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Graphical tags

Initially, benefits to the consumer are most likely to be via specialised equipment such as RFID-enabled washing machines and microwave ovens. We won't be able to use RFID to interact with objects and places as we now do with webpages (at least not in the near future) because most PCs and mobile phones aren't equipped with built-in RFID readers.

However, most mobile phones have a camera. One obvious method for tagging places or objects so that they can be interrogated automatically using handheld devices is some sort of graphical marking that can be read digitally. The humble barcode is such a graphical mark and it would be quite possible, using specific software, to scan barcodes using a mobile phone's camera. Although ordinary barcodes are capable of representing only short strings of digits, newer types of barcodes can represent much longer alphanumeric strings.

One advanced barcode that is popular in Japan is called the Quick Response (QR) code. You can read how it works on page 133. The Active Print project (www.activeprint.org) is a group of companies that aims to explore how printed materials and digital displays can be linked to online content, services and applications using a mobile phone. If the aspirations of Active Print come to fruition, we can expect these square QR barcodes to start popping up here in the UK on anything and everything from concert posters to bus stops and tourist information plaques.

What happens when someone points their camera phone at something tagged with a QR code? Active Print partner HP is developing an application called Glass, which runs on a camera phone. "The data we encode is rather like that in a hyperlink in a webpage: there's a Uniform

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Resource Identifier (URI) and some text that links to it. The URI could be a web URL, a telephone number to dial, a text message, or just some data, as in a business card. Whichever type of URI is involved, Glass makes the phone respond to it as though the user had just typed it in," explained Tim Kindberg, senior researcher at HP's Bristol laboratory.

"So the phone requests a webpage, dials a number, sends an SMS and so forth. And the text in the code pops up and scrolls across the phone's screen when you read the code, before there has been any network access. We find that users really like that responsiveness."

But the need to have special software in the phone to interrogate QR codes would seem to limit the take-up of this technology. A way of doing this without requiring additional software would be for the user to transmit an image of the code via a picture message so it could be interpreted remotely. HP explored both possibilities. "We have found through extensive user trials that real-time responsiveness is vital to the user experience," said Kindberg. "With Glass, the user points the camera at the code running at video rate and moves the phone slightly until they see the pop-up text appear. With a mechanism involving taking a picture, the user first takes a still image of the code, secondly sends it to a service, thirdly waits an indeterminate amount of time until the answer comes back, and finally is almost certainly told 'could not decode' because the image was blurred, or not all the code was in the picture. [You're] back to step one and frustration."

Physical education

The QR code seems to be just one contender for hyperlinking real-world objects. Could Yellow Arrow, Grafedia, RFID, QR codes and other barcode variants coexist in the future or would one become the standard method? According to Kindberg "We at HP Labs have been pioneers in what we called the 'Real-world wide web', long before the term 'Internet of Things' became popular. We experimented with various technologies to create what we called physical hyperlinks: infrared beacons, RFID tags, barcodes, iButtons and so on. Any mechanism involving significant input into a handset and hence user effort is good only for niche applications. So that eliminates Yellow Arrow and Grafedia tags from having a future."