Appendix75Glossary 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 Multi-frequency) You send DTMF signalswhen you enter numbers by pressing the digit keys.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 Car Kit - An accessory that permits a driver touse a wireless phone without lifting or holding thehandset – an important safety feature for automobiles,and other motorized vehicles.
