Can you send us over a bit more information about the computer and WiFi network you are using?
Could you let us know the hardware specifications on your machine? Mostly we are looking for the model of your GPU and CPU, as well as the amount of RAM on your machine. Are you running a CUDA compatible Nvidia Graphics card? If so, what version of CUDA are you running and have you updated the Nvidia drivers?
For your WiFi network, would you run a speed test on http://www.speedtest.net and let us know the results?
Also, could you let us know the settings you are using on Skanect?
If you are running into the FPS problem only when multiple networks are in the area, my assumption is that your WiFi router is receiving some feedback from the other signals in the area. Please change the channel on your WiFi router to something that no other router in the area is on or near. Or it could be that the router you are using is broadcasting a weak signal or is an older model utilizing an older WiFi standard.