Anrtisu Cell Master MT8212B, Руководство пользователя, Страница: 195 / 294

Testing T1 Circuits
T1 circuit testing can be done with either of two methods: In service and Out of service
testing.
In service testing is done during routine maintenance and troubleshooting phase. This can
be done on live data without removing the T1 circuit from service or done on live data.
Monitoring live data allows wireless service provider technicians to detect alarms, bipolar
violations (BPV) and frame errors but bit errors cannot be measured. However they may be
estimated by measuring CRC errors or frame errors.
Out of Service testing is done when T1 is initially installed and before final acceptance
from the LEC. At that time the circuit should be subjected to critical testing to guarantee the
level of service per contract. Out of service testing may also be performed when the circuit
performance is very poor. For Out of service testing T1 should be removed from service
which allows detailed performance testing of the T1 circuit.
In Service Testing
In service testing can only be done when the equipment has a test port. When testing a T1
circuit in service it is always better to perform a bridged or monitoring test, to avoid dis-
rupting service. Even when the T1 circuit is down these tests will help to verify and identify
the correct fault circuit. The following measurements can be used to check the T1 perfor-
mance during regular maintenance:
q
V
pp
Measurement
q
Carrier
q
Frame Sync
q
CRC Errors, for Extended Super Frame (ESF)
Required Equipment
q
MT8212B Cell Master with Option 50
q
Bantam Cables, Anritsu Part Number 806-16 (2)
Vpp Measurement Procedure
Step 1. Press the MODE key, select
T1 Tester
, and press ENTER .
Step 2. Select the
Vpp
soft key.
Step 3. Press the
Terminate/Bridged
soft key and select
Bridged
mode.
Step 4. Press the
Start/Stop Measure
soft key to start or stop the peak to peak voltage
measurement.
If the measurement meets the customer requirements for this system, proceed to the BERT
measurement.
NOTE: Vpp measurement can be displayed in dBdsx format by pressing the
Vpp/dBdsx soft key.
BERT Measurement Setup
Step 1. Press the MODE key, select
T1 Tester
, and press ENTER .
9-4
Chapter 9 T1 Measurements