Evaluating IEEE 802.11s mesh channel switching using open source solution

To avoid interference from a detected radar signal, or to reassign mesh station (STA) channels to ensure the connectivity, IEEE 802.11s defines a procedure on how to propagate the channel switch attempt throughout the mesh network, known as mesh Basic Service Set (MBSS) channel switch. Wireless Mesh Network (WMN) that utilizes single-radio nodes with omni-directional and directional antennas is ideally suited for rural area where cost and simplicity take precedence over service quality. However, single-channel single-radio mesh network is easily affected by the interference from its neighborhood, especially from co-located Wi-Fi deployment or other devices operating in the same frequency channel. Thus, the ability to switch to a new channel for self healing is indeed appealing to single-channel single-radio mesh network. The implementation of 802.11s in Linux kernel is available since the year 2007, but the MBSS channel switching has yet to be implemented. This paper describes the MBSS channel switching in details and also discusses our efforts to implement this in the Linux wireless subsystem. Our implementation are verified and evaluated in our experimental testbed.