Emergency call localization for IP-based telephony

An emergency call system comprising a Telephony Application Server (TAS)-Proxy, an emergency call application, and a replication database, said system configured to perform a method for localizing an initial point of an Internet Protocol (IP)-based telephone call, said method comprising:

• receiving, by a Telephony Application Server (TAS)-Proxy, the IP-based telephone call originating from a Voice-over-IP (VoIP) subscriber, said IP-based telephone call characterized by an IP address of the VoIP subscriber and by a called telephone number of an entity being called;
• ascertaining, by the TAS-Proxy, that the IP-based telephone call is an emergency call;
• by an emergency call application in response to said ascertaining, transmitting to a replication database a request for emergency call data configured to be used for identifying an initial point of the emergency call, said request comprising the IP address;
• by a software application comprised by the replication database in response to the replication database having received the transmitted request, determining the emergency call data from the IP address followed by transmitting the emergency call data to the emergency call application, said emergency call data identifying a local responsible Public Safety Answering Point and comprising an Emergency ID that includes a reference to technical data that can be used to locate the initial point of the emergency call;
• by the emergency call application in response to having received the transmitted emergency call data, sending the emergency call data to the TAS-Proxy;
• by the TAS-Proxy in response to having received the emergency call data sent by the emergency call application, routing the IP-based emergency call to the local responsible Public Safety Answering Point and transmitting the Emergency ID to the local responsible Public Safety Answering Point for enabling the local responsible Public Safety Answering Point to locate the initial point of the emergency call;
• by the Public Safety Answering Point forwarding the Emergency ID to a control centre service;
• by the control centre service retrieving the technical data from the replication database as a function of the Emergency ID and then using the retrieved technical data to receive access to an actual address of the VoIP subscriber and to further receive access to an other information identifying the VoIP subscriber, where the actual address and the other information may be accessed from an operations database;
• by the control centre service accessing the actual address of the VoIP subscriber and the other information identifying the VoIP subscriber from the operations database;
• and
• by the control centre service transmitting the actual address of the VoIP subscriber and the other information identifying the VoIP subscriber to the Public Safety Answering Point,
• wherein the emergency call data is replicated at a plurality of locations which are separated from the replication database, and wherein said transmitting the emergency call data to the emergency call application comprises transmitting the emergency call data from a one location of the plurality of locations to the emergency call application.