363-206-285
Transmission and Synchronization Interfaces
5-2 Issue 3 June 2001
Transmission Interfaces 5
The DDM-2000 OC-3 Multiplexer supports DS1, DS3, 10/100 BaseT and 100
BaseFX low-speed interfaces, EC-1 low-speed and high-speed interfaces, OC-3
low-speed and high-speed interfaces, OC-1 low-speed and high-speed interfaces,
and an IS-3 interface. The DS1 and DS3 interfaces accept any DSX-1 or DSX-3
compatible signal (clear channel interfaces) and can be mixed on a per-STS-1
basis.
Figure 5-1 is an overall block diagram of the DDM-2000 OC-3 Multiplexer in a
terminal configuration. Internally, the OC-3 Multiplexer uses synchronous optical
network (SONET) standard multiplexing (refer to Appendix A). On the low-speed
side, each group of 28 DS1 signals map into 28 asynchronous floating mode
VT1.5 signals. The VT1.5 signals are combined into seven VT groups and then
multiplexed to one STS-1 signal. A DS3 signal maps directly to an STS-1 signal
via the asynchronous mapping. An EC-1 or OC-1 signal is converted to an STS-1
signal. Three internal STS-1 signals are multiplexed to an STS-3 signal and
converted to an OC-3 optical signal.
In the opposite direction, a received OC-3 signal is converted back to an electrical
STS-3 signal. The STS-3 signal is then demultiplexed to three STS-1 signals.
DS3, EC-1, and OC-1 signals are recovered from their STS-1 signals, while a
DS1-formatted STS-1 signal is demultiplexed to 7 VT1.5 groups and then to 28
VT1.5 signals.
To Next Page
Loading...
Need help?
General
