XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. 1.0.1
14.3
The DS1 Framing Structure
A single T1 frame is 193 bits long and is transmitted at a frame rate of 8000Hz. This results in an aggregate bit
rate of 1.544 Mbit/s. Basic frames are divided into 24 timeslots numbered 1 thru 24 and a framing bit as shown
in Figure 110. Each timeslot is 8 bits in length and is transmitted most significant bit first, numbered bit 0. This
results in a single timeslot data rate of 8 bits x 8000/sec = 64 kbit/s.
FIGURE 110. T1 FRAME FORMAT
DS1 Frame
125µs
Timeslot
Timeslot
24
Timeslot
2 - 23
Timeslot
23
F-bit
1
0
1
2
3
4
5
6
7
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
0
1
2
3
4
5
6
7
255
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