Hi guys...As always, before doing a WiFi site survey, I read a lot about how to properly do it.
Ok, for example, there is pretty new WLAN installation. I need to plan it.
I configure my AP, put it into the corner... Later I check the coverage area and RSSI, SNR values...
But the question is: why other WiFi guys talks about passive survey? You can do active survey mostly always... You can connect to your WLAN and your adapter will collect all the necessary data from active(connected) channel and from the other channels too...
You also can get some additional information about your network by sending some ICMP packets to the AP and so on...
I mean, why do passive survey, if you can do active?
A good site survey involves more than just AP placement.
What about pre-existing WLAN signals and sources of interference.
How are you going to decide on the channels to use if you don't know what is already in place? Are you going to try them all in your site survey?
The reasoning for doing a Passive scan along with an active is to analyze the air. You won't to basically just listen without associating with APs.
Yes, No need for Passive Site Survey, if we ultimately have to go for Active Site Survey...
But, please suggest me one thing:
I want to purchase a Laptop, so what would you suggest:1- Check Online first, get brand/configuration/price details etc., then go to market/online.2- Directly purchase from market/online without searching anywhere.
I hope you get your answer.
BrijeshCWTS, CWNA, CWDP, CWNT
I feel you need to do both. Passive to know your environment (other WLANS in your BSA, Channel and Frequency selection) pre deployment. Active to know performance and provision of insight on how to optimize.
I'm talking about brand new WLANs, without existing infrastructure. You can't rely on your neighbors WLANs/SSIDs too much. Yes, it's crucial to measure interference (noise) , but to plan channels on your own? Who does this these days? Everything is left for the controller and RRM (radio resource management) software. RRM will do this job.
For the survey, you need to find best locations for your APs. It will mostly depend on RSSI and SNR values. So don't you think, there is a difference how you are collecting this data? I mean, there should be a difference, if you collect the data in "connected" state (higher RSSI) vs "not-connected" (just passive scanning).
I have read more posts, on different sites, about the problems with RRM, than I have heard talking the virtues of using it.
Howard I agree.
I like it when I hear an experienced tech, not in wireless, say thing like "oh for wireless these days it is easy in a big deployment, just set them up and turn on automatic configuration and you are done."
This is literally the worst thing you could possibly do. I see these quite often in enterprise environments in my area. There are so many experienced guys that either are too limited to be able to pre-configure the APs before deployment so rely on things such as RRM from Cisco which in my opinion is not very good. Or you have inexperienced guys that are trying to show off and put them up and invoke RRm to let the system "heal itself" and it winds up being horrible. A successful deployment should include a proper channel map to include power levels after there has been a passive site survey to see what is existing and then if you choose to invoke something such as RRm then turn it on after those APs have had time to adjust to the channel map and in theory they should settle themselves around the channel they were configured with. Obviously the wireless spectrum is influenced all the time even by things as small as a Mylar balloon floating in the air but its still a good idea to go off of data. Active surveys are great as well. Everything has its place in a wireless deployment.