Patent ID: 7353026
Filing Date: 2008-04-01
Classification: H04W

Abstract:
1. A method for performing a hard hand-off in a cellular mobile communication system, the method comprising the steps of: setting an area of services covered with a frequency assignment (FA) of a plurality of FAs of a base station currently engaged in communication with a mobile communication terminal, to be a boundary cell, the FA is only included in FAs of the base station not in adjacent stations of the base station; entering into the boundary cell by the mobile communication terminal during communication; receiving a candidate frequency search request message, commanding the mobile communication terminal to search common FAs of only adjacent stations, except the base station currently engaged in communication, from a Base Station Controller (BSC); and searching FAs of only adjacent stations excluding the base station currently engaged in communication with said mobile communication terminal in response to the command, so as to determine a target FA, with which the mobile communication terminal is to perform the hard hand-off; wherein the target FA is determined by the mobile communication terminal through searching common FAs of adjacent stations to perform the hard hand-off therewith; wherein determination of the target FA includes a step of recognizing that the mobile communication terminal is currently engaged in communication in the boundary cell, and commanding the mobile communication terminal to search FAs of the adjacent stations excluding the base station currently engaged in communication with said mobile communication terminal by means of a base station controller (BSC), which controls the hand-off of the mobile communication terminal.