User Manual

MBF, Multi Band Repeater

PRODUCT DESCRIPTION AND USER'S MANUAL

4.5 Repeater Heartbeat

On regular intervals, the repeater sends a heartbeat report to the AEM to confirm that the repeater is

functioning. The heartbeat message contains information about the RF-configuration and the alarm sources. It

ensures that the data communication from the repeater to the AEM is working properly.

The heartbeat interval can be set from 1 to 1440 minutes. Setting the heartbeat to 0 disables the transmission

of heartbeats.

Slave repeaters in OMU-repeater system send the heartbeat messages to the OMU. The heartbeats are sent on

to the AEM by the OMU.

4.5.1 Heartbeat Tasks

With the heartbeat reports, a number of tasks are carried out.

4.5.1.1 Ensuring Repeater to AEM Communications path

By configuring the repeater to regularly establish a connection to the AEM, the functionality of the data

communications path between the repeater 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 repeater site might experience a power failure, and the battery backing up the Control

Module and modem is empty

 Broken donor antenna – If the repeater antennas have been tampered with, the repeater might not get

adequate signal to establish a connection to the AEM

 Failing BTS – If the feeding BTS for some reason goes down, the repeater will loose its network

connection, and hence fail to establish a connection to the Axell Element Manager.

4.5.1.2 AEM Database Synchronization

The Axell Element Manager stores all repeater parameters in a database. This database is populated during

the repeater integration into the AEM, when the AEM downloads all the repeater parameters. If the AEM

operator wants to monitor the configuration of the repeater, the parameters can be read from the database

without having to connect to the repeater.

In case of an alarm, the AEM updates the database with the status of the alarm source. In case the repeater

failed to deliver the alarm to the AEM, there will be a discrepancy between the repeater configuration and the

configuration in the database. Furthermore, if a technician at site makes changes to the RF-configuration of

the repeater, the configuration will differ from the AEM configuration.

For this reason, each heartbeat report contains all the relevant RF-parameters and status of all the alarm

sources in the repeater. This means that each heartbeat report will update the AEM with all status and RF

parameters.

Note! Once the repeater is integrated to the Axell Element Manager, it is recommended that all

reconfigurations are made from the AEM.

Note! If a user logs in to the repeater making changes, as soon as the user logs out, an alarm will be

transmitted to the AEM informing the operator that a change has been made. When this alarm is received, the

operator can initiate repeater synchronization where all repeater parameters will be updated.

4.5.1.3 Time Synchronization

Each heartbeat message transmitted to the AEM contains a time stamp of the local time inside the repeater.

Upon reception in the AEM, the time stamp is compared to the Axell Element Manager time. If the difference

between the repeater and AEM time is too big, time synchronization is initiated by the AEM, adjusting the

time in the repeater. In this ways, we ensure that a repeater integrated to the Axell Element Manager always

contains the correct time information.