Patent ID: 8644253

Claim:
A method, comprising: at a Radio Access Point (RAP) device in a network, servicing a voice call between mobile User Equipment and an Enterprise Session Initiation Protocol (SIP) Services Environment using, at least in part, Voice over Internet Protocol Multimedia Subsystem (VoIMS); detecting at the RAP device that the User Equipment is moving out of range of RAP infrastructure servicing the User Equipment; and in response to detecting, initiating from the RAP device a procedure to hand out the voice call and anchor the voice call in a Mobile Switching Center (MSC) of a macro service provider by sending a voice call continuity (VCC) setup message to a domain transfer number to anchor signaling and media in the MSC, wherein the VCC setup message identifies the MSC to trigger the MSC to send a VCC invite message to the Enterprise SIP Services Environment to allow the User Equipment to access the Enterprise SIP Services Environment via the MSC; receiving at the RAP device a message from a Call State Control Function (CSCF) in the network to tear down a link between the RAP device and the Enterprise SIP Services Environment; in response to receiving the message from the CSCF, sending from the RAP device an acknowledgement message to the CSCF confirming the tear down of the link; determining whether the User Equipment is eligible for enhanced services by analyzing a User Equipment ACCEPT message that comprises SIP registration information; and receiving the SIP registration information to trigger the RAP infrastructure to perform a SIP register at the RAP device on behalf of the User Equipment.