Hello Cisco WLAN-experts,
this hospital is using a 9800-WLC togehter with a high density WLAN-AP 9130 concept.
I was wondering about the many 2.4GHz-antennas that were moved into Monitoring state by FRA using a
FRA Sensitivity of low which is Coverage Overlap Factor of 100%.
Therefore i tried to reduce the TPCv1 Power Control Threshold to bring up more antennas again.
But to my surprise the APs still see each other not only from same floor but also from floors above and downstairs.
Here is an example from 4th floor (AP-B1-4-xy) showing many APs in neighborhood with far better RSSI compared to the -75dBm TPC-value:
The 9130 APs has the following Power settings for its 2.4GHz-Antenna:
9130 15/12/9/6/3/0/-3/-4
The RF-Profile I'm using looks like this:
What I do not understand:
Why do the 9130-APs not reduce their sending power further to avoid coverage overlap and FRA deactivation of their 2.4Ghz-antennas and to adapt their Sending power level to -75dBm of the third AP in neighborhood ?
Who has an explanation for this behaviour?
Do I need to restart all APs to make RRM work correctly ?
Please advise
Thank You for Your tipps
Kind regards
Wini
P.S. We are running Version 17.9.5.
There is a bug dealing with a RRM-problem where the Max. Min-values are not selected by RRM
Is this bug still open in version 17.9.5 ?
https://community.cisco.com/t5/wireless/wlc-9800-rrm-and-power-levels/td-p/4394533
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs06271
Hello Leo,
this hospital is still using old medical devices that support 2.4ghz-only. And to my surprise, there are many patients and stuff that use brand-new Android mobiles that also support 2.4ghz only for private purposes on our guest WLANs.
In the menatime, I have reduced TPCv1Pweor Control Threshold to -80dBm and Minimum Power Level to -4dBm. But even with these values, many of the WLAN-APs turn 2.4Ghz-antenna into Monitoring and do not reduce sending power beyond 3dBm.
Maybe the reason for this is the 6dBm hysteresis built in the TPCv1 calculation.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_RRM_White_Paper/tpc.pdf
Here are the power levels for 9130 15/12/9/6/3/0/-3/-4
The screenshot taken from my test environment in a multi-floor building shows the 4th. floor. And the neighborhood table of an AP still sending in 2.4GHz shows far better RSSI connections to APs on floor 5 and even outside this building.
The second buidling near by to the left is showing 9130 using 9 dBm. These ones are driven with our normal RF-Profile which limits Tx-Power to 9dBm to avoid long-distance connections and interference and sticky clients. So TPC seems to work somehow but not for Power levels beyond 0 dBm apparently,
I'm really wondering whether TPC is running correctly in 2.4GHz on 9800-WLC running 17.9.5-software.
Maybe I will accept interference instead and disable FRA and go back to a TPCv1 value of around -67dBm.
The higher sending power will also make sure that all rooms are covered by 2,4GHz.
Kind regards
Wini
