Patent ID: 6229807
Filing Date: 2001-05-08
Classification: H04L

Abstract:
In a digital communication system comprising a primary station and a plurality of secondary stations remote from the primary station and in which the primary station exchanges data with the ones of said plurality of secondary stations which are currently associated with said primary station; a process of sequentially monitoring the activity status of each one of the associated secondary stations under the control of said primary station, said process being characterized by the steps of:a) determining (12) that the monitored secondary station is still currently associatedb) determining (16) whether any data from said monitored secondary station have been received by said primary stationc) if not, transmitting (24) to said monitored secondary station invitations to send back a message ""I am alive"",d) initiating (20) a routine for de-associating said monitored secondary station if the number of said invitations transmitted thereto reaches a predetermined number without said monitored secondary station sending back said message,wherein step c) comprises the step of checking (22) whether the number of said invitations to send back a message ""I am alive"" is divisible by a factor which is selected based upon fading conditions of said monitored secondary station and transmitting a new invitation to said monitored secondary station only if this number is divisible by said factor.