Ss7 ansi-40 to sip based call signaling conversion gateway for wireless voip e911

Abstract

An SS7-based call protocol conversion gateway that translates between circuit-switched SS7 protocols and session initiation protocol (SIP) oriented protocol, allowing an E911 call initiated over a switched network to be routed by a VoIP network. The SS7-based call protocol conversion gateway provides a PSAP with MSAG quality (street address) information about a VoIP dual mode phone user without the need for a wireless carrier to invest in building out an entire VoIP core. Thus, wireless carriers may continue signaling the way they are today, i.e., using the J-STD-036 standard for CDMA and GSM in North America, yet see benefits of a VoIP network core, i.e., provision of MSAG quality location data to a PSAP.

1 . (canceled) 
     
     
         2 . A method comprising:
 converting, by a conversion gateway, a Voice Over Internet Protocol (VoIP) call into an Signaling System Number 7 (SS7) based call;   transmitting, from the conversion gateway via Session Initiation Protocol (SIP) call signaling associated with the VoIP call, a request to a VoIP positioning center for routing information associated with the VoIP call;   receiving, at the conversion gateway, routing information associated with the VoIP call; and   translating, by the conversion gateway, the routing information into wireless E911 routing elements.   
     
     
         3 . The method of  claim 2 , further comprising:
 routing the converted SS7 based call based on the translated wireless E911 routing elements.   
     
     
         4 . The method of  claim 3 , wherein:
 the converted SS7 based call is routed to a particular Public Safety Answering Point (PSAP).   
     
     
         5 . The method of  claim 2 , wherein:
 the converted SS7 based call is a Transaction Capabilities Application Part (TCAP) based call.   
     
     
         6 . The method of  claim 2 , wherein:
 the routing information associated with the VoIP call includes National Emergency Number Association (NENA) i2 standard elements.   
     
     
         7 . The method of  claim 6 , wherein:
 the NENA i2 standard elements include an emergency services query key (ESQK) and an emergency services routing number (ESRN) for the VoIP call.   
     
     
         8 . The method of  claim 2 , wherein:
 the E911 elements include an emergency services routing key (ESRK) for the converted SS7 call.   
     
     
         9 . The method of  claim 8 , wherein:
 the E911 elements further include a trunk select code for the converted SS7 based call.   
     
     
         10 . The method of  claim 9 , wherein:
 the E911 elements further include a i1 Public Switched Telephone Network (PSTN) number associated with the converted SS7 based call.   
     
     
         11 . The method of  claim 9 , wherein:
 the VoIP positioning center queries a location information service/subscriber line database (LIS/SLDB) to determine the routing information for the VoIP call.   
     
     
         12 . The method of  claim 2 , wherein:
 the converted SS7 based call is routed to a particular Public Safety Answering Point (PSAP).   
     
     
         13 . The method of  claim 2 , wherein:
 the VoIP call is initiated with a dual-mode wireless device.   
     
     
         14 . The method of  claim 2 , wherein:
 the converted SS7 based call is a Mobile Action Part (MAP) based call.   
     
     
         15 . The method of  claim 2 , wherein:
 the converted SS7 based call is a Integrated Services Digital Network (ISDN) User Part (ISUP) based call.   
     
     
         16 . A gateway comprising one or more computing devices, the gateway being configured to:
 convert a Voice Over Internet Protocol (VoIP) call into a Signaling System Number 7 (SS7) based call;   transmit, via Session Initiation Protocol (SIP) call signaling associated with the VoIP call, a request to a VoIP positioning center for routing information associated with the VoIP call;   receive routing information associated with the VoIP call, wherein the routing information includes an emergency services query key (ESQK) and an emergency services routing number (ESRN) for the VoIP call; and   translate the routing information into wireless E911 routing elements.   
     
     
         17 . The gateway of  claim 16 , wherein:
 the converted SS7 based call is routed based on the E911 routing elements.   
     
     
         18 . The gateway of  claim 17 , wherein:
 the converted SS7 based call is routed to a particular Public Answering Safety Point (PSAP).   
     
     
         19 . The gateway of  claim 16 , wherein:
 the converted SS7 based call is one of a Transaction Capabilities Application Part (TCAP) based call, a Mobile Application Part (MAP) based call and an Integrated Services Digital Network (ISDN) User Part (ISUP) based call.   
     
     
         20 . A system comprising:
 a mobile switching center (MSC) configured to receive a Voice Over Internet Protocol (VoIP) call from a mobile device; and   a conversion gateway configured to:
 convert the VoIP call into a Signaling System Number 7 (SS7) based call; 
 transmit, via Session Initiation Protocol (SIP) call signaling associated with the VoIP call, a request to a VoIP positioning center for routing information associated with the VoIP call; 
   receive routing information associated with the VoIP call, wherein the routing information includes an emergency services query key (ESQK) and an emergency services routing number (ESRN) for the VoIP call;   translate the routing information into wireless E911 routing elements; and   provide the wireless E911 routing elements to the MSC.   
     
     
         21 . The system of  claim 20 , further comprising:
 a selective router that is configured to route the converted SS7 based call to a particular Public Safety Answering Point (PSAP) based on the E911 routing elements.