Fulfillment-Based Fairness: A New Fairness Notion for Multi-AP Wireless Hotspots

Today, most wireless hotspots deploy multiple APs (Access Points) to improve the network performance and to provide fair and satisfactory services to clients. However, without a well-defined fairness objective function and the corresponding service provision schemes, the desired improvements may not be achieved. On the other hand, it has been realized that existing fairness notions proposed for single-AP wireless hotspots exhibit various performance anomalies in multi-AP wireless hotspots: bandwidth anomaly with Bandwidth-based Fairness (BbF) and association anomaly with Timeshare-based Fairness (TbF). To answer this challenge, we propose a new fairness notion, called the Fulfillment-based Fairness (FbF), for multi-AP wireless hotspots. It emphasizes allocation of bandwidth to clients in proportion to their respective maximum attainable bandwidth allocations. Extensive simulation shows that FbF outperforms BbF and TbF in terms of aggregate system throughput by up to 40% and 70%, respectively. It performs particularly well when the clients present a high degree of transmission rate diversity and/or in the presence of bottleneck clients that can only communicate with a single AP at low transmission rates.