12
Installation PTN-2-C37.94 with E1/PTN-2-C37.94 with T1
Release 01 02/2018
Frame = 125 µs = 32 time slots
Bit slot
Time slot
F = Framing
S = Signaling
0
1
2
16
31
Frame
1
1
16
Multiframe = 2 ms
F
S
Figure 6
E1 Framing
2.2.3
T1 Framing
T1 is a 1.544 Mbps bi-directional (full duplex) link through which the data is transported in a
digital way in frames. One frame consists of 24 time slots + 1 bit (Figure 7). The extra bit is
used for framing. The bandwidth of one time slot is 64 kbps (8 bits). One frame thus consists
of (24*8)+1 = 193 bits and lasts 125 µs. Depending of the framing algorithm applied either
12 or 24 frames are packed together in one multiframe. Signaling bits are transported in the
Least Significant Bit of the time slots in each multiframe agreed upon (in-band).
NOTE:
Multiframe = (E)SF (=(Extended) Super Frame) = future support;
Frame = 125 µs = 24 time slots
Bit slot
Time slot
0
F
Frame
1
1
12
Multiframe (SF)
23
Multiframe (ESF)
or
1
24
1
Figure 7
T1 Framing
2.2.4
C37.94 Framing
A C37.94 optical link is a 2.048 Mbps bi-directional (full duplex) link through which the data
is transported in a digital way in frames. One frame consists of a Header (=H), Overhead
(=OH) and Timeslots (=T) including Channel Data, see figure below. The Header is used for
framing and synchronization. The Overhead includes the number (=N) that indicates the
amount of transported data channels (N = 1, 2, …, 12). Each data channel bit in the timeslots
is transmitted twice. It means that each time slot comprises 8*2 = 16 bits. Unused timeslots
are filled with ones. The bandwidth of one timeslot is 64 kbps (=8 bits/125 µs).
