The Consumer's Guide to Wireless Phones and Service Plans

Analog DigitalmdashWhatrsquos the Difference bull Chapter 2 23

as a result they are better suited to fit todayrsquos needs for communica-tions on the gomdashstaying in touch no matter where you are A simpleway to explain it is to compare a wireless phone to a CB radio or awalkie-talkie

Both CB radios and walkie-talkies are simplex devicesThis meansthat two people that communicate on a CB radio talk on the same fre-quency but only one person can talk at a timeA wireless phone is aduplex deviceA duplex device uses two frequencies One frequency isused for talking and a second separate frequency is used for listeningAmong many other uses a wireless phone (or duplex device) allowsboth people on a call to talk at once Not only does the wireless phoneeliminate the need to use terms such as ldquoRogerrdquo and ldquoover and outrdquobut also more importantly makes the flow of the conversationsmoother From a userrsquos standpoint talking on a wireless phone feelsmuch like talking on your home phoneThe only difference is that youcan be a hundred miles from any city house or telephone pole

Wireless technology is based on the car-mounted police radios ofthe 1920s Mobile telephone service became available to private cus-tomers in the 1940s In 1947 Southwestern Bell and ATampT launchedthe first commercial mobile phone service in St Louis Missouri butthe Federal Communications Commission (FCC) limited the amountof frequencies available which made only 23 simultaneous phone con-versations available within a service area (the mobile phones offeredonly six channels with a 60 KHz spacing between them)Unfortunately that spacing schema led to very poor sound quality dueto cross-channel interference much like the cross talk on wirelinephonesThe original public wireless systems generally used single high-powered transmitters to cover the entire coverage area In order to uti-lize the precious frequencies allotted to themATampT developed an ideato replace the single high-powered transmitters with smaller strategi-cally placed transmitters throughout the metropolitan area calls wouldswitch between transmitters as they needed a stronger signalAlthoughthis method of handling calls certainly eased some of the problems itdid not eliminate the problem altogether In fact the problem of toofew voice channels plagued the wireless phone industry for several years

The main problem was that demand always seemed to exceed supplySince the FCC refused to allocate more frequencies for mobile wirelessuse waiting lists became ATampTrsquos temporary solution as the companystrove for the technological advances necessary to accommodate

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