WO2014114777A2

WO2014114777A2 - Handling of user equipment undetected emergency call

Info

Publication number: WO2014114777A2
Application number: PCT/EP2014/051476
Authority: WO
Inventors: Peter Leis; Miikka Juhana POIKSELKÄ; Jari Mutikainen
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2013-01-28
Filing date: 2014-01-27
Publication date: 2014-07-31
Also published as: WO2014114777A3

Abstract

Methods, apparatuses, and computer program products for handling of undetected emergency calls are provided. One method includes detecting that a call initiated by a UE, but not detected by the UE as an emergency call, is indeed an emergency call. The method may then include requesting that a bearer for the UE undetected emergency call be modified to an emergency bearer and/or emergency PDN connection. The method may also include modifying the R-URI to include a SOS URN and forwarding the SOS URN to an E-CSCF, for example.

Description

DESCRIPTION

TITLE

HANDLING OF USER EQUIPMENT UNDETECTED EMERGENCY CALL

CROSS REFERENCE TO RELATED APPLICATIONS:

[0001] This application claims priority to United States Provisional Application No. 61 /757,421 , filed on January 28, 2013. The entire contents of this earlier filed application is hereby incorporated by reference in its entirety.

BACKGROUND: Field:

[0002] Embodiments of the invention generally relate to wireless communications networks, such as, but not limited to, the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) and/or Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN). Some embodiments may specifically relate to the Internet Protocol Multimedia Subsystem (IMS).

Description of the Related Art:

[0003] Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) refers to a communications network including base stations, or Node Bs, and for example radio network controllers (RNC). UTRAN allows for connectivity between the user equipment (UE) and the core network. The RNC provides control functionalities for one or more Node Bs. The RNC and its corresponding Node Bs are called the Radio Network Subsystem (RNS). In case of E-UTRAN (enhanced UTRAN) no RNC exists and most of the RNC functionalities are contained in the eNodeB (evolved Node B, also called E-UTRAN Node B).

[0004] Long Term Evolution (LTE) or E-UTRAN refers to improvements of the UMTS through improved efficiency and services, lower costs, and use of new spectrum opportunities. In particular, LTE is a 3rd generation partnership project (3GPP) standard that provides for uplink peak rates of at least 50 megabits per second (Mbps) and downlink peak rates of at least 100 Mbps. LTE supports scalable carrier bandwidths from 20 MHz down to 1 .4 MHz and supports both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD). Advantages of LTE are, for example, high throughput, low latency, FDD and TDD support in the same platform, an improved end- user experience, and a simple architecture resulting in low operating costs.

[0005] Further releases of 3GPP LTE (e.g., LTE Rel-1 1 , LTE-Rel-12) are targeted towards future international mobile telecommunications advanced (IMT-A) systems, referred to herein for convenience simply as LTE-Advanced (LTE-A). LTE-A is directed toward extending and optimizing the 3GPP LTE radio access technologies. A goal of LTE-A is to provide significantly enhanced services by means of higher data rates and lower latency with reduced cost. LTE-A will be a more optimized radio system fulfilling the international telecommunication union-radio (ITU-R) requirements for I MT- Advanced while keeping the backward compatibility.

[0006] The Internet Protocol Multimedia Subsystem (IMS) is an architectural framework for delivering internet protocol (IP) multimedia services. In particular, IMS can aid the access of multimedia and voice applications from wireless and wireline terminals. IMS is the standardised solution for multimedia telephony over IP based networks, with Voice over LTE (VoLTE) utilizing IMS. To ease the integration with the Internet, IMS uses internet engineering task force (IETF) protocols, such as session initiation protocol (SIP), where available.

SUMMARY:

[This section will be completed when claims are finalized].

BRIEF DESCRIPTION OF THE DRAWINGS:

[0007] For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:

[0008] Fig. 1 illustrates a system according to one embodiment;

[0009] Fig. 2 illustrates a signaling diagram according to an embodiment;

[00010] Fig. 3 illustrates a signaling diagram according to another embodiment; [00011] Fig. 4 illustrates an apparatus according to one embodiment; and [00012] Fig. 5 illustrates a flow diagram of a method according to an embodiment.

DETAILED DESCRIPTION: [00013] It will be readily understood that the components of the invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of embodiments of methods, systems, apparatuses, and computer program products for handling of emergency calls, as represented in the attached figures, is not intended to limit the scope of the invention, but is merely representative of selected embodiments of the invention.

[00014] If desired, the different functions discussed below may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions may be optional or may be combined. As such, the following description should be considered as merely illustrative of the principles, teachings and embodiments of this invention, and not in limitation thereof.

[00015] Certain embodiments of the invention are directed to treating emergency calls such that the emergency call is detected in the network, the network assigns priority to the emergency call, the network enables single radio voice call continuity (SRVCC) for the emergency call, and the network ensures that dialled digits as received from the user equipment (UE) are available in the public safety answering point (PSAP).

[00016] Some countries or jurisdictions require support for emergency call number and related categories which are not downloaded to the UE in the list of local emergency numbers. Since these numbers are not downloaded, the UE may be unable to detect that a dialled number is for an emergency call and, in this case, the call is treated in the UE as a regular call. Certain embodiments of the invention, therefore, provide a mechanism to treat the bearer for the UE undetected emergency call as an emergency bearer/PDN connection.

[00017] Within 3GPP standardized systems, an emergency call can indicate a type of emergency service, in addition to the emergency number. 3GPP has specified the following categories: police, ambulance, fire brigade, marine guard, and mountain rescue.

[00018] However, the regulatory regimes in some countries may require additional categories, over and above what has been standardized in 3GPP. As mentioned above, if the network does not provide the list of these local emergency numbers to the UE, the UE is unable to detect that the dialed digits are for an emergency call, and in this case the call is treated in the UE as a regular call. Often, with the current circuit switched network deployments, the local emergency numbers are not provided to the UE.

[00019] Therefore, a common way to handle emergency calls when the dialed digits do not map to one of the above categories is to handle these calls as normal calls in the UE, and then let the network perform the necessary actions for the emergency call.

[00020] According to an embodiment, some issues that are addressed for such an approach include:

• Call that is not detected as emergency call in U E is modified to an emergency call in the network;

• Original dialed digits are kept available;

• Network assigns priority for the call ;

• Network ensures that the IP connectivity access network (IPCAN) bearer gets modified such that the call is using an emergency bearer; · Network ensures that SRVCC for emergency call is possible.

[00021] In an embodiment, for network operators that want to allow the county specific emergency categories to be supported, the following handling of emergency calls may be provided:

1 . Such emergency calls are treated as a regular call in UE;

2. UE uses a normal packet data network (PDN) connection, U E uses normal IMS registration ;

3. Proxy Call Session Control Function (P-CSCF) detects that it is an emergency call.

P-CSCF modifies the relative uniform resource identifier (R-URI) such that the R- URI will contain an SOS uniform resource name (URN) and the To header field still contains the originally dialed digits;

4. P-CSCF will check whether emergency bearer service is supported in the network.

If it is, P-CSCF will request via Policy and Charging Rules Function (PCRF) that the existing normal PDN connection will get an emergency indication. This may be done via Rx;

5. PCRF instructs PDN gateway (PGW) via Gx to modify the PDN connection accordingly;

6. PGW informs the mobility management entity (MME) about the emergency indication for the existing PDN connection such that this PDN connection can be used for emergency;

7. MME understands that the existing normal PDN connection is used for an emergency call, i.e., emergency bearer service is available. SRVCC for emergency call can be initiated.

[00022] Fig. 1 illustrates an example of the flow for an emergency call where the UE 100 does not detect that this is an emergency call, according to one embodiment. In the example of Fig. 1 , a user dials 1 18, which is, for example, the number of a poison help line. Of course, embodiments of the invention are not limited to this example or any one type of emergency call. The UE 100 does not detect that the numbers dialed by the user are for an emergency call. Therefore, the UE 100 uses a normal PDP connection to send a session setup request (INVITE) to the P-CSCF 105. Then, the P-CSCF 105 detects that it is an emergency call and requests the PCRF 1 10 to modify the existing bearer characteristics to get an emergency indication. The PCRF 1 10 instructs the PGW 1 15 to modify the bearer characteristics accordingly. Meanwhile the P-CSCF 105 modifies the R-URI such that the R-URI will contain an SOS URN and forwards it to the emergency CSCF (E-CSCF) 120. The E-CSCF 120 may take the To header into account in order to route the call to the correct PSAP 125.

[00023] Fig. 2 illustrates a signaling diagram of application function (AF) session modification triggering the IP-CAN session modification, according to one embodiment.

In the example of Fig. 2, at step 1 , AF in P-CSCF detects the emergency call. At step 2, AF defines service information. Then, at step 3, AF indicates via Rx reference point to the visited PCRF (V-PCRF) that the existing AF session is modified from a regular call to emergency call. [00024] In an embodiment, the Service-URN can be used as such an indicator of an emergency call as it is already present in the Diameter AAR command. The AAR command, for example, indicated by the Command-Code field set to 265 and the 'R' bit set in the Command Flags field, is sent by an AF to the PCRF in order to provide it with the Session Information. [00025] An example message format for the AAR may be:

<AA-Request> ::= < Diameter Header: 265, REQ, PXY >

< Session-Id >

{ Auth-Application-ld }

{ Origin-Host }

{ Origin-Realm }

{ Destination-Realm }

[ Destination-Host ]

[ AF-Application-ldentifier ]

*[ Media-Component-Description ]

[ Service-Info-Status ]

[ AF-Charging-ldentifier ]

[ SIP-Forking-lndication ]

^*[ Specific-Action ]

*[ Subscription-Id ]

^*[ Supported-Features ]

[ Reservation-Priority ]

[ Framed-IP-Address ]

[ Framed-IPv6-Prefix ]

[ Called-Station-ld ]

[ Service-URN ]

[ Sponsored-Connectivity-Data ]

[ MPS-ldentifier ]

[ Rx-Request-Type ]

[ Origin-State-Id ]

^*[ Proxy- Info ]

*[ Route-Record ]

*[ AVP ]

[00026] The Service-URN AVP (e.g., AVP code 525) is of type OctetString, and may indicate that an AF session is used for emergency traffic. It may contain values of the service URN including subservices. The string "urn:service:" in the beginning of the URN can be omitted in the AVP and all subsequent text may be included. Examples of valid values of the AVP include "sos", "sos.fire", "sos. police" and "sos. ambulance".

[00027] Fig. 3 illustrates an example of a signaling diagram of network initiated bearer modification, according to an embodiment. As illustrated in Fig. 3, at step 1 , the PCRF submits the modified session rules to the PCEF in PDN GW in a Diameter RAR command, for example. According to an embodiment, this command can be enhanced to carry the emergency indicator, for example, the Service-URN AVP as described above. [00028] The RAR command, indicated by the Command-Code field set to 258 and the 'R' bit set in the Command Flags field, may be sent by the PCRF to the BBERF or PGW in order to provision QoS rules using the PUSH procedure initiate the provision of unsolicited QoS rules. It is used to provision QoS rules, event triggers and event report indications for the session.

[00029] An example message format for the RAR may be:

<RA-Request> ::= < Diameter Header: 258, REQ, PXY

< Session-Id >

{ Auth-Application-ld }

{ Origin-Host }

{ Origin-Realm }

{ Destination-Realm }

{ Destination-Host }

{ Re-Auth-Request-Type }

[ Session-Release-Cause ]

[ Origin-State-Id ]

*[ Event-Trigger ]

*[ QoS-Rule-Remove ]

*[ QoS-Rule-lnstall ]

[ QoS-lnformation ]

[ Default-EPS-Bearer-QoS ]

*[ Proxy- Info ]

*[ Route-Record ]

*[ Service-URN ]

*[ AVP]

[00030] Returning to Fig. 3, at steps 2 and step 3, the PDN GW updates the bearer to the SGW, and SGW updates the bearer to MME. According to an embodiment, the

Update Bearer Request command is enhanced to carry the emergency indicator. The MME then stores the emergency indicator and binds it to the bearer information. The MME does not need to update the UE for emergency information as part of the Modify EPS bearer context request. If the SRVCC occurs for this bearer, the MME treats the call as an emergency call. If the MME needs to move the MM context to a new MME (or

SGSN) due to UE mobility, the emergency indicator is moved as part of the context transfer from the old MME to the new MME/SGSN.

[00031] Once the emergency call is terminated, the emergency authorization provided for the PDN connection can be revoked. This is initiated from the P-CSCF and signaling follows the same path as for assigning authorization.

[00032] Fig. 4 illustrates an example of an apparatus 10 according to an embodiment. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in Fig. 4. In one embodiment, apparatus 10 may be a P-CSCF as discussed above. In other embodiments, apparatus 10 may be a PCRF, PGW, and/or MME.

[00033] As illustrated in Fig. 4, apparatus 10 includes a processor 22 for processing information and executing instructions or operations. Processor 22 may be any type of general or specific purpose processor. While a single processor 22 is shown in Fig. 4, multiple processors may be utilized according to other embodiments. In fact, processor 22 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. [00034] Apparatus 10 further includes a memory 14, which may be coupled to processor 22, for storing information and instructions that may be executed by processor 22. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and removable memory. For example, memory 14 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, or any other type of non-transitory machine or computer readable media. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 22, enable the apparatus 10 to perform tasks as described herein.

[00035] Apparatus 10 may also include one or more antennas 25 for transmitting and receiving signals and/or data to and from apparatus 10. Apparatus 10 may further include a transceiver 28 configured to transmit and receive information. For instance, transceiver 28 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 25 and demodulates information received via the antenna(s) 25 for further processing by other elements of apparatus 10. In other embodiments, transceiver 28 may be capable of transmitting and receiving signals or data directly. [00036] Processor 22 may perform functions associated with the operation of apparatus 10 including, without limitation, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes related to management of communication resources.

[00037] In an embodiment, memory 14 stores software modules that provide functionality when executed by processor 22. The modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable combination of hardware and software.

[00038] In an embodiment, apparatus 10 may be controlled, by memory 14 and processor 22, to detect that an emergency call initiated from a UE is an emergency call, where the UE itself did not detect that the call is an emergency call because, for example, the dialed number are not included in a list of emergency numbers stored in the UE. Apparatus 10 may then be controlled, by memory 14 and processor 22, to request, via a PCRF, that a bearer for the UE undetected emergency call be modified to an emergency bearer and/or emergency PDN connection. In an embodiment, apparatus 10 may be further controlled, by memory 14 and processor 22, to modify the R-URI to include a SOS URN and forwarding the SOS URN to an E-CSCF, for example.

[00039] In an embodiment, apparatus 10 may be controlled, by memory 14 and processor 22, to receive a request to modify an existing bearer and/or PDN connection to an emergency bearer and/or emergency PDN connection. As a result, the PCRF instructs the PGW to modify the PDN connection accordingly.

[00040] In an embodiment, apparatus 10 may be controlled, by memory 14 and processor 22, to receive an instruction to modify an existing bearer and/or PDN connection to an emergency bearer and/or emergency PDN connection. As a result, the PGW provides the emergency indication to the MME such that the PDN connection/bearer can be used for the emergency.

[00041] In an embodiment, apparatus 10 may be controlled, by memory 14 and processor 22, to receive the emergency indication. As a result, the MME stores the information and understands that the PDN connection/bearer is now for emergency communication and subject for emergency SR-VCC.

[00042] Fig. 5 illustrates an example of a flow diagram for a method of handling a UE undetected emergency call, according to one embodiment. The method may include, at 500, detecting that a call initiated by a UE, but not detected by the UE as an emergency call, is indeed an emergency call. The method may then include, at 510, requesting, via a PCRF for example, that a bearer for the UE undetected emergency call be modified to an emergency bearer and/or emergency PDN connection. As a result of the request, the PCRF may instruct the PGW to modify the PDN connection to an emergency PDN connection, and the PGW may then inform the MME about the emergency indication for the existing PDN connection such that the PDN connection can be used for the emergency. The MME would then understand that the existing PDN connection is to be used for an emergency call and a SRVCC for the emergency call is initiated. The method may also include, at 520, modifying the R-URI to include a SOS URN and forwarding the SOS URN to an E-CSCF, for example. In one embodiment, the E-CSCF may ensure that the dialed digits as received from the UE are available in the appropriate PSAP.

[00043] In some embodiments, the functionality of any of the methods described herein, such as that illustrated in Fig. 5 discussed above, may be implemented by software and/or computer program code stored in memory or other computer readable or tangible media, and executed by a processor. In other embodiments, the functionality may be performed by hardware, for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software.

[00044] One embodiment is directed to a method for handling of undetected emergency calls. The method may include detecting that a call initiated by a UE, but not detected by the UE as an emergency call, is indeed an emergency call. The method may then include requesting that a bearer for the UE undetected emergency call be modified to an emergency bearer and/or emergency PDN connection. The method may also include modifying the R-URI to include a SOS URN and forwarding the SOS URN to an E-CSCF, for example.

[00045] Another embodiment is directed to an apparatus including at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured, with the at least one processor, to cause the apparatus at least to detect that a call initiated by a UE, but not detected by the UE as an emergency call, is indeed an emergency call. The apparatus may then be caused to request that a bearer for the UE undetected emergency call be modified to an emergency bearer and/or emergency PDN connection, and to modify the R-URI to include a SOS URN and forward the SOS URN to an E-CSCF, for example.

[00046] In view of the above, according to certain embodiments, regional emergency numbers can be treated as regular calls in the UE which fastens the emergency call setup procedure since the UE does not need to establish emergency PDN connection, emergency bearer and IMS emergency registration prior to call setup.

[00047] One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention.

Claims

2 0 12 02 1 96 WO 2014/114777 PCT/EP2014/051476 12 We Claim:

1 . A method, comprising: detecting, by a network node, that a call initiated by a user equipment is an emergency call, wherein the user equipment did not detect the call as an emergency call; and requesting that a bearer for the call be modified to an emergency bearer and/or emergency packet data network (PDN) connection.

2. The method according to claim 1 , wherein the requesting further comprises instructing a gateway to modify an existing PDN connection to an emergency PDN connection.

3. The method according to claim 2, wherein the modifying of the existing PDN connection to the emergency PDN connection comprises adding an emergency indication to the PDN connection.

4. The method according to any one of claims 2 or 3, wherein the gateway is configured to inform a mobility management entity about the emergency indication for the existing PDN connection such that the PDN connection can be used for the emergency call.

5. The method according to any one of claims 1 -4, further comprising initiating a single radio voice call continuity (SRVCC) for the emergency call.

6. The method according to any one of claims 1 -5, further comprising modifying a relative uniform resource identifier (R-URI) such that the R-URI will contain an SOS uniform resource name (URN). 2 0 12 02 1 96

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7. The method according to any one of claims 1 -6, wherein the network node comprises at least one of Proxy Call Session Control Function (P-CSCF) or a Policy and Charging Rules Function (PCRF).

8. The method according to any one of claims 2-7, wherein the gateway comprises a packet data network gateway (PGW).

9. An apparatus, comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to detect that a call initiated by a user equipment is an emergency call, wherein the user equipment did not detect the call as an emergency call; and request that a bearer for the call be modified to an emergency bearer and/or emergency packet data network (PDN) connection.

10. The apparatus according to claim 9, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to instruct a gateway to modify an existing PDN connection to an emergency PDN connection.

1 1 . The apparatus according to claim 10, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to modify the existing PDN connection to the emergency PDN connection by adding an emergency indication to the PDN connection. 201202196

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12. The apparatus according to any one of claims 1 0 or 1 1 , wherein the gateway is configured to inform a mobility management entity about the emergency indication for the existing PDN connection such that the PDN connection can be used for the emergency call.

13. The apparatus according to any one of claims 9-1 2, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to initiate a single radio voice call continuity (SRVCC) for the emergency call.

14. The apparatus according to any one of claims 9-1 3, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to modify a relative uniform resource identifier (R-URI) such that the R-URI will contain an SOS uniform resource name (URN).

15. The apparatus according to any one of claims 9-14, wherein the apparatus comprises at least one of Proxy Call Session Control Function (P-CSCF) or a Policy and Charging Rules Function (PCRF).

16. The apparatus according to any one of claims 10-1 5, wherein the gateway comprises a packet data network gateway (PGW).

17. An apparatus, comprising: means for detecting that a call initiated by a user equipment is an emergency call, wherein the user equipment did not detect the call as an emergency call; and means for requesting that a bearer for the call be modified to an emergency bearer and/or emergency packet data network (PDN) connection. 201202196

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18. A computer program product, embodied on a computer readable medium, the computer program product configured to control a processor to perform a method according to any one of claims 1-8.