h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Pulse Radio

Not quite popular yet, but far more sophisticated than Digital Radion, Pulse Radio will soon be used to connect portable HitchHiker's Guides to the Univers.

While Digital Radio works by sending 1's and 0's over an AM fixed radio sine wave (ie frequency), Pulse Radio uses a randomly timed square wave signal.

For illustration imagine being in one room with a piccolo and a tuba (playing of course). You will hear them both very distinctly because they are different frequencies. Now imagine the same room with two people clapping hands. The sounds are the same, but the rythum may be different. If one is clapping out "shave and a haircut" and the other is clapping to the beat of "bolero" you will be able to hear both rythums, and could if you like, chose to listen to one or the other.
Pulse Radio works on this principle. The pulses form a pattern which the lister, if properly tuned can understand.

Digital information is passed by very slight changes in the rythum: a "1" is a beat arriving earlier than expected.

Radio experts will point out that when you broadcast square waves you're really broadcasting on every frequency all at once. This is to some extent true. But it is for a very short space of time. So many channels can still coexist as long as they play different rythums. As there are infinite rythums possible, there are infinite number of channels available.

Because pulse radio does not have a frequency, it can better penetrate walls which stop certain frequencies - allowing your portable h2g2 to work indoors. It is also a usefull for xray vision.

There is an irony in pulse radio. Pulse radio means that for the most part we no longer need the government to parsel out radio frequencies to some and not to others - there is a place at the table for everyone; there may not however, be as much room for piccolos and tubas.

In the end, it may be necessary to destroy every radio station, every TV antenae on earth to pave the way for the intergalactic information superhighway. We apologize for the inconvienance.

In memory of Douglas Adams, May 12, 2001
Benjamin Gatti