CN101577889B

CN101577889B - Emergency call system and method for calling back emergency communication acceptance center

Info

Publication number: CN101577889B
Application number: CN2008101766402A
Authority: CN
Inventors: 谢宝国; 郝振武
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2008-11-11
Filing date: 2008-11-11
Publication date: 2011-08-10
Anticipated expiration: 2028-11-11
Also published as: CN101577889A

Abstract

The invention provides an emergency call system and a method for calling back an emergency communication acceptance center. The method comprises the following steps that: when UE needs to be called back, a PSAP sends a session establishing request to the UE through E-CSCF and S-CSCF as call agents so as to establish a session with the UE; after receiving the session establishing request, the UE sends a session establishing response containing address information of the UE and IP-CAN information to the E-CSCF; and the E-CSCF sends the address information and the IP-CAN information to an LRF, and sends the session establishing response containing the address information of the UE which is queried according to the address information and the IP-CAN information returned by the LRF and/or ESQK in association with the address information and the IP-CAN information to the PSAP.

Description

A kind of emergencycallboxsystem and urgency communication are accepted the back calling method at center

Technical field

The present invention relates to the communications field, relate in particular to the back calling method that a kind of emergencycallboxsystem and urgency communication are accepted the center.

Background technology

IP (Internet Protocol, Internet Protocol) IP multimedia subsystem, IMS (IP Multimedia CoreNetwork Subsystem, be called for short IMS) be by third generation partner program (3rd GenerationPartnership Project, abbreviation 3GPP) a kind of IP-based network framework of tissue proposition, it has made up an opening and service environment flexibly, support multimedia application, and provide abundant multimedia service for the user.

IMS is based on the communication network framework of IP, irrelevant with access technology, except being GPRS (General Packet Radio Service, GPRS), WLAN (Wireless LocalArea Network, WLAN (wireless local area network)) etc. packet access network provides outside the business, can also be GSM (Global System for Mobile communications, global system for mobile communications), UMTS mobile cellular networks such as (Universal Mobile Telecommunications System, unified mobile communcations systems) provides professional.

Urgent call (Emergency Call) is distinctive a kind of speech business function in the mobile communication system.As long as portable terminal is in the zone that the mobile network covers, even the subscriber identification module of insertion (SIM) is blocked or is provided with dialing restriction, the user can initiate urgent call by dialing emergency numbers (as: 110,119,911 etc.); The urgent call meeting is transferred to corresponding urgency communication and accepts center (PSAP), as: police office, fire brigade, first-aid centre etc. provide 24 hours emergency assistance services by it for the user.The operation of whole emergencycallboxsystem is finished by the common cooperation of emergency services such as telecom operators and public security, fire-fighting, hospital.

Under the conventional situation, urgent call all is to realize in circuit switching (CS) territory, and along with the progressively IPization of network, packet switching (PS) territory also begins progressively to support emergence call service, and utilizes IMS that emergent session is carried out call signaling control.The emergence call service that the IMS territory provides can abbreviate the IMS urgent call as.

Fig. 1 is the reference frame schematic diagram of IMS emergencycallboxsystem in the prior art.As shown in Figure 1, comprise in the IMS emergencycallboxsystem: subscriber equipment (User Equipment, be called for short UE), Proxy Call Session Control Function (Proxy Call Session Control Function, be called for short P-CSCF), service call conversation control function (Serving Call Session Control Function, be called for short S-CSCF), home subscriber server (Home Subscriber Server, be called for short HSS), emergency call session controlled function (Emergency Call Session Control Function, be called for short E-CSCF), the position obtains function (Location Retrieval Function, be called for short LRF) and urgency communication accept center (Public SafetyAnswering Point, abbreviation PSAP).

Wherein, P-CSCF is used to transmit request and response between UE and the S-CSCF as the agency of UE.S-CSCF is the home service entity of UE, is used to UE that functions such as service logic and control of authority are provided.HSS is used to preserve user's the register information and the information such as business of customization.LRF is used for providing to network user's current location information.PSAP is responsible for the urgent call of accepted user as the emergency call service center.

E-CSCF is a new functional entity of introducing in the IMS territory, itself and P-CSCF are arranged in same network (being user's visited network when the user roams), the emergent session of being responsible for receiving from P-CSCF is set up request, positional information that provides according to the user or positional information and the routing iinformation that obtains from LRF, the emergent session request of setting up is routed to the urgency communication that is connected IP network through Mm accepts center (PSAP), or process Mi/Mg interface route is accepted the center to the urgency communication that is connected PSTN (PublicSwitch Telephone Network is called for short PSTN).Simultaneously, the urgency communication center of accepting can directly obtain user position information by the Le interface from LRF, and gets in touch by Mm/Mw interface and user's home network, with the callback user.

Fig. 2 is the method flow diagram of having initiated urgent call the user of IMS territory normal registration at local network in the prior art, and in this flow process, the local network at UE place can be home network or visited network; As shown in Figure 2, urgent call flow process comprises the steps:

Step 201:UE initiates the IMS emergency call request;

UE at first need adhere at IP-CAN (IP Carrier AccessNetwork, IP carries Access Layer) before initiating emergency call request, is established as the IP carrying of emergency call service, and successfully registers at S-CSCF.

Step 202:P-CSCF judges whether this call request is emergency call request after receiving the call request of UE initiation: if not emergency call request, then according to the ordinary call flow processing, this flow process finishes; Otherwise carry out next step.

Step 203:P-CSCF is routed to call request according to local policy the E-CSCF of local network; The E-CSCF address can be in P-CSCF static configuration.

After step 204:E-CSCF receives emergency call request, send the position to LRF and obtain request message, comprise positional information and the urgency traffic type of UE in this message;

After LRF receives that the position obtains request message, on LRF, obtain the routing address of local PSAP, and the routing address of local PSAP is included in the position obtains and return to E-CSCF in the response message according to the positional information of the UE that comprises in this message.

Step 205:E-CSCF is routed to local PSAP according to the routing address of PSAP with emergency call request; If do not find corresponding PSAP address, E-CSCF can route emergency calls to the local PSAP of acquiescence.

PSAP can be in CS territory, PS territory or PSTN.

Step 206:PSAP confirms this calling, sets up emergency call session between UE and PSAP.

From the system architecture of above-mentioned urgent call and flow process as can be seen, urgent call of the prior art is a kind of business that realizes at local network.After the user roams into visited network, need set up carrying at visited network, find the P-CSCF of visited network then, follow-up emergency calling process is handled and route by the E-CSCF (being the E-CSCF of visited network) of this locality.

When running into emergency (for example natural calamity etc.) and need relief, the user initiates urgent call to PSAP, and after the user finished emergency call session and on-hook with PSAP, PSAP then needed the callback user if wish further to understand information to the user.The method of PSAP callback user in the prior art is described below, specifically may further comprise the steps:

Step 301a: in the CS territory, PSAP sends initial address request message (Initial Address Message is called for short IAM) to MGCF (Media Gateway ControlFunction, MGCF) as if PSAP, and request is set up session with UE.

Step 301b:MGCF analyzes calling number, judges that this calling is the PSAP callback, therefore the callback request of having added the PSAP sign is issued ownership IMS core net and handles.

If PSAP in the PS territory, then uses step 301c step of replacing 301a～301b:

Step 301c: if PSAP is in the PS territory and have an IP ability, PSAP sends INVITE (invitations) conversation request message (also can be called callback request message) of carrying the PSAP sign to IMS home network (abbreviation home network), and request and UE set up session.

S-CSCF in the step 302:IMS home network carries out called initial filter criteria, judge whether carry the PSAP sign in the callback request message: if carry, just ignore (i.e. cancellation) to the supplementary service that this user's limit service (for example roaming restriction) and user contracts, directly send callback request to this UE.

S-CSCF finds the current affiliated P-CSCF of UE according to the contact address information of UE registration, sends the callback request of carrying the PSAP sign to this P-CSCF;

After step 303:P-CSCF receives callback request, judge and whether carry the PSAP sign in the callback request: if carry, then send callback request to UE, realize callback according to the target address information in the callback request.

The priority that P-CSCF can carry the callback request of PSAP sign is set to be higher than other sessions.

Step 304～306:UE replys this to PSAP and calls out, and P-CSCF, the ownership S-CSCF of callback response message under UE is current is routed to PSAP.

Wherein, step 306a～306b is that the IMS core net sends it back the step that concord is answered to the PSAP in CS territory; Step 306c is that the IMS core net sends it back the step that concord is answered to the PSAP in PS territory.

Step 307:PSAP and UE set up VoIP (Voice over IP, IP-based voice) session.

PSAP can be in time by above-mentioned callback flow and UE promptly get in touch.

From above-mentioned PSAP callback flow as can be seen, the PSAP callback flow is to exhale flow process to realize eventually by common IMS; Different is to carry the PSAP sign in PSAP callback request message.Like this, the IMS home network just can be controlled session, ignores user's access restriction and signatory supplementary service etc., directly callback request is issued UE, sets up session with UE.

As from the foregoing, adopt existing IMS to exhale flow process eventually, PSAP can set up session with UE, in time deals with urgent work.But in the actual process of urgent affairs, usually need the positional information of real-time inquiring user.For example to carry out emergency relief, just need know the concrete geographical position at user place in real time.In the emergency calling process that as shown in Figure 2 UE initiates, PSAP can inquire about the positional information of UE in real time by LRF; But in PSAP callback flow as shown in Figure 3, because LRF not in the session path of correspondence, do not preserve the session information of this PSAP callback among the LRF, so PSAP can't inquire about the positional information of UE in real time by LRF.

That is to say, exhale flow process to realize the PSAP callback eventually if adopt existing IMS, no matter UE is at home network or roamed into visited network (being referred to as the local network of UE), though PSAP can set up session with UE, but can't inquire about the geographical location information at respective user place in real time, this brings very big difficulty for the urgent transaction that needs to grasp the user geographical position in real time, may therefore can lose the good opportunity of rescue.

Summary of the invention

Technical problem to be solved by this invention is, overcomes the deficiencies in the prior art, and the back calling method and the emergencycallboxsystem of the positional information that a kind of PSAP of making can obtain UE is provided.

In order to address the above problem, the invention provides the back calling method that a kind of urgency communication is accepted the center, this method comprises:

When needs callback user equipment (UE), urgency communication is accepted center P SAP and is sent session by the service call conversation control function S-CSCF as the home network of the emergency call session controlled function E-CSCF of its Call Agent and UE to UE and set up request, to set up the session with UE;

UE receives after described session sets up request, and the session that will comprise the address information of UE and internet carrying Access Layer IP-CAN information is set up to reply and sent to E-CSCF;

E-CSCF sends to the position with described address information and IP-CAN information and obtains function LRF, and the positional information of the UE that obtains according to described address information and IP-CAN information inquiry that LRF is returned and/or be included in session with the urgency traffic inquiry code ESQK of described address information and IP-CAN associating information and set up and send to PSAP in replying.

In addition, if PSAP in the circuit switching (CS) territory, PSAP adopts following steps to send session by E-CSCF and S-CSCF to UE and sets up request:

A:PSAP sends the initial address request message to MGCF MGCF;

B: after receiving described initial address request message, MGCF sends session by E-CSCF and S-CSCF to UE and sets up request.

In addition, receive calling number and be the described initial address request message of number of described PSAP after, MGCF obtains the address of described E-CSCF according to the PSAP number of this locality configuration and the corresponding relation of E-CSCF address, sends session to described E-CSCF and sets up and ask.

In addition, comprise the prefix number that can be routed to described E-CSCF and the number of UE in the called number of described initial address request message;

After receiving described initial address request message, MGCF sends the session foundation request that called number is the number of described UE according to described prefix number to described E-CSCF.

In addition, PSAP or MGCF or E-CSCF set up in the session of its transmission and add the callback sign in the request;

After S-CSCF receives the session request of setting up and detects described callback sign, the supplementary service of cancellation UE and to the access restriction of UE.

UE to IP-CAN inquiry UE current position information, and is included in session with the positional information that inquires and sets up and send to PSAP by E-CSCF in replying after receiving the session request of setting up and detecting described callback sign.

The present invention also provides a kind of emergencycallboxsystem, is used to UE that emergency call service is provided, and comprises PSAP, E-CSCF, P-CSCF and the LRF of the local network that is positioned at UE, and the S-CSCF that is positioned at the home network of UE;

Described PSAP is used for when the described UE of needs callback, sets up request by sending session as described E-CSCF, the described S-CSCF of the Call Agent of described PSAP and described P-CSCF to described UE, to set up the session with described UE;

Described E-CSCF is used for setting up address information and the IP-CAN information of extracting described UE of replying from the session that described UE sends by described P-CSCF and described S-CSCF, send it to described LRF, and the positional information of the described UE that obtains according to described address information and IP-CAN information inquiry that described LRF is returned and/or be included in session with the ESQK of described address information and IP-CAN associating information and set up and send to described PSAP in replying;

Wherein, when described UE was positioned at visited network, described local network was the visited network of described UE, and when described UE was positioned at home network, described local network was the home network of described UE.

In addition,, be used for receiving described PSAP after request is set up in the session that described UE sends, send session by described E-CSCF, described S-CSCF and described P-CSCF to described UE and set up request if described PSAP in the CS territory, also comprises MGCF in the described system.

In addition, dispose the correspondence relationship information of PSAP number and E-CSCF address among the described MGCF, described MGCF receive that described PSAP sends, be after request is set up in the session of calling number with the number of described PSAP, inquire the address of described E-CSCF according to described correspondence relationship information, and the session request of setting up is sent to described E-CSCF according to the address of described E-CSCF.

After receiving described initial address request message, described MGCF sends the session foundation request that called number is the number of described UE according to described prefix number to described E-CSCF.

In sum, system and method for the present invention makes PSAP can obtain the positional information that LRF inquires about the UE that obtains from callback is replied by E-CSCF is joined in the callback session path; And after PSAP and UE successfully set up session connection, PSAP can use and set up the urgency traffic inquiry code of obtaining from E-CSCF in the process in session and inquire about the UE latest position information in real time, has remedied the defective that exists in the existing P SAP callback flow.

Description of drawings

Fig. 1 is the reference frame schematic diagram of IMS emergencycallboxsystem in the prior art;

Fig. 2 is the method flow diagram of initiating urgent call in the prior art the user of IMS territory normal registration at local network;

Fig. 3 is the method flow diagram that PSAP initiates the IMS callback in the prior art to UE;

Fig. 4 is the configuration diagram of embodiment of the invention emergencycallboxsystem;

Fig. 5 is based on emergencycallboxsystem framework shown in Figure 4, and PSAP initiates the method flow diagram of callback to UE by E-CSCF;

Fig. 6 is based on emergencycallboxsystem framework of the present invention, and PSAP initiates the interacting message figure of callback to UE by E-CSCF.

Embodiment

Because in existing emergencycallboxsystem, the callback that PSAP initiates to UE adopts existing IMS to exhale flow process eventually, the network element that the session path of PSAP callback (path shown in the thick line among Fig. 1) is comprised is: PSAP, S-CSCF, P-CSCF, UE (if PSAP in the CS territory, also comprises MGCF/MGW in the session path of PSAP callback); E-CSCF and LRF be not in this session path.

Therefore, basic thought of the present invention is: E-CSCF is joined in the session path of PSAP callback, and by E-CSCF address and the IP-CAN information of UE is sent to LRF, by LRF according to the address of UE and IP-CAN information inquiry and to the current location information of PSAP feedback UE.

Describe the present invention below in conjunction with drawings and Examples.

Fig. 4 is the configuration diagram of embodiment of the invention emergencycallboxsystem.

When employing emergencycallboxsystem as shown in Figure 4 carries out the PSAP callback (when adopting PSAP callback IMS framework shown in Figure 4), E-CSCF, LRF, UE, P-CSCF are at same IMS network, can be the IMS home network, also can be IMS roaming network (being also referred to as the IMS visited network); And PSAP can be in the CS territory, also can be in the PS territory.If PSAP in the CS territory, can be linked in the IMS network by MGCF.

PSAP callback IMS framework shown in Figure 4 exhales the different place of framework to be with common IMS eventually: increased local E-CSCF and local LRF in the IMS network at local PSAP place, local E-CSCF is as the Call Agent of one or more local PSAP, when PSAP initiates the IMS calling, at first need to call out E-CSCF, replace PSAP to the request of making a call of IMS home network by this E-CSCF as the Call Agent of this PSAP.

As shown in Figure 4, this system comprises: the S-CSCF of local PSAP, local E-CSCF, local LRF, home network, if local PSAP in the CS territory, this system also comprises MGCF.As UE during at home network, above-mentioned local PSAP, local E-CSCF and local LRF are respectively PSAP, E-CSCF and the LRF of home network; As UE during at visited network, above-mentioned local PSAP, local E-CSCF and local LRF are respectively PSAP, E-CSCF and the LRF of visited network.

Wherein, E-CSCF adopts Mg to be connected with the PSAP in CS territory, adopts Mm/Mi to be connected with the PSAP in PS territory.E-CSCF adopts Mw to be connected with the interface of IMS core net, adopts positional information and the session information of the mutual UE of Mi between E-CSCF and the LRF.

Fig. 5 is based on emergencycallboxsystem framework shown in Figure 4, and PSAP initiates the method flow diagram of callback to UE by E-CSCF.

To emergencycallboxsystem of the present invention, and PSAP is briefly described to the method that UE initiates callback by E-CSCF in this emergencycallboxsystem below in conjunction with Fig. 4 and Fig. 5.Flow process shown in Figure 5 comprises following steps:

Step 501, when PSAP callback UE, callback request is issued E-CSCF as the PSAP Call Agent by the Mi/Mg/Mm interface, and the information inquiry of E-CSCF by UE issued the PSAP callback request by Mw the S-CSCF of IMS home network to the address of the IMS home network at UE place; Can carry the callback sign in this callback request.

Step 502, S-CSCF can judge that what receive is the PSAP callback according to callback sign, it is carried out necessary session control, and ignore (i.e. cancellation) user's access restriction and signatory supplementary service, callback request is sent to the P-CSCF that is responsible for the UE session;

Step 503, P-CSCF judges that according to callback sign what receive is the PSAP callback, and it is carried out priority treatment, and callback request is issued UE.

Step 504, receive callback request after, UE can adopt position measurement, or obtains positional information to IP-CAN, and returns callback and reply, and carries IP-CAN information and the address information of UE during this callback is replied.

Step 505 after E-CSCF receives that the callback of UE is replied, sends to LRF with IP-CAN information and the address information of UE.

Step 506, LRF obtains and verifies the positional information of UE to IP-CAN, and set up a PSAP callback conversation recording, comprise positional information, IP-CAN information of address information, the UE of UE etc. in this conversation recording, and be that this PSAP callback conversation recording distributes an ESQK (Emergency Service QueryKey, the urgency traffic inquiry code), inquire about the positional information of UE in real time for PSAP; LRF sends to E-CSCF with positional information and the ESQK of UE.

Step 507, E-CSCF adds the positional information (if the callback that UE sends does not have in replying, or positional information has renewal) of ESQK and UE in callback is replied, and the callback response message is issued PSAP, and final PSAP and UE set up the IMS session.

Step 508, in the conversation procedure of PSAP and UE, when PSAP will inquire about the positional information of UE in real time, can by and LRF between the Le interface, send position enquiring message, carry ESQK in this message; LRF can search corresponding PSAP callback conversation recording according to ESQK, finds address and the IP-CAN information of UE, inquires about to IP-CAN, obtains the positional information of up-to-date UE; Positional information with UE returns to PSAP then.

Fig. 6 is based on emergencycallboxsystem framework of the present invention, and PSAP, specifically comprises the steps: to the interacting message figure that UE initiates callback by E-CSCF

Step 601a, in the CS territory, PSAP sends initial address request message (IAM, Initial Address Message) to the MGCF of this locality as if PSAP, and request is set up session with UE;

Step 601b, MGCF judge that the pairing calling of initial address request message is the PSAP callback, therefore the E-CSCF that acts on behalf of that PSAP is issued in request (also can be called callback request) are set up in the session of having added the callback sign.

MGCF one of can be in the following ways be identified as the PSAP callback with the pairing calling of initial address request message and be routed to local E-CSCF:

First kind of mode: the corresponding relation of the number of all local PSAP of configuration and corresponding local E-CSCF address in MGCF; Whether the calling number that MGCF analyzes in the call request (initial address request message) is the PSAP number, if the PSAP number just is routed to this call request corresponding E-CSCF (promptly sending corresponding callback request message to E-CSCF);

The second way: PSAP before the number of UE, add can be routed to the prefix number of E-CSCF after, with its called number as call request (initial address request message); After MGCF receives the call request (initial address request message) of PSAP transmission, call request is routed to the E-CSCF that acts on behalf of of PSAP according to this prefix number.For example, the number of UE is 123456789, and the pairing prefix number of E-CSCF is 119, and then PSAP uses 119123456789 called numbers as call request (initial address request message); After MGCF receives the call request (initial address request message) of PSAP transmission, need remove the prefix of called number, send callback request message (called number that is callback request message is " 123456789 ") to E-CSCF again.

If PSAP in the PS territory, then uses step 601c step of replacing 601a～601b:

Step 601c, if PSAP is in the PS territory and have an IP ability, PSAP initiates to carry the INVITE (also can be called callback request or session and set up request) of callback sign to E-CSCF, request is set up session with UE;

PSAP add in can route (route) field in INVITE act on behalf of E-CSCF routing address as next hop address, this INVITE will directly send to E-CSCF.

Step 602 after E-CSCF receives the PSAP callback request that PSAP or MGCF send, by the information such as number of UE, inquires the IMS home network address at UE place to HSS, then the PSAP callback request is issued the S-CSCF of IMS home network.

Can carry specific callback sign in the above-mentioned callback request, being used for this call identification is PSAP callback or urgent call.Above-mentioned callback sign can be by PSAP or the MGCF or the E-CSCF interpolation in PS territory.

Step 603, S-CSCF in the IMS core net carries out called initial filter criteria, and judge that by callback sign this conversation request is the PSAP callback request, carry out necessary session control then, supplementary service (the Three-Way Calling for example of cancellation UE, calling transfer) with to the access of UE restriction (for example roaming restriction etc.), directly will send this callback request to this UE.

Step 604, S-CSCF finds the affiliated P-CSCF of UE according to the contact address information of UE registration, sends this callback request to this P-CSCF;

Step 605 after P-CSCF receives callback request, judges that according to the callback sign of wherein carrying this request is the PSAP callback request, sends callback request according to the UE target address information in this callback request to UE then, realizes callback.

The priority that P-CSCF can carry the callback request of callback sign is set to be higher than other conversation request.

Step 606 after UE receives callback request, judges that according to the callback sign of wherein carrying this request is PSAP callback request (UE also can judge whether this request is the PSAP callback request according to calling number or route field);

As optional step, support as if UE, can also adopt the mode (as the GPS location) of position measurement, or inquire about and obtain the positional information at the current place of UE to IP-CAN.

Step 607, UE returns the PSAP callback to P-CSCF and replys (200OK message), and contents such as the address information that carries UE in (also can be called session set up reply) simultaneously, IP-CAN information are replied in this callback.

If UE has current position information, can also in this response message, carry current position information.

Step 608, P-CSCF replys the callback of UE the S-CSCF that issues the IMS home network.

Step 609, the S-CSCF of IMS home network replys the callback of UE the E-CSCF that acts on behalf of that issues PSAP.

Step 610 after E-CSCF receives that the callback of UE is replied, sends the position to LRF and obtains request message, and address information, the IP-CAN information of UE is sent to LRF; In addition, E-CSCF can also be included in the positional information of UE the position and obtains and send to LRF in the request message;

LRF sets up a PSAP callback conversation recording, comprise in this record: the contents such as positional information of the address information of UE, the information of IP-CAN, UE, and distribute an ESQK corresponding with this PSAP callback conversation recording, so that inquire about the positional information of UE in real time according to ESQK.

Do not need checking if in the callback response message of UE, comprise the positional information of UE or the positional information of UE, LRF can carry out position enquiring to IP-CAN according to the IP-CAN information of E-CSCF transmission and the positional information of UE, to obtain the latest position information of UE, and original UE positional information verified, if positional information has renewal, then upgrade PSAP callback conversation recording.

Step 611, LRF obtains response message to the E-CSCF home position, comprises positional information and the ESQK of UE in this message.

Step 612a, in the CS territory, E-CSCF replys to the callback that MGCF sends UE, carries positional information and the ESQK of UE during this is replied as if PSAP.

Step 612b, MGCF sends response message (ANM, Answer Message) to PSAP, the callback request (being the initial address request message) of response PSAP.

If PSAP in the PS territory, then uses step 612c step of replacing 612a～612b:

Step 612c, at the PS network, E-CSCF directly replys to the callback that it sends UE, carries positional information and the ESQK of UE during this is replied as if PSAP.

Step 613, PSAP and UE set up voip conversation, and PSAP sets up in session and has obtained UE current position information and ESQK in the process, and PSAP can inquire about the latest position information of UE in real time by ESQK to LRF.

Step 614, in the conversation procedure of PSAP and UE, PSAP carries ESQK if the positional information that will inquire about UE can send the place information inquiry request message to the LRF of this locality in this message.

Step 615, LRF searches corresponding PSAP callback conversation recording according to the ESQK in the place information inquiry request message, in this record, find address information and the IP-CAN information of UE, then the position enquiring that carries out UE to IP-CAN according to address information and the IP-CAN information of UE.

Step 616 after LRF obtains up-to-date UE positional information, is upgraded and the corresponding PSAP callback of ESQK conversation recording, and the UE latest position information is returned to PSAP, realizes that PSAP inquires about the ability of the positional information of UE dynamically, in real time.

Claims

1. a urgency communication is accepted the back calling method at center, it is characterized in that, this method comprises:

2. the method for claim 1 is characterized in that,

If PSAP is in the circuit switching (CS) territory, PSAP adopts following steps to send session by E-CSCF and S-CSCF to UE and sets up request:

A:PSAP sends the initial address request message to MGCF MGCF;

3. method as claimed in claim 2 is characterized in that,

After receiving calling number and be the described initial address request message of number of described PSAP, MGCF obtains the address of described E-CSCF according to the PSAP number of this locality configuration and the corresponding relation of E-CSCF address, sends session to described E-CSCF and sets up and ask.

4. method as claimed in claim 2 is characterized in that,

Comprise the prefix number that can be routed to described E-CSCF and the number of UE in the called number of described initial address request message;

5. method as claimed in claim 2 is characterized in that,

PSAP or MGCF or E-CSCF set up in the session of its transmission and add the callback sign in the request;

6. method as claimed in claim 2 is characterized in that,

UE to IP-CAN inquiry UE current position information, and is included in session with the positional information that inquires and sets up and send to E-CSCF in replying after receiving the session request of setting up and detecting described callback sign; E-CSCF receive this session set up reply after, the positional information of UE is included in the position obtains and send to LRF in the request message, will be included in session again by the result that the LRF inquiry obtains and set up and send to PSAP in the response message.

7. an emergencycallboxsystem is used to UE that emergency call service is provided, and comprises PSAP, E-CSCF, P-CSCF and the LRF of the local network that is positioned at UE, and the S-CSCF that is positioned at the home network of UE; It is characterized in that,

8. system as claimed in claim 7 is characterized in that,

If described PSAP in the CS territory, also comprises MGCF in the described system, be used for receiving described PSAP behind the initial address request message that described UE sends, send session by described E-CSCF, described S-CSCF and described P-CSCF to described UE and set up request.

9. system as claimed in claim 8 is characterized in that,

Dispose the correspondence relationship information of PSAP number and E-CSCF address among the described MGCF, described MGCF receive that described PSAP sends, be the initial address request message of calling number with the number of described PSAP after, inquire the address of described E-CSCF according to described correspondence relationship information, and the session request of setting up is sent to described E-CSCF according to the address of described E-CSCF.

10. system as claimed in claim 8 is characterized in that,