  In order to dynamically adapt the transmission bandwidth in wireless local
area networks (WLANs), dynamic channel bonding (DCB) was introduced in IEEE
802.11n. It has been extended since then, and it is expected to be a key
element in IEEE 802.11ax and future amendments such as IEEE 802.11be. While DCB
is proven to be a compelling mechanism by itself, its performance is deeply
tied to the primary channel selection, especially in high-density (HD)
deployments, where multiple nodes contend for the spectrum. Traditionally, this
primary channel selection relied on picking the most free one without any
further consideration. In this paper, in contrast, we propose dynamic-wise
(DyWi), a light-weight, decentralized, online primary channel selection
algorithm for DCB that maximizes the expected WLAN throughput by considering
not only the occupancy of the target primary channel but also the activity of
the secondary channels. Even when assuming important delay costs due to primary
switching, simulation results show a significant improvement both in terms of
average delay and throughput.
