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777 . MET rix T v a � : `' "7` u'otii ,•_N; j "<9 Gq # , e t ,.., a S,Y- +. yS^.wca a+ sBEgb 5va i,. _. s •- . u a en k a 4 , , . , ,._� ,r • Human exposure to RF radiation Human exposure to RF radiation 1 hernial effects - at sufficient IeN els, hod + heating can „ E + f n + tr densih ," in units of mN'. ; cm = , is used to become a significant problem. PCS work. It is assumed that the point of - obvious effects include damage to eves vital organs . exposure is in the far field" of the antenna. - Less obvious effects may be important , but research Is - Prolonged exposure to power densities of 10 mW cm' mcunclusnccan cause measurable heaomz nma.n. tissue In wITCICSS eommumeauons- erects. Il ant - still be Nlbtle . l , wdchnes in three speC: n ecnusure ctcrs at he ,o ,t l ontrast the wireless situation wtlh broaocasnng engineers this working with 50,000 watt "hof' towers ' — Exposure recommendations are time averaeed . meanm2 short-term exposure to let cl. _urearer man the ewdchnc Nevertheless, new standards exist that are applicable to arc nermusnble as ion , as ine 11MIC utclaze daeS no; cellular and PCS licensees, as vie shall see exceed the imnauon . Human exposure to RF radiation Human exposure to RF radiation FCC standards : m umm for c.netW Pap ahoniuncw*rouea Exposure - Adopts Maximum Permissible Exposure ( MPE ) limits (power revuency Eiechic fieitl Magnetic field density ) for transmitters pange shength Sr.engm Powe' Dens'N Averaging Lme - Adopts limits for localized ("partial body" ) absorption that Inn",i rvrnv (Alm: imv+tcmi minvieti will apply to certain portable transmitting des ces (SAR)- 313• 614 163 ; ISI' 3G - Specifies two sets of exposure limits : : 3A-3o slut 2 1. 9rl 1K,,F1• 3;, 300 27s 007 os K - A more tolerant, "occupationabcontrol led" exposure. for - 1 ,C - - Scu' x trained personnel "in the business" (many roof tops ). isca- +oo ooe - - A stricter. " general population uncontrolled" exposure. for = neguencv �nM": = Pbne-wave eONvvlent pawet tlensty situations where the general public may be exposed (more usually applicable than "controlled" limitations ). Human exposure to RF radiation Human exposure to RF radiation FCC standards: _-_— _ _ _ —_ What about the •'radiated" house? - Carnets mus[ determine their _ - "Antenna mounting structures" with single carriers at this base station compliance with power level are "categorically excluded" ! However, FCC regulations �' _— !. - Maximum power density is 1.0 m W/cm= at 1900 MHz. - This is simply accomplished - Simple calculation: given the EIRP of our transmitted power _ for single-provider, or F ( 6 x IOOW = 600 W), and the distance R from the antennas multiple wireless carrier, sites 6 � � lin cm, to preserve units ), - It becomes complex in the i, ) , S = 0.64 x EIRP / pi R' , case of multiple providers of r t - '_ E _ i li where S is the power density in mw icm= �. different radio services ! all — S = 0.031 mW/cm2 . f Note this is well within the FCC guideline. Human exposure to RF radiation Human exposure to RF radiation • NN ireless portables are subject to Compliance with SAR limits can be routine environmental evaluation demonstrated by either laboraton for RF exposure prior to measurement techniques or by equipment authorization or use. computational modeling. - The limits to be used for evaluation are - Research continues. but according to the IEFE based on a localized specific absorption Spectrum . no repeatable eN idence exists trial rate (" SAR" ), a measure of the rate of exposure to RF radiation at the let els produced b} energy absorption due to exposure to an RF handheld phones has any health effects. transminmg source . — Digital phones. and widespread deployment of ( 'DMA techniques. will limn phone output powers and resultant exposure lusher- [ 1, P971 JULY 259 2001ill put 1 M9 - 9 - .r A r