An effective channel bonding scheme via CCA adaptation
Fan Zhang · 2015
With the increasing demand for higher performance wireless local area networks (WLANs), channel bonding was first proposed in IEEE 802.11n protocol to offer a higher data rate by combine two 20 MHz channels into a 40 MHz channel. It has been further developed in IEEE 802.11ac protocol to support an even wider bandwidth up to 160 Mhz. Although channel bonding can offer a higher peak throughput theoretically, many works have demonstrated that channel bonding should be carefully considered, otherwise it may degrade the aggregated throughput. Thus, how to make an effective channel bonding decision becomes more and more important. Existing works try to tackle this issue using different methods. However, most of them either make some strong assumptions or do this in a centralized manner. In this thesis, we design a distributed and protocol-compatible channel bonding scheme inspired by the simple observation that a channel bonding decision can be made based on topology information. For example, channel bonding should be promoted when the STA is at the centre of the AP and the AP density is low, otherwise channel bonding should be prohibited. Then, we conduct a measurement with off-the-shelf 802.11 devices to further demonstrate the correctness of our observation in a real-world network environment. Under this observation, we implement a distributed channel bonding scheme by setting an adaptive channel clear assessment (CCA) threshold. After that, we conduct a simulation under a typical enterprise scenario. The results show that our scheme can improve the throughput by 37% and 46% compared to the channel bonding scheme in 802.11 protocol and CSMA/CA respectively