TFRA08C13-DB AGERE [Agere Systems], TFRA08C13-DB Datasheet - Page 34

• Manufacturer Part Number: TFRA08C13-DB
• Description: TFRA08C13 OCTAL T1/E1 Framer
• Manufacturer: AGERE [Agere Systems]

TFRA08C13 OCTAL T1/E1 Framer
Frame Formats
The supported North American T1 framing formats are superframe (D4, SLC -96, and digital data service-DDS)
and extended superframe (ESF). The device can be programmed to support the ITU-CEPT-E1 basic format with
and without CRC-4 multiframe formatting. This section describes these framing formats.
T1 Framing Structures
T1 is a digital transmission system which multiplexes twenty-four 64 kbits/s time slots (DS0) onto a serial link. The
T1 system is the lowest level of hierarchy on the North American T-carrier system, as shown in Figure 7
Table 7. T-Carrier Hierarchy
Frame, Superframe, and Extended Superframe Definitions
Each time slot (DS0) is an assembly of 8 bits sampled every 125 µs. The data rate is 64 kbits/s and the sample rate
is 8 kHz. Time-division multiplexing 24 DS0 time slots together produces a 192-bit (24 DS0s) frame. A framing bit is
added to the beginning of each frame to allow for detection of frame boundaries and the transport of additional
maintenance information. This 193-bit frame, also referred to as a DS1 frame, is repeated every 125 µs to yield the
1.544 Mbits/s T1 data rate.DS1 frames are bundled together to form superframes or extended superframes.
34
T Carrier
T1-C
T1
T2
T3
T4
FRAME 1
F BIT
FRAME 1
DS0 Channels
TIME SLOT 1
FRAME 2
4032
672
1
24
48
96
2
FRAME 2
3
TIME SLOT 2
FRAME 3
4
Figure 7. T1 Frame Structure
5
6
Bit Rate (Mbits/s)
7
274.176
44.736
1.544
3.152
6.312
8
FRAME 11
TIME SLOT 24
FRAME 23
FRAME 12
Digital Signal Level
FRAME 24
Preliminary Data Sheet
DS1C
DS1
DS2
DS3
DS4
Lucent Technologies Inc.
Lucent Technologies Inc.
24-FRAME EXTENDED
12-FRAME SUPERFRAME
193-bit FRAME
8-bit TIME SLOT
DS1 = 125 s
DS0 = 5.19 s
SUPERFRAME
ESF = 3.0 ms
SF = 1.5 ms
October 2000
5-4559(F).br.1