AT&T 2500 series Benutzerhandbuch
1-26
MULTIPLEXED COMMUNICATION
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ROBBED BIT (OPTIONAL)
ROBBED BIT (OPTIONAL)
ROBBED BIT (OPTIONAL)
ROBBED BIT (OPTIONAL)
8-BITS
8-BITS
8-BITS
8-BITS
8-BITS
7-BITS
8-BITS
8-BITS
8-BITS
8-BITS
8-BITS
7-BITS
8-BITS
8-BITS
8-BITS
8-BITS
8-BITS
7-BITS
8-BITS
8-BITS
8-BITS
8-BITS
8-BITS
7-BITS
FRAME BIT
DEFINITIONS
FRAME
NUMBER
FRAME BIT
DATA LINK F BIT (DL)
CRC-6 F BIT
DATA LINK SIGNAL
FRAME SYNC PATTERN
DATA LINK SIGNAL
CRC-6 F BIT
DATA LINK SIGNAL
FRAME SYNC PATTERN
DATA LINK SIGNAL
CRC-6 F BIT
DATA LINK SIGNAL
FRAME SYNC PATTERN
DATA LINK SIGNAL
CRC-6 F BIT
DATA LINK SIGNAL
FRAME SYNC PATTERN
DATA LINK SIGNAL
CRC-6 F BIT
DATA LINK SIGNAL
FRAME SYNC PATTERN
DATA LINK SIGNAL
CRC-6 F BIT
DATA LINK SIGNAL
FRAME SYNC PATTERN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
CHANNEL 1
CHANNEL 2
1
1
0
1
0
0
D
C
B
A
Figure 1-8. The Extended Super Frame
Robbed-Bit Signaling
In every 6th frame, robbed-bit signaling (RBS) replaces (that is, "robs") the least-significant bit (LSB) of
each channel. It replaces this bit with the signaling information for that channel. For D4, the 6th and 12th
frames carry RBS; for ESF, the 6th, 12th, 18th, and 24th frames carry RBS (refer to figures 1-7 and 1-8,
respectively).
each channel. It replaces this bit with the signaling information for that channel. For D4, the 6th and 12th
frames carry RBS; for ESF, the 6th, 12th, 18th, and 24th frames carry RBS (refer to figures 1-7 and 1-8,
respectively).
Because the signaling information is carried embedded within each channel, RBS signaling is also called
inband signaling.
inband signaling.