xr
PRELIMINARY
XRT86VL38
REV. P1.0.6
OCTAL T1/E1/J1 FRAMER/LIU COMBO
396
Now, the CPE uses the AIS signal sent by the Repeater to recover received clock and remain in
synchronization with the system. Upon detecting the incoming AIS signal, the CPE will generate a Yellow
Alarm automatically to the Repeater to indicate the loss of incoming data. Figure 103 below illustrates this
scenario in which the Repeater is sending an AIS to the CPE and the CPE is sending a Yellow Alarm back to
the Repeater.
F
IGURE
102. G
ENERATION
OF
AIS
BY
THE
R
EPEATER
UPON
DETECTION
OF
LINE
FAILURE
E1 Receive
Framer Block
E1 Transmit
Framer Block
E1 Receive
Framer Block
E1 Transmit
Framer Block
E1
Transmit
Section
E1
Transmit
Section
E1
Receive
Section
E1
Receive
Section
CO
Repeater
CPE
The E1 line is
broken
Repeater declares
Red Alarm
internally
Yellow
Alarm
Repeater generates
Yellow Alarm to CO
Repeater
generates AIS
to CPE
AIS