Emergency call routing performed via non-terrestrial networks

Abstract

A solution for routing an emergency call made through a non-terrestrial network (NTN) includes receiving, by the NTN, an emergency call from a user equipment (UE), selecting, by the NTN, a public safety answering point (PSAP) for routing the emergency call, selecting, by the NTN, a packet data network (PDN) gateway (GW) in the terrestrial network (TN) for routing the emergency call, and routing the emergency call to the selected PDN GW. The solution also includes receiving, by the TN, an emergency call made by a UE using the NTN, determining, by the TN, a location of the UE, selecting, by the TN, a PSAP using the location of the UE, and routing the emergency call to the selected PSAP.

Description

Background Art

[0001] Non-terrestrial networks (NTNs) complement terrestrial-based TNs such as cellular networks by providing coverage in remote locations where terrestrial networks (TNs) have difficulty providing services. An NTN service provider may cooperate with a TN service provider by leasing radio spectrum and functioning as a roaming carrier (e.g., a serving network / visited network).

[0002] Cellular networks are configured to follow standardized operations such as those created by the Third Generation Partnership Project (3GPP (registered trademark)). 3GPP Technical Specification (TS) 23.401 is one of the control TSs for cellular networks and currently requires that emergency notifications such as Enhanced 911 (E911) calls be processed by the serving network / visited network. This means that an NTN functioning as a serving network / visited network is required to handle the routing of E911 to a Public Safety Answering Point (PSAP). A PSAP is a call center that responds to emergency notifications such as 911 calls. However, there are thousands of PSAPs in just the United States. Processing the selection of each PSAP and the routing to each PSAP requires significant infrastructure investment and raises the cost associated with NTNs.

Summary of the Invention

Means for Solving the Problems

[0003] The following summary is provided to illustrate examples disclosed in this specification but does not mean to limit all examples to any specific configuration or sequence of operations.

[0004] A solution for routing emergency calls made over a non-terrestrial network (NTN) includes the following: the NTN receiving the emergency call from the user equipment (UE); the NTN not selecting an Emergency Response Authority (PSAP) to route the emergency call; the NTN selecting a Packet Data Network (PDN) gateway (GW) in the terrestrial network (TN) to route the emergency call; and routing the emergency call to the selected PDN GW. The solution also includes the TN receiving the emergency call from the NTN originating from the NTN by the UE using the NTN; the TN determining the location of the UE; the TN selecting a PSAP using the UE's location; and routing the emergency call to the selected PSAP. The solution also includes the UE determining its location; and the UE sending an emergency call to the NTN, the emergency call comprising a message containing the UE's location and the identification information of the UE's Home Public Land Mobile Network (HPLMN). [Brief explanation of the drawing]

[0005] The examples disclosed are described below with reference to the figures in the attached drawings listed below.

[0006] [Figure 1] Figure 1 shows an exemplary architecture that favorably routes emergency calls made via a non-terrestrial network (NTN). [Figure 2] Figure 2 shows further details regarding the user equipment (UE) in Figure 1. [Figure 3] Figure 3 shows further details regarding the emergency call in Figure 1. [Figure 4] Figure 4 shows further details about one of the components of the architecture in Figure 1. [Figure 5] Figure 5 shows a message sequence diagram (also known as a swimlane diagram) illustrating typical messages that may occur in the architecture of Figure 1. [Figure 6]Figure 6 shows an exemplary operation flowchart associated with the architecture example in Figure 1. [Figure 7] Figure 7 shows an additional flowchart of exemplary operation associated with the example architecture in Figure 1. [Figure 8] Figure 8 shows an additional flowchart of exemplary operation associated with the example architecture in Figure 1. [Figure 9] Figure 9 shows an additional flowchart illustrating exemplary operation associated with the architecture example in Figure 1. [Figure 10] Figure 10 shows a block diagram of a computing device suitable for implementing various aspects of the present disclosure.

[0007] Corresponding reference letters, where applicable, indicate the corresponding part throughout the drawings. References made throughout this disclosure relating to specific examples are provided for illustrative purposes only and are not intended to limit all implementations or to exclude the existence of additional implementations incorporating the enumerated features. [Modes for carrying out the invention]

[0008] A solution for routing emergency calls made over a non-terrestrial network (NTN) includes the following: the NTN receiving the emergency call from the user equipment (UE); the NTN not selecting an Emergency Response Authority (PSAP) to route the emergency call; the NTN selecting a Packet Data Network (PDN) gateway (GW) in the terrestrial network (TN) to route the emergency call; and routing the emergency call to the selected PDN GW. The solution also includes the TN receiving the emergency call from the NTN originating from the NTN by the UE using the NTN; the TN determining the location of the UE; the TN selecting a PSAP using the UE's location; and routing the emergency call to the selected PSAP. The solution also includes the UE determining its location; and the UE sending an emergency call to the NTN, the emergency call comprising a message containing the UE's location and the identification information of the UE's Home Public Land Mobile Network (HPLMN).

[0009] The aspects of this disclosure improve public safety while improving the efficiency of NTN operations. NTN may favorably delegate the responsibility of routing emergency calls, such as Extended 911 (E911) or E112 calls, to the UE's home network or any other designated TN, rather than NTN routing the emergency calls themselves to PSAPs. E911 calls automatically provide the caller's location to the 911 dispatcher. 911 is the common emergency number, at least in North America. In the European Union (EU), the emergency number is 112, so emergency calls on cellular networks are E112 calls. Emergency calls originating from some vehicles are called eCalls.

[0010] By enabling established TNs, which already have a proven infrastructure for routing emergency calls to the appropriate PSAPs, to handle emergency calls related to NTN, NTN does not need to invest resources in a redundant manner. The intention behind the request for the serving network to handle emergency calls rather than routing them through the caller's home network is that, due to the conventional geographical distribution of cellular networks and conventional cell phone coverage, the PSAP closest to the caller may also be in the same geographical area as the serving network. Because NTN communicates with UEs using satellites, assumptions about the geographical location of network coverage do not need to apply to the same extent as those for TNs.

[0011] Referring to the diagram, Figure 1 shows an architecture 100 that favorably routes emergency calls made via NTN 110. In architecture 100, since UE 200 is in the vicinity of PSAP 102, UE 200 is within the jurisdiction 104 of PSAP 102. Jurisdiction 104 is within the area of ​​responsibility of PSAP 102, so that emergency calls from callers within jurisdiction 104 should be routed to PSAP 102 so that PSAP 102 can dispatch the appropriate responder (e.g., police, file, ambulance).

[0012] UE200 is serviced by NTN110, and as a result, NTN110 functions as the Visiting Public Land Mobile Network (VPLMN) for UE200. A Public Land Mobile Network (PLMN) is a combination of wireless communication services, such as cellular communication services, provided by a specific operator in a specific location. UE200 has a Home PLMN (HPLMN) that holds subscriber information about UE200. For example, a user of UE200 is a customer of UE200's HPLMN, and UE200's HPLMN is TN.

[0013] When UE200 moves outside the coverage of UE200's HPMLN, which is within the area covered by another TN, and UE200 has roaming coverage, that other TN is the visiting PLMN (VPLMN). However, in the scenario shown in Figure 1, when UE200 is serviced by NTN110, NTN110 is the roaming carrier of UE200 and interfaces with UE200's HPMLN, just like a roaming TN. Therefore, even though NTN has non-terrestrial components, i.e., satellite 111, NTN110 functions as the VPLMN of UE200. In some scenarios, TN130 is the HPMLN of UE200. However, in other scenarios, TN130 is not the HPMLN of UE200, but is instead designated to handle emergency calls on behalf of UE200's HPMLN.

[0014] UE200 communicates with NTN110 via air interface 106a with satellite 111. Satellite 111 communicates with a ground-based gateway (G GW112) via air interface 106b. G GW112 is commutably connected to NTN110's Mobility Management Entity (MME) 113 and Serving Gateway (SGW) 114. MME113 is commutably connected to SGW114 and Diameter Routing Agent (DRA) 115. The MME is the control node for the cellular network, and since NTN110 functions as a cellular network, NTN110 has its own MME. The MME is responsible for UE paging regarding the selection of the serving gateway. The DRA is a functional element that ensures messages are routed between the correct elements in the network.

[0015] NTN110 is connected to TN130 via interconnect 120. TN130 comprises DRA135, Home Subscriber Server (HSS)136, PDN GW134, Policy / Billing Rules Function (PCRF)137, MME133, Internet Protocol (IP) Multimedia System (IMS) IMS core132, and Text Control Center (TCC)131. In some applications, the PDN GW is also referred to as a Packet Gateway (PGW). The HSS is a subscriber database that provides subscriber information to other nodes of TN130. The PCRF accesses the subscriber database in real time to initiate dedicated bearers for IMS services. IMS provides an architectural framework for delivering IP-based multimedia services. Interconnect 120 may use the Internet Network Packet Switching (IPX) or IP Security (IPsec) protocol.

[0016] DRA135 is communicatively connected to HSS136 and MME133. PDN GW134 is communicatively connected to PCRF137, MME113, IMS core 132, and the Internet 160. IMS core 132 is also connected to the Public Switched Telephone Network (PSTN) 161, TCC131, and PSAP102. TCC131 processes text messages transmitted between IMS core 132 and PSAP102. PSAP102 is also communicatively connected to PSTN161.

[0017] When UE200 transmits emergency call 300 via NTN110, NTN110 routes emergency call 300 to PDN GW134 using information stored in MME113 to select PDN GW134 in TN130. TN130 routes emergency call 300 to PSAP102 using information stored in MME133 to select PSAP102. A voice session 528 is set up for emergency call 300 to allow the caller using UE200 to speak with the emergency dispatcher in PSAP102.

[0018] In some examples, TN130 comprises a fifth generation technology (5G) cellular network, a fourth generation technology (4G) cellular network, or another network (e.g., a future 6G network). In some examples, NTN110 emulates a 5G cellular network or another network (e.g., a future 6G network).

[0019] FIG. 2 shows further details regarding UE200. UE200 includes a subscriber identity module (SIM) card 202 that holds international mobile subscriber identity information (IMSI) 204. IMSI 204 includes a mobile country code (MCC) 206, a mobile network code (MNC) 208, and a mobile subscriber identification number (MSIN) 210. Together, MCC 206 and MNC 208 form the HPMLN identifier (ID) 212 of UE200. This is because MCC 206 is the MCC in the country where TN130 is located and MNC 208 is the MNC of TN130 within that country. MSIN 210 is a unique numerical code used to identify UE200 by UE200's HPMLN. In some examples, IMSI 204 has 15 digits. In some examples, NTN110 uses a non-geographical MCC such as 901.

[0020] UE200 transmits its own location 224 in E911 calls and E112 calls. To determine its own location 224, UE200 receives a global positioning system (GPS) signal 220 and uses a GPS receiver 222 to decode the GPS signal 220. In some examples, location 224 is expressed using GPS coordinates.

[0021] Figure 3 shows further details regarding the emergency call 300. In some examples, the emergency call 300 includes a Session Initiation Protocol (SIP) invitation 302. The emergency call 300 includes the location 224 of the UE and at least the HPLMN ID 212. In some examples, the emergency call 300 has the entire IMSI 204 and the HPLMN ID 212 is included as part of the IMSI 204. In some examples, the location 224 of the UE and the IMSI 204 are within the SIP invitation 302.

[0022] Figure 4 shows further details regarding the MME 113 of the NTN 110. The MME 113 includes a data store 402 that holds a database including an emergency PDN GW identification information field 404. The content of the conventional emergency PDN GW identification information field is specified in the 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 23.401, Table 5.7.2-1. However, the emergency PDN GW identification information field 404 instead has a mapping table 406.

[0023] Mapping table 406 has a PLMN column 408 and a PDN GW identification information (ID) column 410. As shown, mapping table 406 has five (5) rows of table inputs, but it should be understood that some implementations may use a different number of rows. Table input 411 maps PLMN values ​​of 310 XXX to the IP address of the PDN GW, and table input 412 maps PLMN values ​​of 310 310 YYY to the IP address of the PDN GW. Table input 413 maps PLMN values ​​of 310 ZZZ to the fully qualified domain name (FQDN) of the PDN GW. Table input 414 maps PLMN values ​​of 262 AA to the P address of the PDN GW, and table input 415 maps PLMN values ​​of 262 BB to the IP address of the PDN GW. The PDN GWs identified in the various table inputs of mapping table 406 may all be different, or some may be common to two or more table inputs. The PLMN value prefix 310 or 310 indicates a PLMN located within North America, and the PLMN value prefix 300 or 300 indicates a PLMN located within Germany. Other countries use various different PLMN value prefixes.

[0024] When MME113 receives emergency call 300 (for example, when receiving SIP invitation 302), MME113 extracts HPMLN ID 212 and finds a matching value in PLMN column 408. The corresponding PDN GW identification information (either an IP address or FQDN) in PDN GW ID column 410 is found. In this way, NTN110 selects PDN GW 134 for UE200.

[0025] Table entries in mapping table 406 may map PLMN values ​​to PDN GWs within the same PLMN, or alternatively, to PDN GWs within different PLMNs. When a PLMN value is mapped to a PDN GW within the same PLMN, any UE providing that PLMN as the HPLMN ID in an emergency call will route its call to its HPLMN. However, when a PLMN value is mapped to a PDN GW within a different PLMN, the UE will route its emergency call to a specified PLMN other than its HPLMN.

[0026] Various schemes may be used to determine which TN provides emergency call routing. For larger TNs, each TN may accept and route emergency calls for its own subscribers (e.g., UE emergency calls are routed to the UE's HPMLN), or it may host emergency calls for smaller TNs and cellular carrier resellers (e.g., UE emergency calls are routed to a designated HPMLN instead of the UE's HPMLN).

[0027] In contrast to the operation of MME113, when PDN GW134 receives emergency call 300, MME133 of TN130 holds a customary call PDN GW identification field specified by 3GPP TS23.401 that identifies PSAP102.

[0028] Figure 5 shows a message sequence diagram 500 illustrating an example of messages that may occur in architecture 100. UE200 registers with NTN110 for voice services using message 502. UE200 obtains its location (504) and initiates an emergency call 300 using SIP invitation 302 in message 506 to G GW112 via satellite 111. G GW112 forwards the emergency call 300 to MME113 using message 508. MME113 selects PDN GW134 (510) and notifies SGW114 using message 512.

[0029] SGW114 forwards emergency call 300 to PDN GW134 using message 514, and PDN GW134 routes emergency call 300 to IMS core 132 using message 516. In some examples, IMS core 132 routes emergency call 300 to PSAP102 following the procedure specified in 3GPP TS23.167. In some examples, IMS core 132 has its own table to identify PSAP102 based on location 224 of UE200. In such examples, IMS core 132 selects PSAP102 (518).

[0030] However, in some cases, the IMS core 132 utilizes the notification PDN GW identification field 404 stored in the MME 133. In such cases, the IMS core 132 queries the MME 133 using query 520, and the MME 133 selects PSAP 102 (522) and responds to the IMS core 132 with the identification information of PSAP 102 in response 524.

[0031] In either case, when the IMS core 132 identifies PSAP 102 as the appropriate PSAP for location 224 of the UE200, the IMS core 132 routes the emergency call 300 to PSAP 102 using message 526. A voice session 528 is set up for the emergency call 300 to allow the caller using the UE200 to speak with an emergency dispatcher in PSAP 102.

[0032] Figure 6 shows a flowchart 600 of an exemplary operation associated with routing emergency calls 300 through NTN 110 in architecture 100. In some examples, at least a portion of flowchart 600 may be performed using one or more computing devices 1000 in Figure 10 (for example, one of the network nodes in architecture 100 may use an example of computing device 1000). Flowchart 600 begins with UE 200 registering with NTN 110 for voice call services (operation 602), resulting in NTN 110 providing voice call services as the serving network for UE 200.

[0033] UE200 determines its location 224 (operation 604). Operation 604 is performed using operation 606, in which the GPS receiver 222 derives the location 224 of UE200 from the GPS signal 220 received by UE200 (operation 606).

[0034] UE200 sends an emergency call 300 to NTN110 (operation 608). The emergency call 300 includes a message containing the location 224 of UE200 and the HPLMN ID 212, which is the identification information for the HPLMN of UE200. In some examples, the emergency call 300 includes an E911 voice call or an E112 voice call. In some examples, sending the emergency call 300 to NTN110 includes sending a SIP invitation 302, which includes the location 224. In some examples, sending the emergency call 300 by UE200 includes sending the IMSI 204 of the SIM card 202 in UE200. In some examples, the IMSI 204 is stored in the SIM card 202 in UE200. In some examples, the HPLMN of UE200 is identified in the IMSI 204.

[0035] NTN110 receives emergency call 300 from UE200 (operation 610). In some examples, receiving emergency call 300 by NTN110 includes receiving SIP invitation 302. As shown in box 612, NTN110 does not select a PSAP to route emergency call 300 (i.e., NTN110 does not select PSAP 102). Instead, NTN110 determines which PDN GW is designated as handling the emergency call for HPLMN of UE200.

[0036] Operation 614 uses operations 616 and 618 to select (operation 614) a PDN GW164 in TN130 to route emergency call 300. In some examples, TN130 is the HPLMN of UE200, while in some other examples, TN130 is not the HPLMN of UE200, but instead a designated PLMN specified for routing emergency calls from UE200. Operation 616 determines the HPLMN of UE200. In some examples, determining the HPLMN of UE200 includes receiving at least a portion of the UE200's IMSI204 from UE200. In some examples, determining the HPLMN of UE200 includes receiving the HPLMN ID212 from UE200 and / or identifying the MCC206 and MNC208. In some examples, the HPLMN of UE200 is TN130 with the selected PDN GW164. In some cases, the HPLMN of the UE200 is a different TN from the TN130, which has the selected PDN GW164.

[0037] Operation 618 uses the HPMLN of UE200 to identify PDN GW164. In some examples, this includes identifying PDN GW164 in the Call PDN GW Identification Field 404. This may also include identifying PDN GW164 in the Mapping Table 406 stored in MME113 of NTN110. In some examples, identifying PDN GW164 includes identifying the FQDN or IP address of PDN GW164. Operation 620 routes the emergency call 300 to the selected PDN GW164. In some examples, routing the emergency call 300 to the selected PDN GW164 includes forwarding the SIP invitation 302 to the selected PDN GW164.

[0038] TN130 receives emergency call 300 from NTN110 (operation 622). In some examples, receiving emergency call 300 by TN130 includes receiving SIP invitation 302 from NTN110. TN130, location 224 of UE200 (operation 624). In some examples, TN130 performs operation 624 using operation 626, extracting location 224 of UE200 from the received emergency call 300 (e.g., from within SIP invitation 302) (operation 626).

[0039] TN130 selects PSAP102 using location 224 of UE200 (operation 628). In some examples, the selection of PSAP102 by TN130 involves using the Call PDN GW Identification Field stored in the database within TN130's MME133, specifically the Call PDN GW Identification Field. In some examples, the selection of PSAP102 involves determining the PSAP having jurisdiction 104 that includes location 224 of UE200. TN130 routes the emergency call 300 to the selected PSAP102 (operation 630).

[0040] Figure 7 shows an exemplary flowchart 700 of operations associated with an example of architecture 100 for routing emergency calls made via NTN. In some examples, at least a portion of flowchart 700 may be performed using one or more computing devices 1000 of Figure 10. Flowchart 700 begins with operation 702, which includes NTN receiving an emergency call from the UE. As shown by 704, NTN does not select a PSAP to route the emergency call. Operation 706 includes NTN selecting a PDN GW in the TN to route the emergency call, and operation 708 includes routing the emergency call to the selected PDN GW.

[0041] Figure 8 shows an exemplary operation flowchart 800 associated with an example of architecture 100. In some examples, at least a portion of flowchart 800 may be performed using one or more computing devices 1000 of Figure 10. Flowchart 800 begins with operation 802, which includes TN receiving an emergency call originating from NTN by a UE using NTN. Operation 804 includes TN determining the location of the UE. Operation 806 includes TN selecting a PSAP using the UE location. Operation 808 includes routing the emergency call to the selected PSAP.

[0042] Figure 9 shows a flowchart 900 of exemplary operations associated with an example of architecture 100. In some examples, at least a portion of the flowchart 900 may be performed using one or more computing devices 1000 of Figure 10. The flowchart 900 begins with operation 902, which includes the UE determining the location of the UE. Operation 904 includes the UE sending an emergency call to NTN, the emergency call comprising a message containing the location of the UE and identification information of the UE's HPLMN.

[0043] Figure 10 shows a block diagram of a computing device 1000, which may be used as any component described herein that may require computing or storage capacity. The computing device 1000 comprises at least a processor 1002 and a memory 1004 that holds program code 1010, a data area 1020, and other logic storage 1030. The memory 1004 is any device that allows information, such as computer-executable instructions and / or other data, to be stored and retrieved. For example, the memory 1004 may include one or more random access memory (RAM) modules, flash memory modules, hard disks, solid-state disks, persistent memory devices, and / or optical disks. The program code 1010 comprises computer-executable instructions and computer-executable components, including any instructions necessary to perform the operations described herein. The data area 1020 holds any data necessary to perform the operations described herein. Memory 1004 also includes other logic storage 1030 that perform or facilitate other functions disclosed herein or otherwise required by the computing device 1000. Input / output (I / O) components 1040 facilitate receiving input from the user and input from other devices, and generating displays for the user and outputs for other devices. Network interface 1050 enables communication with a remote node 1070 via network 1060, the remote node 1070 may represent another implementation of the computing device 1000. For example, the remote node 1070 may represent another of the aforementioned nodes within architecture 100.

[0044] Additional examples An exemplary method for routing emergency calls made via NTN includes NTN receiving the emergency call from UE, NTN not selecting a PSAP to route the emergency call, NTN selecting a PDN GW in TN to route the emergency call, and NTN routing the emergency call to the selected PDN GW.

[0045] An exemplary system for routing emergency calls made via NTN comprises a processor and a computer-readable medium storing instructions, wherein, when executed by the processor, the instructions operate to receive an emergency call from a UE via NTN, not select a PSAP via NTN to route the emergency call, select a PDN GW in TN to route the emergency call via NTN, and route the emergency call to the selected PDN GW.

[0046] One or more exemplary computer storage devices store computer executable instructions that, when executed by a computer, cause the computer to perform an action, the action including: NTN receiving an emergency call from UE; NTN not selecting a PSAP to route the emergency call; NTN selecting a PDN GW in TN to route the emergency call; and routing the emergency call to the selected PDN GW.

[0047] Another exemplary method for routing emergency calls made via NTN includes: TN receiving emergency calls originating from NTN by UEs using NTN; TN determining the location of the UE; TN selecting a PSAP using the UE location; and TN routing the emergency calls to the selected PSAP.

[0048] An exemplary method for routing emergency calls made by a UE via NTN includes the UE determining the UE's location and the UE sending an emergency call to NTN, the emergency call comprising a message containing the UE's location and the UE's HPLMN identification information.

[0049] Alternatively, or in addition to other examples described herein, examples are as follows: - Emergency calls must include an E911 voice call or an E112 voice call. - Receiving an emergency call via NTN includes receiving a SIP invitation. -Routing emergency calls to the selected PDN GW includes forwarding SIP invitations to the selected PDN GW. - Selecting a PDN GW involves determining the HPLMN of the UE. -Selecting a PDN GW involves determining which PDN GW will be designated as the one to handle emergency calls for the UE's HPLMN. - The PDN GW is located within the TN. -Selecting a PDN GW includes identifying the PDN GW in the notification PDN GW identification information field. -Selecting a PDN GW involves identifying the PDN GW in the mapping table stored in NTN's MME. Determining the HPLMN of the UE involves receiving at least a portion of the UE's IMSI from the UE. -UE is equipped with a mobile phone. - Regarding UE, NTN will provide voice call services as a serving network. -NTN will function as the VPLMN for the UE. -SIP invitations must include the UE location. - Receiving an emergency call via NTN includes receiving a SIP invitation from the UE. Determining the HPLMN of a UE includes receiving HPLMN identification information from the UE. - The HPLMN of the UE is identified within the IMSI of the UE. - The UE's IMSI is stored in the SIM card located within the UE. Determining the HPLMN of the UE involves identifying the MCC and MNC of the HPLMN. -UE's HPLMN is a TN with the selected PDN GW. -UE's HPLMN is a different TN from the TN that has the selected PDN GW TN. - Identifying a PDN GW includes identifying the FQDN or IP address of the PDN GW. - Receiving an emergency call via NTN includes receiving a SIP invitation from NTN. - Determining the UE's location by TN includes extracting the UE's location from the received emergency call. -Selecting a PSAP involves determining which PSAP has jurisdiction over the location of the UE. -TN is not VPLMN of UE. -TN is not HPLMN of UE. -TN is HPLMN of UE. -TN is a designated PLMN specified for routing emergency calls from the UE. -Selecting a PSAP by TN includes identifying the PSAP using the TN's MME. - Sending an emergency call to NTN includes sending a SIP invitation. -UE registers with NTN for voice call services, and as a result, NTN provides the UE's serving network. - Determining the location of a UE by the UE includes deriving the location of the UE from the GPS signal received by the UE. - Sending an emergency call via UE includes sending the IMSI of the SIM card located within the UE. Includes any combination of the above.

[0050] The execution or order in which the actions in the examples of the disclosure shown and described herein is not required unless otherwise specified. That is, the actions may be performed in any order unless otherwise specified, and the examples of the disclosure may include additional or fewer actions than those disclosed herein. For example, it is assumed that performing or doing a particular action before, simultaneously with, or after another action is within the scope of the aspects of the disclosure. It will be understood that the aforementioned advantages and effects may be in relation to one embodiment or several embodiments. When introducing elements of the aspects of the disclosure or the examples of the disclosure, the articles "a," "an," "the," and "said" are intended to mean that one or more of the elements exist. The terms "equip," "include," and "have" are intended to be inclusive and mean that additional elements other than those listed may exist. The term "exemplary" is intended to mean "an example of."

[0051] While the aspects of this disclosure have been described in detail, it will be apparent that modifications and changes are possible without departing from the scope of the aspects of this disclosure as defined in the attached claims. Since various changes may be made in the above-described configurations, products, and methods without departing from the scope of the aspects of this disclosure, it is intended that all matters included in the above description and shown in the attached drawings be interpreted as illustrative and not restrictive.

Claims

1. A method for routing emergency calls made via a non-terrestrial network (NTN), The aforementioned method, NTN will receive emergency calls from user equipment (UE), The aforementioned NTN does not select an Emergency Response Agency (PSAP) to route the emergency call, The aforementioned NTN selects a packet data network (PDN) gateway (GW) in the terrestrial network (TN) that routes the emergency call, The emergency call is routed to the selected PDN GW, including, A method characterized by the following:

2. The aforementioned emergency call is, E911 voice call or E112 voice call, Equipped with, The method according to claim 1.

3. Receiving the emergency call via the aforementioned NTN means that Receiving a Session Initiation Protocol (SIP) invitation, Includes, Routing the emergency call to the selected PDN GW is: To forward the SIP invitation to the selected PDN GW, including, The method according to claim 1.

4. Selecting the aforementioned PDN GW means To determine the Home Public Land Mobile Network (HPLMN) of the aforementioned UE, To determine the Packet Data Network (PDN) gateway (GW) that will be designated to handle emergency calls for the HPLMN of the UE, Includes, The PDN GW is located within the TN. The method according to claim 1.

5. Selecting the aforementioned PDN GW means In the notification PDN GW identification information field, the PDN GW identification is specified as follows: including, The method according to claim 4.

6. Selecting the aforementioned PDN GW means Identifying the PDN GW in the mapping table stored in the NTN's Mobility Management Entity (MME), including, The method according to claim 4.

7. Determining the HPLMN of the aforementioned UE is, To receive at least a portion of the International Mobile Subscriber Identification Information (IMSI) of the UE from the UE, including, The method according to claim 4.

8. A system for routing emergency calls made via a non-terrestrial network (NTN), The aforementioned system, Processor and A computer-readable medium that stores instructions, Equipped with, When the aforementioned instruction is executed by the processor, NTN receives emergency calls from user equipment (UE), The aforementioned NTN does not select an Emergency Response Service (PSAP) to route the emergency call. The aforementioned NTN selects a packet data network (PDN) gateway (GW) in the terrestrial network (TN) that routes the emergency call, The system operates to route the emergency call to the selected PDN GW. A system characterized by the following features.

9. The aforementioned emergency call is, E911 voice call or E112 voice call, Equipped with, The system according to claim 8.

10. The reception of the emergency call by NTN is Receiving a Session Initiation Protocol (SIP) invitation, Includes, The routing of the emergency call to the selected PDN GW is as follows: Transfer of the SIP invitation to the selected PDN GW, including, The system according to claim 8.

11. The selection of the aforementioned PDN GW is, The determination of the aforementioned UE's home public land mobile network (HPLMN), The determination of a Packet Data Network (PDN) gateway (GW) that is designated to handle emergency calls for the HPLMN of the UE, Includes, The PDN GW is located within the TN. The system according to claim 8.

12. The selection of the aforementioned PDN GW is, Identification of the PDN GW in the Notification PDN GW Identification Information field, including, The system according to claim 11.

13. The selection of the aforementioned PDN GW is, Identification of the PDN GW in the mapping table stored in the NTN's Mobility Management Entity (MME), including, The system according to claim 11.

14. The determination of the HPLMN of the aforementioned UE is Receipt of at least a portion of the International Mobile Subscriber Identification Information (IMSI) of the said UE from said UE, including, The system according to claim 11.

15. One or more computer memory devices that store computer executable instructions that, when executed by a computer, cause the computer to perform an action, The aforementioned operation is, The non-terrestrial network (NTN) receives emergency calls from user equipment (UE), The aforementioned NTN does not select an Emergency Response Agency (PSAP) to route the emergency call, The aforementioned NTN selects a packet data network (PDN) gateway (GW) in the terrestrial network (TN) that routes the emergency call, The emergency call is routed to the selected PDN GW, including, One or more computer storage devices characterized by the following:

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