Chapter 6; Topic 6

Basic DCA Operations

Correct channel assignment is paramount when multiple APs are used in a wireless network because it facilitates client mobility and efficient use of airtime. A new AP uses the first non-overlapping channel in each band when it first powers up. In the case of channel 1, it uses 2.4GHz, while in the case of channel 36, it uses 5GHz. The DCA algorithm tends to look at each AP individually to find the ones with the worst RF conditions and the lowest CM. The algorithm identifies the one that can be improved by moving them to a better channel. The DCA algorithm also uses a sensitive threshold to keep channel changes under control.

Basic DCA Operations; Internet Source

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_RRM_White_Paper/dca.htmlThe Dynamic Channel Assignment maintains the performance of individual radios by adjusting the channel dynamically. It also manages 20/40/80/160 MHz bandwidth OBSS’s actively. The DCA makes decisions using an RSSI-based cost metric function which evaluates performance based on interference for each available channel. Additionally, the DCA manages channel assignments for an RF group in a dynamic system and evaluates the assignments on a per AP per radio basis. Under the DCA algorithm, the group leader maintains the neighbor lists for all APs in the RF Group. The group leader also organizes these neighbors into RF Neighborhoods. It uses metrics like DCA sensitivity and channel load to track each AP in the RF Group.