User's Manual

Safety High Power Wideband Radio Head (WRH-V)
1-2 044-05251 Rev A
❑ The FON unit contains a class IIIb laser transmitter that emits 2 – 4mW invisible laser
radiation during operation. Avoid direct exposure from unconnected laser transmitter or
fiber cord.
❑ Do not power up the FON unit if a fiber cable is not attached to the fiber output UL port,
neither if a fiber cable is attached to the port but unattached in the other end.
❑ Never look in the end of a fiber cable. The 1310nm and 1550nm laser light is not
visible, so no signal identification can be made anyway. Use always an instrument,
such as a power meter to detect signaling.
❑ Never use any kind of magnifying devices that can focus the laser light to an
unaided eye.
Human Exposure of RF Radiation
Safe distances must be kept when working around antennas. The following paragraphs describe the cautions
to be aware of during the installation and maintenance of antenna systems and how to calculate safety
distances needed for RF radiation at different antenna power and frequencies.
Antennas
To be able to receive and transmit signals, a WRH-V is connected to a donor antenna directed towards the
base station and a service antenna directed towards the coverage area. A fiber optic cable from the base
station might, however, be substituted for the donor antenna.
Installation and Maintenance of Antenna Systems
Installation and maintenance of all antenna systems must be performed with respect to the radiation exposure
limits for public areas. The antenna radiation level is affected by WRH-V output power, antenna gain, and
transmission devices such as cables, connectors, splitters and feeders. Also have in mind the system minimum
coupling loss, typically between 25dB and 35dB, is determined by a standard with the purpose to protect base
stations from noise and other performance dropping effects.
Radiation Exposure
The World Health Organization (WHO) and International Commission on Non-Ionising Radiation Protection
(ICNIRP) have determined recommendations for radiation exposure. ICNIRP recommends not to exceed the
following radiation power for public exposure:
Frequency Radiation power
800/900 MHz 4.5W/m²
1800/1900 MHz 9.0W/m²
2100 MHz 10.0W/m²
For antennas larger than 20cm the maximum radiation power can be calculated by using the following formula:
Electrostatic Discharge (ESD)
ESD can severly damage essential parts of the equipment if not handled carefully. Parts on
printed circuit board assemblies (PCBA) as well as other parts in the equipment are sensitive
to ESD. Never touch the PCBA or uninsulated conductor surfaces unless absolutely
necessary.
If you must handle the PCBAs or uninsulated conductor surfaces, use ESD protective
equipment or first touch the chassis with your hand. Never let your clothes touch PCBAs or
uninsulated conductor surfaces and always store PCBAs in ESD-safe bags.
S= P/(4
πr
2
)
S = Radiation power in W/m²
P = Output power in W
r = Distance between antenna and human in meters