Cellular Phones Cellular phones allow you to make and receive phone calls almost anywhere. They gained popularity initially in cars, but as batteries became smaller and more powerful and circuitry shrank, cellular phones became small enough to fit into a pocket. Cellular phones were first introduced in 1983, when one million customers were predicted to be using them by the year 2000. At the end of 1993 there were more than 16 million subscribers with an estimated 14,000 users signing on every day.
Cellular phones are basically low-power radio telephones.
FM band to transmit signals from phone to transmitter to phone. The transceiver is a radio that transmits the signal from the antenna to the handset. The word cellular refers to geographic cells in which the FM transmitter towers are located. Each call is assigned a carrier wave signal unique to the cell from which it is transmitted. Because the signals from each cell are too weak to interfere with those of other cells operating on the same frequency, more channels can be used than with high-power radio frequency transmission.