That means there is too much activity on a channel. It could be traffic, interference or a combination of both. You can help by:
- dropping broadcast and multicast (broadcast applications are not efficient and are typically designed for wired networks and waste a lot of traffic)
- reduce the number of access points on a channel by making the channel size 20 MHz instead of 40 or 80.
- remove lower rates - management traffic and data will be sent at higher, faster rates and use less time to do it. Some clients will even roam better when you remove the lower rates
- if you have clients that support dfs, enable some dfs channels, so that other channels can be used. If most of your clients do not scan on dfs channels, this is not an option.
- locate and remove interference like unauthorized wireless and microwave ovens and wireless video cameras.
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