While it all generally works, you have to remember that this is wireless, just like cell phones, walkie talkies, etc... Line-of-sight outdoors can work quite a distance, but indoors, with walls and electrical devices, you get more interference and much less obvious coverage patterns. (For example, the area on the other side of the wall behind my oven is a dead zone, just 10 feet from where I type this with OK reception.) Also, other 2.4GHz devices, like some cordless phones and the upcoming Bluetooth devices, can cause temporary gaps in operation. Periodically I have to click on a link a second time, more than I think I used to. I haven't optimized the location of my wireless access point yet. Higher is better I hear. Still, it is pretty useful. I love checking email along with the newspaper at breakfast without any wires. When I see something I need to print out, I just click on "Print" and soon I hear the faint sounds of the printer in the other room on another PC doing its thing.

For sure, wireless is more fragile than communication over wire. A link working at 2.4GHz may be immune to some types electromagnetic radiation (speed drives, motors, etc) but possibly not so impervious to quite a few others. Top offenders include microwave ovens, microwave comms and radar systems, electrical welding machines, walkie-talkies, cell phones other wireless datacomms systems, etc.

It might seem reasonable to assume that such interference might cause loss of data packets or a slowing down of transfer speed. After all, we have all experienced loss of mobile phone connection quality by just moving a few centimetres. It seems reasonable to expect the same problems occurring with industrial wireless networks. However FHSS technology can deal with this sort of thing. But first, what is hidden behind the acronym?