Idle sense with transmission priority in fibre-wireless networks

Abstract

The convergence of fibre and wireless technologies realised the fibre-wireless (FiWi) networks. Despite huge capacity offered by fibre, the user experiences a network bottleneck caused by the wireless side. This study investigates wireless local area network (WLAN), the wireless side of the FiWi networks with a gigabits passive optical network (GPON) as the backhaul. The work aims to improve WLAN performance by utilising information gained from GPON. The proposed technique enables all contending stations in multiple access points (APs) WLAN to achieve a desired downlink-to-uplink transmission ratio, k while maintaining maximum throughput. Optimum contention window (CW) sizes for the APs and associate wireless users (WUs) are derived by incorporating the principles of idle sense (IS) and asymmetric AP. However, fairness problem between WUs occurred when they contend the channel with different CW sizes. Hence, this study simplifies the IS scheme to increase fairness between WUs. Furthermore, AP self-adapting and WU adjusting algorithms are proposed to assist the network to achieve the desired k, while maintaining the throughput fairness amongst basis service sets. The robustness of the proposed scheme is demonstrated under various conditions: achieved target k with nearly perfect fairness and gained near-to-maximum throughput within 96% of the theoretical optimum.