Carry your Personal Network

Once upon a time, you hunted around for discounts or sales in the market on your weekly shopping trip. Then came ads and flyers that told you about the fantastic deals available. 

Browsing newspapers or looking out for ‘Sale’ banners will become a thing of the past, if WPANs (Wireless Personal Area Networks) can deliver all that the hype promises. As you walk down a street, shops that offer discounts will wirelessly send that information to your cellphone or PDA. 

WPAN? What’s that?



A WPAN connects your wireless device to all other wired or wireless devices, whether in markets, offices, banks, or dance parties. The defined range between two WPAN devices is about 10 m. So the minute you walk into the range of any wireless-ready device, there’ll be information exchange between it and your device. 

So what makes wireless devices talk with each other? That’s where standards come into the picture, like the

much-talked-about Bluetooth, or the slow-and-steady infrared. You’ll find more about these in a separate article in this issue. 

Up, close and personal



There’s also a concept that envisaged the human body itself becoming the connecting device in a network. Sounds intriguing? Here’s how.

Incubated in MIT’s Media Labs, and later developed at IBM’s Almaden Research Lab by Thomas Zimmerman around 1996, the idea of this PAN was really personal. It derived its wireless-ness by using the human body as the conducting wire, as the natural salinity of the body makes it a good conductor of electricity. Using a PAN receiver and transmitter, an external electric field can be created, which passes a tiny electric current through the body, over which data is transferred. The electrical current passed was one-billionth of an amp (or a nanoamp), which is lower than the natural currents already flowing in the body. In fact, IBM research claims that the electrical field created when you comb your hair is 1,000 times greater than what this technology used.

The prototype that IBM developed used a transmitter the size of a deck of cards that stored data on a microchip and a slightly larger receiver. When two people who had these devices (stored in their pockets maybe), shook hands with each other, they created a data link, over which they could exchange their business-card information. Other applications of this could be networking all the devices that you carry with you, so that your watch could be your display and your cellphone your input device; carrying your medical history around on such a chip, which your doctor can access simply by touching you–an especially useful application in emergencies; or in everyday life–your car or ATM machine can recognize you the minute you touch it, you could login to your office network through this.

Though commercial applications of Zimmerman’s work are far yet, WPANs have come closer to us. 

Pragya Madan