Backhaul Analyzer Measurement Guide : T1/T3 Analyzer (Option 53)  : T3 Pattern/Loop Menu
 
T3 Pattern/Loop Menu
The Pattern/Loop menu includes 12 defined patterns (refer to Table: Pattern Descriptions and Applications). Up to 6 user‑defined patterns can be created by pressing the Set User Pattern submenu key.
Use this function to select a pattern, to set and select a user pattern, to use an inverse pattern, to select a loop code, or to loop up or loop down.
Submenu keys for the Pattern/Loop Menu are described in T3 Pattern/Loop Menu.
Pattern Descriptions and Applications
Pattern
Description
Application
QRSS
1,048,575 bit pattern
Simulates live traffic including both high and low-density sequences
1 IN 8
Eight bit pattern of a 1 and 7 zeros
Checks clock recovery on circuits optioned for B3ZS
2 IN 8
Eight bit pattern of two ones and 6 zeros
Used to determine correct optioning of AMI or B3ZS line coding
3 IN 24
24 bit pattern with 3 ones and 15 consecutive zeros. 12.5% ones density
Stresses AMI optioned circuits for minimum ones density and maximum consecutive zeros performance. Forces zero substitutions in B3ZS optioned circuits
ALL ONES
All ones sent as payload in a framed sequence
Stresses ability of circuit to operate under maximum power conditions
ALL ZEROS
All zeros sent as payload in a framed sequence
Checks for B3ZS optioning. Circuit will drop if optioned for AMI
1010
Alternating 1s and 0s
Stresses ability of circuit to operate under 50% power conditions
PRBS-9 (511)
511 bit pseudo-random pattern
Test sub-rate DDS circuits operating below 56 kb/s
PRBS-11 (2047)
2047 bit pseudo-random pattern
Test 56 kb/s DDS circuits
PRBS-15
32,767 bit pseudo-random pattern. Generates up to 14 consecutive zeros and 15 consecutive ones
Tests to CCITT Recommendations O.151 and G.703. Provides maximum number of zeros for testing non‑B8ZS circuits
PRBS-20
1,048,575 bit pseudo-random pattern Generates up to 19 consecutive zeros and 20 consecutive ones
Used to test synchronous T1 circuits only
PRBS-23
8,388,607 bit pseudo-random pattern Generates up to 22 consecutive zeros and 23 consecutive ones
Used to test synchronous T1 and T3 circuits