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AppendixAppendix
Electromagnetic Immunity
a
Field strengths from xed transmitters, such as base stations for radio (cellular/
cordless) telephones and land mobile radios, amateur radio, AM and FM radio
broadcast, and TV broadcast, cannot be predicted theoretically with accuracy. To assess
the electromagnetic environment due to xed RF transmitters, an electromagnetic site
survey should be considered. If the measured eld strength in the location in which the
equipment is used exceeds the applicable RF compliance level above, the equipment
should be observed to verify normal operation. If abnormal performance is observed,
additional measures may be necessary, such as reorienting or relocating the equipment.
Recommended Separation Distances Between Portable and
Mobile RF Communications Equipment and the System
You can help prevent electromagnetic interference by maintaining a minimum
distance between portable and mobile RF communications equipment
(transmitters) and the System, as recommended below, according to the
maximum output power of the communications equipment.
Rated
maximum
output power
of transmitter,
in watts
Separation distance according to frequency of transmitter,
in meters
150 kHz to 80 MHz
d = 1.17 √P
80 MHz to 800 MHz
d = 0.35 √P
800 MHz to 2.5 GHz
d = 0.7 √P
0.01 0.12 0.035 0.070
0.1 0.37 0.11 0.22
1 1.17 0.35 0.7
10 3.70 1.11 2.21
100 11.7 3.5 7.0
For transmitters rated at a maximum output power not listed above, the recommended
separation distances in meters (m) can be estimated using the equation applicable to the
frequency of the transmitter, where P is the maximum output power rating of the transmitter
in watts (W) according to the transmitter manufacturer.
NOTE 1: At 80 MHz and 800 MHz, the separation distance for the higher frequency range
applies.
NOTE 2: ese guidelines may not apply in all situations. Electromagnetic propagation is
aected by absorption and reection from structures, objects, and people.
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