Cell+Phones+CBuchanan

wireless communication can trace its roots to the invention of the radio by Nikolai Tesla in the 1880s (formally presented in 1894 by a young Italian named Guglielmo Marconi).Both walkie-talkies and CB radios are **half-duplex** 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 **full-duplex** device. They were called cell phones because their working area s were split up into areas or cells.FSK uses **two frequencies**, one for 1s and the other for 0s, **switching** between the two to send information between the cell tower and the phone. Clever modulation and encoding schemes are required to convert the analog information to digital, compress it and convert it back again while maintaining an acceptable level of voice quality.