ADC FlexWave Prism System Reference Manual page 168

Initial Prism System Setup
For dual DART configurations, such as dual-pcs, smr800/smr900 and
dual-aws, both DARTs must have
The diversity status of the Host DART will extend to the Remote DART connected to it.
For further information, see
e e In the
DART Forward Gain
loaded forward path signal level from the Base Station. The Host DART expects
signal levels from
DART forward gain should be set to 0 dB, if the fully loaded signal is -25 dBm,
then the DART Forward Gain should be set to 30 dB. The equation is:
DART Forward Gain = 5 - fullyLoadedBasestationSignal.
If you are setting up the system when no calls are going through, you must allow
headroom for a fully loaded forward path. For CDMA protocols, the difference from
unloaded to fully loaded is typically 8dB, so if the unloaded signal is - 15dBm, then the
fully loaded input would be - 7 dBm and the Host Forward Gain should be set to 5- (- 7)
= 12 dB.
The same rules applies for GSM carriers, except that the unloaded to loaded is
determined by the equation 10*log10(# RF Channels). So if there are 4 GSM RF Channels,
then the loaded forward path is 6 dB above unloaded.
If sufficient headroom is not present, then the LPA can be over- powered causing a Loss
Of Service.
When configured correctly, the Host DART Forward input can handle peaks of 14dB
above the BTS signal level. For example, if the fully loaded CDMA carrier is - 25dBm, then
peaks up to - 11 dBm can be handled (CDMA peak to average is typically 10- 12 dB). If
the peaks exceed the 14 dB of headroom, then Automatic Level Control (ALC) will occur
to prevent over- driving the A/D Converter.
f f Set the
DART Reverse Gain
the Remote to the output of the Host DART. The range is:
• to
5 36 dB
AWS DARTs
• to
0 31 dB
Page 154
© 2009 ADC Telecommunications, Inc
DART Diversity Status
"Link the Host and Remote DARTs." on page
list, set this value (0 to 31 dB) based upon the fully
to . If the fully loaded signal is +5 dBm, then the
-25 +5 dBm
value to achieve the required gain from the input to
for Cellular, SMR800, SMR900, Narrowband PCS & Narrowband
for Fullband GSM1800, UMTS, Fullband AWS, and EGSM900
FlexWave Prism Host, Remote and EMS 5.1 System Reference
set to
nonDiversity
159.
ADCP-77-073 • Issue 2 • 11/2009
CORNING EX1005, page 168
IPR2021-00762
.