If you are new to surveys or perhaps you have a few hundred already under your belt. The common theme to a good active survey is to understand your lowest powered clients and sensitive applications and their limitations. It is also important to understand the environment in which these devices will operate. Then calibrate your survey cards to these lower devices, which can be tricky for someone with limited experience.
There are many decent tools in which you can conduct active site surveys. One of these tools in which I am very familiar with is AirMagnet Surveyor. But never ever assume ANY old wifi card is OK to conduct a survey. In fact, when conducting active surveys you want to use the identical card or one very close to which will be used by your customer.
Example -- If you are surveying for Vocera B2000, Cisco 7921,7925, Ascom i75 deployment you don’t want to roll in with a 200mW card or a crappy chipset and let it run loose!?
When I survey for a Voice assessment I like to use that device during my assessment. Why? Because you know WITHOUT QUESTION how that phone / vocera badge / ascom phone will operate.
When I survey for a Vocera deployment, I will use the badge in survey mode in combination with AirMagnet. I will wear the badge around my neck enter the room, door closed and my back to the door and see what the Vocera badge is telling me. You will be surprised when you see what a pcmcia card reads and what the badge reads! In fact the majority of Vocera deployment failures is due to poor assessments. Thus the reason why Vocera has pulled in the assessment portion for their deployments.
Same holds true for handset deployments with Cisco, Ascom and others. These devices have a site survey mode as well. I will put these devices in site survey mode and use in combination with AirMagnet. Then one day at lunch many years ago I attached my Cisco handset to my laptop! Light bulb went off! What better way to survey and easily see the phones survey readings!
I hope you find this helpful during your surveys as well!