by the ePDG selection information.

In Example 2, the subject matter of Example 1 may optionally include: the ePDG selection information is pre-configured information in a configuration file stored in a memory, the ePDG selection information including a list of ePDGs and a selection rule.

In Example 3, the subject matter of one or any combination of Examples 1-2 can optionally include the processing circuit being further arranged to obtain the ePDG selection information from an Access Network Discovery and Selection Function (ANDSF) server.

In Example 4, the subject matter of one or any combination of Examples 1-3 can optionally include the ePDG selection information comprising an ANDSF Management Object (MO), regardless of whether the ePDG selection information is dynamic information or static information.

In Example 5, the subject matter of one or any combination of Examples 1-4 may optionally include: the processing circuit is further arranged to configure the transceiver to obtain ePDG selection information through the AP using a Wireless Local Area Network (WLAN) Access Network Query Protocol (ANQP), the ANQP response including a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network and which operators support S2b and are deployed with one or more ePDGs.

In Example 6, the subject matter of one or any combination of Examples 1-5 may optionally include: the ANQP query including an Info ID field indicating that an ANQP response to the UE is to use a generic container, the generic container including: a version field indicating a version of the generic container; a header length field defining the number of octets following a length of the header length field; and a payload field including a plurality of information element identifiers (IEIs).

In Example 7, the subject matter of one or any combination of Examples 1-6 can optionally include selecting the ePDG selection information using radio access network (RAN) rules stored in the memory, the ePDG selection information comprising a list of ePDGs and the selection rules.

In Example 8, the subject matter of one or any combination of Examples 1-7 may optionally include: the UE further comprising a memory, the ePDG selection information being preconfigured information in a configuration file stored in the memory, and the processing circuitry being further arranged to: configure the transceiver to dynamically obtain the ePDG selection information from the server through the AP, and if the ePDG selection information cannot be dynamically obtained, obtain the ePDG selection information from the memory.

In Example 9, the subject matter of Example 8 may optionally include: the processing circuit being further arranged to configure the transceiver to dynamically obtain the ePDG selection information through the AP using an Access Network Discovery and Selection Function (ANDSF) server; and configuring the transceiver to dynamically obtain the ePDG selection information using a Wireless Local Area Network (WLAN) Access Network Query Protocol (ANQP) when the ePDG selection information cannot be obtained from the ANDSF server.

In Example 10, the subject matter of one or any combination of Examples 1-9 may optionally include at least one of the following: a) in response to determining that the UE is not roaming, the processing circuit is further arranged to: use the HePDG fully qualified domain name (FQDN) and a domain name server (DNS)-based mechanism to obtain an Internet Protocol (IP) address; and configure the transceiver to connect to the HePDG through the AP using the IP address, and b) in response to determining that the UE is to connect to the VePDG, create a fully qualified domain name (FQDN) based on the VPLMN, and connect to the VePDG based on the FQDN of the VePDG.

In Example 11, the subject matter of one or any combination of Examples 1-10 can optionally include, regardless of whether the ePDG selection information includes dynamic information or static information, the ePDG selection information including a list comprising a plurality of prioritized VPLMNs, wherein the HPLMN policy is not preferred.

In Example 12, the subject matter of Example 11 may optionally include: the processing circuit is further arranged to configure the transceiver to create a fully qualified domain name (FQDN) of a VPLMN having a highest priority among the plurality of prioritized VPLMNs in the list, obtain an Internet Protocol (IP) address of an ePDG of the highest priority VPLMN using a domain name server (DNS) mechanism, and connect to the ePDG of the highest priority PLMN through the AP using the obtained IP address.

In Example 13, the subject matter of one or any combination of Examples 1-12 may optionally include: the ePDG selection information including a HPLMN_ePDG_Preference flag, and the processing circuit is further arranged to, in response to determining that the UE is roaming, determine whether the HPLMN has instructed the UE to use VePDG based on the setting of the HPLMN_ePDG_Preference flag.

In Example 14, the subject matter of one or any combination of Examples 1-13 may optionally include: the processing circuit is further arranged to determine that the UE cannot connect to any PLMN, in response to determining that the UE cannot connect to any PLMN, extract a default fully qualified domain name (FQDN) corresponding to the specific PLMN from the ePDG selection information, and connect to the ePDG corresponding to the specific PLMN through the AP based on the default FQDN.

In Example 15, the subject matter of one or any combination of Examples 1-14 may optionally include: the processing circuit is further arranged to, in response to determining that the UE desires Voice over WiFi (VoWiFi) service, determine whether to connect to the HePDG or the VePDG based on: whether a roaming agreement between the VPLMN and the HPLMN allows use of the VoWiFi service, and if the roaming agreement between the VPLMN and the HPLMN allows use of the VoWiFi service, whether the VoWiFi service is deployed by the VPLMN and is operational.

In Example 16, the subject matter of one or any combination of Examples 1-15 can optionally include an antenna configured to transmit and receive communications between the transceiver and the AP.

In Example 17, an apparatus includes an access point (AP), comprising: a transceiver arranged to communicate with a Third Generation Partnership Project Long Term Evolution (3GPP LTE) network and with a user equipment (UE); and a processing circuit arranged to: configure the transceiver to send enhanced packet data gateway (ePDG) selection information to the UE from an access network discovery and selection function (ANDSF) server or in response to a wireless local area network (WLAN) access network query protocol (ANQP) query, the enhanced packet data gateway (ePDG) selection information indicating whether to attempt to connect to a home public land mobile network (HPLMN) ePDG (HePDG) or a VPLMN ePDG (VePDG); and configure the transceiver to connect the UE to the one of the HePDG and the VePDG indicated by the ePDG selection information.

In Example 18, the subject matter of Example 17 can optionally include: the processing circuit is further arranged to configure the transceiver to send the ePDG selection information from the ANDSF server using an ANDSF management object (MO), the ANDSF MO including the home network preference data, the S2b connectivity preference data, the HPLMN_ePDG_Preference Flag, the preferred FQDN data, the service provider data, the FQDN data, the priority data, the default_FQDN data, and the visited_ePDG_SPL list.

In Example 19, the subject matter of Example 17 or 18 may optionally include: the processing circuit is further arranged to: configure the transceiver to send the ePDG selection information using a WLAN ANQP response, wherein the WLAN ANQP response includes a list of public land mobile network (PLMN) identifiers supported by the WLAN network and which operators support S2b and are deployed with one or more ePDGs.

In Example 20, the subject matter of Example 19 may optionally include: the ANQP query including an Info ID field indicating that an ANQP response to the UE is to use a generic container, the generic container including: a version field indicating a version of the generic container; a header length field defining the number of octets following the length of the header length field; and a payload field including a plurality of information element identifiers (IEIs).

In Example 21, the subject matter of one or any combination of Examples 17-20 may optionally include: the UE is not roaming, and the processing circuit is further arranged to configure the transceiver to connect the UE to the HePDG based on an Internet Protocol (IP) address obtained using a fully qualified domain name (FQDN) of the HePDG and a domain name server (DNS) based mechanism.

In Example 22, the subject matter of one or any combination of Examples 17-21 may optionally include at least one of the following: a) the ePDG selection information includes a list comprising a plurality of prioritized VPLMNs, wherein the HPLMN policy is not preferred, and the processing circuit is further arranged to: configure the transceiver to: send to the UE, using a domain name server (DNS) mechanism, an Internet Protocol (IP) address of the ePDG of the VPLMN with the highest priority among the plurality of prioritized VPLMNs in the list, and connect the UE to the ePDG of the highest priority PLMN using the IP address; and b) the ePDG selection information includes an HPLMN_ePDG_preference flag, which allows the UE to determine, when roaming, whether the HPLMN has indicated that the UE is to use the VePDG based on the setting of the HPLMN_ePDG_preference flag.

In Example 23, a non-transitory computer-readable storage medium storing instructions, the instructions being executed by one or more processors of a user equipment (UE) to configure the UE to communicate with a Third Generation Partnership Project Long Term Evolution (3GPP LTE) network through an access point (AP) of a non-secured network, the one or more processors configuring the UE to: when the UE is not roaming, connect to a Home Public Land Mobile Network (HPLMN) ePDG (HePDG) through the AP; when the UE is roaming, obtain enhanced packet data gateway (ePDG) selection information indicating whether to attempt to connect to the HePDG or a Visited Public Land Mobile Network (VPLMN) ePDG (VePDG), and connect to the one of the HePDG and the VePDG indicated by the ePDG selection information through the AP; and when the UE is roaming and cannot connect to any PLMN, extract a default fully qualified domain name (FQDN) corresponding to a specific PLMN from the ePDG selection information, and connect to the ePDG corresponding to the specific PLMN through the AP based on the default FQDN.

In Example 24, the subject matter of Example 23 may optionally include: the ePDG selection information includes a list and selection rules of ePDGs, the ePDG selection information is one of the following items: pre-configured information in a configuration file stored in a memory of the UE, or dynamic information obtained by the AP from an Access Network Discovery and Selection Function (ANDSF) server or from a Wireless Local Area Network (WLAN) Access Network Query Protocol (ANQP) response, the Wireless Local Area Network (WLAN) Access Network Query Protocol (ANQP) response including a list of PLMN identifiers supported by the WLAN network and which operators support S2b and are deployed with one or more ePDGs, wherein the ePDG selection information is obtained from the memory after it cannot be dynamically obtained.

In Example 25, the subject matter of Example 23 or 24 may optionally include: regardless of whether the ePDG selection information is dynamic information or static information, in a case where the HPLMN policy is preferred or not, the ePDG selection information includes a list including multiple prioritized VPLMNs, and the one or more processors configure the UE to: create a fully qualified domain name (FQDN) of a VPLMN with the highest priority among the multiple prioritized VPLMNs in the list, obtain an Internet Protocol (IP) address of the ePDG of the highest priority VPLMN using a domain name server (DNS) mechanism, and connect to the ePDG of the highest priority PLMN through the AP using the obtained IP address.

Although the embodiments have been described with reference to specific example embodiments, it will be apparent that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the present disclosure. Accordingly, the description and drawings should be regarded as illustrative and not restrictive. The drawings forming a part thereof illustrate specific embodiments of the practical subject matter by way of example and not limitation. The embodiments shown are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom so that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Therefore, this specific embodiment should not be regarded as having a limiting meaning, and the scope of the various embodiments is limited only by the appended claims together with the full range of equivalents to which such claims are entitled.

These embodiments of the inventive subject matter may be referred to herein individually and/or collectively as the term "invention," which is merely for convenience and is not intended to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one invention or inventive concept is actually disclosed. Therefore, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement obtained to achieve the same purpose may replace the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of the various embodiments. Combinations of the above embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art after reading the above description.

In this document, as is common in patent documents, the term "a" is used to include one or more than one, independent of any other instance or usage of "at least one" or "one or more." In this document, unless otherwise stated, the term "or" is used to refer to a non-exclusive or, so that "A or B" includes "A but not B," "B but not A," and "A and B." In this document, the terms "include" and "in which" are used as the plain English equivalents of the respective terms "comprise" and "wherein." Moreover, in the appended claims, the terms "include" and "comprising" are open-ended, that is, systems, UEs, articles, compositions, formulas, or processes that include elements in addition to those listed after the item in the claim are also deemed to fall within the scope of protection of the claim. In addition, in the appended claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

The Abstract of the Disclosure is provided to comply with the requirement of 37 C.F.R. §1.72(b) to provide an abstract that enables the reader to quickly ascertain the nature of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, it will be seen in the foregoing Detailed Description that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the appended claims reflect, inventive subject matter lies in fewer features than all of the features of a single disclosed embodiment. Accordingly, the appended claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims (54)

1. An apparatus for a user equipment (UE), comprising: A transceiver, configured to communicate with the 3GPP LTE network via an access point (AP) in an unsecured network; and The processing circuit is arranged as follows: When the UE is roaming to access a Public Land Mobile Network (VPLMN) and attempting to connect to the AP, it obtains Enhanced Packet Data Gateway (ePDG) selection information, which indicates whether to attempt to connect to the Home Public Land Mobile Network (HPLMN) ePDG (HePDG) or the VPLMN ePDG (VePDG); and Configure the transceiver to connect to the HePDG and the VePDG indicated by the ePDG selection information; The processing circuitry is also configured to: configure the transceiver to obtain the ePDG selection information via the AP using the Wireless LAN Access Network Query Protocol WLANANQP, wherein: The ANQP query includes an Info ID field, which indicates that the ANQP response to the UE will use a generic container. This generic container includes: a version field, indicating the version of the generic container; a header length field, defining the number of octets following the length of the header length field; and a payload field, which includes multiple Information Element Identifiers (IEIs). The ANQP response includes a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network, as well as which operators support S2b and have deployed one or more ePDGs. 2. The apparatus according to claim 1, wherein: The ePDG selection information is pre-configured information stored in a configuration file in the memory. The ePDG selection information includes a list of ePDGs and selection rules. 3. The apparatus according to claim 1 or 2, wherein the processing circuit is further arranged as follows: Configure the transceiver to obtain the ePDG selection information from the Access Network Discovery and Selection Function (ANDSF) server. 4. The apparatus according to claim 3, wherein: The ePDG selection information includes the ANDSF management object MO, regardless of whether the ePDG selection information is dynamic or static. 5. The apparatus according to claim 1 or 2, wherein: The ePDG selection information is selected using radio access network (RAN) rules stored in the memory, and the ePDG selection information includes a list of ePDGs and selection rules. 6. The apparatus according to claim 1 or 2, wherein: The UE also includes a memory. The ePDG selection information is pre-configured information stored in a configuration file in the memory, and The processing circuit is further arranged as follows: Configure the transceiver to dynamically obtain the ePDG selection information from the server via the AP, and If the ePDG selection information cannot be dynamically obtained, then the ePDG selection information is obtained from the memory. 7. The apparatus of claim 6, wherein the processing circuit is further arranged as follows: Configure the transceiver to use the Access Network Discovery and Selection (ANDSF) function to dynamically obtain the ePDG selection information through the AP; and The transceiver is configured to dynamically acquire the ePDG selection information using the WLAN ANQP when the ePDG selection information cannot be obtained from the ANDSF server. 8. The apparatus according to claim 1 or 2, wherein at least one of the following is performed: a) In response to determining that the UE is not roaming, the processing circuitry is further configured to: The HePDG's fully qualified domain name (FQDN) and a DNS-based mechanism are used to obtain Internet Protocol (IP) addresses; and Configure the transceiver to connect to the HePDG via the AP using the IP address, and b) In response to determining that the UE wants to connect to the VePDG, create a fully qualified domain name (FQDN) based on the VPLMN, and The FQDN based on the VePDG is connected to the VePDG. 9. The apparatus according to claim 1 or 2, wherein: Regardless of whether the ePDG selection information includes dynamic or static information, the ePDG selection information includes a list of multiple prioritized VPLMNs, where the HPLMN strategy is not preferred. 10. The apparatus of claim 9, wherein the processing circuitry is further arranged to configure the transceiver to: Create the fully qualified domain name (FQDN) of the VPLMN with the highest priority among the multiple prioritized VPLMNs in the list; Use the DNS (Domain Name System) mechanism to obtain the Internet Protocol (IP) address of the ePDG of the highest priority VPLMN; and Use the obtained IP address to connect to the ePDG of the highest priority PLMN via the AP. 11. The apparatus according to claim 1 or 2, wherein: The ePDG selection information includes the HPLMN_ePDG_preference flag, and The processing circuitry is also configured to determine, in response to determining that the UE is roaming, whether the HPLMN has instructed the UE to use the VePDG based on the setting of the HPLMN_ePDG_preference flag. 12. The apparatus according to claim 1 or 2, wherein the processing circuit is further arranged as follows: It is determined that the UE cannot connect to any PLMN; In response to determining that the UE cannot connect to any PLMN, the default fully qualified domain name (FQDN) corresponding to the specific PLMN is extracted from the ePDG selection information; and Based on the default FQDN, the connection is made via the AP to the ePDG corresponding to the specific PLMN. 13. The apparatus according to claim 1 or 2, wherein the processing circuit is further arranged as follows: In response to determining that the UE expects WiFi Voice (VoWiFi) service, the system determines whether to connect to the HePDG or the VePDG based on the following: The roaming agreement between the VPLMN and the HPLMN allows the use of the VoWiFi service; and If the roaming agreement between the VPLMN and the HPLMN allows the use of VoWiFi service, then the VoWiFi service is deployed by the VPLMN and is operational. 14. The apparatus of claim 1 or 2, further comprising: an antenna configured to transmit and receive communication between the transceiver and the AP. 15. An apparatus for an access point (AP), comprising: A transceiver configured to communicate with the 3GPP LTE network and with user equipment (UE); and The processing circuit is arranged as follows: The transceiver is configured to send Enhanced Packet Data Gateway (ePDG) selection information to the UE. This ePDG selection information indicates whether to attempt to connect to the Home Public Land Mobile Network (HPLMN) ePDG (HePDG) or access the Public Land Mobile Network (VPLMNePDG) (VePDG). The ePDG selection information is sent from the Access Network Discovery and Selection Function (ANDSF) server or in response to a WLAN ANQP query, which includes an Info ID field indicating that the ANQP response to the UE will use a generic container. Configure the transceiver to connect the UE to the HePDG and the VePDG indicated by the ePDG selection information; The processing circuitry is also configured to: configure the transceiver to send the ePDG selection information using the ANQP response, the ANQP response including a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network and which operators support S2b and have deployed one or more ePDGs; The generic container used in the ANQP response includes: a version field indicating the version of the generic container; a header length field defining the number of octets following the length of the header length field; and a payload field including multiple Information Element Identifiers (IEIs). 16. The apparatus of claim 15, wherein the processing circuit is further arranged as follows: Configure the transceiver to send the ePDG selection information from the ANDSF server using an ANDSF management object MO, the ANDSF MO including home network preference data, S2b connectivity preference data, HPLMN_ePDG_preference flag, service provider data, FQDN data, priority data, and access_ePDG_SPL list. 17. The apparatus according to claim 15 or 16, wherein: The UE is not roaming, and The processing circuitry is also configured to connect the transceiver to the HePDG based on an Internet Protocol IP address obtained using the HePDG's Fully Qualified Domain Name (FQDN) and a DNS-based mechanism. 18. The apparatus according to claim 15 or 16, wherein at least one of the following is performed: a) The ePDG selection information includes a list of multiple prioritized VPLMNs, where the HPLMN strategy is not preferred, and The processing circuitry is also configured to configure the transceiver to: The Internet Protocol (IP) address of the ePDG of the highest-priority VPLMN among the multiple prioritized VPLMNs in the list is sent to the UE using the Domain Name Server (DNS) mechanism; and Using this IP address, the UE is connected to the ePDG of the highest priority PLMN, and b) The ePDG selection information includes the HPLMN_ePDG_preference flag, which allows the UE to determine whether the HPLMN has instructed the UE to use the VePDG based on the setting of the HPLMN_ePDG_preference flag when roaming. 19. A method performed by a user equipment (UE), comprising: Communicating with the 3GPP LTE network via access points (APs) in the unsecured network; When the UE is roaming to access a Public Land Mobile Network (VPLMN) and attempting to connect to the AP, it obtains Enhanced Packet Data Gateway (ePDG) selection information, which indicates whether to attempt to connect to the Home Public Land Mobile Network (HPLMN) ePDG (HePDG) or the VPLMN ePDG (VePDG); and Connect to the one of the HePDG and the VePDG indicated by the ePDG selection information; The method further includes: using the Wireless Local Area Network Access Network Query Protocol (WLAN ANQP) to obtain the ePDG selection information through the AP, wherein: The ANQP query includes an Info ID field, which indicates that the ANQP response to the UE will use a generic container. This generic container includes: a version field, indicating the version of the generic container; a header length field, defining the number of octets following the length of the header length field; and a payload field, which includes multiple Information Element Identifiers (IEIs). The ANQP response includes a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network, as well as which operators support S2b and have deployed one or more ePDGs. 20. The method of claim 19, wherein: The ePDG selection information is pre-configured information stored in a configuration file in the memory. The ePDG selection information includes a list of ePDGs and selection rules. 21. The method according to claim 19 or 20, further comprising: The ePDG selection information is obtained from the ANDSF server of the Access Network Discovery and Selection Function. 22. The method according to claim 21, wherein: The ePDG selection information includes the ANDSF management object MO, regardless of whether the ePDG selection information is dynamic or static. 23. The method according to claim 19 or 20, wherein: The ePDG selection information is selected using radio access network (RAN) rules stored in the memory, and the ePDG selection information includes a list of ePDGs and selection rules. 24. The method according to claim 19 or 20, wherein: The UE also includes a memory. The ePDG selection information is pre-configured information stored in a configuration file in the memory, and the method further includes: The ePDG selection information is dynamically obtained from the server via the AP, and If the ePDG selection information cannot be dynamically obtained, then the ePDG selection information is obtained from the memory. 25. The method of claim 24, further comprising: The ANDSF server dynamically obtains the ePDG selection information through the AP using the Access Network Discovery and Selection (ADS) function; and When the ePDG selection information cannot be obtained from the ANDSF server, the ePDG selection information is dynamically obtained using the WLAN ANQP. 26. The method according to claim 19 or 20, wherein at least one of the following is performed: a) In response to determining that the UE is not roaming, the method further includes: The HePDG's fully qualified domain name (FQDN) and a DNS-based mechanism are used to obtain Internet Protocol (IP) addresses; and Connect to the HePDG via the AP using the IP address, and b) In response to determining that the UE wants to connect to the VePDG, create a fully qualified domain name (FQDN) based on the VPLMN, and The FQDN based on the VePDG is connected to the VePDG. 27. The method according to claim 19 or 20, wherein: Regardless of whether the ePDG selection information includes dynamic or static information, the ePDG selection information includes a list of multiple prioritized VPLMNs, where the HPLMN strategy is not preferred. 28. The method of claim 27, further comprising: Create the fully qualified domain name (FQDN) of the VPLMN with the highest priority among the multiple prioritized VPLMNs in the list; Use the DNS (Domain Name System) mechanism to obtain the Internet Protocol (IP) address of the ePDG of the highest priority VPLMN; and Use the obtained IP address to connect to the ePDG of the highest priority PLMN via the AP. 29. The method according to claim 19 or 20, wherein: The ePDG selection information includes the HPLMN_ePDG_preference flag, and The method further includes: in response to determining that the UE is roaming, determining whether the HPLMN has instructed the UE to use the VePDG based on the setting of the HPLMN_ePDG_preference flag. 30. The method according to claim 19 or 20, further comprising: It is determined that the UE cannot connect to any PLMN; In response to determining that the UE cannot connect to any PLMN, the default fully qualified domain name (FQDN) corresponding to the specific PLMN is extracted from the ePDG selection information; and Based on the default FQDN, the connection is made via the AP to the ePDG corresponding to the specific PLMN. 31. The method according to claim 19 or 20, further comprising: In response to determining that the UE expects WiFi Voice (VoWiFi) service, the system determines whether to connect to the HePDG or the VePDG based on the following: The roaming agreement between the VPLMN and the HPLMN allows the use of the VoWiFi service; and If the roaming agreement between the VPLMN and the HPLMN allows the use of VoWiFi service, then the VoWiFi service is deployed by the VPLMN and is operational. 32. An apparatus for a user equipment (UE), comprising: Apparatus for communicating with a 3GPP LTE network via an access point (AP) in an unsecured network; A means for obtaining enhanced packet data gateway ePDG selection information when the UE is roaming to access a public land mobile network (VPLMN) and attempting to connect to the AP, the ePDG selection information indicating whether to attempt to connect to the home public land mobile network (HPLMN ePDG, i.e., HePDG) or the VPLMN ePDG, i.e., VePDG; A means for connecting to the HePDG and the VePDG indicated by the ePDG selection information; and A means for obtaining ePDG selection information through the AP using the Wireless Local Area Network Access Network Query Protocol ANQP, wherein: The ANQP query includes an Info ID field, which indicates that the ANQP response to the UE will use a generic container. This generic container includes: a version field, indicating the version of the generic container; a header length field, defining the number of octets following the length of the header length field; and a payload field, which includes multiple Information Element Identifiers (IEIs). The ANQP response includes a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network, as well as which operators support S2b and have deployed one or more ePDGs. 33. The device according to claim 32, wherein: The ePDG selection information is pre-configured information stored in a configuration file in the memory. The ePDG selection information includes a list of ePDGs and selection rules. 34. The device according to claim 32 or 33, further comprising: A means for obtaining the ePDG selection information from the Access Network Discovery and Selection Function (ANDSF) server. 35. The device according to claim 34, wherein: The ePDG selection information includes the ANDSF management object MO, regardless of whether the ePDG selection information is dynamic or static. 36. The device according to claim 32 or 33, wherein: The ePDG selection information is selected using radio access network (RAN) rules stored in the memory, and the ePDG selection information includes a list of ePDGs and selection rules. 37. The device according to claim 32 or 33, wherein: The UE also includes a memory. The ePDG selection information is pre-configured information stored in a configuration file in the memory, and the device also includes: A device for dynamically obtaining the ePDG selection information from the server via the AP, and A means for retrieving the ePDG selection information from the memory if the ePDG selection information cannot be dynamically retrieved. 38. The apparatus of claim 37, further comprising: A means for using the Access Network Discovery and Selection (ANDSF) server to dynamically obtain the ePDG selection information through the AP; and A means for dynamically acquiring the ePDG selection information using the WLAN ANQP when the ePDG selection information cannot be obtained from the ANDSF server. 39. The device according to claim 32 or 33, comprising at least one of the following: a) Means for performing the following operations in response to determining that the UE is not roaming: The HePDG's fully qualified domain name (FQDN) and a DNS-based mechanism are used to obtain Internet Protocol (IP) addresses; and Connect to the HePDG via the AP using the IP address, and b) means for creating a fully qualified domain name (FQDN) based on the VPLMN in response to determining that the UE wants to connect to the VePDG, and A means for connecting the VePDG to the VePDG via an FQDN based on the VePDG. 40. The device according to claim 32 or 33, wherein: Regardless of whether the ePDG selection information includes dynamic or static information, the ePDG selection information includes a list of multiple prioritized VPLMNs, where the HPLMN strategy is not preferred. 41. The device according to claim 40, further comprising: A means for creating the fully qualified domain name (FQDN) of the highest priority VPLMN among the plurality of prioritized VPLMNs in the list; A means for obtaining the Internet Protocol IP address of the ePDG of the highest priority VPLMN using the DNS mechanism; and A device for connecting an ePDG to the highest priority PLMN via the AP using the acquired IP address. 42. The device according to claim 32 or 33, wherein: The ePDG selection information includes the HPLMN_ePDG_preference flag, and The device further includes means for determining, in response to determining that the UE is roaming, whether the HPLMN has instructed the UE to use the VePDG based on the setting of the HPLMN_ePDG_preference flag. 43. The device according to claim 32 or 33, further comprising: A device used to determine that the UE cannot be connected to any PLMN; A means for extracting the default fully qualified domain name (FQDN) corresponding to a specific PLMN from the ePDG selection information in response to determining that the UE cannot connect to any PLMN; and A device for connecting to the ePDG corresponding to the specific PLMN via the AP based on the default FQDN. 44. The device according to claim 32 or 33, further comprising: A means for determining whether to connect to the HePDG or the VePDG in response to determining that the UE expects WiFi Voice (VoWiFi) service, based on the following: The roaming agreement between the VPLMN and the HPLMN allows the use of the VoWiFi service; and If the roaming agreement between the VPLMN and the HPLMN allows the use of VoWiFi service, then the VoWiFi service is deployed by the VPLMN and is operational. 45. A computer-readable storage medium comprising code, which, when executed by a processor of a user equipment (UE), causes the UE to perform the method as described in any one of claims 19-31. 46. A method performed by an access point (AP), comprising: In collaboration with third-generation partners, we plan to evolve 3GPP LTE networks over the long term and communicate with user equipment (UE). The UE is sent Enhanced Packet Data Gateway (ePDG) selection information, indicating whether to attempt to connect to the Home Public Land Mobile Network (HPLMN) ePDG (HePDG) or access the Public Land Mobile Network (VPLMN) ePDG (VePDG). This ePDG selection information is sent from the Access Network Discovery and Selection Function (ANDSF) server or in response to a WLAN ANQP query, which includes an Info ID field indicating that the ANQP response to the UE will use a generic container. Connect the UE to the HePDG or the VePDG indicated by the ePDG selection information; The method further includes: sending the ePDG selection information using the ANQP response, the ANQP response including a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network and which operators support S2b and have deployed one or more ePDGs; The generic container used in the ANQP response includes: a version field indicating the version of the generic container; a header length field defining the number of octets following the length of the header length field; and a payload field including multiple Information Element Identifiers (IEIs). 47. The method of claim 46, further comprising: The ANDSF Management Object (MO) is used to send the ePDG selection information from the ANDSF server. The ANDSF MO includes home network preference data, S2b connectivity preference data, HPLMN_ePDG_preference flag, service provider data, FQDN data, priority data, and access_ePDG_SPL list. 48. The method according to claim 46 or 47, wherein: The UE is not roaming, and The method further includes connecting the UE to the HePDG based on the fully qualified domain name (FQDN) of the HePDG and the Internet Protocol IP address obtained using a DNS-based mechanism. 49. The method according to claim 46 or 47, wherein at least one of the following is performed: a) The ePDG selection information includes a list of multiple prioritized VPLMNs, wherein the HPLMN strategy is not preferred, and the method further includes: The Internet Protocol (IP) address of the ePDG of the highest-priority VPLMN among the multiple prioritized VPLMNs in the list is sent to the UE using the Domain Name Server (DNS) mechanism; and Using this IP address, the UE is connected to the ePDG of the highest priority PLMN, and b) The ePDG selection information includes the HPLMN_ePDG_preference flag, which allows the UE to determine whether the HPLMN has instructed the UE to use the VePDG when roaming, based on the setting of the HPLMN_ePDG_preference flag. 50. A device for an access point (AP), comprising: Apparatus for communicating with 3GPP LTE networks and with user equipment (UE); A means for sending enhanced packet data gateway ePDG selection information to the UE, the selection information indicating whether to attempt to connect to the Home Public Land Mobile Network (HPLMN) ePDG (HePDG) or access the Public Land Mobile Network (VPLMN) ePDG (VePDG). The ePDG selection information is sent from the Access Network Discovery and Selection Function (ANDSF) server or in response to a WLAN ANQP query, the WLAN ANQP query including an Info ID field indicating that the ANQP response to the UE will use a generic container. A means for connecting the UE to the HePDG and the VePDG indicated by the ePDG selection information; and A means for sending the ePDG selection information using the ANQP response, the ANQP response including a list of Public Land Mobile Network (PLMN) identifiers supported by the WLAN network and which operators support S2b and have deployed one or more ePDGs. The generic container used in the ANQP response includes: a version field indicating the version of the generic container; a header length field defining the number of octets following the length of the header length field; and a payload field including multiple Information Element Identifiers (IEIs). 51. The device according to claim 50, further comprising: A means for sending ePDG selection information from the ANDSF server using an ANDSF management object MO, the ANDSF MO including home network preference data, S2b connectivity preference data, HPLMN_ePDG_preference flag, service provider data, FQDN data, priority data, and access_ePDG_SPL list. 52. The device according to claim 50 or 51, wherein: The UE is not roaming, and The device further includes means for connecting the UE to the HePDG based on an Internet Protocol IP address obtained using the fully qualified domain name (FQDN) of the HePDG and a DNS-based mechanism. 53. The device according to claim 50 or 51, further comprising at least one of the following two: a) The ePDG selection information includes a list of multiple prioritized VPLMNs, where the HPLMN strategy is not preferred, and the device further includes: A means for sending to the UE the Internet Protocol IP address of the ePDG of the highest-priority VPLMN among the plurality of prioritized VPLMNs in the list, using a Domain Name Server (DNS) mechanism; and A device for connecting the UE to the ePDG of the highest priority PLMN using the IP address, and b) The ePDG selection information includes the HPLMN_ePDG_preference flag, which allows the UE to determine whether the HPLMN has instructed the UE to use the VePDG based on the setting of the HPLMN_ePDG_preference flag when roaming. 54. A computer-readable storage medium comprising code, which, when executed by a processor of an access point (AP), causes the AP to perform the method as described in any one of claims 46-49.