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WCS and automatic Tx power level of access points

Hi all!

I've been busy building up my WCS environment. I work at a hospital and I have multiple buildings and each with multiple floors. I now have 140 access points in WCS and I have started to notice a problem.

When I started importing AP's, started with floor nr.2. The Tx Power level assignments were fine, and the wireless signal was able to reach all rooms on the floor.

When I have imported AP's to the floor above and below the power level assignments have dropped, they are at level 5 (5dBm) and the heatmap shows a clear reduction in the signal strength on the floor. I have also been getting phonecalls from users complaining that the signal has been getting weaker.

I love this automatic channel and power assignment of the WCS, but it is starting to be a problem now, I'm guessing that WCS starts seeing the AP's above and below and starts tuning down the signal strength resulting in weaker signal on all the floors overall.

I really do not want to manually edit the power level assignment of each AP, that is defeating some of the purpose of having the WCS in the first place.

Is there anything I can do to up the signal strength?

Note: This is a hospital, often with thick concrete walls and floors, so the weak signal is affecting us.

Hope this made sense...

With best regards,


Cisco Employee

Re: WCS and automatic Tx power level of access points

Well it really isn't WCS that is causing the problem if there is one. Per the docs:

The controller dynamically controls access point transmit power based on real time wireless LAN conditions. Normally, power can be kept low to gain extra capacity and reduce interference. The controller attempts to balance the access points' transmit power according to how the access points are seen by their third strongest neighbor.

The transmit power control algorithm only reduces an access point's power. However, the coverage hole algorithm can increase access point power, thereby filling a coverage hole. For example, if a failed access point is detected, the coverage hole algorithm can automatically increase power on surrounding access points to fill the gap created by the loss in coverage.

Have you verified there is indeed a problem with connectivity? Low power isn't necessarily a bad thing unless there is a hole where there shouldn't be one.