Appendix82Glossary of TermsAirtime - Actual time spent talking on the wireless phone.Most carriers bill customers based on how manyminutes of airtime they use each month.Antenna - A device for transmitting or receiving signals. Thesize and shape of antennas is determined, in part, by thefrequency of the signal they receive. Wireless phonesand the base station must have antennas.Base Station - The fixed radio transmitter / receiver thatmaintains communications with mobile radiotelephones within a given area. (Typically seen as cell orcell site.)CDMA – (Code Division Multiple Access) A spread-spectrumapproach to digital transmission. With CDMA, eachconversion is digitized and then tagged with a code. Themobile phone deciphers only a particular code to pickthe right conversation off the air. The transmitted signalis just above noise level across the available bandwidth.Channel - Communications signals transmit along pathscalled channels.Deactivation - The process of rendering a wireless phoneinactive.DTMF - (Dual-tone Modulated Frequency) You send DTMFsignals when you enter numbers by pressing the digitkeys.Frequency - A measure based on time, as one or more wavesper second, in an electrical or lightwave informationsignal. A signal’s frequency is stated in cycles-per-second or Hertz (Hz).Hands-Free - A feature that permits a driver to use a wirelessphone without lifting or holding the handset – animportant safety feature for automobiles, tractors andmost other motorized vehicles.
