MPE 2

FCC ID: LDK102092

RF Exposure Info

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FCCID_2396211

Custom EMC Test Report No: EDCS - 1326277 Maximum Permissible Exposure (MPE) Calculations 15.247: U-NII devices are subject to the radio frequency radiation exposure requirements specified in Sec. 1.1307(b), Sec. 2.1091 and Sec. 2.1093 of this chapter, as appropriate. All equipment shall be considered to operate in a ``general population/uncontrolled'' environment. Applications for equipment authorization of devices operating under this section must contain a statement confirming compliance with these requirements for both fundamental emissions and unwanted emissions. Technical information showing the basis for this statement must be submitted to the Commission upon request. 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 mW/cm^2 Combine equations and rearrange the terms to express the distance as a function of the remaining variables: d=√((30*P*G)/(3770*S)) Changing to units of power in mW and distance in cm, using: P(mW)=P(W)/1000 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) G(numeric)=10^(G(dBi)/10) yields d=0.282*10^((P+G)/20)/√S Equation (1) and s=((0.282*10^((P+G)/20))/d)^2 Equation (2) wher d=MPE distance in cm P=Power in dBm G=Antenna Gain in dBi S=Power Density in mW/cm^2 Page No: 116 of 118 This document is uncontrolled. Please refer to the electronic copy within EDCS for the most up to date version. Cisco Systems, Inc. Company Confidential

Custom EMC Test Report No: EDCS - 1326277 Equation (1) and the measured peak power are used to calculate the MPE distance. Note that for mobile or fixed location transmitters such as an access point, the minimum separation distance is 20 cm even if the calculations indicate that the MPE distance may be less. S=1mW/cm^2 maximum. The highest supported antenna gain is 4 dBi (7dBi with beamforming). Using the peak power levels recorded in the test report along with Equation 1 above, the MPE distances are calculated as follows. MPE Calculations: Peak Power Transmit Antenna MPE Frequency Density Power Gain Distance Limit Margin (MHz) (mW/cm^2) (dBm) (dBi) (cm) (cm) (cm) 5745 1 20.6 7 6.76 20 13.24 5785 1 20.3 7 6.54 20 13.46 To maintain compliance, installations will assure a separation distance of at least 20cm. Using Equation 2, the MPE levels (s) at 20 cm are calculated as follows: Peak MPE Transmit Antenna Power Frequency Distance Power Gain Density Limit Margin (MHz) (cm) (dBm) (dBi) (mW/cm^2) (mW/cm^2) (mW/cm^2) 5745 20 20.6 7 0.11 1 0.89 5785 20 20.3 7 0.11 1 0.89 Page No: 117 of 118 This document is uncontrolled. Please refer to the electronic copy within EDCS for the most up to date version. Cisco Systems, Inc. Company Confidential

Custom EMC Test Report No: EDCS - 1326277 Appendix C: Test Equipment/Software Used to perform the test Equip # Manufacturer Model Description Last Cal Next Due CIS‐50378 Agilent N9030A PXA Spectrum Analyzer 2/27/2013 2/27/2014 Page No: 118 of 118 This document is uncontrolled. Please refer to the electronic copy within EDCS for the most up to date version. Cisco Systems, Inc. Company Confidential


Document Created: 2013-11-27 13:27:30
Document Modified: 2013-11-27 13:27:30
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