Abstract: An enhanced Session Initiation Protocol (“SIP”) registration message having extended header information that is used by an Internet Protocol Multimedia Subsystem (“IMS”) core to determine the registration status of a mobile device and the physical location of the mobile device. The extended header information includes hardware and subscriber identifiers, such as an International Mobile Equipment Identity (“IMEI”) and International Mobile Subscriber Identity (“IMSI”). The IMS core queries an equipment identity register to validate IMEI/IMSI identifiers in the header to determine whether to deny registration to a mobile device. The IMS core also queries a capability database using an IMEI to determine which location determination techniques are supported by or suitable for the associated mobile device.

Abstract: A location mapping service (“LMS”) that allows the integrations of an IMS core with the location-based billing methods of a legacy core network. The LMS uses the estimated location of a mobile device during an IMS session in order to determine a Cell Global Identification (“CGI”) to associate with the session. The LMS then provides the determined CGI to the legacy core network, so that a billing gateway may determine the billing region to associate with the IMS session. The LMS thereby facilitates location-based billing for IMS sessions in the absence of actual CGI information.

Abstract: An enhanced Session Initiation Protocol (“SIP”) registration message having extended header information that is used by an Internet Protocol Multimedia Subsystem (“IMS”) core to determine the registration status of a mobile device and the physical location of the mobile device. The extended header information includes hardware and subscriber identifiers, such as an International Mobile Equipment Identity (“IMEI”) and International Mobile Subscriber Identity (“IMSI”). The IMS core queries an equipment identity register to validate IMEI/IMSI identifiers in the header to determine whether to deny registration to a mobile device. The IMS core also queries a capability database using an IMEI to determine which location determination techniques are supported by or suitable for the associated mobile device.

Abstract: An E-CSCF receives a Session Initiation Protocol (“SIP”) invitation message initiating an emergency communication session from a calling device. The E-CSCF generates an information request message based on the received SIP message and sends the information request message to a location server. The location server determines a geographical location of the calling device and uses the geographical location to determine a destination emergency response center, such as a Public Safety Access Point (PSAP). The location server provides location information for the destination PSAP to the E-CSCF. The E-CSCF generates a modified SIP invitation message using the presence information and sends the modified SIP invitation message to an emergency services network where it is routed to the emergency response center.