Telecommunications Techniques Corporation interceptor 147, Reference Manual, Page: 263 / 280

D-5
D
INTERCEPTOR 147 2 Mbit/s and Data Analyzer
Understanding G.821 Performance Analysis
10
-3
. We are still in unavailable time, so these seconds are
counted as Unavl Sec; now the total Avl Sec count = 79
and the total Unavl Sec count = 71.
Figure D-5
Sliding Window after 160th Test Second
Transition to Available Time
Beginning with the 151st second, the BER for that second
is less than 10
-3
, as shown in Figure D-5. It is still counted
as an Unavl Sec since we are still in unavailable time and
the transition has not been made to available time. A BER
less than 10
-3
also occurs for the 152nd through the 160th
seconds. Since there are now 10 consecutive seconds with
a BER less than 10
-3
, the transition is made from unavailable
time to available time.
As each of these 10 seconds occurred, it was added to the
Unavl Sec count (Unavl Sec = 81, Avl Sec = 79, and SES
= 3). Now that those consecutive seconds have triggered
the transition to available time, they are deducted from the
Unavl Sec count and added to the Avl Sec count. Now the
Unavl Sec count = 71 and and the Avl Sec count = 89.
The monitoring of available and unavailable time continues
for the duration of the test.
sec
151
BER
<
sec
152
BER
<
sec
153
BER
<
sec
154
BER
<
sec
155
BER
<
sec
156
BER
<
sec
157
BER
<
sec
158
BER
<
sec
159
BER
<
sec
160
BER
<