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5pt'- <br />■I;?? <br />It <br />IP <br />'i V" <br />fi <br />P-Ublic Sllfer-- <br />In rv-c.-nt vears there has '-e- .-roern ..ver <br />radira. and olher'sources. The frequencies used i'y the cellular pnone nenverK are the stutie ones <br />assigned previously to certain fHF TV channels. .,nd so have been in the airaavcs for mans sears. <br />The American Naiioniii Standards insiiiute X * - <br />. ANSI) has esiabiis.aed a standard idr >are c.^- <br />pt^sure levels to RF energj'. That standard is <br />compared below to other household sources <br />and a topical cellular phone antenna. Cellular <br />antennas transmit relatively short distances and <br />operate at very low power levels. As the hypot­ <br />hetical illustration suggests, the amount ot en­ <br />ergy from a single cellular phone channel is <br />tvpicallv about the same as .i lOO-watl liuht <br />bulb. While there may ''ctween eicht an., <br />fiity channels operaiiny from one cell ate. <br />channels rarely all transmit at the s.ime time <br />and each operates at a Jifferem trequcncy. <br />J'v <br />, .. <br />. r.i-*.'-,:- • •• <br />H - *V <br />I \ <br />Some antennas in the .-ellular phone network <br />.ire m.cr.' Aave rcaiy antennas that [r.in.Mnit .ind <br />r.*:-nhor.r* mts'iages from ceilut.ir sites <br />;o the wiretin.e :e:-"''hone network. The ''iunal <br />antennas is in a directed beam. <br />\NM so :he di>persion of RF energy outside this <br />na.'ro'v ■’’e.-.m ‘s 'n'-’C’^iticanl. fcven directly <br />lene.ith .; .eiiuiar antenna, the e.vposurc is <br />..bout liait mat o: an ordinary’ cordless phone, <br />or less than one percent of the A.N'SI standard. <br />To ma.ximtze the capacity of the system. celluUi .uuenruis tranami: This^.lous <br />the .same frequencies to be u.sed simultaneously in non-adiacent ceils. LS WEST New Vector Group <br />operates hundreds of cell .sites in fourteen .late:- ..nJ h:o: never expenenced any mtertcrcnce <br />problems with other transmissions. <br />Radio frequencies are a sort of {>recitnis n.i- <br />lional resource for which there is a tremendous • <br />and growing demand. The Federal Commum- ^ ^ \ <br />cations Commi.ssion (FCC) regiil.iies the use oi \ <br />radio trequencics throughout the I , ,,..... <br />States. The graphs illu.strate the broad range ^ <br />frequencies "and the narrow segment ot ihr. <br />spectrum that con.stilutes radio .md telex i«ion * " <br />frequencies .ind those allotted to cellular phone <br />transmissions.