A novel optimization based algorithmic technique to improve QoS of high efficiency WLANs using M/D/1 model

Abstract

Wireless Local Area Networks (WLANs) transmission is practically based on half duplex mode from the WiFi Access Point (AP) to a connecting station and vice versa. Performance in Uplink (UL) transmissions of a station is deteriorated when preference is given to the Downlink (DL) transmissions from WiFi AP. This causes problem for WLAN to operate efficiently on half duplex mode. This paper hypothesizes the problem by suggesting optimization based algorithms to reduce the waiting times of UL transmission and increase the waiting times of DL transmission in WLANs of typical M/D/1 based queuing model. Increase in the waiting times of DL transmission was based on the idea of pre-emptive and non-pre-emptive causing UL waiting times to reduce, thereby improving Quality of Service(QoS) in WLAN of M/D/1 model. In the case of pre-emptive, DL transmissions can interrupt the flow of UL transmissions while in the case of non-pre-emptive it can’t do so, therefore, from the simulation results it was observed that improvement in the waiting times of UL transmission was 6.33% more in non-pre-emptive case than the pre-emptive having UL arrival rate of 1 packet/slot.