7-4
Enhanced Receive Multicoupler (ERMC) tests
411-2051-500
Draft
00.01
November 1999
ERMC gain adjustment
This section refers to the RF Engineering Guidelines for 800 MHz Cellular
Systems, 411-2131-007, specifically the Talk-in Talk-out (TITO) adjustment.
Gain setting are factory preset to 16 dB but specific cell site requirements
may differ. Refer to the 800 MHz ERMC Deployment Guide, 411-2131-940,
for more information on the ERMC.
Note: Use caution when attempting to adjust the ERMC variable
attenuator. Overall system performance may suffer seriously, therefore a
thorough understanding of the RF Engineering Guidelines should be
acquired.
Talk-In/Talk-out (TITO) balance test
The main purpose of the Talk-In/Talk-Out (TITO) test is to ensure that the
ERMCs are tuned correctly. If they are not, the user could get noisy channels
usually due to co-channel interference, low RF levels, or both. This usually
happens to sites with large coverage where the multicoupler does not have
sufficient gain to balance to talk-in path.
This test is required when there is a problem with the receive path and the
ERMCs are suspected of faulty operation.
If the ERMCs are suspected to be faulty this test will verify if they actually
are. There are two tasks that are done at the same time with this test after a
call has been set-up.
1. You are monitoring a channel and RSSI (Receive Signal Strength
Indicator) from the mobile.
2. You are monitoring the same channel and RSSI at the cell site.
Figure 7-2 shows the call setup for a TITO balance test.
CAUTION
Service affecting
This test is service affecting and will take two TRU Radios off
line. This test should be done when there is a problem; not as a
regular maintenance routine.
Summary of Contents for DualMode 800
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Page 6: ...vi Publication history Nortel Networks Confidential 411 2051 500 Draft 00 01 November 1999...
Page 82: ...2 20 Periodic maintenance 411 2051 500 Draft 00 01 November 1999...
Page 90: ...3 8 Test equipment and precautions 411 2051 500 Draft 00 01 November 1999...
Page 100: ...5 6 Master Oscillator tests 411 2051 500 Draft 00 01 November 1999...
Page 106: ...6 6 Antenna and transmission line tests 411 2051 500 Draft 00 01 November 1999...
Page 116: ...8 4 Alarm Control Unit ACU tests 411 2051 500 Draft 00 01 November 1999...
Page 138: ...10 2 ICRM tests 411 2051 500 Draft 00 01 November 1999...
Page 200: ...12 10 Enclosure maintenance 411 2051 500 Draft 00 01 November 1999...
Page 208: ...A 8 Appendix A Frequency table 411 2051 500 Draft 00 01 November 1999...
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