1100G Site Survey

[croninj]

Let me start of by saying I work for a school district. Funds are low. We have Cisco AP1121G and HP laptops with various built in wireless. Mostly Intel cards.

This past week I was given the project of doing a wireless survey in one of our schools. I understand the limit to 3 channels. I have configured many of these AP for use on our COWS(MAUS). We have some set for distance and others set for through put. We use AES CCMP + TKIP and a shared WPA key. We do not broadcast our SIDDs.

We are now deploying 9 COWS in one of our schools. This is not acceptable since some AP will conflict with others. So we are doing the survey to have them mounted. I used the windows default wireless software and a free download called WiFi Hopper to do the survey.

Here is what my probelm/question is. I mount the AP in an area. Walk away from it with my laptop. I get to a certain signal strength. As soon as i drop to below an "Excellent" siganl strength i can no longer get an IP adress. It will say that my signal is very good or good. Why can i not get an IP adress? Is it because i have the AP set for maximum throughput and at that range it can not garentee the maximum? I obviously have a signal at this point. Will it interfear with other AP's at this range even though i can't get an IP adress? I plan on clustering 3 AP's at each mount point on channels 1,6, and 11. I know I do not have tools at my disposal to do this survey correctly. So thanks for the help.

[shh5455]

Does COWS mean computer on wheels? If so I'm not sure I understand your arrangement. If I were you, I would try using NetStumbler as it will give you a signal strength reading in dBm. You should put the edge of your cells at about -67 dBm (or -72 if you have no plans for voice). Also, do your surveying with an SSID that is both unencrypted and requires no authentication. This should keep configuration problems from interfering with your survey. Run a continuous ping to your AP just to verify connectivity throughout the survey, but keep your eye on the signal strength for the real measure.

[croninj]

Yes, COWS means computers on wheel's. We currently have 9 cows in the school. We want to take our AP that are mounted to the cows and mount them to the walls. this way to prevent colisions and drops and bad signals. Sorry i was not clearer.

WiFi Hopper did give me dBm signal strengths. But i had alot of movement in the strength of the signal. I would bounce up and down rather quickly too. From -36dBm to -62dBm. Even if i was stationary. I attributed this to bouncing and reflection off of my school concrete walls and windows and chalk boards. Is this true?

If i did my survey with no encryption and authentication would that not be a true survey of how "MY" wireless network would be setup? Does turning of encryption and authentication effect siganl strength and/or bandwith?

Is it possible to have very good signal strength but not be able to ping my AP? Is it a feture of my 1100AP that if it can't garentte bandwith it will drop me but yet i can still see a signal? It seems that was what happened in my survey.

[croninj]

Somebody please help. Thanks.