Cell Phones and CBs A good way to understand the sophistication of a cell phone is to compare it to a CB radio or a walkie-talkie. Simplex vs. Duplex: Both walkie-talkies and CB radios are simplex devices. That is, two people communicating on a CB radio use the same frequency, so only one person can talk at a time. A cell phone is a duplex device. That means that you use one frequency for talking …showed first 75 words of 355 total…

…showed last 75 words of 355 total…phones but in a different way. Analog systems do not fully utilize the signal between the phone and the cellular network. Analog signals cannot be compressed and manipulated as easily as a true digital signal. The same reasoning applies to many cable companies that are going to digital -- so they can fit more channels within a given bandwidth. It is amazing how much more efficient digital systems can be. ------------------------------------------------------------------------ **Bibliography** How stuffworks.com