User's Manual Part 5

SYSTEM SETUP ROI-S05749
3-18
3.5.2 Automatic Protection Switching (APS) (OPT INTFC Optional
APS Configuration) (SONET)
(a) Line Protection
The Automatic Protection Switching (APS) provides for uni-
directional line protection against optical cable interface failures. It is
performed by detected alarm condition or remote control signal.
Fig. 3-2 OPT APS System
The OC-3 (OPT) INTFC monitors the OPT line input signal interface
condition and when an alarm condition occurs in the optical cable or
optical interface module, APS is activated. Also the APS is activated
when remote control signal is received.
Uni-directional APS is performed only in the receiving section of the
local side when a failure or signal degradation of the received signal
is detected in one direction. Fig. 3-3 shows APS switching mode.
OC-3 (OPT)
INTFC
MODEM
Working
OPT IN
OPT OUT
Protection
MODEM
only 1+1
OC-3 (OPT)
INTFC
SW
SW
LOS/LOF/BER
DET
LOS/LOF/BER
DET
OPT IN
OPT OUT
CTRL
Remote
Module Failure
Module Failure
SW CTRL
SW CTRL