CI Wireless CDR801, Руководство оператора

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Installation of the CDR812 CI Wireless Inc.
MirrorCell Select CDR812 Manual
7-2
Rev. X1
less than 15
°
are ideal candidates for the donor antenna. Microwave dish antennas also
provide the recommended front-to-back ratio of greater than or equal to 25dB to help
achieve the required antenna isolation.
The server antenna should provide the desired coverage and also provide the
recommended front-to-back ratio of 25dB. Many different types of antennas will work as a
server, such as panel antennas, Yagi antennas, and, for indoor applications, Omni-
directional antennas.
The isolation between antennas must be at least 10dB greater than the gain setting of the
repeater or the repeater could go into oscillation. Specific ways to achieve proper
isolation include:
•
using high gain, directional antennas with good front-to-back ratios (>25dB).
Also evaluate and select antenna with the desired antenna radiation pattern
(vertical and/or horizontal) that provides adequate insertion loss at angle(s)
of separation.
•
pointing the donor and server antennas opposite each other; ie, at 180
°
from
each other
•
physical separation of the repeater’s donor and server antennas, either
vertically or horizontally
•
external shielding, such as wire mesh or a grounded metal plane.
Antenna isolation limits the amount of gain to which the repeater should be set.
Therefore, if isolation is less than 105dB, the repeater cannot be set to the maximum gain
of 95dB.
7.4 Antenna Mounting
7.4.1 Donor Antenna
Use the following steps to mount the donor antenna.
1. Mount donor antenna at initially desired location.
2. Measure the received signal strength from the donor site. The amount of power the
repeater can produce is dependent on this signal level. Note whether the donor is
loaded or unloaded, as this will affect the amount of power needed.
3. If a greater signal strength is needed, try raising the donor antenna’s height, or use a
higher gain antenna, if possible.
4. Measure the pilot tone strength received after the donor antenna and verify that the
proper base station sector is being received. The pilot tone of the desired base
station should be at least 15dB higher than any of the other received pilot tones. If
this is not the case, the donor antenna should be adjusted until the desired pilot tone
is 15dB greater than any other received pilot tones. (Note that this requires a CDMA
signal measurement device.)