T1: The T1 Generator - Wavetek TETRA MS Test Operating Instructions Manual

Modes of operation

T1: The T1 generator

This is a mode of operation in which the mobile station reads a signal with a
special data format (called "T1 signal") from the test equipment; the signal allows
the MS to synchronize with the test equipment. The signal can be used to perform
receiver measurements, assuming the data received in the mobile are evaluated
by the mobile itself or forwarded to an external PRBS analyzer.
The T1 signal is a PRBS sequence on a logical channel supported by TETRA.
For type approval, tests with the T1 signal are required on the following logical
channels: TCH/7.2, SCH/F, SCH/HD, TCH/2.4. For receiver testing in the field,
tests on TCH/7.2 are most appropriate because the data on this logical channel
are not protected against degradation due to RF interference, fading and Doppler
effect. The other logical channels carry redundancy; this helps the receiver detect
reception errors and possibly correct them. Since the purpose of receiver meas-
urements is to test the performance of the receiver itself, and not the error
recovery software, the STABILOCK only supports tests on the unprotected
TCH/7.2.
Outside the specified logical channel, the STABILOCK transmits a modified
Broadcast Network Channel BNCH/T and a Base Synchronization Channel
BSCH on frame 18 of each multiframe, in accordance with conformance testing
specification ETS 300 394-1.
In order to start the T1 bit pattern generator, follow the procedure below:
•
On the DEF.SET mask, the scroll field on the right hand side of the Channel
Offset field can be in either of two states: Sign.Trace or Measurements. Use
the
[UNIT/SCROLL]
•
Press the key (Fig. 10.8). The
{T1}
generator again and to return to the basic menu.
Fig. 10.8:
The T1 bit pattern generator uses the par-
ameters from the left-hand side of the basic,
mask, especially the scrambling parameters
MCC, MNC, and BCC.
"
In all cases where a special testmode software (reading out BER value from the
mobile) is not available, see also chapter "Paging sensitivity search function".
key to switch to Measurements.
{RETURN}
TETRA MS Test
key can be used to stop the
10
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