Patent ID: 7480519

Claim:
A cell reselection method for preventing ping-pong in a mobile communications system, comprising the steps of: acquiring first and second duration thresholds and first and second occurrence number thresholds for controlling a cell reselection procedure, the second duration threshold being shorter than the first duration threshold and the second occurrence number threshold being less than the first occurrence number threshold; setting a user equipment (UE) to a high-speed state if the number of cell reselections of the UE to the same cell during the second duration threshold exceeds the second occurrence number threshold; setting the UE to a non-high-speed state if the number of cell changes of the UE during the first duration threshold is equal to or less than the first occurrence number threshold; setting the UE to the high-speed state if the number of cell reselections of the UE to the same cell during the second duration threshold is equal to or less than the second occurrence number threshold and if the number of cell changes of the UE during the first duration threshold exceeds the first occurrence number threshold; selectively performing cell reselection according to a predetermined cell reselection time limit in the non-high-speed state in the UE; and selectively performing cell reselection according to a scaled-down value of the predetermined cell reselection time limit in the high-speed state in the UE.