3. Installation
1. The repeater’s main function is to improve weak RF signals to an area.
2. Selecting the appropriate accessories that are compatible with the
frequency of the repeater is very important for optimal system
performance. An 850Mhz Repeater needs to be used with accessories
that supports the 850Mhz band. In the same way, choosing accessories in
the 1900Mhz Band needs to go with a 1900Mhz Repeater etc. For dual
band or multi-band repeaters, please ensure the peripheral components
used supports all the frequencies needed.
3. The signal strength from the outdoor antenna directly affects the efficiency
of the indoor coverage. Therefore it is very important to choose the
location of the outdoor antenna carefully. With this in mind, it is not
recommended that the donor antenna be installed in an attic or at the side
of a building.
4. The repeater is a two-way (full duplex) signal amplifier. Therefore there
needs to be proper isolation between the outdoor antenna and indoor
antenna in order to avoid signal oscillation on the repeater. (Interference)
There needs to be more than 15dB of isolation above the repeater gain.
For example, if the repeater gain is 60dB, then you need 75dB of isolation
between outdoor antenna and indoor antenna.
5. The repeater gain is adjustable for both the uplink / downlink individually.
Depending on the environment, the end-user may need to adjust the
repeater gain to achieve optimum performance and desired coverage.
6. The repeater is designed to amplify the input signal, filter it and retransmit
it to the desired area via service antennas. In order to reach the best
performance, the outdoor signal should be greater than -80dBm, and not
over +10dBm. If the outdoor signal is very weak, then a pre-amplifier may
be used.
7. Calculating the Link budget before setting the repeater gain.
Link budget calculation:
Outdoor signal strength – Loss of accessories (cable, connectors,
splitters, Directional Couplers) + Antenna gain (outdoor antenna, indoor
antenna) + Repeater gain = Indoor signal strength.
8. For all cellular applications, you need to use 50 Ohm rated coax.
Besides affecting voice quality, using any other impedance of coax will
put an extra load on your repeater and shorten its life span.
3.1 Installation Procedure
Site Survey
Installation Planning
Link Budget Calculating
Install Outdoor Antenna
Cable Installation
Install Repeater
Install Indoor Antennas
Signal Measurement
Gain Adjustment
Test for Call Quality
Trouble Shooting
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