Agilent Technologies N4906B Serial BERT User Manual page 32

Setting up Patterns
32
• PRBS23_1-2.ptrn
• PRBS23_6-8.ptrn
• PRBS23_7-8.ptrn
• PRBS7-1_1-2.ptrn
TI P
The file names indicate how the patterns are configured. For example,
PRBS23_6-8.ptrn has a pattern length of 2^23 (8,388,608) bits and a
mark density of 3/4 (6/8 or 75 percent).
NO TE
PRBS7-1_1-2 is an emulation of a hardware-generated PRBS 2^7
pattern with a mark density of 50 percent.
SDH CID This directory contains the following pattern:
• SDH_STM-16_CID.ptrn
Pattern is a SDH STM-16 rate Consecutive Identical Digit (CID )
pattern, same length as a SDH frame with nine bytes of all 1s and
nine bytes of all 0s separated by random data. This implementation
uses one SDH "frame" to carry the CID pattern as follows: A1, A2,
and C1 bytes as per a normal frame, followed by a block of bytes set
to all 1s, then the normal scrambler sequence (2^7 PRBS) starting
with 1111 111. Half way through the frame, at row 5 column 40, an
A1, A2, and C1 sequence is inserted again followed by a block of
bytes set to all 0s, then the normal scrambler sequence starting with
1111 111 again. The length is 148,992 bits (STM-16) corresponding
to a time constant of about 4 msec.
SDH STM4
• SDH STM-4.ptrn
A standard SDH STM-4 frame and payload. Total pattern length of
77,760 bits.
SDH STM16
All patterns are STM-16 SDH frame, standard pattern, scrambler ON,
and 1010... payload:
• SDH_STM-16.ptrn
Pattern contains no errors or alarms
• SDH_STM-16_HP-BIP.ptrn
Pattern for testing frames with erred parity check sums, (B3) error
• SDH_STM-16_HP-REI.ptrn
Pattern for testing Remote Error Indication (RDI) alarm
Agilent N4906B Serial BERT, User's Guide, October 2005
User Patterns