The phone is one of many things that we take for granted, since it has been around for so many years. In fact, the only time we really think about phone lines is when we see them on poles overhead. Well, before you make that next call from your home receiver, take a few minutes to read about the technology that makes our lives so much easier and more convenient.
The phone cord, or base cord for a cordless phone, connects to a jack in the wall that features a switch and two copper wires. This switch is flipped when you pick up the receiver and allows you to hear the dial tone and make your call. Once your voice enters your phone through the receiver, it is sent down the line via sound waves.
If you have above-ground wiring, your lines connect to a larger grouping of other cables inside a black casing suspended from a nearby telephone poll. If your cables are buried, all of the wires from the neighboring few houses meet inside a pale green telephone box, which will usually reside in someone's front yard. This box gives the phone company easy access if there is a problem with your line or if a new line needs to be added.
Next, the wires head from your telephone box or pole to a larger box, called a digital concentrator, that contains about 100 pairs of cable for a good portion of your neighborhood, or your line and the others go directly to the switch.
A few miles down the road, or closer, depending on where you live, there will be a small windowless building that bears the logo of your local telephone company. All of the wires for your area will eventually meet here, at the switch. This is the building where the magic happens. Your call will be digitized here if it was not already converted at the digital concentrator. This allows the computer system to transmit your call according to the instructions you gave by dialing the phone number.
Depending on whether your call is local or long distance and who your carrier is, it will continue along a new line made of coax cable or fiber optic cable or it will be beamed out to be sent by satellite. All of this happens in the time it takes the phone to ring on the other end.