Cisco 1252s with regular 802.3af PoE switches - what are the impacts?

Question

Does anyone have any real-life experience with deploying the 1252s on regular 802.3af PoE switches?  I have a few 1252s one some 3560 PoE ports and the show up with "low power" alarms.
I am wondering what the real world impact is with this scenario.  The 1252s have both 2.4 Ghz and 5.0 Ghz radios in them and I have HT enabled on the controller.
I'm wondering what capabilities I am losing by running on 802.3af power besides the annoyance of the alarms.
Thanks in advance!

Answer 1

Sorry in advance for the book I have just written.
I have three 1252s on 75 feet of Cat5e cable running to a 3560 PoE switch. Sometimes, but not always, I see a low power alarm on the access point(s). This is in a small building that is built like a fortress so the RF environment is somewhat challenging. I am watching WCS closely and see all three 2.4 GHz radios powered all the way up to power level 1. I notice that two of the 5GHz radios are on power level 1, and one is on level 3. I thought that RRM would not power anything down until you had at least four access points as RF neighbors. I believe I read that in a Ciscopress book and it seems to be true everywhere in our network when I look at buildings with 3 or less WAPs.
The building in question does not have any other buildings close by with any 5GHz radios in operation - or at least I didn't see any when I did the survey.
I'm wondering if the power setting of the radios is also related to the length of the Cat5e cabling. Seems to me a shorter run would have less resistance than longer runs, allowing the radio to have more power.
My main concern is not this building in question, since we went for coverage and not client density in the design. We several other buildings on the radar, all libraries, which are going to be both RF challenging (bookshelves, furniture, cubicles, cubbies) and client-density challenged. These buildings have hundreds of WLAN clients in them at times - and I mean devices, not just people.
Someone else told me (reputable source) that channel bonding is not an option when on 802.3af power. Makes sense, actually. I would never even think of bonding in the 2.4 GHz range for obvious reasons, but up in the 5GHz range it is a definate possibility in these buildings. Seems to be that we might be shooting ourselves in the foot by not using 802.3at power in these buildings.
If channel bonding is disabled and the upper two MCS rates (using 800ns guard interval) of 117 and 130 are disabled, then I'm looking at maximum MCS rate of 104 Mbit/s compared to 270 Mbit/s with 802.3at with channels bonded in the 5GHz range.