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Figure 14-6. T3 Stuff Block Structure
M1
Subframe
F4 Stuff
Bit 1
Info
Bit 2
Info
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Info
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Info
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Info
Bit 6
Info
Bit 7
Info
Bit 8
...... Info
Bit 84
M2
Subframe
F4 Info
Bit 1
Stuff
Bit 2
Info
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Info
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Info
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Info
Bit 6
Info
Bit 7
Info
Bit 8
...... Info
Bit 84
M3
Subframe
F4 Info
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Info
Bit 2
Stuff
Bit 3
Info
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Info
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Info
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Info
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Info
Bit 8
...... Info
Bit 84
M4
Subframe
F4 Info
Bit 1
Info
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Info
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Stuff
Bit 4
Info
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Info
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Info
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Info
Bit 8
...... Info
Bit 84
M5
Subframe
F4 Info
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Info
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Info
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Info
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Stuff
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Info
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Info
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Info
Bit 8
...... Info
Bit 84
M6
Subframe
F4 Info
Bit 1
Info
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Info
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Info
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Info
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Stuff
Bit 6
Info
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Info
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...... Info
Bit 84
M7
Subframe
F4 Info
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Info
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Info
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Info
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Info
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Stuff
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...... Info
Bit 84
14.8 E13 Basics
E13 multiplexing is a two-step process of merging 16 E1 lines into a single E3 line. First, four of the E1
lines are merged into a single E2 rate and then four E2 rates are merged to form the E3. The first step of
this process is called a E12 function since it is merging E1 lines into E2. The second step of this process
is called a E23 function since it is merging E2 lines into a E3. The term E13 implies that both E12 and
E23 are being performed to map 16 E1 lines into the E3. These two steps are independent and will be
discussed separately.
Table 14-5. E Carrier Rates
E CARRIER
LEVEL
NOMINAL DATA
RATE (Mbps)
E1 2.048
E2 8.448
E3 34.368