Unit installation

FCD-E1 E1 Environment C-1
Appendix C
Operating Environment
C.1 Scope
This appendix presents a concise description of the operating environment of
FCD-E1 systems, to provide th
e background information required for understanding the FCD-E1 configuration
and performance monitoring parameters.
C.2 E1 Environment
E1 (CEPT) Signal Structure
The E1 line operates at a nominal rate of 2.048 Mbps. The data transferred over
the E1 line is organized in frames. The E1 frame format is shown in Figure C-1.
Time Slot 0 Time Slot 16 Time Slots 1-15, 17-31
FAS MAS
a. Even Frames (0,2,4-14)
b. ODD Frames (1,3,5-15)
a. Frame 0
b. Frames 1-15
Channel Data
10011011
I 1 ANNNNN
0000XYXX
ABCDABCD 12345678
32 Time Slots/Frame
8 Bits/
Time Slot
16 Frames/Multiframe
TS
0
TS
1
TS
2
TS
3
TS
4
TS
5
TS
6
TS
7
TS
8
TS
9
TS
10
TS
11
TS
12
TS
13
TS
14
TS
15
TS
16
TS
17
TS
18
TS
19
TS
20
TS
21
TS
22
TS
23
TS
24
TS
25
TS
26
TS
27
TS
28
TS
29
TS
30
TS
31
FR
0
FR
1
FR
2
FR
3
FR
4
FR
5
FR
6
FR
7
FR
8
FR
9
FR
10
FR
11
FR
12
FR
13
FR
14
FR
15
Notes
ABCD
X
Y
MAS
I
N
A
FAS
International Bit
National Bit
Alarm Indication Signal (Loss of Frame Alignment - Red Alarm)
Frame Alignment Signal, Occupies alternate
(but not necessarily even) frames
ABCD Signaling Bits
Extra Bit
Loss of Multiframe Alignment
Multiframe Alignment Signal
Figure C-1. E1 (CEPT) Frame Format
Each E1 frame includes 256 bits. The 256 bits are arranged in 32 timeslots of eight
bits each that carry the data payload. The frame repetition rate is 8,000 per
second, and therefore the data rate supported by each timeslot is 64 kbps. The
number of timeslots available for user data is maximum 31, because timeslot 0 is
reserved.