Specifications

FCD-E1LC Ver. 1.0 E1 Environment C-1
Appendix C
Operating Environment
This appendix presents a concise description of the operating environment of
FCD-E1LC systems, to provide the background information required for
understanding the FCD-E1LC configuration and performance monitoring
parameters.
This Appendix covers the following issues:
• E1 environment –
Section A.2 .
• IP environment –
Section A.3 .
• Ethernet transmission technology –
Section A.4 .
C.1 E1 Environment
The E1 line interfaces of FCD-E1LC comply with the applicable requirements of
ITU-T Rec. G.703, G.704, G.711, G.732, G.736 and G.823.
E1 Signal Structure
The E1 line operates at a nominal rate of 2.048 Mbps, using a line signal encoded
according to High-Density Bipolar 3 (HDB3) code. The data transferred over the
E1 line is organized in frames. Each E1 frame includes 256 bits.
The E1 frame format is shown in
Figure A-1 .
The 256 bits included in a frame are organized of 32 timeslots of eight bits each.
The frame repetition rate is 8,000 per second, 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 always used for frame synchronization.
The frames are organized in larger patterns, called multiframes. Two types of
multiframes are generally used:
• G732N (also called 256N) multiframes.
• G732S (also called 256S) multiframes.