User's Manual

Fiber Optics Powerwave
1 - 4 Rev. P1A9-Draft 2004-11 VM100 56/EN – User’s Manual
Radiation Exposure
WHO, World Health Organization, and ICNIRP, International Commission on Non-
Ionising Radiation Protection, have determined recommendations for radiation
exposure.
ICNIRP recommends not to exceed the following radiation power for public exposure:
Frequency Radiation power
900MHz 4,5W/m²
1800MHz 9,0W/m²
2100MHz 10,0W/m²
For antennas larger than 20cm the maximum radiation power can be calculated by using
the following formula:
where
S = Radiation power in W/m².
P = Output power in W.
r = Distance between antenna and human in meter.
To tackle the worst case successfully, the calculation does not consider system power
reducing actions, such as power control and DTX.
Figure 1-1 shows the safety distance to an antenna due to the RF radiation. The distance
is depending on the antenna output power and frequency, which is illustrated with two
graphs in the figure.
One of the graphs applies to 4.5W/m
2
(900MHz) and the other to 9.0W/m
2
(1800MHz)
or 10.0W/m
2
(2100MHz).
The safety distance range in Figure 1-1 is 0 to 1.4 meter that covers an antenna power
range of 10dBm to 50dBm (0.01W to 100W).
Radiation Safety Distances
This section illustrates the safety distances to the antennas for some typical repeater
configurations.
Outdoor GSM 900MHz
The safety distance can be read to 0.75 meter in Figure 1-1 as the maximum radiation
power is 4.5W/m² for 900MHz.
S
P
4
S r
2
uu
-------------------
=
Repeater output power +33dBm
Feeder loss –5dB
Antenna gain +17dBi
EIRP +45dBm