RFID: Wireless Shopping.

So wireless networking has got rid of your network wires and your USB wires... what can it do next? Well, the answer might surprise you: wireless is going shopping.

RFID: Electronic Barcodes.

Yes, that's right: RFID (Radio Frequency Identification) is a replacement for the barcode, using wireless radio technology. But what's wrong with barcodes, you ask? Well, they need to be scanned, for a start. Supermarkets and other shops have small armies of staff in their stores, in fact, doing almost nothing but scanning barcodes and taking money.

RFID lets barcodes be replaced with radio signals, which can automatically be scanned. In theory, you could have a shopping cart full of RFID-labelled products, put it near an RFID scanner, and the things in your cart would be detected and their prices added up instantly.

Imagine being able to stop in front of a machine at the supermarket's exit, and do nothing but put your credit card in a machine before you leave (if your credit card is RFID-enabled too, you might not even need to do that). You can checkout in a matter of seconds! It's a win-win situation: it saves you time, and it saves the supermarket money. The only people who lose out are the ones getting paid to sit around scanning barcodes, but hey, that's technology for you.

How on Earth Does It Work?

Believe it or not, RFID tags contain tiny antennas, allowing them to transmit small amounts of data by radio. The majority of tags in use today do not have their own power supply (a power supply makes the tag larger and more expensive), which means that they must rely on power they receive through the air by radio. This is such a tiny amount of power that it is only just enough to transmit an ID number. This does work, however, from as much as five metres away.

For shopping use, tags that send numbers are sufficient -- a barcode is just a number in the form of lines, after all. These tags are now as cheap as 40 cents, and mass production means the price is only going to come down -- RFID is likely to become widespread in the next decade. The smallest RFID tags are already thin enough to be almost invisible.

Privacy and Other Uses of RFID.

There are privacy concerns around the use of RFID, simply because it makes it so quick and easy to tag just about anything -- and the tags can be scanned without any human interaction. This, however, is also what makes the system very useful.

Pets are already implanted with RFID tags so that they can be identified if found, and the idea of humans being made to have RFID implants as a replacement for identity cards isn't as science fiction as it sounds -- it is possible today. As long ago as 1998, a professor was able to implant a tag in his arm. The technology is being considered for used on prisoners. In countries that already have ID cards or that will have them soon, RFID tracking probably won't be far behind.

If RFID shopping tags are left on things, then people could leave tags on their clothes or other products without realizing it. This has all sorts of implications -- someone might be able to point an RFID scanner at your house and get a list of everything in it that still has a tag, for example.

RFID is already widely used in many industries. Warehouses use them to track pallets of goods, some libraries put them in books and airlines use them to track baggage. Usage is particularly common in building access control (the ID cards for employees that open the door automatically).

Travel is another growth area: many parts of the USA have the option of using RFID cards to pay at toll booth's, and the London Underground now uses RFID payment cards known as Oyster cards. There are even RFID car keys that can open the door while they're still in your pocket, without you doing a thing.

Environmental Concerns.

As a footnote to all this, many people are concerned about the environmental impact RFID could have. Although they are small, using computer chips as a replacement for barcodes could lead to the equivalent of many thousands of computers being thrown away every year.