Patent ID: 7593423
Filing Date: 2009-09-22
Classification: H04W

Abstract:
1. A method for providing differentiated quality of service (QoS) in a time slotted network, the method comprising: calculating by a computing device, a transmission failure probability for a transmission over the time slotted network, wherein the transmission failure probability comprises a ratio of failed transmissions to attempted transmissions; determining a contention window target value for a contention window according to a mapped function of the transmission failure probability; altering the contention window stepwise according to a scaling function of the contention window target value, the scaling according to the QoS for the transmission; and retrieving statistical data from a network driver interface for the time slotted network, wherein the statistical data retrieved from the network driver interface provides the transmission failure probability, and wherein the time slotted network is a wireless local area network (WLAN) following an Institute of Electrical and Electronics Engineers (IEEE) 802.11 protocol; wherein the altering the contention window further comprises determining a new contention window for the transmission, and wherein the new contention window is determined by applying a change to a prior contention window, the change determined according to: wherein ΔCW represents the amount by which to change the prior contention window, CW targ represents the contention window target value, CW cur represents the prior contention window, and S represents the scaling function.