Patent ID: 7640036

Claim:
A method, comprising: receiving a session set-up message from a mobile station to a call state control function; determining inter-system handover support of the mobile station in said call state control function; providing said session set-up message to a first call control node in response to said inter-system handover support of the mobile station; requesting an allocation of a first media gateway from said first call control node; receiving a handover request to said first call control node from said mobile station via said call state control function; determining in said first call control node an identity of a second call control node based on cell information in said handover request; sending the handover request from said first call control node to said second call control node; receiving a handover number to said first call control node from said second call control node in response to said handover request; routing a handover session from said first call control node to said second call control node using said handover number; receiving an answer message to said first call control node from said second call control node; receiving a handover completion message to said first call control node from said call state control function; and requesting a removing of at least one packet switched media bearer from said media gateway.