Explicit airtime allocation for 802.11-based wireless networks

Wireless technology has become an essential part of everyday life. The growth in the availability of wireless networks, the number of wireless devices, and the number of users leads to a stronger demand for better performance. However, the shared nature of the wireless channel among multiple transmitters makes it hard for wireless networks to provide fair, throughput-efficient and energy-efficient performance. In this dissertation, we explore how wireless channel resource management can help to improve performance in terms of fairness, throughput and energy-efficiency for 802.11-based wireless networks. Specifically, we investigate traffic management and energy management using explicit airtime allocation as a method of wireless channel resource management for multi-hop wireless mesh networks and centralized WLANs domains. We first introduce CNA, a lightweight mechanism that allows unmodified TCP to work efficiently in multi-hop wireless networks. CNA explicitly allocates the wireless channel resource represented by airtime to each active pair of communicating neighbors in a wireless neighborhood, so that it enables TCP to improve fairness and throughput while mitigating interference. Next, we present POLICE, a passive on-line method for determining the conflict graph in centralized WLANs. Accurate interference relationship inferred by POLICE enables designing an interference-aware traffic management with explicit airtime allocation for centralized WLANs. We also describe Snooze, an application-agnostic energy management technique for 802.11n. In Snooze, the AP monitors traffic on the WLAN and explicitly schedules airtime for each client, so that clients can sleep in order to improve energy-efficiency when they are not scheduled to use the wireless channel.