In
the release 8.1 of Cisco Wireless LAN Controller, a new feature has been
introduced called Dynamic Bandwidth Selection (DBS). This algorithm is
aimed to improve the channel reuse pattern and overall help improve the
performance of the Wireless network as a whole.
The 802.11ac standard introduced
wider channel width like 80MHz, 160MHz and 80+80 MHz. In environments
where 11ac and 11n (and legacy) networks exists simultaneously, the
channel reuse can become an issue. Due to the static nature of the
channel width (40MHz, 80MHz etc), there can be an overlap of 11ac APs on
a particular 80MHz channel and 11n or legacy AP serving on a subset of
that 80MHz channel. DBS allows 11ac APs operating on higher channel
widths like 80MHz and 160MHz (future), to change the operating channel
width lower / narrower bandwidths such as 20MHz or 40MHz. This is
particularly useful for networks that have 11ac APs along with legacy
APs and or clients, which only have the narrower bandwidths.