User's Manual

3. DAS 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 this digital
frequency repeater is very important for optimal system performance. Since
this is a multiband repeater, it’s important that all the peripheral components
used in the DAS supports all the frequencies that are going to be needed
and that all the components are Low PIM rated.
3. The signal strength and quality at the donor 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
recommended that the donor antenna be installed in clear line of sight
(LOS) to the serving sector/s.
4. The repeater is a two-way (full duplex) digital signal amplifier so, there needs
to be proper isolation between the outdoor antenna and indoor antennas in
order to avoid signal oscillation of the repeater. (Feedback) There needs to
be more than 15dB of isolation above the repeaters gain. For example, if
the repeater gain is 80dB, then you need 95dB 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 better than -80dBm with an Ec/Io
<6 and an RSRQ of <12dB. 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, Path Loss) + Antenna gain (outdoor antenna, indoor
antenna) + Repeater gain = Indoor signal strength.
8. For all cellular applications, you should only use 50 Ohm rated coax.
Besides affecting voice quality, using any other impedance of coax will
affect the throughput performance of services over LTE as well as shorten
the life of the repeater.
3.1 Installation Procedure
Site Survey
Carrier Coordination
Link Budget
Calculation
Retransmit Agreement
Install Donor Antenna
Install Cables & Sweep
Install Repeater
Install Indoor Antennas
Commission System
Gain Adjustment
Call & Data Quality
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System Optimization