CSI CSI-DSP85-250-AW, Руководство по эксплуатации продукта

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System Set-Up Considerations
All cables should be checked for shorts and opens. Also verify that there are no cables with loose or poor
connections. RF leakage could cause oscillation to occur under some conditions.
The rooftop antenna (Donor Antenna), if directional, should be checked for proper alignment along the calculated
compass heading. Typically, the directional antenna would be aimed at the same site that your handset uses, but it
may not always be so.
It is critical the installer contact the service provider for information on, and
approval of, the cell site he or she has selected before the system is turned on.
If cables and alignment are acceptable and a problem persists, it may be necessary to use a spectrum analyzer to
examine the signal environment in which the repeater is operating. The existence of strong adjacent channel
signals within the frequency band(s) can cause the AGC to reduce the amplifier’s gain or cause alarms. In some
cases additional filtering or attenuation might be required to reject these unwanted signals. In some instances, the
donor antenna can be reoriented horizontally, to place the interference source in an antenna pattern “null”. There
also may be some cases where the interference from outside signals is so great that they cannot be filtered or
otherwise reduced or eliminated without expensive and possibly prohibitive measures. In these cases it may not
be practical to use the repeater for providing coverage to these sites.
Selection of external attenuators to be used in line with the Antenna Port(s):
1:1 PORT CONFIGURATION
Input : One single band duplex port, from the dual band donor.
Output : One single band duplex port to the DAS.
DONOR PORT
If a unit is installed in an area with very strong desired and/or undesired signals, it is important to ensure that the
overall signal levels are optimized to be within the best operating range of the repeater. Additionally, de-sensing of a
nearby base station site must be avoided. These goals can be accomplished by properly attenuating the antenna
port(s) in the path of the donor antenna(s). In effect, one can imagine that the particular repeater deployment is
electrically moved farther from the base station using attenuators that are equivalent to increasing the path loss from
the donor antenna to the base station. The following potential outcomes result from the use of attenuators on the
donor port(s) of the repeater: Uplink output power, as reported by the unit, is reduced by the value of the attenua-
tion, protecting nearby base stations. Downlink signal to noise ratio is high at the point of the attenuator, resulting in
slight but negligible reduction in downlink performance. Other performance is essentially unchanged.
SERVER PORT
Server port attenuation may also be necessary, particularly where a powered DAS is present. The selection guide-
lines below apply to both server and donor ports. In order to properly measure uplink signal strength, a signal
generator should be used. If a signal generator is not available, placing a test call while under the server antenna
with the least path loss to the repeater should provide reasonable data.
The following potential outcomes result from the use of attenuators on the server port(s) of the
repeater : Downlink
output power, as reported by the unit, is reduced by the value of the attenuation. Uplink incoming power from the
DAS is reduced, along with potentially strong and/or harmful out-of-band signals (including noise) that are generated
by the DAS.