User's Manual

RS- 5180CDMA800/1900 Dual Band Indoor Fiber Optic
Repeater
Comba Telecom
Edition
2.0
Date
2001-06 24 of 31
1800 > 0dBm. When one of them is off, it means that the input level of the
correspondent one is smaller than this normal value.
If only GSM 900MHz or CDMA1900Hz needs to be opened, 50 standard load
should be connected with the RF connector not in use. Then, the correspondent
uplink gain adjustment thumb wheel does not function and the correspondent
downlink RF power LED indicator is off.
4.1.2 Uplink Level Adjustment
Uplink level adjustment is a quite important step in the optimization of
system operation. If uplink level is too high, it may have impact on high drop
call rate of BTS (including GSM BTS and 1800 BTS), or even block BTS. If it
is too low, it may reduce the uplink sensitivity at the remote coverage area. In
practice, uplink attenuation should be determined according to the signal
coupling way and coupling degree of BTS. In general, the noise level of signal
input into BTS antenna port should be ≤ -125dBm BW300KHZ . On the panel,
for GSM, UP ATT manual attenuation adjustment figure 4.1-1: 16 and 17 can
provide the maximum adjustment range of over 30dBm with step of 2dB, and
the correspondent attenuations are 2, 4, 8, 8, and 16dB when DIP code 1, 2, 3,
4, and 5 are at the “ON” position. For 1800, it provides the maximum
adjustment range of over 25dBm with step of 1dB., and the correspondent
attenuations are 1, 2, 4, 8, and 16dB when DIP code 1, 2, 3, 4, and 5 are at
the “ON” position.