MPE 702W 5745-5825 Report

FCC ID: LDK102092

RF Exposure Info

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FCCID_2129638

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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