tfra08c13 ETC-unknow, tfra08c13 Datasheet - Page 33

• Manufacturer Part Number: tfra08c13
• Description: Tfra08c13 Octal T1/e1 Framer
• Manufacturer: ETC-unknow

Preliminary Data Sheet
October 2000
Lucent Technologies Inc.
Lucent Technologies Inc.
LIU-Framer Interface
CEPT: High-Density Bipolar of Order 3 (HDB3)
The line code used for CEPT is described in ITU Rec. G.703 Section 6.1 as high-density bipolar of order 3 (HDB3).
HDB3 uses a substitution code that acts on strings of four zeros. The substitute HDB3 codes are 000V and B00V,
where V represents a violation of the bipolar rule and B represents an inserted pulse conforming to the AMI rule
defined in ITU Rec. G.701, item 9004. The choice of the B00V or 000V is made so that the number of B pulses
between consecutive V pulses is odd. In other words, successive V pulses are of alternate polarity so that no direct
current (dc) component is introduced. The substitute codes follow each other if the string of zeros continues. The
choice of the first substitute code is arbitrary. A line code error consists of two pulses of the same polarity that is not
defined as one of the two substitute codes. Excessive zeros consists of any zero string length greater than four
contiguous zeros. Both excessive zeros and coding violations are indicated as bipolar violations. An example is
shown in Table 6.
Table 6. ITUHDB3 Coding
HDB3 with 5 Double BPVs
HDB3-coded Levels
HDB3-coded Data
Input Bit Stream
(continued)
1011
1011
–0+–
–0+–
0000
000V
000–
–000
1-BPV
01
01
0+
0+
0000
000V
000+
+00+
3-BPV
0000
B00V
–00–
0–– –
5-BPV
TFRA08C13 OCTAL T1/E1 Framer
0000
B00V
+00+
+00+
0000
B00V
–00–
–00–
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