Patent ID: 7336951
Filing Date: 2008-02-26
Classification: H04W

Abstract:
1. A method for handing over a terminal from a first base station to a second base station in a mobile communication system while the terminal is in communication with the first base station, wherein said mobile communication system includes said first base station for providing a communication service in a first communication mode, a first base station controller connected with said first base station and a first mobile switching center, said second base station for providing a communication service in a second communication mode, said second communication mode being different from said first communication mode, a second base station controller connected with said second base station and a second mobile switching center, and a roaming gateway for performing a standard conversion operation with respect to messages transmitted and received between said first mobile switching center and said second mobile switching center, and wherein said method comprises: a) controlling said terminal by said first base station controller such that said terminal performs an initialization operation based on said second communication mode with said second base station, upon determining that said terminal must hand over to said second base station; b) notifying said first mobile switching center by said first base station controller that said terminal has completed said second communication mode-based initialization operation, if said terminal completes said second communication mode-based initialization operation with said second base station; c) notifying said second mobile switching center by said first mobile switching center, via said roaming gateway that said terminal must hand over to said second base station; d) controlling said second base station controller by said second mobile switching center such that said second base station pages said terminal; e) notifying said first mobile switching center by said second mobile switching center via said roaming gateway that said terminal is ready to hand over to said second base station, upon recognizing that said second base station controller has completed the paging of said terminal; f) controlling said second mobile switching center by said roaming gateway, such that said second base station controller sets up a call with said terminal, as said terminal is ready to hand over to said second base station; g) notifying said first mobile switching center by said second mobile switching center via said roaming gateway that the call setup with said terminal has been completed, upon recognizing that said second base station controller has completed said call setup with said terminal; and h) controlling said first base station controller by said first mobile switching center to cause said first base station controller to release current communication of said terminal with said first base station, as said call setup with said terminal is completed.