9-12
Performing tests using a DCSM
411-2051-500
Draft
00.01
November 1999
Troubleshooting action
If the test fails then it should be repeated for verification. Should the test still
fail the following hardware components may be at fault:
•
the TRU
•
ICRM packs (the AX50s, AX47s, AX87s)
•
the T1 transmission equipment used
•
the ICP cards (the AX50s)
The signal may be rerouted to eliminate and pinpoint faulty hardware
components, or the equipment may be swapped one at a time with known
good units and the test repeated. When the test passes the faulty unit may have
been found.
The MTX RF Low and High Tests (MRLT and MRHT)
The MTX RF Low and High tests measure an audio tone which has been looped
at the DCSM. The test verifies the RF path on the forward and reverse links of
the DUT. The test therefore verifies the RF portion of the circuit. The MRLT
test measures the following three parameters of the circuit:
•
the Loop Loss
•
the Loop Noise
•
the Path Far-to-Near Loss
The MRLT and MRHT tests can be invoked in the following ways:
•
from a posted transceiver at the VCH MAP levels
•
from the CTT level (all available VCH are tested starting with the first
available)
•
automatically using Table CTTSCHED (this also selects the first available
VCH)
Once the test is invoked a call is terminated to the DCSM mobile. The DCSM
then transmits a 1004 Hz tone at 2.9 kHz deviation for 5 seconds, after which
the FWD audio is looped to the REV audio. The TTT then transmits a tone
(level and frequency determined in Table CTTPARMS) which is transmitted
on the forward RF path by the DUT to the DCSM. The DCSM subsequently
loops the forward audio to the reverse audio and transmits the tone to the
DUT through the reverse RF path. The returned audio is finally measured by
the TTT. The values measured are returned in the log report which is
subsequently reported to the technician at the MAP terminal through MTX
Log 303. Figure 9-4 shows the test path and the measured path measurements.
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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