Patent ID: 8897259
Filing Date: 2014-11-25
Classification: H04W

Abstract:
1. A method of changing a serving Base Station (BS) in a mobile communication system, the method comprising: receiving DownLink (DL) quality values for a current serving BS of a User Equipment (UE) and respective BSs included in an active set of the UE from the UE periodically based on a predefined period; determining if an UpLink (UL) quality value for the serving BS is less than a minimum UL quality threshold; when, as a result of the determination, the UL quality value for the serving BS is less than the minimum UL quality threshold, selecting BSs, which have UL quality values equal to or greater than the minimum UL quality threshold among the BSs included in the active set, as candidate BSs; and determining a new serving BS, which has a maximum DL quality value among the candidate BSs, wherein the minimum UL quality threshold is a minimum value at or above which the DL quality values for the serving BS and the BSs included in the active set can be received from the UE.