SOSMAC: Separated operation states in Medium Access Control for emergency communications on IEEE 802.11-like crowded networks

We propose a sequential staging access scheme to minimize the occurrence of channel-access collisions in infrastructure IEEE 802.11 (WiFi) networks under emergency and crowded scenarios in this paper. The proposed scheme is based on separating the functions performed by station for channel access and dedicating states for contention and transmission separately rather than using a single shared state as done in IEEE 802.11. The result is an increase in access success ratio and avoidance of throughput collapse 802.11. The proposed scheme overcomes the throughput and utilization collapse of IEEE 802.11 under crowded scenarios and increases bandwidth utilization. This access is critical for crowded networks under emergency scenarios where many stations suddenly and intensively contend for network access. This scheme may also fits as a fallback mechanism of IEEE 802.11 networks to avoid throughput collapse under crowded scenarios and thus, to enable reliable communications in critical situations. Our simulation results show significant improvements on bandwidth utilization and throughput as compared to IEEE 802.11 under crowded conditions.