User Manual

Table Of Contents
Optical Master Unit
PRODUCT DESCRIPTION AND USER’S MANUAL
© Axell Wireless Ltd A1829300 rev H 43 (86)
3.5 OMU Heartbeat
The OMU and connected repeaters can be configured to transmit heartbeat reports to the Axell Element
Manager, AEM with regular intervals. If the AEM does not receive a heartbeat report within expected interval,
an alarm can be generated and displayed to the operator. In this way, the AEM is ensured that the
communication with the OMU works as intended.
Each heartbeat contains a complete status report regarding the sending unit at the time of the report. This
ensures that the AEM always has the correct status information even if some alarm reports should fail to
transmit successfully.
When it is time for the OMU to send a heartbeat report, a connection to the AEM is established, after which
heartbeat reports from all nodes in the repeater system is transmitted. This is the sequence of events.
A connection to the AEM is established
All non-acknowledged alarms in the alarm log are transmitted
The OMU polls the heartbeat from all the nodes and transmits them to the AEM
Heartbeat is transmitted for the OMU unit
The OMU disconnects from the AEM
The heartbeat interval can be set from 1 to 1440 minutes. Setting the heartbeat to 0 disables the transmission of
heartbeats.
Select
“Configuration “ and
“Reports”
3.5.1 Heartbeat Tasks
With the heartbeat reports, a number of tasks are carried out.
3.5.1.1 Ensuring OMU to AEM Communications path
By configuring the OMU to regularly establish a connection to the AEM, the functionality of the data
communications path between the OMU and the AEM is verified. This ensures that for instance the alarms will
be transmitted properly.
If an expected heartbeat is not received by the AEM, an alarm is generated to the AEM operator. Reasons for a
heartbeat message failing to be delivered can be:
No power – the OMU site might experience a power failure, and the battery backing up the Control
Module and modem is empty
Failing modem communication – The modem might be broken, the modem antenna compromised or the
service down in the modem’s frequency area
Broken link to BTS - If the link to the BTS has been tampered with, the OMU might not get adequate
signal to establish a connection to the AEM
Failing BTS – If the feeding BTS for some reason goes down, the OMU will loose its network connection,
and hence fail to establish a connection to the Axell Element Manager.