Patent ID: 6901081

Claim:
A method of determining a parameter associated with a retransmission time-out feature in a data unit transmitter implementing a protocol that provides an acknowledgment feature of sending acknowledgment messages for the correct receipt of data units from the receiver to the sender of a communication, and provides said retransmission time-out feature of retransmitting data units if an acknowledgment does not arrive at the sender within a time-out period, comprising the steps of: measuring a round trip time value the round trip time being indicative of the time that passes between the sending of a given data unit and the receipt of the acknowledgment corresponding to said given data unit, calculating a new smoothed round trip time value at least on the basis of a stored smoothed round trip time value and said measured round trip time value, calculating a new mean deviation value indicative of the mean deviation of said round trip time values over time, at least on the basis of a stored mean deviation value, said measured round trip time value and said stored smoothed round trip time value, and calculating said parameter at least on the basis of said new smoothed round trip time value said new mean deviation value, where a contribution of said measured round trip time value to said new mean deviation value is different if said measured round trip time value is smaller than a predetermined threshold that is determined on the basis of said stored smoothed round trip time value, than if said measured round trip time value is greater than said predetermined threshold.