TV Services
There are an increasing number of mobile broadcast TV trials of the different technologies competing to provide services, and the World Cup is predicted by some to showcase mobile TV as never before. But there has already been one major sporting event this year where one of those technologies – DVB-H – was put to the test, albeit in trial conditions.
In March 2006 the Commonwealth Games had a new participant — DVB-H (digital video broadcasting – handheld) mobile television. In a landmark showcase, the emerging technology, supported by leading broadcast infrastructure group Broadcast Australia, was demonstrated to the broadcasting and telecommunications industry at the Melbourne Games. The showcase tested the strength of DVB-H mobile television at large broadcasting events, with up to seven channels of live Commonwealth Games television broadcast from 15 to 26 March.
The DVB-H showcase was the product of a cooperative effort between Broadcast Australia, Microsoft and Telstra. As a pioneer in digital terrestrial broadcasting technologies, Broadcast Australia was responsible for the successful design, installation and commissioning of the RF transmission component of the showcase system, located at 120 Collins Street, in the heart of the Melbourne CBD.
Talking about the detailed effort to meet the targeted coverage requirements, Broadcast Australia Product Development Manager, David Hilliger revealed, “In the planning phase, we used specialised computer modelling tools to design the service to cover as many Melbourne 2006 Commonwealth Games venues as possible. Our team was responsible for field strength measurements and performance verification; the planning work was verified through field testing, which showed good correlation between the predicted model and achieved coverage.”
Distributed antennas
The Broadcast Australia component of the DVB-H system incorporated an 800-watt transmitter plus sophisticated QPSK modulation and monitoring equipment. Broadcast Australia, Telstra and Finland’s Cardinal Information Systems worked together to deliver the DVB-H transmission stream to the inner city broadcast site using an optical fibre configuration.
Broadcast technology group Radio Frequency Systems (RFS) provided the UHF antenna system, which comprised multiple antenna panels mounted on different faces of the Collins Street building. Whereas conventional broadcast panel arrays must be mounted close together, back to back, for tight alignment of RF signals, Broadcast Australia achieved the required coverage using a distributed antenna system, by taking advantage of the particular characteristics of OFDM modulation during system design. The antenna system delivered up to 7.5 kilowatts of effective radiated power.
Specially equipped receiver
To view the DVB-H mobile television, a specially equipped mobile receiver was required. The receiver, provided by DiBcom, was integrated into an eTEN Windows Mobile Smartphone that also acts as a Personal Digital Assistant (PDA). The showcase DVB-H system utilised Microsoft Windows Media Video 9 compression technology (Microsoft’s implementation of the VC-1 codec), plus a DVB-H head-end from Cardinal to encapsulate IP data and perform the time-slicing of the data stream. This equipment was located in Telstra’s facility at the Melbourne 2006 Commonwealth Games International Broadcasting Centre.
According to Clive Morton, Broadcast Services Director at Broadcast Australia, Broadcast Australia’s participation in the Melbourne 2006 Commonwealth Games DVB-H showcase complemented the company’s one-year trial of DVB-H technology underway in Sydney. “The Melbourne system used a number of different technologies compared with the Sydney trial,” he said. “This has allowed us to build upon our foundation of DVB-H knowledge. DVB-H is still an emerging technology. It’s important to look at all the options available and explore their various capabilities.”