Method And Apparatus For Handling Emergency Calls

Abstract

A method and apparatus for obtaining location information for subscribers connected to an IP access network ( 300 ), in order to enable supply of such location information in connection with emergency calls directed to a multimedia service network ( 302 ). A request is received ( 3:1 ) at the multimedia service network from a subscriber (A) containing an IP address currently assigned to the subscriber. In response thereto, the multimedia service network sends a location query ( 3:2 ) including said IP address to the IP access network, which then can retrieve ( 3:3, 3:4 ) location information for the subscriber based on the IP address, by determining at which point of access in the IP access network the IP address is currently used. The IP access network then submits ( 3:5 ) the obtained location information to the multimedia service network in response to the location query.

1 . A method, of obtaining location information for a subscriber currently connected to an IP access network at a certain point of access, the method executed in a session managing node of a multimedia service network and comprising the following steps:
 receiving a request from said subscriber containing an IP address currently assigned to the subscriber when connected to said point of access,   sending a location query for the subscriber including said IP address to the IP access network, and   receiving location information for said point of access of the subscriber in response to the location query, thereby enabling supply of the received location information to an emergency centre in connection with an emergency call from said subscriber.   
     
     
         2 . The method according to  claim 1 , wherein the received request relates to an emergency call, and the obtained location information is added to the request before sending it to said emergency centre. 
     
     
         3 . The method according to  claim 2 , wherein said emergency centre is selected for the request, based on the obtained location information. 
     
     
         4 . The method according to  claim 2 , wherein the multimedia service network is an IMS network using SIP signalling, and said request relating to an emergency call is a SIP INVITE message. 
     
     
         5 . The method according to  claim 1 , wherein it is determined that the received request is a registration request, and the obtained location information is saved for later retrieval in the case of a subsequent emergency call from said subscriber. 
     
     
         6 . The method according to  claim 5 , wherein the multimedia service network is an IMS network using SIP signalling, and said registration request is an SIP REGISTER message. 
     
     
         7 . The method according to  claim 1 , wherein the multimedia service network is an IMS network, the method being executed in an IMS core entity such as a P-CSCF node in the IMS network. 
     
     
         8 . The method according to  claim 1 , wherein the location query is sent to a location retrieval unit in the IP access network. 
     
     
         9 . An arrangement in a session managing node of a multimedia service network, for obtaining location information for a subscriber currently connected to an IP access network at a certain point of access, the arrangement comprising:
 means for receiving a request from said subscriber containing an IP address currently assigned to the subscriber when connected to said point of access,   means for sending a location query for the subscriber including said IP address to the IP access network, and   means for receiving location information for said point of access of the subscriber in response to the location query, thereby enabling supply of the received location information to an emergency centre in connection with an emergency call from said subscriber.   
     
     
         10 . The arrangement according to  claim 9  further comprising
 logic means for determining whether the received request relates to an emergency call, and   means for adding the obtained location information to the request before sending it to said emergency centre.   
     
     
         11 . The arrangement according to  claim 10 , wherein the logic means is configured to select said emergency centre for the request, based on the obtained location information. 
     
     
         12 . The arrangement according to  claim 10 , wherein the multimedia service network is an IMS network using SIP signalling, and said request relating to an emergency call is an SIP INVITE message. 
     
     
         13 . The arrangement according to  claim 9 , further comprising
 logic means for determining whether the received request is a registration request, and   means for storing the obtained location information for later retrieval in the case of a subsequent emergency call from said subscriber.   
     
     
         14 . The arrangement according to  claim 13 , wherein the multimedia service network is an IMS network using SIP signalling, and said registration request is a SIP REGISTER message. 
     
     
         15 . The arrangement according to  claim 9 , wherein the multimedia service network is an IMS network, the arrangement being implemented in an IMS core entity such as a P-C3CF node in the IMS network. 
     
     
         16 . The arrangement according to  claim 9 , wherein said sending means is configured to send the location query to a location retrieval unit in the IP access network. 
     
     
         17 . A method, executed in an IP access network. of providing location information to a session managing node of a multimedia service network for a subscriber currently connected to said IP access network at a certain point of access, the method comprising the following steps:
 receiving a location query for said subscriber containing an IP address currently assigned to the subscriber when connected to said point of access,   retrieving location information for said point of access of the subscriber based on said IP address, and   providing the retrieved location information for the subscriber to said session managing node in response to the received location query.   
     
     
         18 . The method according to  claim 17 , wherein a location retrieval unit in the IP access network retrieves a point of access identity, currently associated with the received IP address, from an IP address administrator in the IP access network. 
     
     
         19 . The method according to  claim 18 , wherein the location retrieval unit further retrieves said location information based on the retrieved point of access identity, from a location database in the IP access network. 
     
     
         20 . The method according to  claim 10 , wherein said location information is given together with the retrieved point of access identity. 
     
     
         21 . The method according to  claim 18 , wherein the point of access identity is a layer 2 address, such as an Ethernet MAC address, ATM VPI/VCI or other relevant network address, depending on the network configuration. 
     
     
         22 . The method according to  claim 17 , wherein the multimedia service network is an IMS network and the retrieved location information is provided to an IMS core entity such as a P-CSCF node in the IMS network. 
     
     
         23 . A location retrieval unit in an IP access network for providing location information to a session managing node of a multimedia service network for a subscriber currently connected to said IP access network at a certain point of access, the location retrieval unit comprising:
 means for receiving a location query for said subscriber containing an IP address assigned to the subscriber when connected to said point of access,   means for retrieving location information for said point of access of the subscriber based on said IP address, and   means for providing the retrieved location information for the subscriber to said session managing node in response to the received location query.   
     
     
         24 . The location retrieval unit according to  claim 23 , wherein the retrieving means is configured to retrieve a point of access identity currently associated with the received IP address, from an IP address administrator in the IP access network. 
     
     
         25 . The location retrieval unit according to  claim 24 , wherein the retrieving means is further configured to retrieve said location information, based on the retrieved point of access identity, from a location database in the IP access network. 
     
     
         26 . The location retrieval unit according to  claim 24 , wherein the retrieving means is further configured to obtain said location information together with the retrieved point of access identity. 
     
     
         27 . The location retrieval unit according to  claim 24 , wherein the point of access identity is a layer address, such as an Ethernet MAC address, ATM VPI/VCI or other relevant network address, depending on the network configuration. 
     
     
         28 . The location retrieval unit according to  claim 23 , wherein the multimedia service network is an IMS network and the providing means is configured to provide the retrieved location information to an IMS core entity such as a P-CSCF node in the IMS network.