All Tangled Up in A Wireless System

I HIT a pothole on the way to the Information Superhighway the other day. A data pothole actually. A computer glitch.

For three days I had lugged around a cellular-telephone modem attachment. When the time came to try it out, I pulled over onto a parking lot and laid out the rented cellular phone, my modem, the cellular modem attachment, my portable computer. The front seat of the car rapidly filled up with wires and gadgets. A techno-tangle. I dialed headquarters.

The first time didn't work. The second time I reached the computer in Boston. The familiar prompt popped up on my screen. Then suddenly it was gone again, swallowed by a string of garbage characters. I tried again. Same prompt. Same garbage. Moving data along wireless systems is in its infancy. It's not ready for the rest of us.

Deep down, I suspected this. I had already spent an hour with the technical person at the cellular-rental company, trying to figure it out. What MNP (error-checking standard) did I have? I had MNP 5. He told me I needed MNP 10.

We tried to change the way my software would handle the cellular call. In vain.

Cellular data transmission isn't impossible. A year ago, two colleagues experimented successfully with it. (Of course, they had MNP 10.) It's just that its potential is limited as long as it's harder than sending data through a regular telephone line. I'm not the only skeptic.

``It's too unreliable. It's too expensive. And it's too slow,'' says Ira Brodsky, president of Datacomm Research Company in Wilmette, Ill. ``That sounds pretty daunting. But in fact, there are a number of technologies that are in gestation and they're just about ready to go.''

Pinpoint Communications is preparing one of them: a radar-based network for fleet companies. The system lets traffic managers track their vehicles within a metropolitan area and, at the same time, send and receive messages. Drivers can get written instructions (``Delivery at 28 Oak St.'') and respond in kind.

Systems already exist to do this. Police departments, for one, are big users. But the technology is expensive. By using what's called spread-spectrum technology, Pinpoint says it can charge its users less than half a penny to send a packet of 22 characters. By 1998, it expects to have wired up the top 50 United States markets.

Another small company - Metricom Inc. - is trying to expand its wireless data systems for utility companies to deliver general data cheaply. These companies face enormous competition from well-financed companies, such as Motorola and the regional Bell operating companies. The latter are converting their cellular systems to work digitally, which should make it much easier to transmit data over cellular phones.

Another potential problem is interference. The new low-cost systems operate in a part of the radio spectrum commonly known as the junk band. That's because the frequencies are shared by all kinds of gizmos: from new cordless phones to those plastic security tags that stores put on expensive clothes.

That's all right for the moment because of spread-spectrum technology. The same bit of information gets sent over so many channels that it's almost certain to get through. Russia's Boris Yeltsin reportedly uses an American-made spread-spectrum modem to make international calls. If this part of the spectrum gets really crowded, technologists hope constant channel-hopping will solve the problem.

But it's a fair question whether anybody, outside of a few truckers, will really use this stuff. I think the answer is yes.

Consider what happens when your car breaks down. Either you get a ride to a gas station or find a phone to call an auto club. Drivers hooked up to Pinpoint's system could press a button, alerting the auto service of the problem. Because of the system, the service would know your exact location. Or suppose you drive during rush hour. A wireless car could download the specifics of your route and suggest alternates if there's congestion.

Of course, it will have to be simple. It's tough driving the Information Superhighway with a tangle of wires on your front seat.

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