ple could use radiotelephones due to the lack of channels. With the current cellular system any none adjacent cell can use the same frequency, so the amount of phones that can be used are nearly limitless. These cells also mean that each phone does not need a strong transmitter, so the phone can be a lot smaller.
             With the innovation of digital phones, many great features are now available, such as caller id, Internet access, and several other new features. It also meant that the phone would need a microprocessor to convert from analog to digital, this complicated the circuitry, but left it with new technology available the industry was able to make the phone as small as possible. The only restriction in size became the user-input devices, and the screen size.
             Usefulness of the Digital Cell Phone
             The digital cellular phone offers many advantages to today's society. The conveniences that it offers over simply not having one are obvious and they vary from person to person. But there are many advantages over other types of phones as well. The cellular phone not only allows people to communicate with others while they are on the go, but it also offers many other features to help people. With the services that digital provides, people can access email and find information almost anywhere in the world for a reasonable fee. In the future, as the integration of phones and computers grow, people will be able to access tutorials in the field, and use them to communicate with specialists saving a great amount of time for many researchers.
             Today digital cell phones, such as the one shown in Appendix C figure 1, can process millions of calculations per second in order to compress and decompress the voice stream. In order to do this each phone is equipped with a circuit board that contains many different chips. The circuit board of a common phone is shown in Appendix C figure 2.
             Two chips described earlier are the Analog-to-D...