MPE

FCC ID: H8NWLL0010

RF Exposure Info

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FCCID_380028

                       RF EXPOSURE REPORT


                          REPORT NO.: RF921113R02
                           MODEL NO.: WLL0010


                          ACCORDING: FCC Guidelines for Human Exposure
                                     IEEE C95.1


                       APPLICANT: ASKEY COMPUTER CORP.

                        ADDRESS: 10F,NO.119, CHIENKANG RD.,CHUNG-
                                 HO,TAIPEI TAIWAN R.O.C.



                       ISSUED BY: Advance Data Technology Corporation

                 LAB LOCATION: 47 14th Lin, Chiapau Tsun, Linko, Taipei,
                               Taiwan, R.O.C.




                                                0528
                                              ILAC MRA       Lab Code: 200102-0




Report No: 921113R02                      1


           RF Exposure Measurement (Mobile Device)
1. Introduction
In this document, we try to prove the safety of radiation harmfulness to the human body
for our product. The limit for Maximum Permissible Exposure (MPE) specified in FCC
1.1310 is followed. The Gain of the antenna used in this product is measured in a Fully
Anechoic Chamber (FAC) calibrated for antenna measurement in ADT, and also the
maximum total power input to the antenna is measured. Through the Friis transmission
formula and the maximum gain of the antenna, we can calculate the distance, away from
the product, where the limit of MPE is reached.
Although the Friis transmission formula is a far field assumption, the calculated result of
that is an over-prediction for near field power density. We will take that as the worst case
to specify the safety range.


2. RF Exposure Limit

According to FCC 1.1310: The criteria listed in the following table shall be used to
evaluate the environmental impact of human exposure to radio-frequency (RF) radiation
as specified in 1.1307(b)

LIMITS FOR MAXIMUM PERMISSIBLE EXPOSURE (MPE)

   Frequency            Electric Field   Magnetic Field   Power Density    Average Time
     Range             Strength (V/m)    Strength (A/m)     (mW/cm2)         (minutes)
     (MHz)
                   (A)Limits For Occupational / Control Exposures
    300-1500                 …                …              F/300                6
 1500-100,000                …                …                5                  6
             (B)Limits For General Population / Uncontrolled Exposure
    300-1500                 …                …              F/1500               6
 1500-100,000                …                …                1.0               30
F = Frequency in MHz




Report No: 921113R02                           2


3. Friis Formula


Friis transmission formula : Pd = (Pout*G) / (4*pi*r2)


where
Pd = power density in mW/cm2
Pout = output power to antenna in mW
G = gain of antenna in linear scale
Pi = 3.1416
R = distance between observation point and center of the radiator in cm


If we know the maximum Gain of the antenna and the total power input to the antenna,
through the calculation, we will know the MPE value at distance r.

Ref. : David K. Cheng, Field and Wave Electromagnetics, Second Edition,
      Page 640, Eq. (11-133).



4 EUT Operating condition
The software provided by Manufacturer enabled the EUT to transmit and receive data at
lowest, middle and highest channel individually.



5. Classification

This modular is specified to be installed in access point which is connected with host
through wire. So it is easy to be re-located in the place where at least 20cm far away
from the body of the user. Warning statement to the user for keeping at least 20cm or
more separation distance with the antenna should be included in users manual. So, this
device is classified as Mobile Device.




Report No: 921113R02                         3


6 Test Results

6.1 Antenna Gain
The maximum Gain measured in Fully Anechoic Chamber is 3dBi or 1.995 (numeric)

6.2 Output Power Into Antenna & RF Exposure value at distance 20cm:
 for CCK technique
                Channel                                                  Limit of
                                 Output Power to Power Density
   Channel     Frequency                                              Power Density
                                  Antenna (mW)     (mW/cm2)
                 (MHz)                                                  (mW/cm2)
       1          2412                 56.234              0.022           1.0
       6          2437                 51.286              0.020           1.0
      11          2462                 50.119              0.020           1.0




Report No: 921113R02                          4



Document Created: 2003-12-01 10:57:02
Document Modified: 2003-12-01 10:57:02

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