Method and system of PSAP call back of IN subscriber

A system for establishing a connection from a Public Safety Answering Point (PSAP) to a terminal subscribed to Intelligent Network (IN) services, comprising:

• means for receiving by the PSAP, a call report with the number of the terminal, wherein the number is a Mobile Station International Subscriber Directory Number (MSISDN);
• means for assigning a separate calling party category to connect the call to the terminal (collectively, the calling party category and MSISDN are referred to as “digits”);
• means for receiving the digits, via a Base Station (BS) and a Base Station Controller (BSC) in a Visiting Mobile Switching Center (V-MSC);
• means for analyzing, by the V-MSC, the calling party category and MSISDN;
• means for routing the call to a Gateway Mobile Switching Center (GMSC) used by the terminal without stripping or altering the calling party category or the MSISDN;
• means for performing, at the GMSC, B-number (called party number) and Signaling Connection and Control Part (SCCP) analysis, wherein a global title “Routing Case” provides the Signaling Point (SP) of a Home Location Register (HLR);
• means for sending, by the HLR, a Mobile Application Part (MAP) message “Send Routing Information” by Message Transport Part (MTP);
• means for receiving, by the GMSC, Terminating CAMEL Subscription Information (T-CSI) data from HLR, wherein the T-CSI data indicates that Customized Applications for Mobile Network Enhanced Logic (CAMEL) services are to be applied to mobile terminating calls and routing to a GSM Service Switching Function (gmSSF) is invoked;
• means for sending a Service Key (SK) from HLR, and data for CAMEL, from gsmSSF to SCP to identify the service to be invoked in the SCP;
• means for sending, by a Service Control Point (SCP), interrogations about a subscriber to a Service Data Point (SDP), to check if a call is allowed and, if so, for how long;
• and
• means for, in an IN platform, addressing an A-number (calling party number) prefix in such way that a Service Control Point (SCP) always allows the connection of a call with the PSAP calling party category in the call from the PSAP.