TMXF28155 Supermapper
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
Data Sheet
June 2002
12 28-Channel Framer Registers (continued)
Table 397. FRM_PMLR4, Performance Monitor Link Register 4 (COR) (continued)
Address* Bit
Name
Function
Reset
Default
0x8LP83 10
FRM_AIS
Alarm Indication Signal. A 1 indicates the framer is currently
receiving an AIS pattern or receiving an AIS indication on the
TDM bus from the mapper.
0
DS1: Option 0: AIS occurs upon detection of an unframed sig-
nal with a ones density of at least 99.9% for a time between
3 ms and 75 ms. AIS is removed if the signal does not meet the
99.9% ones density or the unframed criteria for a period
between 3 ms and 75 ms. (ANSI T1.231, Section 6.1.2.2.3,
T1.403, Section H, G.775, Section 5.4.)
Option 1: AIS is detected if the signal has one or less zeros in
24 frames (3 ms/4632 bits). AIS is removed if the signal has two
or more zeros in 24 frames. (ANSI G.775, Section I.2.)
CEPT: Option 0: AIS is detected when loss of frame alignment
occurs and there are two or less zeros in a double frame period
(512 bits per double-frame period). AIS is cleared on receipt of
a signal not conforming to the AIS defect criteria. (ANSI G.775,
Section I.2; G.965, Section 16.1.2.)
Option 1: AIS is detected when there are two or fewer zeros in
each of two consecutive double-frame periods (512 bits per
double frame period). AIS is cleared when each of two consecu-
tive double frame periods contain three or more zeros or the
frame alignment signal (FAS) is found. (ANSI G.775, Section
5.2.)
Option 2: AIS is detected when there are three or less zeros in a
four frame period (0.5 ms/1024 bits) and the signal is out of
frame. AIS is cleared if there are four or more zeros in a four-
frame period or the signal is in frame alignment. (ANSI G.775,
Section I.2.)
Option 3: AIS is detected when there are one or fewer zeros in
each of two consecutive double-frame periods (512 bits per
double-frame period) and the FAS is not detected. AIS is
cleared when each of two consecutive double-frame periods
contain three or more zeros or the frame alignment signal (FAS)
is found. (ANSI G.775, Section I.2.)
* See Table 393 on page 279 for values of L and P.
282
Agere Systems Inc.
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