An interesting column appears regularly in the Belleville News Democrat, Belleville, Illinois. It’s called “Roger, the Answer Man” and, in his column, Roger attempts to give simple answers to common questions people wonder about and finally take the time to ask. Recently, Roger was asked why it is possible to talk on the telephone and work online at the same time when you have DSL, but not when you are using a dial-up connection. Roger said: “I had to check with the Internet service providers in my area to come up with the answer.”
Roger then explained that it has to do with the frequency of the signal being transmitted over the telephone line. It seems that copper telephone wires can handle a number of frequencies — from low to high. Before the Internet, however, phone companies had no practical use for the higher frequencies. The sound of the human voice is in the low frequency range — the same range used by dial-up connections. As a result, a person can’t talk on the phone and be online at the same time because both require the same frequency. DSL, however, takes advantage of the higher frequencies. Gadgets called splitters send DSL signals in one direction and voice signals in another, allowing the same phone line to be used simultaneously for both voice calls and the Internet. Is DSL available where you live? You can search for DSL providers by zip code to find out.