Patent ID: 6278877
Filing Date: 2001-08-21
Classification: H04W

Abstract:
A method of operating a wireless local area network system having a plurality of base stations and a mobile station, comprising the steps of:transmitting beacon messages from the base stations at regular intervals, each beacon message including an identification of the respective base station transmitting that message;operating the mobile station in a normal mode wherein beacon messages from a first base station only are monitored;determining a communications quality value for the beacon messages from the first base station;determining if the communications quality value becomes unacceptable, and if so, changing the operating mode of the mobile station to a search operating mode wherein beacon messages received from any of the base stations are monitored;selecting one of the base stations which provide an acceptable communications quality value for monitored beacon messages; andchanging the operating mode of the mobile station to the normal operating mode wherein beacon messages from the selected base station only are monitored,wherein the step of selecting one of the base stations which provides an acceptable communications quality value includes the steps of:monitoring successively received beacon messages until a beacon message having an acceptable communications quality value is received; andselecting the base station providing the beacon message having the acceptable communications quality value, wherein determining if the communications quality value becomes unacceptable includes the steps of:comparing the communications quality value with a first predetermined threshold value; andidentifying the communications quality value as unacceptable if the communications quality value is below the first predetermined threshold value,wherein the step of monitoring successively received beacon messages includes the steps of:comparing the communications quality value of successively received beacon messages with a second predetermined threshold value; andidentifying such communications quality value as acceptable if such communications quality value is above the second predetermined threshold value.