MC8805 Module FCC MPE Evaluation

FCC ID: N7NMC8805

RF Exposure Info

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FCCID_1878531

 MPE Evaluation for
MC8805 Radio Module

       December 31, 2012


1. Introduction
     In this application we seek for modular approval to the MC8805 wireless
     module for use in standalone and collocated simultaneous transmission
     under mobile configuration. This Maximum Permissive Exposure (MPE)
     report demonstrates compliance analysis for MC8805 wireless module
     with FCC CFR 47 §2.1091 and IC RSS-102 for standalone and collocated
     transmission in mobile exposure conditions. The MPE analysis is limited
     for US / Canada bands only.

     The general population/uncontrolled exposure limits are applicable to
     situations in which the general public may be exposed or in which persons
     who are exposed as a consequence of their employment may not be
     made fully aware of the potential for exposure or cannot exercise control
     over their exposure.

     Any collocated transmitter must have a valid FCC ID documenting
     equivalent or degraded RF characteristics with the collocated parameters
     defined in this MPE report. A separation distance of 20cm or more shall be
     maintained between the end user and each WWAN, WiMAX or WLAN,
     and Bluetooth transmitting antenna.

     Portable user conditions or additional collocated transmitters not allowed
     based on this RF exposure analysis require a Class II permissive change
     and updated RF exposure report.


2. RF Exposure Limits and Equations
     FCC RULES:

     According to FCC OET Bulletin 65 Supplement C, 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.




             Table 1 : Limits for Maximum Permissible Exposure (MPE)

     IC RULES:

     IC has adopted the RF field strength limits established in Health Canada’s
     RF exposure guideline. The limits are shown in Table 2 below per RSS-
     102.




         Table 2 : RF Field Strength Limits for Devices Used by the General Public
                                (Uncontrolled Environment)


          EQUATIONS:

          Power density is given by :

                  S = EIRP / (4 * Pi * D^2)

          where
                  S = Power density (mW/cm^2)
                  EIRP = Equivalent Isotropic Radiated Power (mW)
                  D = Separation distance (cm)

 3. Product Declarations
   The MC8805 wireless module can be installed for use in any mobile host as
   long as the antenna gain of the host antenna does not exceed the gain listed
   in table 2.

   This MPE analysis is applicable to any collocated transmitters with transmit
   power:
      - less than or equal to 29.0dBm for WLAN/WiMAX; and
      - less than or equal to 15.0dBm for BT.

       Specific FCC IDs for those devices are not necessary or identified in this
       analysis providing they are classified as mobile transmitters. A 100% duty
       cycle is used for calculations to present a worse-case analysis when
       applicable.

                                                    Maximum
                         Max                        Conducted     Max Antenna Gain (dBi)
         Equipment                  Transmitter
Mode                  Transmitter                     Power
          Category                  Range (MHz)
                      Duty Cycle
                                                   (dBm)   (W)    Standalone   Collocated
                                       824-849     33.0    2.00      6.5          3.0
GPRS      Class 10       25%
                                     1850-1910     30.0    1.00      3.0          3.0
                                       824-849     28.0    0.63      6.5          3.0
EDGE      Class 12       50%
                                     1850-1910     27.0    0.50      3.0          3.0
           HSDPA                      824 - 849    23.5    0.22      6.5          3.0
UMTS                     100%
           HSUPA                     1850 - 1910   23.5    0.22      3.0          3.0

   Table 2: MC8805 Standalone and Collocated Transmission Declarations


                4. MPE Calculations
                      The WWAN MPE calculations are based on conservative conducted
                      transmit power exceeding those listed in the FCC ID N7NMC8805 and IC
                      number 2417C-MC8805 filing. The higher transmit power levels are used
                      to present a worst case assessment.

                      The WiMAX, WLAN, and BT transmit power and antenna gain parameters
                      represent a maximum transmit power for a given frequency band.

                      Integration of either a WiMAX or WLAN, and BT module that exceeds the
                      parameters requires a new FCC authorization or permissive change
                      application. A maximum antenna gain of 5 dBi for WLAN/WiMAX/BT has
                      been assumed for all collocated antennas.

                      Table 3, 4, and 5 summarize transmitter parameters associated with this
                      analysis.

                  4.1. Individual Transmitter Calculations

                      4.1.1. Maximum Output Power

                              The maximum power calculations for MC8805 per wireless
                              technology are shown in Table 3

                                                                    Maximu
                                             Maximum     Maximum                                               Max
                                                                       m               Max    Max     Max
                               Frequency     Conducted   Conducte             Duty                            output
                 Technology                                         Antenna           EIRP    EIRP    ERP
                                 (MHz)         Power     d Power              Cycle                           power
                                                                     Gain             (dBm)    (W)    (W)
                                               (dBm)       (W)                                                 limit
                                                                     (dBi)
                 GPRS 2 UL      824-849        33.0       1.995       6.5     0.250   39.5            5.43   7 W ERP
MC8805 module




                  EDGE 4UL      824-849        28.0       0.631       6.5     0.500   34.5            1.72   7 W ERP
 (Standalone)




                 GPRS 2 UL     1850-1910       30.0       1.000       3.0     0.250   33.0    1.995          2 W EIRP

                  EDGE 4UL     1850-1910       27.0       0.501       3.0     0.500   30.0    1.000          2 W EIRP

                   UMTS         824 - 849      23.5       0.224       6.5     1.000   30.0            0.61   7 W ERP

                   UMTS        1850 - 1910     23.5       0.224       3.0     1.000   26.5    0.447          2 W EIRP


                              Table 3: MC8805 Maximum Output Power Calculation


                      4.1.2. Standalone Power Density

                       The power density calculations for the individual transmitters per wireless
                       technology at an exposure minimum separation distance of 20cm are
                       shown in Table 4.

                       For frequency dependent limit, the lowest transmitter frequency was used
                       to represent the lowest MPE limit in this analysis (eg. 824MHz =
                       0.549mW/cm2)

                                               Maximum                 Maximum             Power
                                                           Maximum                                    FCC MPE
                                  Frequency    Conducted               Antenna   Duty     Density @
                   Technology                              Conducted                                  Limit
                                    (MHz)        Power                  Gain     Cycle      20cm
                                                           Power (W)                                  (mW/cm^2)
                                                 (dBm)                  (dBi)            (mW/cm^2)
                    GPRS 2 UL      824-849       33.0        1.995       6.5     0.250      0.44        0.549
MC8805 Module




                    EDGE 4UL       824-849       28.0        0.631       6.5     0.500      0.28        0.549
 (Standalone)




                    GPRS 2 UL     1850-1910      30.0        1.000       3.0     0.250      0.10        1.000
                    EDGE 4UL      1850-1910      27.0        0.501       3.0     0.500      0.10        1.000
                     UMTS         824 - 849      23.5        0.224       6.5     1.000      0.20        0.549
                     UMTS        1850 - 1910     23.5        0.224       3.0     1.000      0.09        1.000


                                     Table 4: MC8805 Standalone MPE Calculation

                   4.2. Collocated MPE Calculation

                       The WiMAX, WLAN, and BT power levels listed represent the worse-case
                       scenario for corresponding frequency ranges given.

                                               Maximum                 Maximum             Power
                                                           Maximum                                    FCC MPE
                                  Frequency    Conducted               Antenna   Duty     Density @
                   Technology                              Conducted                                  Limit
                                    (MHz)        Power                  Gain     Cycle      20cm
                                                           Power (W)                                  (mW/cm^2)
                                                 (dBm)                  (dBi)            (mW/cm^2)
                    GPRS 2 UL      824-849       33.0        1.995       3.0     0.250      0.20        0.549
MC8805 Module




                    EDGE 4UL       824-849       28.0        0.631       3.0     0.500      0.13        0.549
 (Collocated)




                    GPRS 2 UL     1850-1910      30.0        1.000       3.0     0.250      0.10        1.000
                    EDGE 4UL      1850-1910      27.0        0.501       3.0     0.500      0.10        1.000
                     UMTS         824 - 849      23.5        0.224       3.0     1.000      0.09        0.549
                     UMTS        1850 - 1910     23.5        0.224       3.0     1.000      0.09        1.000
                     WLAN        2400 - 2500     29.0        0.794       5.0     1.000      0.50        1.000
Other Collocated




                     WLAN        5150 - 5850     29.0        0.794       5.0     1.000      0.50        1.000
 Transmitters




                     WiMax       2300 - 2400     29.0        0.794       5.0     1.000      0.50        1.000
                     WiMax       2500 - 2700     29.0        0.794       5.0     1.000      0.50        1.000
                     WiMax       3300 - 3800     29.0        0.794       5.0     1.000      0.50        1.000
                       BT        2400 - 2500     15.0        0.032       5.0     1.000      0.02        1.000


                                     Table 5: MC8805 Collocated MPE Calculation


Per OET Bulletin 65 and KDB 447498 D01, when transmitters are used in mobile
exposure conditions for simultaneous transmission operations, the sum of the
MPE ratios for all simultaneous transmitting antennas incorporated in a host
device must not exceed 1.0.

The maximum MPE ratio of MC8805 = 0.20/0.549 = 0.36
The maximum MPE ratio of other collocated transmitters = 0.5/1 = 0.5

Therefore the sum of the MPE ratios for all simultaneous transmitting antennas
will not exceed 0.86 (=0.36+0.5).



5. Conclusion
   Based on FCC OET Bulletin 65 Supplement C and 47 CFR §2.1091, the
   analysis concludes that the MC8805 wireless module, when transmitting
   either in standalone or simultaneously with other co-located radio transmitters
   within a host device, is compliant with the FCC/IC RF exposure requirements
   in mobile exposure condition, provided the conducted power and antenna
   gain do not exceed the limits in Table 6 for each given frequency band per
   wireless technology.

                                                     Maximum     Maximum Antenna Gain
                                       Frequency     Conducted          (dBi)
     Device           Technology
                                         (MHz)         Power
                                                                 Standalone   Collocated
                                                       (dBm)
                                        824 - 849       33.0        6.5          3.0
                           GPRS
                                       1850 – 1910     30.0         3.0          3.0
         MC8805




                                        824 – 849      28.0         6.5          3.0
                           EDGE
                                       1850 - 1910     27.0         3.0          3.0
                                        824 - 849      23.5         6.5          3.0
                           UMTS
                                       1850 - 1910     23.5         3.0          3.0
                     WLAN              2400 - 2500     29.0                      5.0
      Transmitters




                     WLAN              5150 - 5850     29.0                      5.0
       Collocated




                             WiMAX     2300 - 2400      29                       5.0
                             WiMAX     2500 - 2700      29                       5.0
                             WiMAX     3300 - 3800      29                       5.0
                      BT          BT   2400 - 2500      15                       5.0


          Table 6: Summary of Maximum Conducted Power and Antenna Gain



Document Created: 2012-12-31 11:10:58
Document Modified: 2012-12-31 11:10:58

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