On Fri, Sep 02, 2011 at 02:53:18PM +0000, Lay, Daniel wrote:
>
> We have experienced a similar issue. I had 1131's in several buildings
> and coverage was decent. At the time that was acceptable because
> wireless was treated as an convenience. Now perceptions have changed
> to wireless is mandatory; so in light of that we upgraded several
> buildings to the 3500s and even increased the number of AP,s in some
> buildings. As kids have returned we have seen a very large number of
> complaints coming from areas we thought we had the jump on. These are
> also areas that were not perfect with the 1131's (or we would not have
> upgraded) but they were not as high a volume of complaints as before.
> I opened a TAC with Cisco and we discovered that the AP's were at only
> a 7 power setting with RRM and when we moved to manual on the
> periphery AP's the coverage really improved. It makes me wonder if RRM
> is experiencing issues though because there was one AP in new
> construction area that could see other APs far away and I expected the
> power to be a 1 or 2 but it was at 7.
The power management system will only adjust power on APs that can be
heard by three other APs ("neighbors"). Increasing the density of APs
could increase the number of APs heard by three neighbors, and
therefore the number of APs that will have their power levels
adjusted.
APs without three neighbors run at power level 1. As soon as there are
three neighbors then TPC is likely to adjust the AP radio to much
lower power levels. The TPC defaults appear to be designed to
optimally support open cube spaces with few walls and not spaces with
lots of walls like residential buildings, traditional faculty office
buildings, etc:
http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008072c759.shtml#bev
http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008072c759.shtml#tpca
Cisco has an unsupported WLC config checker tool that also shows the
AP neighbor counts. I've found the tool to be useful for config sanity
checking and for looking at some of the system-wide RF issues:
https://supportforums.cisco.com/docs/DOC-1373
-Charles
Charles E. Spurgeon / UTnet
UT Austin ITS / Networking
[email protected] / 512.475.9265
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