Nortel DualMode 800, Maintenance Manual

Page: 133 / 216

Performing tests using the DCSM in the directed mode 9-17
Wireless Solutions DualMode 800 Enclosure Maintenance Manual MTX08
• Combiner
• ICRM packs (the AX50s, AX47s, AX87s)
• T1 transmission equipment used
• ICP cards (the AX50s, AX27s)
• DCSM
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. Additionally, determine if the MALT or MAHT test has passed or
not to isolate the path failure location further.
TEST MRLR
The MTX Radio receiver test. The test measures the following:
• the RSSI (dBm) of the reverse RF path
• the Loop Loss in dB
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 five 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. Once the link has been verified,
the DUT is instructed by the MTX to measure the RSSI of the received RF
signal on the reverse RF path. The measured RSSI is returned to the MTX for
reporting along with the looped level measured by the TTT. Refer to Figure 9-
9 for a diagram of the test operation.
The test either passes or fails depending on the RSSI level returned is within
the limits set by the MRLR tuple in Table CTTPARMS. Table CTTGROUP
defines the RF power level which the DCSM should transmit on the reverse
path.