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Title:
METHODS AND APPARATUS FOR PROVIDING CALL BACK SOLUTIONS TO A PSAP
Document Type and Number:
WIPO Patent Application WO/2016/198920
Kind Code:
A1
Abstract:
A method, in a user equipment, UE, which is registered in a first access network, for providing a call back solution to a Public Safety Answering Point, PSAP, is disclosed. The method comprises initiating registration of the UE with at least one second access network, the at least one second access network being different than the first access network, after an emergency call is made by the UE; and sending identification information obtained during the registration with the at least one second access network to the PSAP, the identification information being usable by the PSAP to call back the UE. A UE for carrying out such a method is also disclosed.

Inventors:
GAVITA EDOARDO (CA)
MIRARCHI ALBERTO (CA)
JOONG DONALD (CA)
Application Number:
PCT/IB2015/054480
Publication Date:
December 15, 2016
Filing Date:
June 12, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ERICSSON TELEFON AB L M (PUBL) (SE)
GAVITA EDOARDO (CA)
MIRARCHI ALBERTO (CA)
JOONG DONALD (CA)
International Classes:
H04W76/00; H04W76/02
Domestic Patent References:
WO2014090338A12014-06-19
WO2008006055A22008-01-10
WO2009137617A12009-11-12
Foreign References:
US20120184238A12012-07-19
Other References:
None
Attorney, Agent or Firm:
NICOLAESCU, Alex et al. (8400 Decarie BoulevardTown Mount Royal, Québec H4P 2N2, CA)
Download PDF:
Claims:
What is claimed is:

1. A method (200), in a user equipment, UE(12), which is registered in a first access network, for providing a call back solution to a Public Safety Answering Point, PSAP (16), the method comprising: initiating registration (220) of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, after an emergency call is made by the UE (12); and sending (230) identification information obtained during the registration with the at least one second access network to the PSAP (16), the identification information being usable by the PSAP (16) to call back the UE (12).

2. The method of claim 1, wherein initiating the registration of the UE (12) with the at least one second access network is responsive to determining that the UE (12) has initiated the emergency call.

3. The method of claim 1, wherein initiating the registration of the UE (12) with the at least one second access network is responsive to determining that the emergency call has been dropped.

4. The method (200) of any of claims 1 to 3, further comprising detecting available networks.

5. The method (200) of any of claims 1 to 4, wherein registering the UE (12) with at least one second access network comprising registering the UE (12) with a plurality of networks, different from the first access network.

6. The method (200) of claim 1, wherein the first access network is part of a cellular network provided by a first service provider and the second access network is part of a second cellular network provided by a second service provider.

7. The method (200) of claim 5, wherein the plurality of networks comprises the second service cellular network and a wireless network.

8. The method (200) of claim 1, wherein the PSAP (16) comprises a database associated therewith and wherein sending identification information obtained during the registration comprises sending the identification information to the database associated with the PSAP.

9. The method (200) of claim 1, wherein registering the UE (12) with at least one second network further comprises receiving a temporary routing number from the at least second network.

10. The method (200) of claim 1, wherein registering the UE (12) with at least one second network further comprises receiving an Internet Protocol, IP, address.

11. The method (200) of claim 10, further comprising obtaining one identification handle from at least one Voice over IP , VoIP, service, the identification handle mapped to the received IP address.

12. A user equipment, UE (12) which is registered with a first access network, comprising: one or more communication interfaces (325); and a circuitry (300) operatively associated with the one or more communication interfaces (325) and configured to: initiate a registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, after an emergency call is made by the UE (12); and send identification information obtained during the registration with the at least one second access network to the PSAP (16), through the one or more communication interfaces (325), the identification information being usable by the PSAP (16) to call back the UE (12).

13. The UE (12) of claim 10, wherein the circuitry (300) further comprises a processor (310) and a memory (320) connected thereto, the memory (320) containing instructions that, when executed, cause the processor (310) to: initiate registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, after an emergency call is made by the UE (12); and send identification information obtained during the registration with the at least one second access network to the PSAP (16), the identification information being usable by the PSAP (16) to call back the UE (12).

14. The UE (12) of claim 13, wherein the processor (310) is configured to initiate the registration of the UE with the at least one second access network in response to determining that the UE (12) is initiating the emergency call.

15. The UE (12) of claim 13, wherein the processor (310) is configured to initiate the registration of the UE (12) with the at least one second access network in response to determining that the emergency call has been dropped.

16. The UE (12) of any of claims 13 to 15, wherein the processor (310) is further configured to detect available networks.

17. The UE (12) of any of claims 13-16, wherein the processor (310) is further configured to register the UE (12) with a plurality of networks, different from the first access network.

18. The UE (12) of any of claims 13 to 17, wherein the first access network is part of a cellular network provided by a first service provider and the second access network is part of a second cellular network provided by a second service provider.

19. The UE (12) of claim 17, wherein the plurality of networks comprises the second service cellular network and a wireless network.

20. The UE (12) of any of claims 12 to 19, wherein the processor (310) is further configured to send, through the one or more communication interfaces (325), the identification information obtained during the registration to a database associated with the PSAP (16).

21. The UE (12) of any of claims 12 to 20, wherein the one or more communication interfaces (325) are configured to receive a temporary routing number from the at least second access network when registering the UE (12) with the at least one second access network.

22. The UE (12) of any of claims 12 to 21, wherein the communication interfaces (325) are configured to receive an Internet Protocol, IP, address when registering the UE (12) with the at least one second access network.

23. The UE (12) of claim 22, wherein the processor (310) is further configured to obtain at least one identification handle from at least one Voice over IP , VoIP, service, the at least one identification handle mapped to the received IP address.

24. A user equipment, UE (12), which is registered with a first access network, comprising: a registering module (410) for registering the UE (12) with at least one second access network, the at least one second access network being different from the first access network after an emergency call is made by the UE (12); and a transmission module (420) for sending identification information obtained during the registration with the at least one second access network to the PSAP (16), the identification information being usable by the PSAP (16) to call back the UE (12).

25. A method (500) for calling back a user who initiated an emergency call using a user equipment, UE (12), the user being registered with a first access network, the method comprising:

receiving (510) an emergency call from the UE (12); and

receiving (520) at least one identification information associated with the UE (12) and resulting from registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable by the PSAP (16) to call back the UE (12) in case the initial emergency call has been dropped.

26. The method (500) of claim 25, further comprising receiving a list of identification information resulting from registration of the UE (12) with a plurality of networks.

27. The method (500) of claim 26, further comprising storing the list in a database (102) associated with a PSAP (16).

28. The method (500) of claim 27, further comprising associating the list of identification information with an automatic number identifier of the user in the database (102).

29. The method (500) of claim 26, further comprising selecting an identification information from the list, to call back the UE (12) in case the initial emergency call has been dropped.

30. A network node (600), for calling back a user who initiated an emergency call using a user equipment, UE (12), the user being registered with a first access network, the network node comprising:

one or more communication interfaces (640); and

a circuitry (610), operatively connected with the one or more communication interfaces (640), the circuitry (610) being configured to:

receive an emergency call from the UE (12); and receive at least one identification information associated with the UE (12) and resulting from registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable to call back the UE (12) in case the initial emergency call has been dropped.

31. The network node (600) of claim 30, wherein the circuitry (610) comprises a processor (620) and a memory (630) connected thereto.

32. The network node (600) of claim 31, wherein the memory (630) comprises instructions that, when executed, cause the processor (610) to:

receive an emergency call from the UE (12); and

receive at least one identification information associated with the UE (12) and resulting from registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable to call back the UE (12) in case the initial emergency call has been dropped.

33. The network node (600) of claim 32, wherein the processor (610) is further configured to receive a list of identification information resulting from registration of the UE (12) with a plurality of networks.

34. The network node (600) of claim 33, further comprising a database (102) associated therewith, the database (102) for storing the received list of identification information.

35. The network node (600) of claim 34, wherein the processor (610) is further configured to associate the list of identification information with an automatic number identifier of the user in the database (102).

36. The network node (600) of claim 33, wherein the processor (610) is further configured to select one identification information from the list when calling back the UE (12), in case the initial emergency call has been dropped.

37. The network node (600) of any of claims 30-36, wherein the network node (600) is a public safety answering point, PSAP, (16).

38. A network node (700), for calling back a user who initiated an emergency call using a user equipment, UE (12), the user being registered with a first access network, the network node comprising:

a first receiving module (710) for receiving an emergency call from the UE (12); and

a second receiving module (720) for receiving at least one identification information associated with the UE (12) and resulting from registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable to call back the UE (12) in case the initial emergency call has been dropped.

Description:
METHODS AND APPARATUS FOR PROVTDTNG CAT J, BACK SOLTTTTONS TO

A PSAP

TECHNICAL FIELD

[0001] This disclosure relates generally to methods and apparatus for providing call back solutions to Public Safety Answering Points (PSAPs).

BACKGROUND

[0002] Enhanced 911

[0003] Enhanced 911 or E-911 is a location technology advanced by the Federal

Communications Commission (FCC) that enables mobile, or cellular, phones to process 911 emergency calls and to enable emergency services to locate the geographic position of the caller. When a person makes a 911 call using a traditional phone with ground wires, the call is routed to the nearest public safety answering point (PSAP). The PSAP then distributes the emergency call to the proper services. The PSAP receives the caller's phone number and the exact location of the phone from which the call was made.

[0004] Prior to 1996, users calling 911 using a mobile phone needed to access their service provider in order to get a verification of their subscription service, before the call was routed to a PSAP. In 1996, the FCC ruled that a 911 call must go directly to the PSAP without receiving a verification of service from a specific service provider. The 911 call must be handled by any available service carrier even by service carriers that are not the customer's specific carrier. Under the FCC's rules, all mobile phones manufactured for sale in the United States after February 13, 2000, that are capable of operating in an analog mode must include this special method for processing 911 calls.

[0005] The FCC has rolled out E-911 in two phases. In 1998, Phase I required that mobile phone carriers identify the originating call's phone number and the location of the signal tower, or cell, accurate to within a mile. In 2001, Phase II required that each mobile phone company doing business in the United States must offer either handset- or network- based location detection capability so that the caller's location is determined by the geographic location of the cellular phone within 100 meter accuracy and not the location of the tower that is transmitting its signal. The FCC refers to this as the Automatic Location Identification (ALI).

[0006] Voice over Internet Protocol (VoIP) Enhanced 911

[0007] Initial implementations of Voice over IP telephone systems were not integrated with the 911 system at all, meaning that customers could not even dial 911 in the event of an emergency. However, the Federal Communications Commission has mandated all VoIP providers to provide 911 services, including the E911 feature.

[0008] On June 3, 2005, the FCC adopted rules requiring providers of VoIP services that connect with the traditional telephone network to supply E-911 capabilities to their customers. The E-911 hookup may be directly with the Wireline E-911 Network, indirectly through a third party, such as a competitive local exchange carrier (CLEC), or by any other technical means. The FCC explained that they felt compelled to issue this mandate because of the public safety concerns. (FCC, Notice of Proposed Rulemaking, WC Docket No. 05-196 available at https://transition.fcc.gov/cgb/voip911order.pdf).

[0009] There are also other proposed features that are intended to allow telephone callers from large corporate telephone networks, on both traditional and VoIP Private Branch Exchanges (PBXs), to be located down to the specific office, on a particular floor of a building.

[0010] Even though E-911 is implemented in most telephone systems, one of the main deficiencies with today's E-911 solutions is that there are no simple and effective ways for PSAPs to re-establish an emergency call with a subscriber when his/her original call is dropped or lost.

[0011] Therefore, it would be desirable to provide systems and methods that obviate or mitigate the above described problems.

SUMMARY

[0012] In a first aspect of the present invention, there is provided a method, in a user equipment, UE, which is registered in a first access network, for providing a call back solution to a Public Safety Answering Point, PSAP. The method comprises: initiating registration of the UE with at least one second access network, the at least one second access network being different from the first access network, after an emergency call is made by the UE; and sending identification information obtained during the registration with the at least one second access network to the PSAP, the identification information being usable by the PSAP to call back the UE.

[0013] In an embodiment of the first aspect, the registration of the UE with the at least one second access network is initiated in response to determining that the UE has initiated the emergency call.

[0014] In another embodiment, the registration of the UE with the at least one second access network is initiated in response to determining that the emergency call has been dropped.

[0015] In a second aspect of the present invention, there is provided a user equipment, UE, which is registered with a first access network. The UE comprises one or more communication interfaces; and a circuitry operatively associated with the one or more communication interfaces and configured to: initiate a registration of the UE with at least one second access network, the at least one second access network being different from the first access network, after an emergency call is made by the UE; and send identification information obtained during the registration with the at least one second access network to the PSAP, through the one or more communication interfaces, the identification information being usable by the PSAP to call back the UE.

[0016] In a third aspect of the present invention, there is provided a user equipment, UE, which is registered with a first access network. The user equipment comprises: a registering module for registering the UE with at least one second access network, the at least one second access network being different from the first access network after an emergency call is made by the UE; and a transmission module for sending identification information obtained during the registration with the at least one second access network to the PSAP, the identification information being usable by the PSAP to call back the UE.

[0017] In a fourth aspect of the invention, there is provided a method for calling back a user who initiated an emergency call using a user equipment, UE, the user being registered with a first access network. The method comprises: receiving an emergency call from the UE; and receiving at least one identification information associated with the UE and resulting from registration of the UE with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable by the PSAP to call back the UE in case the initial emergency call has been dropped.

[0018] In a fifth aspect of the invention, there is provided a network node, for calling back a user who initiated an emergency call using a user equipment, UE, the user being registered with a first access network. The network node comprises: one or more communication interfaces; and a circuitry, operatively connected with the one or more communication interfaces, the circuitry being configured to: receive an emergency call from the UE; and receive at least one identification information associated with the UE and resulting from registration of the UE with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable to call back the UE in case the initial emergency call has been dropped.

[0019] In a sixth aspect of the invention, there is provided a network node, for calling back a user who initiated an emergency call using a user equipment, UE, the user being registered with a first access network. The network node comprises: a first receiving module for receiving an emergency call from the UE; and a second receiving module for receiving at least one identification information associated with the UE and resulting from registration of the UE with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable to call back the UE in case the initial emergency call has been dropped.

[0020] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:

[0022] Figure 1 is a block diagram of a cellular communication network in communication with a Public Safety answering Point (PSAP) according to the prior art;

[0023] Figure 2 is a block diagram of a communication network according to an embodiment of the present invention;

[0024] Figure 3 is a block diagram of a user equipment according to one embodiment of the invention;

[0025] Figure 4 is a flow chart of a method for providing call back solutions to the

PSAP, according to an embodiment of the present invention

[0026] Figure 5 is a block diagram of a user equipment for carrying out the method of Figure 4, according to an embodiment of the present invention;

[0027] Figure 6 is a flow chart of a method for calling back a user equipment, according to an embodiment of the present invention;

[0028] Figure 7 is a schematic block diagram of a network node for carrying out the method of Figure 6, according to an embodiment of the invention; and

[0029] Figure 8 is a schematic block diagram of a network node for carrying out the method of Figure 6, according to another embodiment of the invention. DETAILED DESCRIPTION

[0030] Reference may be made below to specific elements, numbered in accordance with the attached figures. The discussion below should be taken to be exemplary in nature, and not as limiting of the scope of the present invention. The scope of the present invention is defined in the claims, and should not be considered as limited by the implementation details described below, which as one skilled in the art will appreciate, can be modified by replacing elements with equivalent functional elements.

[0031] Figure 1 schematically illustrates a cellular communication network 10 in communication with a PSAP according to the prior art. The cellular communication network 10 comprises an access network and a core network. The access network comprises at least a base station 14A, for accessing the communication network 10. Thecore network could comprise a circuit switched (CS) network or a packet switched (PS) network. In the case of a CS network, the core network comprises at least a Visited Mobile Switching Center (V-MSC) 18 A. It should be understood that the CS network may comprise other elements, such as a MSC and a Home Location Resource (HLR). CS networks are well-known in the art and thus they will not be described in further details. In the case of a PS network, the core network comprises at least a Serving GPRS Support Node (SGSN) 20, a Gateway GPRS Support Node (GGSN) 22, and an Internet Protocol (IP) Multimedia Subsystem (IMS) 24. The PS network may comprise other elements, which are well-known in the art.

[0032] For simplicity and clarity, only elements of the communication network 10 which are used in the communication path with the PSAP are illustrated in Figure 1 and described in this disclosure. Also, it should be noted that even though Figure 1 shows only one base station 14 A, there could be more. The number of each element illustrated in Figure 1 is only exemplary. Depending on the size and infrastructure of the cellular communication network 10, the number of each element may vary.

[0033] A mobile device or user equipment (UE) 12 is usually registered with a service provider (SP), for example service provider A, in order to access the communication network 10, through the base station 14A (of the access network). [0034] For example, it is assumed that the UE 12 wants to make an emergency call to the PSAP 16. As illustrated in Figure 1, once the call is initiated by the UE 12, the call goes to the base station 14A, which sends the call either to the CS network, in the case of a Global System for Mobile (GSM) communications network, or the PS network, in the case of a General Packet Radio Service (GPRS) network, depending on the infrastructure of the network of the service provider A. If the call is sent to the CS network, it goes to the V- MSC 18 A, which then routes the call to the PSAP 16. If the call is sent to the PS network, the call goes to the SGSN 20, then the GGSN 22, then the IMS 24, which finally sends the call to the PSAP 16. The procedures for routing the emergency call in the CS network or PS network are not detailed because they are well-known in the art.

[0035] When the call is received by the PSAP 16, the Automatic Number

Identification (ANI), which includes the calling party number, also called the A-Number, is passed to the PSAP 16. .

[0036] Therefore, the existing PSAPs typically use the callers' ANI to identify who the caller is. But this number does not serve the network operator/service provider or the caller very well if the caller's service provider drops the call, while the call is in progress. In this case, the PSAP 16 will try to call back the user, using the ANI. But this call will also fail since the ANI is the only known path back to the mobile phone; this path uses the same network which has failed, when servicing the initial call. Therefore the same network is not able to serve the caller at that moment.

[0037] Furthermore, existing E-911 regulations do not address how PSAPs can reestablish dropped emergency calls with a subscriber using alternative networks or alternative network resources (ANR). The dropped call can be due to radio or network deficiencies (congestion/failure) from the service provider, for example.

[0038] Generally speaking, embodiments of the present invention provide for call back solutions to a PSAP so that connectivity with the caller of the original emergency call may be re-established, in case the original emergency call has been dropped, due to network issues. More specifically, they provide for a list of 'pre-qualified' alternative network resources to the PSAP, whenever a user initiates a 911 call or emergency call. To do so, upon initiating the emergency call or upon determining/detecting that the emergency call has been dropped, the caller will register with one or more available alternative networks. An alternative network refers to any other available networks which were not used for placing the original/initial emergency call. The registration with the alternative networks results in identification information such as:

[0039] 1) Assignment of a temporary routing number, such as an E.164 number, belonging to another service provider. The PSAP can use this number to re-establish the communication with the caller; and/or

[0040] 2) Identification handles for alternative voice services such as Skype,

Viber, Facetime, Lync, etc. These identification handles can be used by the PSAP to reestablish communication with the caller, using a data network.

[0041] Now turning to Figure 2, a communication network 100 according to an embodiment of the present invention will be described.

[0042] The communication network 100 comprises a first network, belonging to service provider A, for example, and which corresponds to the cellular communication network 10 of Figure 1.

[0043] The communication network 100 also comprises a second network, belonging to service provider B, for example. The second network represents another cellular communication network, which comprises a base station 14B (from the access network), being in communication with a V-MSC 18B. The V-MSC 18B is in turn in communication with the PSAP 16. In that case, the core network of the second network is a CS network. The core network of the second network could also be a PS network and as such would comprise a SGSN, a GGSN and IMS.

[0044] Of course, it should be understood that the second cellular communication network may comprise a plurality of base stations and other elements, which are well- known in the art. For sake of simplicity, those elements are not described.

[0045] Figure 2 also includes a third network, represented by a wireless network accessible through WIFI. More specifically, the WIFI access (or access network) comprises a WIFI hotspot 104, which is in communication with the internet 106. The internet 106 can communicate with FMS 24, which is in communication with the PSAP 16. The PSAP 16 can have a database or repository 102 associated therewith. There is also a Voice Application server 109, connected to the internet 106. The Voice Application server 109 provides for voice application services, such as Skype. The UE 12 may have a Skype client application installed therein. Once registered with Skype, using a username and password, for example, the UE 12 can originate or terminate calls to or from other parties including the PSAP for emergency calls through Skype, if it has IP connectivity. The IP connectivity is obtained through registration with the WIFI hotspot 104.

[0046] It should be noted that there may be more than one hotspot 104 for the third access network and that the communication network 100 may comprise more than one wireless network and a plurality of cellular communication networks, such as 10. Also, it should be understood that the cellular communication networks of Figure 2 could also comprise a Long- Term Evolution (LTE) network and other networks well-known in the art.

[0047] Now turning to Figure 3, a schematic diagram of a UE 12, according to an embodiment of the present invention, will be described.

[0048] In an example embodiment, the UE 12 comprises a circuitry 300, which includes a processor 310 and a memory 320, one or more communication interfaces 325 and optionally a call agent 250.

[0049] The circuitry 300 is operatively associated with the communication interface(s) 325. In an example implementation, the communication interface or interfaces 325 comprise physical-layer interface circuits, which configure the UE 12 to communicate with one or more nodes in the network 100. Correspondingly, the circuitry 300 comprises one or more digital processing circuits, such as one or more microprocessors, Digital Signal Processors or DSPs, Application Specific Integrated Circuits or ASICs, Field Programmable Gate Arrays or FPGAs, or other digital processing circuitry, which are represented by the processor 310.

[0050] In the following, it is assumed that the user of UE 12 is a subscriber of service provider A, to which the first network of the communication network 100 (see Figure 1) belongs. In other words, the UE 12 is registered with the first network or with the first access network.

[0051] When this user initiates an emergency call using UE 12, the circuitry 300 or the processor 310 of the UE 12 can determine that an emergency call is being made. For example, a Subscriber Identity Module (SEVI) card and/or a 3 rd Generation (3G) phone have a preprogrammed list of emergency call numbers. Therefore, the 3G phone or UE 12 can determine when an emergency call is made based on the preprogrammed list. Also, when the UE 12 makes an emergency call using a number known by the GSM network, a special emergency call setup takes place, which is well-known in the art. The emergency call is marked with a flag when travelling through the first network, for example. The flag is used to indicate that the call is an emergency call.

[0052] After the emergency call is made by the UE 12, the circuitry 300 or processor 310 registers the UE with at least one second access network, the at least one second access network being different from the first access network.

[0053] Furthermore, upon determination that the UE 12 is initiating an emergency call, the circuitry 300 or processor 310 of the UE 12 starts scanning for available alternative networks (or available networks). Once an alternative network is identified or detected, the circuitry 300 or processor 310 starts performing registration with the available alternative network. Alternatively, when the UE 12 determines that the emergency call has been dropped, the circuitry 300 or processor 310 starts performing registration of the UE 12 with the available alternative network.

[0054] The circuitry 300 or processor 310 further sends the identification information obtained during the registration with the at least one second access network to the PSAP 16, the identification information being usable by the PSAP 16 to call back the UE 12. This can be done through the communication interfaces 325.

[0055] As an example, when scanning for available alternative networks, the processor 310 of the UE 12 can detect that the base station 14B from service provider B is available, i.e. the access network of the second network is not congested. As such, it will start registering with this second access network, to which the base station 14B belongs. The registration procedures are well-known in the art and will not be described. According to the FCC rules, any service provider has the obligation to accept any users for making an emergency call. Therefore, even though UE 12 is not a subscriber of service provider B, it can register with the network of that service provider. The registration results in the assignment of a temporary record being created in the service providers network (in V- MSC 18B for example), and a temporary assignment of a routing number. The temporary record is specific and dedicated for emergency call handling purposes only. The temporary routing number is to be used by the PSAP 16 to call back or terminate a call to the original caller, using the network of the service provider B. The temporary routing number could be an E.164 number.

[0056] The UE 12 can also attempt to get access to any WIFI hotspot 104 that is available within its proximity, for example. To do so, the processor 310 of the UE 12 scans for any Service Set Identifier (SSID) being broadcast within its proximity.

[0057] If the WIFI hotspot 104 is open with no encryption, which is the case for public hotspots, the processor 310 of the UE 12 can request an IP address. Once the processor 310 receives the IP address from the WIFI hotspot 104, thus providing the UE 12 with IP connectivity, the processor 310 can start registering with the alternative voice applications. But before starting the process of registration, the UE 12 can first take an inventory of all the alternative voice applications available to the UE 12. After the inventory, the processor 310 of the UE 12 can attempt to register with all of the available VoIP services, such as Skype, Viber, Lync, Facetime, etc. However, if the registration fails with some services, for different reasons, then those services will not be reported as possible alternative network resources to the PSAP 16.

[0058] The VoIP services use an identification handle which maps to an assigned

IP address. Once the UE 12 has IP connectivity, the registration with the VoIP services uses the IP address that was assigned to the UE 12 in response to its request for an IP address. It should be noted that it is the responsibility of the individual VoIP application services to continuously update the IP connectivity information to ensure that the application can resolve/map its identification handle to a routable valid IP address. The identification handles can be usernames or email addresses, for example.

[0059] Once the registration is performed, the processor 310 of the UE 12 obtains or has access to the identification handles of the VoIP services and it can submit these identification handles to the serving PSAP 16, through the communication interfaces 315.

[0060] If further authentication is required at the access layer, for example

802.1 lx, or at the network layer, a special set of credentials may be used by the UE 12 to gain access to the data network. Once successful authentication is made and authorization is granted, the processor 310 of the UE 12 can then attempt to register to all or some of the caller/user VoIP services. For example, the special set of credentials could comprise a username and a password. This special set of credentials may be agreed upon by the WIFI hotspot 14 for allowing users to establish IP connectivity for the purpose of servicing E- 911 call handling.

[0061] The VoIP services may be also available to the user in devices such a tablet, netbook, laptop, or wearable devices connected via Bluetooth or other Personal Area Network (PAN).

[0062] The processor 310 of the UE 12 can register the UE 12 with a plurality of available networks. As such, the processor 310 sends a list of identification information, resulting from the registration of the UE 12 with the plurality of available networks, to the PSAP 16.

[0063] Furthermore, the processor 310 of the UE 12 creates/initiates a call registration event (CRE) when it starts registering with the different networks so that the results of the registration are stored in the CRE. Each CRE is associated with the ANI of the UE 12.

[0064] The registration results, i.e. the identification information, can be sent to the

PSAP 16 as soon as they become available. Alternatively, they may be also periodically updated whenever new information from the networks becomes available. In the case where the emergency caller is moving, the registration results may also be updated based on the caller's physical changing location. Indeed, if the UE 12 is moving, different alternative network resources may become available while other previously available network resources may no longer be available. For instance, when the UE moves away from one service provider's base station range, it will be served by another service provider's base station and V-MSC. In this case, a registration is made with the new V- MSC and a new temporary routing number is assigned to the UE 12 and then passed to the PSAP 16. The identification information is sent to the PSAP 16 through the communications interfaces 325, for example.

[0065] The CRE can be stored in the memory 320, following each registration of the UE 12 with a communication network. The memory 320 can also store the list of identification information when the UE 12 is registered with a plurality of available networks.

[0066] Each identification information or the list of identification information can typically be sent as an out-of-band signal to the PSAP 16, using a data network, for example. Once the PSAP 16 receives the list, it stores it in a local memory or in the database 102 which is associated therewith. Each identification information in the list sent to the PSAP 16 is associated with the ANI of the UE 12, that initiated the emergency call, so that the PSAP 16 can distinguish calls and lists from different UEs. Of course, other methods could be used to distinguish lists from different UEs 12, as will be appreciated by persons skilled in the art.

[0067] If the original call is dropped, due to network problems for example, the

PSAP 16 can access the received list and choose any identification information from the list to call back the UE 12. For example, it could use the temporary routing number assigned to the UE 12 in the second cellular network, or use the data network to call the UE 12 using the Skype handle identification. As an implementation preference, the PSAP 16 can use the identification information that was received first or that is on top of the list.

[0068] Now turning to Figure 4, a method 200 for providing a call back solution to a PSAP, according to an embodiment of the present invention will be described. It is assumed that the UE 12 is currently served by a first network having a first access network, i.e. it is registered with the first access network. Or in other terms, the UE (12) is registered with the service provider of the first network.

[0069] The method 200 starts with step 220 where the UE 12 initiates registration of the UE (12) with at least one second access network, the at least second access network being different from the first access network. The second access network belongs to a second network, which could be a cellular communication network belonging to a second service provider, for example. The second network could belong to the same operator/service provider as the first network, as well. The second network could be also a wireless network. Alternatively, the UE 12 can register with a plurality of networks. To do so, the UE 12 first scans for or detects any available networks, with which it can register.

[0070] Step 220, i.e. the registration of the UE (12) with the at least one second access network, can be triggered by (or is responsive to) determining that the UE (12) has initiated/made an emergency call. Alternatively, step 210 can be triggered by (or is responsive to) determining that the emergency call has been dropped. The UE 12 can detect, for example, that the emergency call has been dropped by determining that the emergency call has not been terminated normally, i.e. the END key was not pressed. In such as case, the UE 12 concludes or assumes that the emergency call was dropped by the first network abruptly.

[0071] In step 230, after the registration is finished and successful, the UE 12 sends the identification information, obtained during the registration with the at least one second access network, to the PSAP 16. The identification information could be a temporary routing number for the cellular communication network of the second service provider or an identification handle, such as the username of Skype, Viber, Lync, etc. The identification information is usable by the PSAP 16 to call back the UE 12.

[0072] Alternatively, the UE 12 can send a list of identification information to the

PSAP 16. For example, once it has registered with the cellular communication network of the second service provider and the wireless network, the identification information resulting from the registration with those two networks is stored in the list. Then, the list is sent to the PSAP 16. It should be noted that each identification information of the list could be sent as a separate message to the PSAP 16, so that the PSAP 16 can get a call back path as soon as it receives the message.

[0073] It should be also noted that the registrations to the different networks can be done in parallel so that the list of identification information is made available as soon as possible to the PSAP 1 6.

[0074] Now, turning back to Figure 3, it should be noted that the memory 320 of the UE 12 can contain instructions that, when executed, cause the processor 310 to perform the steps of method 200. Alternatively, the processor 310 can use the optional call agent 250 to perform the steps of method 200. The call agent 250 could take the form of an application for smartphones, as an example.

[0075] Figure 5 illustrates an UE 12 according to another embodiment of the invention.

[0076] The UE 12 comprises a registering module 410, a transmission module 420 and optionally a determining module 400.

[0077] The registering module 410 allows for registering the UE 12 with at least one second access network, after the UE 12 has initiated/made an emergency call. The at least second access network is different from the first access network, of which the UE 12 is a subscriber, i.e. to which the UE 12 is registered. [0078] The transmission module 420 allows for sending identification information obtained during the registration to the PSAP 16. Using the identification information, the PSAP 16 can call back the user of the UE 12 in case the initial call is dropped.

[0079] The optional determining module 400 can determine that the UE 12 has initiated/made the emergency call. In response to this determination, the UE 12 initiates registration with at least one second access network, through the registering module 410. The optional module 400 can also determine that the emergency call has been dropped. In response to that determination, the registering module 410 initiates registration of the UE 12 with the at least one second network.

[0080] Figure 6 illustrates a method 500 for calling back a user who initiated an emergency call using an UE 12, the user being registered with a first access network.

[0081] Method 500 starts with step 510 in which a network node, such as the

PSAP 16, receives an emergency call from the UE 12.

[0082] In step 520, the network node receives at least one identification information associated with the UE 12 and resulting from registration of the UE 12 with at least one second access network, the at least one second access network being different from the first access network. The at least one identification information can be used by the PSAP 15 to call back the UE 12 in case the initial emergency call has been dropped.

[0083] Now turning to Figure 7, a network node 600 for carrying method 500 will be described. The network node 600 can be the PSAP 16, for example.

[0084] The network node 600 has a circuitry 610, which includes a processor 620 and a memory 630, and one or more communication interfaces 640.

[0085] The circuitry 610 is operatively associated with the communication interface(s) 640. In an example implementation, the communication interface or interfaces 640 comprise physical-layer interface circuits, which configure the network node 600 to communicate with one or more nodes in the network 100. Correspondingly, the circuitry 610 comprises one or more digital processing circuits, such as one or more microprocessors, Digital Signal Processors or DSPs, Application Specific Integrated Circuits or ASICs, Field Programmable Gate Arrays or FPGAs, or other digital processing circuitry, which are represented by processor 620. [0086] A repository or database, such as 102 (of Figure 2), can be associated with the network node 600.

[0087] More specifically, the memory 620 contains instructions that, when executed, cause the processor 620 to carry out the method 500.

[0088] The processor 620 is further configured to receive a list of identification information resulting from registration of the UE 12 with a plurality of networks. The list can be stored in the repository 102 associated with the network node 600.

[0089] The processor 620 is further configured to associate the list of identification information with an automatic number identifier of the user in the database/repository 102.

[0090] The processor 620 is further configured to select one identification information from the list when calling back the UE 12, in case the original call was dropped.

[0091] With reference to Figure 8, a network node 700, according to another embodiment, for carrying method 500 will be described. The network node 700 can be the PSAP 16, for example.

[0092] The network 700 has a first receiving module 710 and a second receiving module 720.

[0093] The first receiving module 710 is configured to receive an emergency call from the UE (12).

[0094] The second receiving module 720 is configured to receive at least one identification information associated with the UE (12) and resulting from registration of the UE (12) with at least one second access network, the at least one second access network being different from the first access network, and the at least one identification information being usable to call back the UE (12) in case the initial emergency call has been dropped.

[0095] It should be noted that, in this disclosure, the terms user, subscriber, caller, customer have been used to refer to a person that uses the UE 12 to make an emergency call. These terms can be used interchangeably.

[0096] Also, it should be noted that some parts of the disclosure mention that the user is registered with a network and other parts mention that the UE is registered with the network. These two statements are similar. Generally the UE 12 does the registration as it performs the necessary steps and processes to register to a network or application service. However, the credential used for the registration is typically associated with a subscription or a user. Further, the disclosure sometimes states that the UE 12 is registered with an access network and sometimes the UE 12 is registered with a network. These two statements are similar as well.

[0097] Further yet, it should be appreciated that the term UE may refer to a user terminal, a wireless terminal, a wireless communication device, a mobile phone, a cell phone, a smartphone, a Portable Digital Assistant (PDA), a portable computer, and may include Machine Type Communication (MTC) devices, which do not necessarily involve human interaction.

[0098] The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the invention, which is defined solely by the claims appended hereto.