Being prepared in Australia’s unpredictable weather

29 Sep 2009

With the bushfire and seasonal storms on the horizon, Broadcast Australia is gearing up for any eventualities given the unpredictable nature of Australian weather. Broadcast Australia’s network design and comprehensive pre-planning can help minimise the impact of such disasters.

Australia's climate has always been one of extremes. This was demonstrated to a large extent in recent months when the country was subjected to a succession of heatwaves, bushfires, floods and storms. The impact of these weather variations was massive. The tragic loss of life and damage to homes and infrastructure underlined the destructive power of such events.

Here, Broadcast Australia's country-wide broadcast network did not escape unscathed. With fires and floods sweeping through a number of transmission sites, and cyclones battering antenna arrays, Broadcast Australia's Network Operations Centre (NOC)-a central point from which its transmission sites are remotely monitored and managed-had its work cut out for it.

With a communications connection to transmission sites, the NOC constantly monitors the status of all sites and services in the Broadcast Australia network. This ability to remotely operate and manage transmission sites is key to keeping broadcast services on-air on a day-to-day basis. When the network came ‘under attack' in early 2009, the NOC played a critical role in Broadcast Australia's emergency response plan, and enabled damaged infrastructure to be brought back online quickly.

In an emergency situation, such as a fire, flood or storm, it is essential that broadcast infrastructure and broadcasters' services are safeguarded, or brought back online as soon as possible. Broadcast Australia plays a critical role in the provision of broadcast services, which has been further reinforced in the preliminary recommendations by a Royal Commission into this February's Victorian bushfires.  The Commission has so far made recommendations which extend the broadcasting of official warnings to commercial radio and television, for which a significant amount of the infrastructure is provided by Broadcast Australia. 

Broadcast Australia's well-established emergency-response procedures also play a crucial role. Furthermore, having access to a comprehensive suite of information, such as network diagnostics and operational data-obtained from the NOC-simplifies the implementation of these procedures and allows informed decisions to be made.

While the NOC oversees critical parameters associated with each service and transmission site in the network, it is also responsible for monitoring weather conditions via the Bureau of Meteorology and Country Fire Authority (CFA). Much of this information is leveraged to safeguard broadcast infrastructure prior to a natural disaster taking place. From the NOC, operation of standby generators can be monitored, standby equipment status assessed and network system checks executed. When safe, site teams are deployed to perform any required manual safeguarding tasks, such as physically securing equipment or performing manual shutdowns.

If a fire, flood or storm hits and broadcast services are lost, a ‘Crisis Management Plan' is executed. Headed up by the NOC Operations Manager, the Crisis Management Team works with other technical specialists, local authorities, broadcasters and other relevant stakeholders to ensure that services are restored as soon as possible. Furthermore, a dedicated help desk is set up at the NOC to coordinate restoration activities and field incoming inquiries.

The immediate restoration of broadcast services-especially local radio-to the local area is a high priority of the site restoration team. In such disaster situations, it is often local radio that provides important information to the public and support services. As a result, the restoration of these broadcast services often takes precedence. Here, portable temporary transmission facilities play a significant role.

Deployed to nearby safe areas after fire, floods and storms, these portable temporary transmission facilities permit the receiving and retransmitting of services from nearby sites, or act as an all-in-one self-contained mini studio with on-board transmitter to provide entirely new broadcast services. Frequency agile emergency broadcast systems' (fly-away kits) were utilised extensively after Victoria's recent bushfires, as well as floods in Ingham, Queensland, and Pannawonica, Western Australia.

While there isn't a lot that can be done to physically safeguard broadcast infrastructure from a rampaging bushfire or rising floodwaters, there are measures that can be taken to provide broadcasters with a greater chance of keeping services online following a disaster-particularly if the site only sustains partial damages.

Broadcast Australia's country-wide broadcast network has been designed with layers of built-in redundancy. A number of sites are equipped with duplicated equipment and antenna systems, such as automatic ‘fail-over', or ‘n+1' systems. Depending on the role of the site in the network, switching to standby equipment is achieved manually or automatically, locally or remotely from the NOC.

Furthermore, some antenna systems have been designed to allow switching between the top or bottom half of the antenna. This permits continuous operation-albeit at reduced power-even if part of the antenna system is damaged. It also allows transmissions to continue during regular maintenance and troubleshooting.

On some sites, high levels of redundancy have been integrated into the program input equipment with measures in place to receive transmissions from an alternate source, such as landline, satellite and off-air. Many sites are also equipped with back-up diesel generators in the event that mains power is lost.

For any given transmission site in Broadcast Australia's network, the NOC will monitor several critical parameters associated with each service and the site as a whole. These include the input feed and equipment (such as satellite/microwave link or off-air receiver/repeater), transmitters and associated ancillary equipment (such as modulators and exciters), antenna systems, environmental control equipment (such as air-conditioning) and power. With around 50 per cent of faults swiftly and easily rectified by a remote reset of equipment from the NOC, means mobilisation of field maintenance technicians can often be avoided, and the service restored within minutes of the remote diagnosis.

Luckily, these days, most terrestrial broadcast transmission sites across the world are unmanned, so in the event of a natural disaster, the direct threat to human life is minimised. However, the loss or damage to broadcast infrastructure still has the potential to significantly impact the safety of the wider community.

Evacuees, support services and local authorities are reliant on broadcast communications (in the affected area and those areas supported by retransmission sites). It is, therefore, important that broadcast infrastructure providers implement resilient network designs and formulate well-drilled emergency response plans, to minimise the immediate and long-term impact of natural disasters on broadcast services.