Symphony: synchronous two-phase rate and power control in 802.11 wlans

Adaptive transmit power control in 802.11 Wireless LANs (WLANs) on a per-link basis helps increase network capacity and improves battery life of Wifi-enabled mobile devices. However, it faces the following challenges: (1) it can exacerbate receiver-side interference and asymmetric channel access, (2) it can incorrectly lead to lowering the data rate of a link, (3) mobility-induced channel variations at short timescales make detecting and avoiding these problems more complex. Despite significant research in rate and power control, state of the art solutions lack comprehensive techniques to address the above problems. In this paper, we design and implement Symphony--a Synchronous Two-phase Rate and Power control system, whose agility in adaptation enables us to systematically address the three problems, while maximizing the benefits of power control on a per-link basis. We implement Symphony in the Linux MadWifi driver, and show that it can be realized on hardware that supports transmit...

• Type: Conference
• Year: 2008
• Where: MOBISYS
• Authors: Kishore Ramachandran, Ravi Kokku, Honghai Zhang, Marco Gruteser
• Keywords: Adaptive Transmit Power, Lower Transmit Power, MOBISYS 2008, Transmit Power Control, Wireless Networks