Optimization of Wireless Local Area Networks


wlan_diagramThe rapid deployment of high density wireless LANs poses many new challenges for network management, such as the dynamic channel assignment problem. Since cell sizes in WLANs are so small, it is common for traffic statistics to fluctuate significantly as users move from one cell to another. Thus, by dynamically assigning the wireless frequency channels used by different access points, network throughput can be optimized. The channel assignment is made based on periodically updated signal and traffic measurements, which are then piped into an interference model that assigns weights to a graph, and finally a semidefinite program is used to solve the max k-cut problem on that graph. Our experiments on a real-world 500 square-meter testbed demonstrate average throughput increases of up to 40%.

This is joint work in collaboration with NEC Research Labs in Beijing, China, where I worked for a summer while participating in the Stanford-Tsinghua Engineering Exchange Program.

  • Liu, Yongqiang; Wu, William; Wang, Bo; et al. Measurement-Based Channel Assignment in WLANs. IEEE Wireless Communications and Networking Conference 2010.
  • Wang, Bo; Wu, William; Liu, Yongqiang. Dynamic Channel Assignment in Wireless LANs. IEEE Power Electronics and Intelligent Transportation Systems, 2008.
  • Wu, William; Chen, Jiehua.SCP-Based Channel Assignment. (In progress. I would like someone to implement our algorithms on a real WLAN testbed and evaluate the performance, so that we can strengthen the paper. If you are interested, please contact me.)