RM3000_5150-5250_MHz_MPE_Report

FCC ID: LDK102086

RF Exposure Info

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FCCID_1893396

Custom EMC Test Report No: EDCS - 1229782




Maximum Permissible Exposure (MPE) Calculations
15.407: 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=Numerica 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)
        where
                d=MPE distance in cm
                P=Power in dBm
                G=Antenna Gain in dBi
                S=Power Density in mW/cm^2




                                                   Page No: 188 of 190

       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 - 1229782




        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. Using the peak power levels recorded in the test report along with Equation 1
        above, the MPE distances are calculated as follows.

                                        Peak
                              Power   Transmit Antenna   MPE
         Frequency Bit Rate   Density  Power    Gain   Distance Limit Margin
           (MHz)     (Mbps) (mW/cm^2) (dBm)     (dBi)    (cm)   (cm) (cm)
            5180       54       1        17      10      6.31    20    13.69
            5240       54       1        17      10      6.31    20    13.69
        MPE Calculations


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 Bit Rate Distance Power     Gain     Density   Limit     Margin
          (MHz)   (Mbps)     (cm)    (dBm)    (dBi)  (mW/cm^2) (mW/cm^2) (mW/cm^2)
           5180      54       20       17      10       0.10       1        0.90
           5240      54       20       17      10       0.10       1        0.90




                                                   Page No: 189 of 190

       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: 2013-02-04 10:21:20
Document Modified: 2013-02-04 10:21:20

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