Patent ID: 6819711
Filing Date: 2004-11-16
Classification: H04L

Abstract:
Apparatus for determining quality of a communications channel carrying information units for reception, said apparatus having:input means for receiving information identifying if correct or incorrect reception of transmissions on the communications channel occurred; storage means for storing quality data indicative of the quality of the communications channel and update means coupled with said input means for performing a first update operation to update the quality data in a first event of incorrect reception of information units and for performing a second update operation to update the quality data in a second event of correct reception of information units; wherein the quality data is updated to an extent dependent on the quality data stored by the storage means immediately before the occurrence of one of said first event and said second event, so that more recent errors weigh more than errors that occurred earlier, and wherein the quality data includes a value, the first update operation increases the value and the second update operation decreases the value, such that the value stored by the storage means increases or decreases with each operation by an amount dependent on the value stored immediately before the occurrence of said one of said first event and said second event, and wherein the storage means includes a two byte counter and for each event of correct reception the counter is decremented by a value obtained by subtracting the value that is held in the high byte of the counter immediately before the event.