[acqq]

Observing the situation when I'm in the densely populated area where I have problem in communicating with my own WiFi base because of the noise from other people's stations, I can imagine exactly two potential problems:

1) In densely packed areas, the devices first installed stop working as soon as there are more devices, due to noise.

2) In far-away places, not enough energy for devices to work.

[adestefan]

It's not noise from other WiFi devices that cause problems in denay packed environment. The problem is the available bandwidth is consumed by other devices. Bluetooth uses the same frequencies as WiFi, but overcomes the problem by using frequency hopping and a method of adapting to the environment.