Abstract
To support applications that demand high-speed wireless communication, the ongoing standardization of the next generation Wi-Fi increases the channel bonding from 40 MHz in 802.11n to 80, and even 160 MHz under certain conditions in 802.11ac. However, inefficiency and unfairness issues arise when devices that use different channel widths coexist in a contention domain. In this paper, we propose a dynamic channel bonding (DyB) protocol in which a node is allowed to start a transmission as long as there are some idle narrow channels and it gradually increases channel width during transmission whenever new narrow channels become available. A challenge is the communication over uncertain channels. To enable fast spectrum agreement between transmitter and receiver, a partial spectrum correlation method is introduced. In addition, DyB considers the severe contention in a wide band of spectrum. A compound preamble is designed to make collisions detectable in the frequency domain and a parallel bitwise arbitration is used to quickly resolve the collisions in the time domain. We implemented and evaluated the DyB through both the GNU Radio/USRP platform and ns-2 simulations. Experimental results and simulations show that DyB can well address the inefficiency and unfairness issues caused by heterogeneous radio coexistence.