Emergency service support for non-cellular wireless access

Abstract

A method for obtaining information for establishing emergency service sessions over a non-3GPP wireless access network, the method comprising: by a wireless device: Sending an initial query for emergency service public land mobile network (PLMN) information to a Domain Name System (DNS) server; receiving a first response including a list of one or more PLMNs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server; Selecting a PLMN from the list of one or more PLMNs; Sending a second query for emergency service evolved packet data gateway (ePDG) information to the DNS server; receiving a second response including a list of Internet Protocol (IP) addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server; and Sending a third query for local emergency number information to a DNS server located in a country in which the wireless device is roaming; and Receiving a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the country in which the wireless device is roaming.

Description

AREA

[0001] The described embodiments generally relate to wireless communications, including methods and apparatus for supporting emergency service sessions over non-cellular wireless access networks by a wireless communication device. BACKGROUND

[0002] Fourth-generation (4G) wireless cellular access networks, which use newer radio access technologies implementing one or more Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) and LTE Advanced (LTE-A) standards, are being rapidly developed and deployed by network operators worldwide. The newer cellular wireless networks provide a range of packet-based services in parallel with older second-generation (2G) and third-generation (3G) wireless networks, which can provide both circuit-switched voice services and packet-switched data services. The cellular wireless networks overlap with several wireless local area network (WLAN)-based networks, which provide additional localized high-speed access for various services. Wireless communication devices may include capabilities to provide a range of services based on various criteria, such as:Connecting to different wireless networks individually or in parallel based on which wireless networks are available at a particular location, based on various characteristics of available wireless networks, based on capabilities of the wireless communication device, based on characteristics of particular services provided by one or more of the wireless networks, and / or based on service subscriptions to which the wireless communication device and / or the user thereof is assigned. Wireless communication devices may include wireless radio switching logic that supports communication over multiple radio frequency interfaces that may be connected individually and / or in parallel by different wireless networks.Providers of cellular wireless network services add WLAN connectivity to provide access to cellular services over WLAN networks for cellular service subscribers to complement access over cellular wireless access networks, including access to emergency services such as 911 and e911, or their equivalents, over non-cellular wireless access networks. Therefore, there is a need for mechanisms to support access to emergency service sessions for a wireless communication device while roaming in a visited country / territory.

[0003] The document 3GPP TS 23.402 V13.5.0: Architecture Enhancements for non-3GPP accesses (Release 13), March 2016, describes the architecture and functionality for the integration of non-3GPP access networks into the 3GPP mobile radio system.

[0004] The document 3GPP TS 23.003 V13.5.0: Numbering, Addressing and Identification (Release 13), March 2016, defines the basic principles and plans for numbering, addressing, and identification in 3GPP systems (Release 13). It covers various identification methods and their application in mobile networks. SUMMARY

[0005] The invention is defined in the independent claims. Advantageous embodiments are defined in the dependent claims.

[0006] Apparatus and methods for supporting emergency service access over non-mobile wireless networks for a wireless communication device, such as user equipment (UE), are disclosed. Representative embodiments include methods and apparatus for selecting an evolved packet data gateway (ePDG) for emergency service sessions when the UE is roaming in a foreign network and for determining local emergency service numbers for Internet Protocol Multimedia Subsystem (IMS) sessions over a non-mobile wireless access network, such as over an untrusted wireless local area network (WLAN).When the UE is used in a foreign network (roaming), the UE determines a PLMN with an ePDG supporting emergency services by querying a network-based server, such as a Domain Name System (DNS) server, for PLMNs supporting emergency service ePDGs and associated with a Mobile Country Code (MCC) for a country / territory where the UE operates. The UE also determines an ePDG of the PLMN supporting emergency services by further querying the network-based server. In response to detecting an attempt to establish an emergency service session over a non-mobile wireless access network, the UE establishes a connection with the ePDG of the PLMN supporting emergency services. The UE further determines a set of local emergency service numbers, each number associated with an emergency service category type, by querying the network-based server.The solutions provided herein may be used as part of and / or in conjunction with one or more 3GPP wireless communication protocols.

[0007] This summary is provided solely for the purpose of summarizing some example embodiments to provide a basic understanding of some aspects of the subject matter described herein. Accordingly, it is understood that the features described above are merely examples and should not be construed as limiting the scope or spirit of the subject matter described herein in any way. Additional features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, figures, and claims.

[0008] Further aspects and advantages of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which illustrate by way of example the principles of the described embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The described embodiments and the advantages thereof can best be understood by reference to the following description, provided in conjunction with the accompanying drawings. These drawings are not necessarily drawn to scale, and they are not intended in any way to limit or preclude foreseeable modifications thereto in form and detail that may be made by one skilled in the art at the time of this disclosure. Fig. 1 illustrates an example wireless communication device configurable to be connected individually or in parallel by a cellular wireless access network and a non-cellular wireless access network, according to some embodiments. Fig. 2 illustrates example network elements of wireless access networks and a core network according to some embodiments. Fig. 3 illustrates a sequence diagram for an example message exchange for providing emergency service support information to a wireless communication device, according to some embodiments. Fig. 4 illustrates an example method for a wireless communication device to obtain emergency service information according to some embodiments. Fig. 5 illustrates another example method for a wireless communication device to obtain emergency service information according to some embodiments. Fig. 6 illustrates another example method for a wireless communication device to obtain emergency service information in accordance with some embodiments. Fig. 7 illustrates an exemplary set of elements for supporting emergency services in a wireless communication device according to some embodiments. Fig. 8 illustrates, in block diagram format, an exemplary representative set of elements of a wireless communication device that may be used to implement the various components and techniques described herein, according to some embodiments. DETAILED DESCRIPTION

[0010] Representative examples of supporting emergency service sessions over non-cellular wireless access networks for wireless communication devices while roaming are provided herein. These examples are provided to add context to and aid understanding of the subject matter of this disclosure. It should be appreciated that the present disclosure may be practiced with or without some of the specific details described herein. Furthermore, various modifications and / or changes may be made to the subject matter described herein and illustrated in the corresponding figures to achieve similar advantages and results without departing from the spirit and scope of the disclosure. overview

[0011] Disclosed are devices and methods for supporting emergency service sessions by network elements and by a wireless communication device, such as user equipment (UE), over non-mobile wireless access networks when the UE is used in a foreign network (roaming). Representative embodiments include methods and devices for supporting the UE, when roaming, obtaining and / or providing to the UE emergency service information that the UE can use to establish emergency service sessions in a country / territory where the UE is operating.Emergency service sessions may be established when the UE is unable to authenticate, such as when the UE does not have an installed Universal Subscriber Identity Module (USIM), including an available physical SIM or an available electronic SIM (eSIM) for an embedded Universal Integrated Circuit Card (eUICC), or when the UE is operating in a location where no available SIM or eSIM can be used, such as when a regular service is restricted due to the geographical location of the UE, or when the UE is operating in a visited network without a roaming agreement in place between the UE's Home Public Land Mobile Network (PLMN) and a Visited PLMN (VPLMN).Since not all PLMNs may support emergency service access over non-mobile wireless access networks when the UE is roaming in a foreign network, the UE may determine one or more PLMNs that support emergency service sessions over non-mobile wireless access applicable to a country / territory where the UE is operating. The UE may send a query to a network-based server, such as a Domain Name System (DNS) server, to obtain a response including a list of PLMNs that support emergency service sessions through evolved Packet Data Gateways (ePDGs) that connect non-mobile wireless access networks to Internet Protocol (IP) networks via Packet Data Network (PDN) gateways. The query to the network-based server may include a Mobile Country Code (MCC) for the country / territory where the UE is operating.The response from the network-based server may list PLMNs applicable to the MCC provided by the UE. Each PLMN supporting emergency service sessions may provide one or more ePDGs capable of providing connections for emergency service sessions. The UE selects a PLMN based on information obtained from the network-based server. Since the selected PLMN may have a limited number of ePDGs supporting emergency service sessions, the UE may also send a query to the network-based server to obtain a list of IP addresses for ePDGs supporting emergency service sessions.

[0012] When a UE is roaming and detects an attempt to establish an emergency service session over a non-mobile wireless access network, the UE may select an applicable ePDG that supports emergency service sessions of a PLMN in the country / territory where the UE is located. In some embodiments, the UE is already connected to an ePDG that supports emergency service sessions for the local country / territory where the UE is operating. In some embodiments, the UE is connected to an ePDG that does not support emergency service sessions for the local country / territory where the UE is operating, or the UE is not connected to any ePDG. The UE may determine an MCC for the area in which the UE operates and send one or more queries to a network-based server to determine a PLMN and / or an IP address of an ePDG for a PLMN supporting emergency service sessions for the country / area in which the UE operates.In some embodiments, the UE sends one or more DNS Name Authority Pointer (NAPTR) queries to a DNS server to obtain information to identify one or more PLMNs for the country / territory in which the UE operates and one or more ePDGs of a selected PLMN. The UE may use DNS NAPTR queries to determine an ePDG that supports emergency service sessions for the country in which the UE operates, in particular when roaming in a visited country / territory that is different from a home country / territory to which the UE is assigned. In some embodiments, the UE sends queries formatted using a generic domain name resolvable by the UE and / or by network nodes, e.g., a network-based server, wherein the generic domain name includes an indication that the UE is roaming in a foreign network, e.g., B.using a "visited-country" part of the domain name, and also includes an MCC value that uniquely identifies the country / territory in which the UE is operating. In some embodiments, the MCC value is a three-digit numeric value. In some embodiments, the generic domain name has the following form:<service_id> .mcc. <mcc>.visited-country.pub.3gppnetwork.org

[0013] In some embodiments, the "service_id" field uses the value "epdg.epc" to point to a Fully Qualified Domain Name (FQDN) service for the visited country in which the UE is operating. In some embodiments, a specific domain name (including a specific value for the MCC) of epdg.epc.mec <mcc>.visited-country.pub.3gppnetwork.org may be used by the UE to determine whether regulatory requirements dictate the selection of ePDGs in the visited country in which the UE is operating through which non-emergency service sessions are to be established.

[0014] To obtain information for selecting ePDGs through which to establish emergency service sessions, the UE may use another specific domain name, including the specific value for the MCC in which the UE operates, with a service_id value of "sos.epdg.epc" to specify a query for information for emergency service sessions (and not for non-emergency service sessions). The specific domain name used may be as follows: sos.epdg.epc.mcc <mcc>.visited-country.pub.3gppnetwork.org, which may represent a "Not-ePDG-FQDN" and may have a total of eight name parts. The last three name parts may be "pub.3gppnetwork.org," the fourth name part may be "visited-country," the third name part may uniquely identify the MCC of the visited country / territory, while the first three name parts may be "sos.epdg.epc." The UE may send a DNS NAPTR query to a DNS server to resolve the "Not-ePDG-FQDN." The DNS server may provide a response to the UE, which may include information to identify one or more PLMNs for the MCC identified in the DNS NAPTR query, and which may support emergency service sessions over one or more ePDGs for access through non-mobile wireless access networks by the UE.The DNS response to the DNS query may include multiple records, with each record identifying a PLMN of the visited country / territory that can be used to select an emergency service session ePDG. A representative format for a DNS response record may include: sos.epdg.epc.mnc. <mnc>.mcc <mcc>.pub.3gppnetwork.org, where the PLMN is uniquely identified by the combination of the Mobile Network Code (MNC) and MCC values contained in the record. The last three parts of the name can be "pub.3gppnetwork.org," while the combination of the third and fourth parts can uniquely identify the PLMN supporting emergency service sessions over a non-cellular wireless access. The first three parts of the name can be "sos.epdg.epc."

[0015] The UE can select a PLMN to use when attempting emergency service sessions over non-mobile wireless access according to a selection procedure. If the UE is connected to a VPLMN over a mobile wireless access and the response from the DNS server to the DNS query included a record indicating that the VPLMN to which the UE is connected supports emergency service sessions over non-mobile wireless access, the UE can select the VPLMN for emergency service sessions. If the UE is not connected to a VPLMN or is connected to a VPLMN that does not support emergency service sessions over non-mobile wireless access networks, e.g., no record in the list includes the VPLMN to which the UE is connected, the UE determines a PLMN for emergency service sessions as follows. If the UE is provided with information for selecting an ePDG for emergency services, e.g.,provided by an HPLMN to which the UE is connected, the UE may select an ePDG from a PLMN included in the response from the DNS server to the DNS query, e.g., a PLMN listed in the record as supporting emergency service sessions and also listed in the emergency service ePDG selection information provided by the HPLMN to which the UE is associated. In some embodiments, the UE selects the PLMN listed in the response from the DNS server that has the highest priority, as indicated by the emergency service ePDG selection information provided by the HPLMN.If no information is provided to the UE to select an ePDG for emergency services, or if the emergency service PLMN / ePDG selection information provided by the HPLMN does not include any of the PLMNs included in the response from the DNS server, the UE may select one of the PLMNs in the response from the DNS server based on a UE-specific implementation. Using the selected PLMN, the UE may send a second DNS query to the DNS server. The second DNS query includes an ePDG FQDN including a unique identifier, e.g., an MCC / MNC value pair, for the selected PLMN, beginning with "sos.epdg.epc" and ending with "pub.3gppnetwork.org." The DNS server may respond to the second DNS query with a set of one or more IP addresses for one or more ePDGs that support emergency service sessions over non-cellular wireless access networks.The DNS server may resolve the ePDG FQDN included in the second DNS query for the UE, so that the UE can use the provided IP addresses to access an ePDG configured to support emergency service sessions over non-mobile wireless access networks. If the UE does not receive a DNS response from the DNS server to resolve the ePDG FQDN included in the second DNS query for the selected PLMN, the UE may select a different PLMN and retry resolving a different ePDG FQDN by sending additional DNS queries to the DNS. In some embodiments, the UE selects PLMNs specified in the response from the DNS server to the first DNS query based on a priority order for PLMNs, as specified in information provided by the HPLMN.If the UE is unable to receive a response to resolve an ePDG FQDN for a selected PLMN, the UE may use an ePDG specified for emergency service sessions for the HPLMN to which the UE is associated.

[0016] In addition to PLMNs and ePDGs that support emergency service sessions over non-mobile wireless access networks, the UE may attempt to determine a set of one or more local emergency service numbers to use when roaming in a VPLMN in a visited country / territory. In some embodiments, a local emergency service number may be used by the UE to access emergency services of a particular emergency service type. In some embodiments, the UE may perform an IMS emergency service session invocation procedure using one or more local emergency service numbers to access emergency services through a non-mobile wireless access network. If the UE is able to access the VPLMN network over a mobile wireless access network when used in a foreign network (roaming), the UE may obtain a set of local emergency service numbers from the VPLMN, e.g.,in an ATTACH ACCEPT message received from the wireless mobile network and / or in a TRACKING AREA UPDATE ACCEPT message. In some embodiments, the UE may store the set of local emergency service numbers obtained from the VPLMN for use when connected to the VPLMN and / or when disconnected from the VPLMN while operating in the same country / territory of the VPLMN. In some embodiments, the UE may reuse the set of local emergency service numbers obtained from the VPLMN when operating in the same country / territory as the VPLMN. In some embodiments, the UE may obtain a list of local emergency service numbers from an access point (AP) to which the UE is associated. The list of local emergency service numbers obtained from the AP may be applicable to a country / territory (geographical location) in which the AP is located (and in which the UE is operating).In some embodiments, the list of local emergency service numbers may be obtained from the AP using Access Network Query Protocol (ANQP) techniques during and / or after the UE associates with the AP. In some embodiments, local emergency service numbers may be obtained from Hotspot 2.0 compatible Wi-Fi APs.

[0017] The UE may obtain a set of local emergency service numbers for accessing emergency services of different emergency service types by querying a network-based server, e.g., by sending a DNS query to a DNS server, which may be located in the same country / territory where the UE is operating. The UE may obtain from the ePDG an IP address of the DNS server from which the set of local emergency service numbers is obtained. The UE may use a domain name including a service ID for local emergency service number access. In some embodiments, the domain name includes a service ID of "emergency-number-list.epc." In some embodiments, the UE sends a DNS query to a DNS server using an emergency number FQDN with the following format: emergency-number-list.epc.mcc <mcc>.visited-country.pub.3gppnetwork.org, where the fourth name part of the FQDN includes an MCC value that uniquely identifies the country / territory in which the UE operates. The last three name parts of the emergency number list FQDN are "pub.3gppnetwork.org," the fourth name part is "visited-country," and the first two name parts are "emergency-number-list.epc." In some embodiments, the UE sends a DNS NAPTR query to a DNS server to resolve the emergency number list FQDN. In response to the DNS NAPTR query, the DNS server may provide a list of one or more records, each record in the DNS response including a local emergency service number applicable to a corresponding emergency service type and usable within the country / territory specified by the MCC value included in the DNS NAPTR query. In some embodiments, the emergency service category is determined according to Technical Specification (TS) 24.008 of the 3GPP. In some embodiments, each DNS response record may include one of the following emergency service categories: sos-police, sos-ambulance, sos-fire, sos-marine, or sos-mountain. Non-mobile wireless access

[0018] Wireless service providers deploy non-mobile wireless access networks, such as wireless local area networks (WLANs), in parallel with cellular wireless access networks to extend options for accessing Evolved Packet Core (EPC) services, such as Internet Protocol Multimedia Subsystem (IMS)-based services, including Voice over IP (VOIP), and application services, including Visual Voice Mail (WM), Short Message Service (SMS), and Multimedia Message Service (MMS). Access to these EPC services through a trusted WLAN can be implemented using an S2a reference point interface, and access through an untrusted WLAN network can be implemented using an S2b reference point interface.Wireless communication devices can support packet data network (PDN) connections through multiple wireless interfaces, such as a cellular wireless interface and a trusted or untrusted WLAN interface, both individually and in parallel. Wireless service providers can control access to services based on various criteria, including a location of the wireless communication device, whether the wireless communication device is in a home network or a roaming network, the type of connection over which the wireless communication device connects, including a security device, a radio access technology (RAT) type for the access connection, a wireless communication device, and / or a user subscription profile, among others.To ensure secure communication, connections through a wireless communication device that traverse an S2b reference point may use an Internet Key Exchange Version 2 (IKEv2) protocol between the wireless communication device and an evolved Packet Data Gateway (ePDG).

[0019] To establish a connection, the wireless communication device uses authentication methods based on EAP-AKA for access over an untrusted WLAN or based on EAP-AKA for access over a trusted WLAN without requiring input from a user of the wireless communication device. An authentication failure may occur for various reasons, such as when the wireless communication device accesses over a WLAN provided by a visited PLMN (VPLMN) for which the wireless communication device is not authorized to roam, or when the wireless communication device and / or a user thereof is not authorized to access the services of the EPC for the mobile service provider.However, access to emergency services may be required regardless of the location where the wireless communication device is operated or by a subscription service for a user of the wireless communication device. Indeed, a wireless communication device without an installed SIM (physical or electronic) may be configured to provide access to emergency services, and wireless service providers may allow the establishment of emergency service sessions for the wireless communication device without completing a regular authentication and authorization procedure. A wireless service provider may provide access to emergency services over a mobile wireless access network or over a non-mobile wireless access network.

[0020] While roaming in a visited country / territory, a wireless communication device may obtain emergency service information, such as which PLMNs in the visited country / territory maintain ePDGs capable of providing emergency service access over non-mobile wireless access networks. Furthermore, the wireless communication device may also obtain a set of local emergency service numbers for various emergency service categories to use when attempting to access emergency services in the visited country / territory, including when attempting to establish an IMS connection over a non-mobile wireless access network. The wireless communication device may obtain the emergency service information by querying a network-based server and receiving responses that list applicable PLMNs for the visited country / territory, ePDG IP addresses associated with a selected PLMN, or local emergency service numbers for the visited country / territory.

[0021] In this section, reference is made to the accompanying drawings, which form a part of the disclosure, and in which are shown, by way of illustration, various implementations corresponding to the described embodiments herein. While the embodiments of this disclosure are described in sufficient detail to enable one skilled in the art to practice the described implementations, it is to be understood that these examples are not to be construed as overly limiting or all-inclusive.

[0022] According to various embodiments described herein, the terms "wireless communication device," "wireless device," "mobile device," "mobile station," and "user equipment" (UE) may be used interchangeably herein to describe one or any number of common consumer electronic devices that may be capable of performing methods in connection with various embodiments of the disclosure.According to various implementations, each of these consumer electronic devices may refer to a mobile phone or smartphone, a tablet computer, a laptop computer or a netbook computer, a media player, an electronic book device, a MiFi® device, a wearable computing device, and any other type of electronic computing device with fourth generation (4G) LTE and LTE Advanced (LTE-A) or similar "later generation" cellular wireless access communication capabilities and wireless local area network communication capabilities. In various embodiments, these capabilities may enable a respective UE to communicate and manage concurrent IP flows across multiple wireless access networks.

[0023] Furthermore, it should be understood that the UEs described herein may be configured as multi-mode wireless communication devices that, in addition to communicating with 4G wireless networks, are also capable of communicating over legacy third-generation (3G) and / or second-generation (2G) RATs, as well as communicating using one or more different wireless local area networks. Multi-mode UEs may include support for communication according to one or more different wireless communication protocols developed by standards organizations, e.g., 3GPP's Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), LTE and LTE-A standards, or 3GPP's CDMA2000 standards (1xRTT, 2xEV-DO, HRPD, eHRPD). Multi-mode UEs may also support communication using wireless local area network protocols, e.g., IEEE 802.11a / b / g / n.11 (Wi-Fi), IEEE 802.16 (WiMAX), and wireless personal area network protocols, such as Bluetooth®. Multiple wireless communication protocols may provide complementary functions and / or different services for a multi-mode UE.

[0024] Fig. 1 illustrates an example wireless system 100 including an example wireless communication device, e.g., a user equipment (UE) 102, including wireless switching logic that can be configured to connect the UE 102 individually or in parallel to one or more wireless networks. The UE 102 includes both cellular wireless switching logic 104A that can be configured to connect the UE 102 to various services provided over an Internet Protocol (IP) packet-based network 110 through a cellular wireless access 106 (which may also be referred to as a cellular wireless access network), and non-cellular wireless switching logic 104B that can be configured to connect the UE 102 to the same IP network 110 through a non-cellular wireless access 108 (which may also be referred to as a non-cellular wireless access network).An LTE Evolved Packet System (EPS) provides services to the UE 102 using an IP protocol, both "real-time" services such as voice / video conferencing calls and data communication services such as web browsing and email access. The LTE EPS, as introduced in Release 8 of the 3GPP wireless communication standard, defines an architecture in which heterogeneous wireless access systems, such as a combination of the cellular wireless access 106 and the non-cellular wireless access 108, can be used by the UE 102 to connect to a common core network (not shown). The UE 102 can establish a Packet Data Network (PDN) connection through one wireless access and subsequently add or modify a second wireless access.The UE 102 may communicate over multiple wireless access points, such as the cellular wireless access point 106 and the non-cellular wireless access point 108, individually or simultaneously using the same PDN connection. Under certain circumstances, a wireless service provider may enable access to emergency services through each type of wireless access point, e.g., the cellular wireless access point 106, and through another type of wireless access point, e.g., the non-cellular wireless access point 108, without requiring the UE 102 to complete authentication. Thus, the UE 102 may access emergency services through a non-cellular wireless access network, such as an untrusted WLAN, via an S2b interface IPSec tunnel, or through a cellular wireless access network.The UE 102 may obtain a list of one or more PLMNs applicable to a visited country / territory in which the UE 102 operates for accessing emergency services via the non-mobile wireless access 108. The UE 102 may also obtain a set of IP addresses for ePDGs supporting emergency service sessions for a selected PLMN applicable to the visited country / territory in which the UE 102 operates. The UE 102 may further obtain a set of local emergency service numbers to use when attempting, for example, to establish an emergency service session IMS connection via an ePDG of a selected PLMN in a visited country / territory in which the UE 102 operates.

[0025] The cellular wireless circuitry 104A and the non-cellular wireless circuitry 104B support wireless radio frequency (RF) connections between the UE 102 and parallel wireless networks connected to the IP network 110 via the cellular wireless access 106 and the non-cellular wireless access 108, respectively. In some embodiments, the wireless circuitry 104A / B includes one or more baseband processors and a set of RF analog front-end circuitry. In some embodiments, the wireless circuitry 104A / B and / or a portion thereof may include or be referred to as one or more wireless transceivers or transceivers or radios.The terms circuit, circuit logic, component, and component block may be used interchangeably herein in some embodiments to refer to one or more operational units of a wireless communication device that process and / or act on digital signals, analog signals, or digital data units used for wireless communication. For example, representative circuits may perform various functions that convert digital data units into transmitted analog radio frequency waveforms and / or convert received analog waveforms into digital data units, including intermediate analog and intermediate digital forms. The wireless circuit logic 104A / B may include components of analog RF front-end circuitry, e.g.,a set of one or more antennas that may be connected to additional supporting RF circuitry that may include filters and other analog components that may be "configured" to transmit and / or receive analog signals via one or more corresponding antennas to one or more wireless access networks and / or wireless access equipment contained therein.

[0026] Fig. 2 illustrates an example wireless system 200 including the UE 102 communicatively coupled to the IP network 110 through a 3GPP cellular access point 206 and / or through an IP-based non-3GPP wireless access point 208. In some embodiments, the 3GPP cellular wireless access point 206 includes an Evolved Universal Terrestrial Access Network (E-UTRAN) or other network elements of an LTE / LTE-A wireless network. In some embodiments, the non-3GPP IP access point 208 includes a wireless local area network (WLAN) or portions thereof, e.g., a wireless access point, and thus, the non-3GPP IP access point 208 may also be referred to as a WLAN access point. In some embodiments, the WLAN access point may also be referred to as Wi-Fi access to correspond to a WLAN operating according to an IEEE 802.11 wireless communication protocol.The UE 102 can be configured to connect individually and / or simultaneously to a given packet data network (PDN) via the 3GPP mobile wireless access point 206 and the IP-based non-3GPP wireless access point 208. The 3GPP mobile wireless access point 206 is connected to a serving gateway (GW), which is connected to a PDN gateway 216 through an S5 reference point 220 or an S8 reference point 220 for roaming users. The PDN gateway 216 provides a connection to the IP network 110 through which a variety of services can be accessed. The non-3GPP IP access point 208 is connected to an evolved packet data gateway (ePDG) 212, which is connected to the PDN gateway 216 through an S2b reference point 218. Each of the serving gateway 210, the ePDG 212 and the PDN gateway 216 is also connected to a Policy and Charging Rules Function (PCRF) 214.

[0027] The 3GPP S2b reference point 218 between the ePDG 212 and the PDN gateway 216 provides a mechanism for the UE 102, when connected via a non-3GPP IP access network (e.g., the non-3GPP IP access 208), to securely connect to the IP network 110 via a 3GPP Evolved Packet System (EPS) network and access services over the secure connection. The UE 102 may establish a secure connection, e.g., an Encapsulating Security Payload (ESP) tunnel based on an IP Security (IPsec) protocol using an IKEv2 protocol, which signals an exchange between the UE 102 and the ePDG 212, which in turn establishes a secure tunnel, e.g., a 3GPP Evolved Packet System (EPS) tunnel. B. a proxy Mobile IPv6 (PMIP) or GTP tunnel to which PDN Gateway 216 can establish when anchoring a session for UE 102. Support for emergency service access

[0028] In some embodiments, when establishing a new connection via the S2b reference point 218, the UE 102 may indicate to the non-3GPP IP access 208, such as a WLAN access, that the new connection should be specifically dedicated to emergency services, e.g., by providing an indication in a message sent to the ePDG 212 when the new connection is established. When the UE 102 is used in a visited country / territory (roaming), the UE 102 may attempt to obtain emergency service information applicable to the visited country / territory. The UE 102 may communicate with a network-based server to obtain a list of one or more different PLMNs that support emergency service sessions via an ePDG 212 and via the non-3GPP IP access 208.The UE 102 may query a DNS server to obtain a list of PLMNs and further query the DNS server to obtain one or more IP addresses for the ePDGs 212 to use for emergency services when attempting to establish an emergency service session over the non-3GPP IP access 208. The UE 102 may also query the DNS server to obtain a list of local emergency service numbers, which may be categorized according to different emergency service types provided by accessing the local emergency service number.

[0029] Fig. 3 illustrates, according to some embodiments, a sequence diagram 300 for an exemplary message exchange for providing emergency service support information for a wireless communication device. The UE 102 detects a roaming state in which the UE 102 is used in a visited country / area (roaming). In some embodiments, the visited country / area differs from a country / area of the HPLMN to which the UE 102 is normally associated. The UE 102 sends a query to a network-based server, e.g., a DNS query to the DNS server 304, wherein the query includes an indication that the UE is located in a visited country / area, an MCC value determined by the UE 102 for the visited country / area, and a service identifier (service_id) specified for emergency service queries.In some embodiments, the indication that the UE is located in the visited country / territory includes the name part "visited-country" in the DNS query. In some embodiments, the query includes the name part "sos.epdg.epc" in the query to indicate that the UE is seeking information for emergency services. In some embodiments, the DNS query includes a total of eight name parts, where the last three name parts are "pub.3gppnetwork.org", the fourth name part is "visited-country", the third name part uniquely identifies the MCC of the visited country / territory, and the first three name parts are "sos.epdg.epc". In some embodiments, the UE 102 sends a DNS NAPTR query to the DNS server 304 using the eight name parts and receives a response including a list of PLMNs that support emergency services via at least one ePDG to provide emergency services over non-mobile wireless access networks, e.g.via the non-mobile wireless access 108 and / or the non-3GPP IP access 208 to access emergency services. In some embodiments, a record in the DNS response identifies a PLMN of the visited country / territory, which can be used to select an ePDG for emergency services. In some embodiments, the record in the DNS response replaces a PLMN identity. In some embodiments, the DNS response includes an FQDN consisting of eight name parts, where the first three name parts are "sos.epdg.epc," the fourth and fifth name parts identify the PLMN, and the last three name parts are "pub.3gppnetwork.org." In some embodiments, the PLMN is identified by a pair of values: a first value for a Mobile Network Code (MNC) and a second value for the MCC.In some embodiments, the third name portion includes "mnc" appended to a numeric MNC value, and the fourth name portion includes "mcc" appended to a numeric MCC value. In some embodiments, the numeric values are three-digit values. In some embodiments, the numeric values are two-digit values, three-digit values, or a combination thereof.

[0030] The UE 102 selects a PLMN from the list of PLMNs provided in the DNS response from the DNS server 304. If the UE 102 is already connected to a PLMN via the mobile access 106 or via the 3GPP mobile access 206 and the PLMN is identified in the list of PLMNs provided in the DNS response from the DNS server 304, the UE 102 selects the PLMN to which it is connected to select an emergency service ePDG 302 for accessing emergency services. If the UE 102 is not connected to a PLMN via the mobile access 106 or via the 3GPP mobile access 206, or if the UE 102 is connected to a PLMN that is not included in any of the records of the DNS response from the DNS server 304, the UE 102 selects a PLMN from the list of PLMNs provided in the DNS response from the DNS server 304.If emergency service selection information is provided to the UE 102 by the HPLMN of the UE 102, the UE 102 selects a PLMN included in the DNS response that has the highest priority according to the emergency service selection information provided by the HPLMN of the UE 102. If no emergency service selection information is provided to the UE 102 by the HPLMN of the UE 102, or if emergency service selection information is provided to the UE 102 by the HPLMN of the UE 102 but none of the PLMNs in the DNS response are also included in the emergency service selection information provided by the HPLMN, the UE 102 selects a PLMN from those listed in the DNS response from the DNS server 304 using a UE-specific implementation.

[0031] After selecting a PLMN from the set of PLMNs specified in the DNS response received from the DNS server 304, the UE 102 sends another query, e.g., a second DNS query, to the DNS server 304 to obtain information about the emergency service ePDG 302. The second DNS query includes an indication of the selected PLMN, e.g., an MNC / MCC pair, as two name parts within an FQDN beginning with "sos.epdg.epc" and ending with "pub.3gppnetwork.org." The indication of the selected PLMN may be in accordance with the format provided by the DNS response, e.g., "mnc" appended to an MNC value, followed by "mcc" appended to an MCC value, with the two values separated by a period.The UE 102 sends the second DNS query to the DNS server 304 to resolve the constructed ePDG FQDN into a set of one or more IP addresses of one or more emergency service ePDGs 302 that support emergency service sessions over a non-mobile wireless access, e.g., over the non-mobile wireless access 108 or over the non-3GPP IP access 208.

[0032] If the UE 102 does not receive a DNS response to the second DNS query and emergency service selection information provided by the first DNS response to the first DNS query includes multiple PLMNs for the visited country / territory, the UE 102 may select a different PLMN value and repeat the second DNS query to obtain IP addresses of emergency service ePDGs 302 for the subsequently selected PLMN. In some embodiments, the UE 102 selects different PLMNs according to a priority order for PLMNs as indicated by provisioning information from the HPLMN with which the UE 102 is associated. In some embodiments, if no response from DNS queries is received for any of the PLMNs in the list of PLMNs provided by the first DNS response to the first DNS query, the UE 102 may attempt to access emergency services via an ePDG 302 of the HPLMN.

[0033] In an exemplary embodiment where the UE 102 is used in the country Hungary (roaming), the UE 102 sends a DNS NAPTR query to the DNS server 304 with the MCC value set to "216", where the DNS query includes, for example, the following string: sos.epdg.epc.mec216.visited-country.pub.3gppnetwork.org and the DNS server 304 returns a DNS response including a list of entries that may be comma-separated as follows: sos.epdg.epc.mnco1.mcc216.pub.3gppnetwork.org, sos.epdg.epc.mnc30.mcc216.pub.3gppnetwork.org.

[0034] In the exemplary embodiment, the UE 102 is provided by its HPLMN with emergency service selection information, including a set of PLMN identifiers listed in a priority order as follows: mec216.mnc70, mec216.mnc30, mec216.mnc1, where MNC value 70 is prioritized over MNC value 30 over MNC value 01. The UE 102 may select the PLMN corresponding to the name portions "mcc216.mnc30" listed in both the response from the DNS server 304 and the emergency service selection information provided by its HMPLN, which has a higher priority than the other PLMN also listed. The UE 102 may send a second DNS query to the DNS server 304 to resolve the following string into an IP address: sos.epdg.epc.mnc30.mcc216.pub.3gppnetwork.org.

[0035] The UE 102 may also query a DNS server for local emergency service numbers applicable to the visited country / territory in which the UE 102 operates. In some embodiments, the DNS server from which the UE 102 obtains local emergency service numbers may be located in the same visited country / territory in which the UE 102 operates. In some embodiments, the UE 102 obtains an IP address for the DNS server from which local emergency service numbers are obtained from the emergency service ePDG 302. In some embodiments, the DNS server from which the UE 102 obtains local emergency service numbers is DNS server 304. In some embodiments, the DNS server from which the UE 102 obtains local emergency service numbers is different from DNS server 304, e.g. B. if the DNS server 304 to which the initial query for emergency service PLMN information is made is not located in the country / territory in which the UE 102 is operating.In the following description, the DNS server from which the local emergency numbers are obtained is indicated as DNS server 304; however, it is understood that each of the different queries for emergency service PLMN information, for emergency service ePDG information, and for local emergency service numbers may be sent to the same DNS server or to different DNS servers. At least for the query for local numbers of local emergency services, the query sent by the UE 102 may be sent to a DNS server located in the country / territory in which the UE 102 is operating. In some embodiments, an IP address for the DNS server from which local numbers of local emergency services are obtained may be obtained from the emergency service ePDG 302.

[0036] The UE 102 can send the following string to the DNS server 304: emergency-number-list.epc.mcc <mcc>.visited-country.pub.3gppnetwork.org, which includes a service ID for local emergency service numbers and two name parts specified as "emergencynumber-list" in the first name part and "epc" in the second name part. The third name part of the string can uniquely identify the country / territory in which the UE 102 is operating, e.g., using a numeric MCC value appended to "mcc." The fourth name part can be "visited-country" to indicate that the UE 102 is used in a visited country / territory (roaming), while the last three name parts can be set to "pub.3gppnetwork.org." The UE 102 sends a DNS NAPTR query to the DNS server 304, which may be located in the same country / territory in which the UE is operating, to obtain local emergency service numbers applicable to the country / territory indicated by the MCC value included in the DNS NAPTR query.In some embodiments, the UE 102 may obtain an IP address of the DNS server 304 from the ePDG 302. The DNS server 304 may respond with one or more local emergency service numbers, which may also be categorized according to the emergency service type to which the local number corresponds. In some embodiments, the DNS server 304 responds with a list of one or more FQDNs, where each FQDN is formatted with six name parts as follows: . <emergency-number> . <emergency-service-category>.mcc <mcc>.pub.3gppnetwork.org, where the first name part includes a numeric value for the local emergency service number applicable to the country / territory specified by the MCC value of the third name part and for the emergency service category specified by the second name part. The last three name parts can be "pub.3gppnetwork.org." The DNS response can include a record of multiple local emergency service numbers separated by commas. Each record in the DNS response can include a local emergency service number corresponding to a particular emergency service category type. In some embodiments, the emergency service category types can include one or more of sos, sos-police, sos-ambulance, sos-fire, sos-marine, or sos-mountain.

[0037] As an exemplary embodiment, when used in the visited country Japan (roaming), the UE 102 may send a DNS query including the MCC value "440" to indicate Japan to the DNS server 304, where the DNS query is formatted as follows: emergency-number-list.epc.mcc440.visited-country.pub.3gppnetwork.org, to which the DNS server 304 may respond with a list of local emergency service numbers categorized and formatted as follows: 110.sos-police.mec440.pub.3gppnetwork.org, 119.sos-ambulance.mec440.publ3gppnetwork.org, 119.sos-fire.mec440.publ3gppnetwork.org, where the value "110" is the local emergency number applicable in Japan for accessing police emergency services. emergency service number, the value "119" is the local emergency service number applicable in Japan for accessing medical services, and the value "119" is the local emergency service number applicable in Japan for accessing fire services.As the example shows, different emergency service category types may use the same local emergency number or different local emergency numbers, depending on regulatory requirements for the visited country / territory.

[0038] After detecting emergency service session information, such as a PLMN supporting emergency service sessions, an ePDG IP address of the PLMN, and / or local numbers for accessing emergency services, the UE 102 may establish an emergency service session with an emergency service-capable ePDG 302 in response to detecting an attempt to establish an emergency service connection. In some embodiments, the emergency service-capable ePDG 302 may be reached using an ePDG IP address obtained from the DNS server 304. In some embodiments, the UE 102 uses a local emergency service number obtained from the DNS server 304 to establish the emergency service connection via the emergency service ePDG 302. In some embodiments, the emergency service connection for the UE 102 may be via the emergency service ePDG 302 with access over a non-mobile wireless access network, e.g., a cellular / UMTS / GPRS network. B. via the wireless non-mobile access 108 or via the non-3GPP IP access 208.In some embodiments, the emergency service connection for the UE 102 may be established via the emergency service ePDG 302 without requiring the completion of any authentication and / or authorization procedures.

[0039] Fig. 4 illustrates a flowchart 400 of an example method for a wireless communication device to obtain emergency service information, according to some embodiments. At 402, the UE 102 is used in a visited country / territory (roaming). At 404, the UE 102 sends a first query for emergency service PLMN information to a network-based server, e.g., to the DNS server 304. At 406, the UE 102 receives from the network-based server, e.g., from the DNS 304, a first response including a list of PLMNs that support emergency services over a non-mobile wireless access network, e.g., over the non-mobile wireless access 108 or over the non-3GPP IP access 208. At 408, the UE 102 sends a second query for emergency service ePDG information to the network-based server, e.g., B. to the DNS server 304. At 410, the UE 102 receives from the network-based server, e.g.from the DNS 304, a list of ePDG IP addresses for ePDGs that support emergency services over a non-mobile wireless access network, e.g., over the non-mobile wireless access 108 or over the non-3GPP IP access 208.

[0040] In some embodiments, the queries sent by the UE 102 include DNS queries formatted as described herein. In some embodiments, the query for emergency service PLMN information includes an indication that the UE 102 is being used in a visited country / territory (roaming). In some embodiments, the query for emergency service PLMN information includes a service ID indicating emergency services. In some embodiments, the query for emergency service PLMN information includes a unique identifier for the country / territory in which the UE 102 is operating. In some embodiments, the responses received by the UE 102 include DNS responses formatted as described herein. In some embodiments, the response includes a list of PLMNs, where each PLMN in the list may provide emergency service sessions over a non-mobile wireless access network, e.g.,via the non-mobile wireless access 108 or via the non-3GPP IP access 208. In some embodiments, each PLMN is identified by an MNC / MCC value pair. In some embodiments, the UE 102 selects a PLMN from the list of PLMNs returned by the network-based server based at least in part on emergency service information provided to the UE 102 by an HPLMN with which the UE 102 is associated. In some embodiments, the second query for emergency service ePDG information sent by the UE 102 includes the selected PLMN identified by a corresponding MNC / MCC value pair. In some embodiments, the response includes a list of ePDG IP addresses formatted as described herein.

[0041] Fig. 5 illustrates a flowchart 500 of another example method for a wireless communication device to obtain emergency service information, according to some embodiments. At 502, a UE 102 determines an MCC for a country / territory in which the UE 102 is operating. At 504, the UE 102 sends a first query to a network-based server, such as the DNS 304, for information regarding PLMNs supporting emergency services over a cellular wireless access network, such as over the non-cellular wireless access 108 or over the non-3GPP IP access 208. The first query may include an indication of the MCC determined by the UE 102, e.g., a recognized numeric value that uniquely indicates the country / territory in which the UE 102 is operating.At 506, the UE 102 receives from the network-based server, such as the DNS server 304, a first response to the first query, wherein the first response includes a list of PLMNs supporting emergency services over a non-mobile wireless access network for the MCC specified in the first query. At 508, if the UE 102 is associated with a PLMN, the UE 102 determines whether the PLMN to which the UE 102 is associated is included in the list of PLMNs in the first response received from the network-based server. If the UE 102 is associated with a PLMN that is also listed in the list of PLMNs received from the network-based server, the UE 102 may select the associated PLMN for emergency service sessions over a non-mobile wireless access network at 510.If the UE is connected to a PLMN that is not included in the list of PLMNs received from the network-based server, or if the UE is not connected to a PLMN, the UE 102 may select a PLMN from the PLMNs listed in the first response from the network-based server as follows. At 512, if the UE 102 is provided by a home PLMN (HPLMN) with ePDG emergency service information, such as a list of PLMNs in a prioritized order, the UE 102 determines whether at least one PLMN in the provided information is also listed in the list of PLMNs provided in the first response to the UE 102 by the network-based server.If at least one PLMN is present that is included in both the list of PLMNs received from the network-based server and the ePDG emergency service information provided by the HPLMN, the UE 102 may, at 516, select a PLMN from the list of PLMNs received in the first response from the network-based server based on a prioritization of PLMNs specified in the provided ePDG emergency service information received from the HPLMN. If none of the PLMNs listed in the PLMN list provided in the first response to the UE 102 by the network-based server is also listed in the ePDG emergency service information provided by the HPLMN, the UE 102 may, at 514, select a PLMN from the PLMN list provided in the first response to the UE 102 by the network-based server, e.g., using a UE-dependent selection procedure.

[0042] After selecting a PLMN at 510, 514, or 516, the UE 102 sends a second query at 518 to the network-based server, e.g., to the DNS server 304, for information regarding ePDGs supporting emergency service sessions for the selected PLMN. At 520, the UE 102 receives a second response from the network-based server, e.g., from the DNS server 304, including one or more IP addresses for one or more ePDGs supporting emergency service sessions over a non-mobile wireless access network for the selected PLMN. In some embodiments, the queries sent to the network-based server and / or the responses received from the network-based server are formatted as NAPTR queries, as described herein.For example, the queries to the network-based server may include a name portion indicating that the UE 102 is being used in a visited country (roaming) and a name portion indicating that the UE 102 is seeking information for emergency services. In some embodiments, the queries to the network-based server include a numeric value for an MCC, and the responses from the network-based server include at least one numeric value pair for the MCC and an MNC, which together uniquely indicate a PLMN supporting emergency service sessions over a non-mobile wireless access network.In some embodiments, the second request for information related to ePDGs includes the numeric value pair for the MCC and the MNC that uniquely indicate a PLMN selected by the UE 102, and the second response includes at least one IP address for an ePDG that supports emergency service sessions over a non-mobile wireless access network for the PLMN selected by the UE 102.

[0043] Fig. 6 illustrates a flowchart 600 of another example method for a wireless communication device to obtain emergency service information, according to some embodiments. At 602, a UE 102 determines an MCC for a country / territory in which the UE 102 is operating. At 604, the UE 102 sends a query for information regarding local numbers for use for emergency service sessions to a network-based server, e.g., DNS server 304. At 604, the UE 102 receives a response from the network-based server, e.g., DNS server 304, that includes a list of local emergency service numbers categorized by emergency service type.In some embodiments, the query to the network-based server includes a numeric value for the MCC for the country / territory determined by the UE 102, a name portion indicating that the UE 102 is used in a visited country / territory (roaming), and / or a name portion indicating a request for emergency service numbers. In some embodiments, the query sent to the network-based server 102 is formatted as described herein. In some embodiments, the response from the network-based service includes a list of local numbers for use for emergency services, where each number in the list is categorized by a name portion for an emergency service type. In some embodiments, a single local number corresponds to multiple emergency service types.In some embodiments, the response received from the network-based server, including the list of local emergency service numbers, is formatted as described herein.

[0044] Fig. 7 illustrates, according to some embodiments, a diagram 700 of components of a wireless communication device, such as the UE 102, including one or more processors 702 coupled to memory 704, which may collectively be referred to as processing circuitry 706, wireless switching logic 708 that supports wireless radio frequency (RF) connections between the UE 102 and various wireless networks, e.g., the 3GPP cellular access 206 using the cellular wireless switching logic 104A and / or the non-3GPP IP access 208 using the non-cellular wireless switching logic 104B.The UE 102 may also include an emergency service support module 710 that is configurable to operate in conjunction with the processing circuitry 706 and the wireless switching logic 708 to perform one or more operations for the UE 102, as described herein, to provide support for accessing emergency service sessions, such as when the UE 102 is used in a visited country / territory (roaming) and looks up information for PLMNs, ePDGs, and / or local numbers for emergency service sessions that may be established over a non-mobile wireless access network. In some embodiments, the wireless switching logic 708 includes one or more baseband processors and a set of RF analog front-end circuitry. In some embodiments, the wireless switching logic 708 and / or a portion thereof may include, or be referred to as, a wireless transceiver or transceiver or radio.The terms circuit, circuit logic, component, and component block may be used interchangeably herein in some embodiments to refer to one or more operational units of a wireless communication device that process and / or act on digital signals, analog signals, or digital data units used for wireless communication. For example, representative circuits may perform various functions that convert digital data units into transmitted analog radio frequency waveforms and / or convert received analog waveforms into digital data units, including intermediate analog forms and intermediate digital forms. The wireless circuit logic 708 may include components of analog RF front-end circuitry, e.g.,a set of one or more antennas that may be connected to additional supporting RF circuitry, which may include filters and other analog components that may be "configured" to transmit and / or receive analog signals via one or more corresponding antennas to one or more wireless networks.

[0045] The processor(s) 702 and the wireless circuitry 708 may be configured, according to various implementations, to perform one or more functionalities of the UE 102 and / or to control its performance. The processor(s) 702 and the wireless circuitry 708 may provide functionality for querying for information to establish connections (establish sessions), including emergency service sessions, as described herein. The processor(s) 702 may include multiple processors of various types that may support wireless communication management and / or higher-layer functions, according to one or more embodiments of the disclosure. For example, one or more of the processors 702 may be configured to perform data processing, application execution, and / or other device functions.The UE 102 or portions or components thereof, such as the processor(s) 702, may include one or more chipsets, each of which may include any number of coupled microchips thereon.

[0046] In some embodiments, the processor(s) 702 may be configured in a variety of different forms. For example, the processor(s) 702 may be associated with any number of microprocessors, coprocessors, controllers, or various other computing or processing devices, including integrated circuits such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or any combination thereof.In various scenarios, multiple processors 502 of the UE 102 may be coupled to each other and / or configured in operational communication, and these components may be configured together to support obtaining information for emergency service sessions, including when the UE 102 is roaming in a visited country / territory and attempting to obtain PLMNs, ePDGs, and / or local numbers for emergency service sessions. In some implementations, the processor(s) 702 may be configured to execute instructions that may be stored in the memory 704 or that may otherwise be accessible to the processor(s) 702 in another device memory.Therefore, the processor(s) 702, whether configured as hardware or a combination of hardware and software, or in conjunction therewith, may be capable of performing operations according to various implementations described herein when appropriately configured. In various embodiments, the memory 704 in the UE 102 may include multiple storage devices, which may be associated with any common volatile or non-volatile memory type. In some scenarios, the memory 704 may be associated with a non-transitory computer-readable storage medium that can store various computer program instructions that can be executed by the processor(s) 702 during normal program executions.In this context, memory 704 may be configured to store information, data, applications, instructions, or the like to enable UE 102 to perform various functions according to one or more embodiments of the disclosure. In some implementations, memory 704 may be in communication with and / or otherwise coupled to processor(s) 702 and one or more system buses for routing information between and among the various device components of UE 102. Representative embodiments

[0047] In some embodiments, a method for obtaining information for establishing emergency service sessions over a non-3GPP wireless access network by a wireless device includes: (i) sending a first query for emergency service Public Land Mobile Network (PLMN) information to a Domain Name System (DNS) server; (ii) receiving a first response including a list of one or more PLMNs that support emergency service sessions over the non-3GPP wireless access network from the DNS server; (iii) selecting a PLMN from the list of one or more PLMNs; (iv) sending a second query for emergency service evolved Packet Data Gateway (ePDG) information to the DNS server; and (v) receiving a second response including a list of Internet Protocol (IP) addresses for ePDGs that support emergency service sessions over the non-3GPP wireless access network from the DNS server.

[0048] In some embodiments, the first query includes an indication that the wireless device is being used in a foreign network (roaming) and a unique identifier for a country in which the wireless device is being used (roaming). In some embodiments, each PLMN in the list of one or more PLMNs is associated with the country indicated by the unique identifier. In some embodiments, the second query includes an indication of the PLMN selected from the list of PLMNs. In some embodiments, each ePDG identified in the list of IP addresses is associated with the selected PLMN.In some embodiments, the method performed by the wireless device further includes determining a Mobile Country Code (MCC) for an area in which the wireless device operates, wherein the first query includes an indication of the MCC and the list of one or more PLMNs identifies PLMNs for the MCC specified in the first query. In some embodiments, if the wireless device is associated with one of the PLMNs listed in the list of one or more PLMNs, the wireless device selects the PLMN to which the wireless device is associated.In some embodiments, if the wireless device is not connected to any of the PLMNs listed in the list of one or more PLMNs, and the wireless device is provided by a home PLMN (HPLMN) with an ePDG emergency service list that includes at least one PLMN listed in the list of one or more PLMNs, the wireless device selects the PLMN from the list of one or more PLMNs that has the highest priority based on the ePDG emergency service list provided by the HPLMN.In some embodiments, the method performed by the wireless device while roaming in a visited PLMN further includes the wireless device performing: sending a third query for local emergency service number information to a DNS server located in a country where the wireless device is used (roaming); and receiving a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the country where the wireless device is used (roaming).In some embodiments, the method performed by the wireless device when roaming in a visited PLMN further includes the wireless device performing: sending a query for an IP address of a DNS server located in the country where the wireless device is used (roaming) to an ePDG identified in the list of IP addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network; and receiving the IP address of the DNS server located in the country where the wireless device is used (roaming) from the ePDG identified in the list of IP addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network.In some embodiments, the method performed by the wireless device includes: detecting an attempt to establish an emergency services call; and establishing an emergency services connection based at least in part on the list of IP addresses or the list of local emergency services numbers.

[0049] In some embodiments, a wireless device includes wireless circuitry having one or more antennas; processing circuitry having one or more processors communicatively coupled to a memory storing instructions and to the wireless circuitry; and an emergency services support module communicatively coupled to the processing circuitry, wherein execution of the instructions on the one or more processors causes the wireless device to: (i) send a first query for emergency services Public Land Mobile Network (PLMN) information to a Domain Name System (DNS) server, wherein the first query includes an indication that the wireless device is being used in a foreign network (roaming) and a unique identifier for a country in which the wireless device is being used (roaming);(ii) receiving a first response including a list of one or more PLMNs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server, wherein each PLMN in the list of one or more PLMNs is associated with the country specified by the unique identifier; (iii) selecting a PLMN from the list of one or more PLMNs; (iv) sending a second query for emergency service-evolved Packet Data Gateway (ePDG) information to the DNS server, wherein the second query includes an indication of the PLMN selected from the list of PLMNs; and (v) receiving a second response including a list of Internet Protocol (IP) addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server, wherein each ePDG identified in the list of IP addresses is associated with the selected PLMN;

[0050] In some embodiments, execution of the instructions on the one or more processors further causes the wireless device to determine a Mobile Country Code (MCC) for an area in which the wireless device operates; and the unique identifier includes the MCC. In some embodiments, if the wireless device is associated with one of the PLMNs listed in the list of one or more PLMNs, the wireless device selects the PLMN to which the wireless device is associated.In some embodiments, if the wireless device is not connected to any of the PLMNs listed in the list of one or more PLMNs, and the wireless device is provided by a home PLMN (HPLMN) with an ePDG emergency service list that includes at least one PLMN listed in the list of one or more PLMNs, the wireless device selects the PLMN from the list of one or more PLMNs that has the highest priority based on the ePDG emergency service list provided by the HPLMN.In some embodiments, execution of the instructions on the one or more processors further causes the wireless device to: send a third query for local emergency service number information to a DNS server located in the country in which the wireless device operates; and receive a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the country in which the wireless device operates. In some embodiments, execution of the instructions on the one or more processors further causes the wireless device to: detect an attempt to establish an emergency service call; and establish an emergency service connection based at least in part on the list of IP addresses or the list of local emergency service numbers.

[0051] In some embodiments, a device configurable for operation in a wireless device includes one or more processors communicatively coupled to a memory that stores instructions that, when executed by the one or more processors, cause the wireless device to: (i) send a first query for emergency service Public Land Mobile Network (PLMN) information to a Domain Name System (DNS) server, wherein the first query includes a unique identifier for an area in which the wireless communication device is operating; (ii) receive a first response including a list of one or more PLMNs that support emergency service sessions over the non-3GPP wireless access network from the DNS server, wherein each PLMN in the list of one or more PLMNs is associated with the area specified by the unique identifier;(iii) selecting a PLMN from the list of one or more PLMNs; (iv) sending a second query for emergency service-evolved Packet Data Gateway (ePDG) information to the DNS server; and (v) receiving a second response containing a list of Internet Protocol (IP) addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server.

[0052] In some embodiments, the second query includes an indication of the PLMN selected from the list of PLMNs, and each ePDG identified in the list of IP addresses is associated with the selected PLMN. In some embodiments, if the wireless device is not connected to any of the PLMNs listed in the list of one or more PLMNs, and the wireless device is provided by a home PLMN (HPLMN) with an ePDG emergency service list that includes at least one PLMN listed in the list of one or more PLMNs, the wireless device selects the PLMN from the list of one or more PLMNs that has the highest priority based on the ePDG emergency service list provided by the HPLMN.In some embodiments, execution of the instructions further causes the wireless device to: (vi) send a third query for local emergency service number information to a DNS server located in the area in which the wireless device is operating; and (vii) receive a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the area in which the wireless device is operating. In some embodiments, execution of the instructions further causes the wireless device to: (viii) detect an attempt to establish an emergency service call; and (ix) establish an emergency service connection based at least in part on the list of IP addresses or the list of local emergency service numbers.

[0053] It is understood that not all of the components, device elements and hardware elements described in relation to the Fig. 7 are essential to this disclosure, and therefore, some of these elements may be omitted, consolidated, or otherwise modified as appropriate. Furthermore, in some implementations, the subject matter in connection with the UE 102 may be configured to include additional or substitute components, device elements, or hardware elements beyond those illustrated in FIG. Fig. 7 shown.

[0054] Fig. Figure 8 illustrates a block diagram 800 of an exemplary representative set of elements of a wireless communication device that can be used to implement the various components and techniques described herein. In particular, the detailed view of the exemplary wireless communication device illustrates various components used in the Fig. 1 illustrated wireless device 102. As shown in Fig. 8, the computing device 800 may include a processor 802 representing a microprocessor or a controller for controlling the overall operation of the computing device 800. The computing device 800 may also include a user input device 808 that allows a user of the computing device 800 to interact with the computing device 800. For example, the user input device 808 may take a variety of forms, such as a button, a keypad, a dial, a touchscreen, an audio input interface, a visual / image capture input interface, input in the form of sensor data, etc. In addition, the computing device 800 may include a display 810 (screen display) that can be controlled by the processor 802 to display information to the user (e.g., visual / silent alarm notifications and / or information about incoming, outgoing, or active communication sessions).A data bus 816 may enable data transfer between at least one memory device 840, the processor 802, and a controller 813. The controller 813 may be used to interface with and control other equipment through an equipment control bus 814. The computing device 800 may also include a network / bus interface 811 that couples to a data link 812. In the case of a wireless connection, the network / bus interface 811 may include wireless switching logic, such as a wireless transceiver and / or baseband processor.

[0055] Computing device 800 also includes a storage device 840, which may comprise a single memory or a plurality of memories (e.g., hard drives), and includes a memory management module that manages one or more partitions within storage device 840. In some embodiments, storage device 840 may include flash memory, semiconductor (solid-state) memory, or the like. Computing device 800 may also include random access memory (RAM) 820 and read-only memory (ROM) 822. ROM 822 may store programs, utilities, or processes to be executed in a non-volatile manner. RAM 820 may provide volatile memory and stores instructions related to the operation of computing device 800.

[0056] The various aspects, embodiments, implementations, or features of the described embodiments may be used separately or in any combination. Some aspects of the described embodiments may further be implemented by software, hardware, or a combination of hardware and software. The described embodiments may also be embodied as computer program code stored on a non-transitory computer-readable medium. The computer-readable medium may be coupled to a data storage device capable of storing data that can subsequently be read by a computer or computer system. Examples of computer-readable media include read-only memory, random access memory, CD-ROMs, solid-state disks (SSD or Flash), HDDs, DVDs, magnetic tape, and optical data storage devices.The computer-readable medium may also be distributed across network-coupled computer systems so that the computer program code can be executed in a distributed manner.

[0057] The foregoing description used specific nomenclature for purposes of explanation in order to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that some of the specific details are not required to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are set forth herein for purposes of illustration and description. These descriptions are not intended to be exhaustive or all-inclusive or to limit the described embodiments to the precise forms or details disclosed. It will be apparent to those skilled in the art that many modifications and variations are possible in light of the above teachings without departing from the spirit and scope of the disclosure.< / mcc> < / emergency-number> < / mcc> < / mcc> < / mcc> < / mnc> < / mcc> < / mcc> < / mcc>

Claims

[1] A method for obtaining information for establishing emergency service sessions over a non-3GPP wireless access network, the method comprising: by a wireless device: Sending an initial query for emergency service public land mobile network (PLMN) information to a Domain Name System (DNS) server; receiving a first response including a list of one or more PLMNs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server; Selecting a PLMN from the list of one or more PLMNs; Sending a second query for emergency service evolved packet data gateway (ePDG) information to the DNS server; receiving a second response including a list of Internet Protocol (IP) addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server; and Sending a third query for local emergency number information to a DNS server located in a country in which the wireless device is roaming; and Receiving a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the country in which the wireless device is roaming. [2] The method of claim 1, wherein: the first query includes an indication that the wireless device is roaming and includes a unique identifier for a country in which the wireless device is roaming. [3] The method of claim 2, wherein: each PLMN in the list of one or more PLMNs is assigned to the country specified by the unique identifier. [4] The method of claim 1, wherein: the second query includes an indication of the PLMN selected from the list of PLMNs; and each ePDG identified in the list of IP addresses is assigned to the selected PLMN. [5] The method of claim 1, further comprising: through the wireless device: Determining a Mobile Country Code (MCC) for an area in which the wireless device is operated, where: the first query includes an indication of the MCC and identifies the list of one or more PLMNs for the MCC specified in the first query; if the wireless device is connected to one of the PLMNs listed in the list of one or more PLMNs, the wireless device selects the PLMN to which the wireless device is connected; and if the wireless device is not connected to any of the PLMNs listed in the list of one or more PLMNs, and the wireless device is provided by a home PLMN (HPLMN) with an ePDG emergency service list that includes at least one PLMN listed in the list of one or more PLMNs, the wireless device selects the PLMN from the list of one or more PLMNs that has the highest priority based on the ePDG emergency service list provided by the HPLMN. [6] The method of claim 1, further comprising: through the wireless device: Detecting an attempt to make an emergency call; and Establishing an emergency service connection based at least in part on the list of IP addresses or the list of local emergency service numbers. [7] A wireless device comprising: wireless circuits with one or more antennas; Processing circuitry comprising one or more processors communicatively coupled to a memory storing instructions and to the wireless circuitry; and an emergency service support module communicatively coupled to the processing circuits, wherein execution of the instructions on the one or more processors causes the wireless device to: Sending a first query for emergency services public land mobile network (PLMN) information to a domain name system (DNS) server, the first query including an indication that the wireless device is roaming and including a unique identifier for a country in which the wireless device is roaming; Receiving a first response including a list of one or more PLMNs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server, wherein each PLMN in the list of one or more PLMNs is associated with the country specified by the unique identifier; Selecting a PLMN from the list of one or more PLMNs; Sending a second query for emergency service evolved packet data gateway (ePDG) information to the DNS server, the second query including an indication of the PLMN selected from the list of PLMNs; Receiving a second response including a list of Internet Protocol (IP) addresses for ePDGs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server, wherein each ePDG identified in the list of IP addresses is associated with the selected PLMN; wherein execution of the instructions on the one or more processors further causes the wireless device to: Sending a third query for local emergency number information to a DNS server located in the country in which the wireless device is operating; and Receiving a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the country in which the wireless device is operating. [8] A wireless device according to claim 7, wherein: execution of the instructions on the one or more processors further causes the wireless device to determine a Mobile Country Code (MCC) for an area in which the wireless device operates; and the unique identifier includes the MCC. [9] A wireless device according to claim 7, wherein: if the wireless device is connected to one of the PLMNs listed in the list of one or more PLMNs, the wireless device selects the PLMN to which the wireless device is connected. [10] A wireless device according to claim 7, wherein: if the wireless device is not connected to any of the PLMNs listed in the list of one or more PLMNs, and the wireless device is provided by a home PLMN (HPLMN) with an ePDG emergency service list that includes at least one PLMN listed in the list of one or more PLMNs, the wireless device selects the PLMN from the list of one or more PLMNs that has the highest priority based on the ePDG emergency service list provided by the HPLMN. [11] The wireless device of claim 7, wherein execution of the instructions on the one or more processors further causes the wireless device to: Detecting an attempt to make an emergency call; and Establishing an emergency service connection based at least in part on the list of IP addresses or the list of local emergency service numbers. [12] A device configurable for operation in a wireless device, the device comprising: one or more processors communicatively coupled to a memory that stores instructions that, when executed by the one or more processors, cause the wireless device to: Sending a first query for emergency service public land mobile network (PLMN) information to a domain name system (DNS) server, the first query including a unique identifier for an area in which the wireless communication device is operating; Receiving a first response including a list of one or more PLMNs supporting emergency service sessions over the non-3GPP wireless access network from the DNS server, wherein each PLMN in the list of one or more PLMNs is associated with the area specified by the unique identifier; Selecting a PLMN from the list of one or more PLMNs; Sending a second query for emergency service evolved packet data gateway (ePDG) information to the DNS server; Receiving a second response including a list of Internet Protocol (IP) addresses for ePDGs that support emergency service sessions over the non-3GPP wireless access network from the DNS server; wherein execution of the commands further causes the wireless device to: Sending a third query for local emergency number information to a DNS server located in the area in which the wireless device is operating; and Receiving a third response including a list of local emergency service numbers categorized by emergency service type from the DNS server located in the area in which the wireless device is operating. [13] Device according to claim 12, wherein: the second query includes an indication of the PLMN selected from the list of PLMNs; and each ePDG identified in the list of IP addresses is assigned to the selected PLMN. [14] Device according to claim 12, wherein: if the wireless device is not connected to any of the PLMNs listed in the list of one or more PLMNs, and the wireless device is provided by a home PLMN (HPLMN) with an ePDG emergency service list that includes at least one PLMN listed in the list of one or more PLMNs, the wireless device selects the PLMN from the list of one or more PLMNs that has the highest priority based on the ePDG emergency service list provided by the HPLMN. [15] The apparatus of claim 12, wherein execution of the instructions further causes the wireless device to: Detecting an attempt to make an emergency call; and Establishing an emergency service connection based at least in part on the list of IP addresses or the list of local emergency service numbers.

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