- The Washington Times - Thursday, July 20, 2006

Sometimes I think that Verizon and Sprint and all the other cell-phone companies are just making it up. Those little phones can’t really work the way they are said to.

A cell phone is just a tiny, sophisticated radio. Like any radio, WPGC for example, it has to transmit on some frequency. There aren’t enough frequencies for thousands of people to talk on their phones at once, just as only a certain number of commercial radio stations can fit on the dial. So how do you fit them in?

Answer: You make the signal from the cell phone very weak, so that it only travels a short distance. Then you put cell-phone towers fairly close together all over the city. Your cell phone communicates only with the tower nearest to you. That way cell phones in other parts of the city can use the same frequencies. The region around each tower is called a “cell,” hence “cell phone.”

OK. When I turn my phone on, it looks for the nearest tower and checks in. The tower, like all towers for the particular phone company, is connected to a central office. The tower tells the office, “Fred’s phone is on, and he’s in Cell 14.”

This information is stored (would you have guessed?) in a database in a computer. When you try to call me, the computer looks up Fred (actually it looks up an identifying number transmitted by my phone) and says, “Aha! He’s in Cell 14.” It then routes the call to Tower 14 (or whatever), which transmits it to me.

If I turn my radio on in California, the system there needs automatically to tell the central office in Washington where to find me. It does, and this is why cell phones work nationally.

Now, as I move from cell to cell, one tower has to hand me off to the next as I get out of range. The system does this by noticing that the strength of my signal is diminishing in one cell and growing in the next as I approach.

The foregoing is exuberantly simplified, but it gives the basic idea. A tremendous amount of slick engineering goes into different kinds of coding — time division, frequency division, code division, what have you. In terms of complexity proportional to size, cell phones are probably the most intricate gadgets we use.

How is this possible in a phone that costs a few dozens of dollars? (Actually, I don’t think it is possible. They probably do it with gremlins or spirits.) The theory is that they have packaged a fantastic amount of processing power police — analog-to-digital conversion, digital signal processing, and so on — into a very few chips. These are churned out by the bazillion in silicon foundries and just sort of stuck together and voila, a cell phone. Weirdly, chips with hundreds of thousands of transistors don’t really cost much.

A few days ago, I was in a car with friends between Richmond and Washington on Interstate 95. With us was a Mexican woman who wanted to call her daughter in a small town in Mexico. Her husband there had a Voiceover Internet account with a 202 number. She borrowed a cell phone, dialed, and in three seconds, the phone rang in Mexico, connection clear as a bell.

I thought about the connections involved, the handoffs, the conversions from one thing to another, the data rates, the mind-boggling unworkable complexity — and decided, “Nah, not possible. Verizon’s cut a deal with Gandalf. They’re dealing in magic.”

Does the FCC allow that? Somebody ought to check.

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