MPE 2

FCC ID: OWS-NIC514

RF Exposure Info

Download: PDF
FCCID_1256803

Silver Spring Networks Report No. 10PRO002 FCC ID: OWS-NIC5514 Model: 340-040304 MAXIMUM PERMISSIBLE EXPOSURE LIMITS §1.1310 The criteria listed in Table 1 shall be used to evaluate the environmental impact of human exposure to radio-frequency (RF) radiation as specified in §1.1307(b), except in the case of portable devices which shall be evaluated according to the provisions of §2.1093 of this chapter. Page 29 of 36

Silver Spring Networks Report No. 10PRO002 FCC ID: OWS-NIC5514 Model: 340-040304 CALCULATIONS Given E =  (30 * P * G) / d and S = E ^ 2 / 3770 where E = Field Strength in Volts/meter P = Power in Watts G = Numeric antenna gain d = Distance in meters S = Power Density in milliwatts/square centimeter Combining equations and rearranging the terms to express the distance as a function of the remaining variables yields: d =  ((30 * P * G) / (3770 * S)) Changing to units of Power to mW and Distance to cm, using: P (mW) = P (W) / 1000 and d (cm) =100 * d (m) yields d = 100 *  ((30 * (P / 1000) * G) / (3770 * S)) d = 0.282 *  (P * G / S) where d = distance in cm P = Power in mW G = Numeric antenna gain S = Power Density in mW/cm^2 Substituting the logarithmic form of power and gain using: P (mW) = 10 ^ (P (dBm) / 10) and G (numeric) = 10 ^ (G (dBi) / 10) yields d = 0.282 * 10 ^ ((P + G) / 20) /  S Equation (1) where d = MPE distance in cm P = Power in dBm G = Antenna Gain in dBi S = Power Density Limit in mW/cm^2 Equation (1) and the measured peak power is used to calculate the MPE distance. Page 30 of 36

Silver Spring Networks Report No. 10PRO002 FCC ID: OWS-NIC5514 Model: 340-040304 LIMITS From §1.1310 Table 1 (B), S = 0.6 mW/cm^2 RESULTS No non-compliance noted: Silver Spring Networks FCC ID: OWS-NIC514 IC: 5975A- NIC514 Utility Meter WLAN Transceiver 2.4 GHz Calculate mW/cm2 here. Enter frequency in MHz: RF Hazard Distance Calculation Calculation of Limits from 1.1310 Table 1 Controlled Uncontrolled Ave 6 min Ave 30 min mW/cm2 from Table1: 0.60 (E: 61 V/m) F(MHz) Actual F, MHz Occ, mW/c2 Gen, mW/cm2 0.3-3 0.5 100.0 100.0 Max RF Power TX Antenna MPE distance S, mW/cm@ Comment 3.0 - 30.0 5 180.0 36.0 P, dBm G, dBi cm at 20 cm 3 0.0-300 55 1.0 0.2 300-1500 902 3.0 0.60 29.0 3.0 14.5 0.32 1500-100000 5555 5.0 1.0 Enter P(mW) Equivalent dBm Enter dBm Equivalent Watts Basis of Calculations: 64 18.1 18.1 64.6 E^2/3770 = S, mW/cm2 E, V/m = (Pwatts*Ggain*30)^.5/d, meters d = ((Pwatts*G*30)/3770*S))^0.5 Pwatts*Ggain = 10^(PdBm-30+GdBi)/10) S@20cm = 20 log (MPE dist/20cm) NOTE: For mobile or fixed location transmitters, minimum separation distance is for FCC compliance is 20 cm, even if calculations indicate MPE distance is less MPE Distance: 14.5 cm NOTE: For mobile or fixed location transmitters, the minimum separation distance is 20 cm, even if calculations indicate that the MPE distance would be less. Page 31 of 36


Document Created: 2010-01-28 09:02:22
Document Modified: 2010-01-28 09:02:22
© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC