MDS 05-3627A01, Rev. D
LEDR Series I/O Guide
105
Receiver Failure
Both receivers are fed via an RF splitter from the antenna port. Each RF
path is buffered and monitored for receive signal integrity for uncorrect-
able bit-errors. If the “active” receive circuitry fails, uncorrectable
bit-errors will be detected. The modem receive switch will first deter-
mine that the “standby” receive path is operational (no uncorrectable bit
errors) and will switch accordingly.
11.3 Configuration Options—Warm or Hot Standby
The protected LEDR radio may be configured for either warm or hot
standby operation. In warm standby, the standby transmitter is powered
down. This offers the advantages of significantly reduced power con-
sumption, since only one transmitter path is powered. However, upon
transmitter failure, the switchover takes longer due to the transmitter
having to be powered up.
In a hot standby link, the standby transmitter is powered up at all times
and transmits into a dummy load. Switchover to active status is less than
50 milliseconds. The hot standby mode offers the advantages of faster
switchover time and increased overall system availability, but results in
higher power consumption for the station.
11.4 PSC Rear Panel Connectors
The following are descriptions of the rear panel connections of the Pro-
tected Switch Chassis. The PSC’s rear chassis is shown in
.
presents an inter-unit cabling diagram for protected configu-
rations.
Figure 22. Protected Switch Chassis—Rear Panel
RF CONNECTORS
530 (A&B)
Antenna
RxA
TxA
TxB
RxB
530 (A&B)
E1
1
2
3
4
EIA-530-A
Service Channel
Ethernet
Protected (A+B)
A
B
External
RX
TX
ETHERNET
E1/T1 DATA
PROTECTED DATA
EIA-530-A
SERVICE
CHANNEL