ZXG10 BS21 (V2.2) Compact Outdoor BTS for GSM Maintenance Manual
164
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gets faulty, the assignment failure ratio and uplink quality
switchover will be influenced, resulting call drop.
viii.
Interference (co-frequency and co-color-codes).
Severe bit errors will occur when MS receives strong interference
from co-frequencies or adjacent frequencies, which make MS
unable to accurately demodulate the BSIC of the adjacent cells and
correctly receive the MS measurement report, resulting drop-out.
ix.
Antenna feeder faults.
¾
The main and diversity antennas are equipped in all cells when a
base station is installed. It is possible that the BCCH and SDCCH of
the cell are sent out from the two different antennas. Different
pitch angles of the two antennas will cause their different coverage.
That is, the MS can receive the BCCH signal but can not occupy the
SDCCH sent out by the other antenna when initiating calls, which
results in drop-out.
¾
The main and diversity antennas are equipped in all cells when a
base station is installed. When the azimuth angles of the two
antennas are different, the MS can receive SDCCH. But once it is
assigned to the TCH transmitted by the other antenna, drop-out
will occur.
¾
Damaged feeder cable, water leakage and poor connector contact
will reduce the transmission power and receiving sensitivity,
resulting in severe call drop.
x.
Transitory transmission interruption
Unstable transmission links will make the lower-layer links unstable
and signaling lost, resulting in Abis interface call drop.
Содержание ZXG10 BS21
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