When I was a kid (and though young whippersnappers may beg to differ, I’m not all that old now) pretty well all telephones were black and had rotary dials: no digital readouts, no push-buttons, no “recent callers” buttons or “redial” buttons or “recall” buttons or any of the other buttons that my current phone boasts.
Phones, in other words, have changed. But, in the immortal words of Randy Bachman, “You ain’t seen n-n-n-nothin’ yet.” (Now you young whippersnappers really think I’m old.)
So far, despite all the changes, telephones have remained, at heart, very similar to the device Alexander Graham Bell patented in 1876 and 1877. Air molecules set vibrating by the speaker’s voice generate matching vibrations in a thin aluminum diaphragm inside the mouthpiece, which are passed on to a metallic box filled with small granules of carbon. These vibrations alternately force the granules closer together, so they conduct electricity more easily, and loosen them up, so electricity has a harder time getting through. The electrical current flowing through the granules therefore varies in strength as it passes into the telephone line.
At the other end, this varying current controls the strength with which an electromagnet attracts a second metallic membrane in the receiving telephone’s earpiece. It vibrates in exactly the same way the mouthpiece membrane in the sending telephone vibrated, recreating the speaker’s voice.
For years, that varying current travelled solely by copper wire, and there’s still lots of it about. Copper works fine for transmitting human voices: in computer terms (the only terms that matter, as you’ll see in a moment), human speech requires only about 55 bits per second of “bandwidth.” (A bit is an on/off signal; computers are basically just collections of on-off switches, so bits are their basic unit of communication.) But today, the telephone system is used for a lot more than just transmitting voice. Increasingly, it’s being used by computers to talk to teach other, and computers can exchange data a lot faster than 55 bits per second: they prefer it in millions of bits per second.
Fiber optic cables can transmit more data faster than copper cables–hence the push to replace copper with fiber optics. And a system called Code Division Multiple Access promises to eclipse even fiber optics, by making all kinds of new radio frequencies available every few kilometres, or even every few hundred yards, for data transmission, without the problems of interference that have always prohibited such heavy use of the airwaves.
But where will all this data be coming from–and where will it be going to?
One communications innovation that needs lots of bandwidth was first demonstrated by Bell Labs at the 1964 World’s Fair but is only now becoming practical: the video phone. For the past couple of years, video phones that use special data compression methods have been available commercially, but they haven’t really taken off for personal use (although a form of video phoning, teleconferencing, is carried out as a matter of course by large businesses). Data compression means poor quality, somewhat jerky video. But as it becomes increasingly easy to push huge amounts of data around, true video phones with images as sharp as those on your TV screen–or sharper–may finally become popular (assuming people really want to see the people they talk to on the phone, a pretty big assumption).
More and more, however, computers will be doing the “talking” over the telephones. There will be convergence of technologies. With a modem, computers already use the telephone lines to communicate, so why not piggyback your communication onto theirs? With the right hardware and software, you can already make long-distance (albeit very poor-quality) “phone calls” via the worldwide computer network called the Internet for a fraction of the cost of a regular long-distance call.
But that’s just the beginning. One of the current advantages of the telephone over the computer is that the telephone is much smaller and, thanks to cellular technology, portable. The ultimate convergence in technology will be the Personal Data Assistant: a hand-held unit which will allow you to communicate with anyone else anywhere in the world from anywhere in the world (thanks to satellites), access the world-wide computer system, pay your bills, dim the lights in your “smart house,” start the car, and probably even set the clock on your VCR.
It’ll be a brave new world of communications, no question. But you know what?
I kind of miss those old black phones.