For a long time wireless technology has been falsely promoted as the cure for all manner of IT ills. But in recent months the marketing has become even more evangelical, resulting in expectations being set far, far higher than what can actually be achieved with current technologies.

Part of the problem comes from a blurring of the distinction between long-reach wireless communications - typically using mobile phone networks - and local wireless links using Bluetooth and 802.11 Ethernet technologies.

Each of these systems has its uses and benefits, but vendors seem to think that the differences are too difficult for end-users to understand. As a result their advertising and promotional material tends to talk about wireless networking as though it were a single, one-size-fits-all solution.

Take, for example, Intel's TV commercial for Centrino-powered notebooks. You know the one, it's where the intrepid explorer gets sent a video clip of the kids from home even though he's in tent, in a blizzard, on the side of Mount Everest.

OK, so his tent is at base camp and it may not have been a blizzard, but wherever and whatever the weather, the implication is the same. Buy a Centrino notebook, Intel is telling us, and you can connect wirelessly to the internet from just about anywhere.

Of course, technologically-savvy readers know this is not possible without additional GPRS or satellite hardware. At least not unless Intel has set up wireless hotspots in tents in Nepal.

Unfortunately, people outside the industry may not know that, and neither are they likely to read the very small print at the bottom of the screen that outlines the limitations of the technology.

Advertising licence, you might say, and I might have agreed until I received an email from someone who bought just such a notebook recently. Why, they enquired, was it not it possible to surf the internet and receive emails wirelessly like the adverts claimed. After all, they'd turned it on and typed in a URL just like the man on the mountain, but nothing worked. Were they missing something?

Unfortunately they were. They were missing a fact that Intel, the notebook and PDA manufacturers, the wireless service providers and everybody else connected with wireless technology would like us all to ignore for now.

The fact is that although wireless networking can be empowering, it's not magic and it doesn't work without some kind of supporting infrastructure.

And, of course, it takes a long time to put that infrastructure in place. So at the moment you will be lucky if you can get a wireless connection in Muswell Hill, let alone the Himalayas.

Let's make one thing clear though - I'm a big fan of wireless networking and think that it has a great future. But currently it is not really fast enough, at least not if you compare it with technologies such as Gigabit Ethernet. And there are currently too many incompatible standards.

Unfortunately these issues do not seem to be of much concern to companies trying to sell wireless products or services.