Telecommunications Techniques Corporation interceptor 147, Reference Manual, Page: 261 / 280

D-3
D
INTERCEPTOR 147 2 Mbit/s and Data Analyzer
Understanding G.821 Performance Analysis
Even though there were 3 consecutive seconds (the 26th,
27th, and 28th) which each had a BER greater than 10
-3
, 10
such consecutive seconds are required to make the transition
to unavailable time. Those 3 individual seconds are still
in available time and they are counted as Avl Sec.
Figure D-2
Sliding Window after 29th Test Second still in
The 3 seconds with a BER greater than 10
-3
are also
included in the count of severely errored seconds (SES),
which are those seconds with a BER greater than 10
-3
that
occur in available time. A signal loss second or a second
in which pattern synchronization is lost is also considered
to be a second with a BER greater than 10
-3
. Therefore, the
current test result values for the Avl Sec count = 29; the
SES count = 3 and the Unavl Sec count = 0.
Figure D-3
Sliding Window after 88th Test Second
sec
20
BER
<=
sec
21
BER
<=
sec
22
BER
<=
sec
23
BER
<=
sec
24
BER
<=
sec
25
BER
<=
sec
26
BER
>
sec
27
BER
>
sec
28
BER
>
sec
29
BER
<=
sec
79
BER
<=
sec
80
BER
>
sec
81
BER
>
sec
82
BER
>
sec
83
BER
>
sec
84
BER
>
sec
85
BER
>
sec
86
BER
>
sec
87
BER
>
sec
88
BER
>