Given the ever-changing broadcast environment, Peter MacAvock, executive director of the Digital Video Broadcasting Project (DVB), announced Monday that DVB will enhance the DVB-T standard.
The new standard is called DVB-T2 and it follows closely behind the February announcement of DVB-SH. The commercial requirements for the DVB-T2 standard were published Monday on the DVB Web site. The next step will be a call for technologies.
MacAvock pointed out that the DVB-S standard was 10 years old in 2004. It was therefore appropriate to upgrade that standard to DVB-S2 in 2005 to take advantage of a new generation of satellites that were being launched specifically for multichannel high-definition television.
Similarly, with the switch-off of analog terrestrial television services visible on the horizon as early as 2009 in some countries, it is appropriate to define an enhanced DVB-T standard to help broadcasters capitalize on the new opportunities that should present themselves after analog switch-off, MacAvock said.
NEW SPECIFICATION
The specification for DVB-T2 will be defined by the first quarter of 2008, allowing just enough time for technology to be delivered in 2009. Higher efficiency to enable multichannel HDTV is one of the key drivers behind the new standard.
The DVB-T2 standard will be backward- compatible with DVB-T; will support fixed, portable and mobile receivers; and will have 30 percent more payload capacity than DVB-T. It will also provide the possibility for a 30 percent increase in lateral spacing between the transmitters in a Single Frequency Network (SFN).
The other big news from the DVB Project is the demonstration of a hierarchical modulation scheme that allows a DVB-T multiplex to contain one or more DVB-H services alongside a high-definition DVB-T service in the same 6 MHz channel.
The DVB demo shows the co-existence of a 13.8 Mbps high-definition television signal and a 5.5 Mbps DVB-H signal within a 19.3 Mbps multiplex.
Using Hierarchical Modulation, the DVB-H stream is embedded as a High Priority service within a Low Priority DVB-T stream. Receivers with good reception conditions (large antenna, low interference and strong signal) can receive both the DVB-H and the DVB-T services. But receivers with poor reception conditions (small antenna, high interference and weak signal) will only receive the more robust DVB-H service.
To add real-world perspective to DVB’s sales pitch for DVB-H, MacAvock was joined in the press conference by Franco Ferri, general manager of RRD, a DVB-H solution provider in Italy, and Scott Wills, president and COO of Hiwire, a division of Aloha Partners, the largest owner of 700 MHz spectrum in the United States.
NETWORK CONCERNS
Ferri shared some of his real-world experiences in setting up a DVB-H network. He presented the bad news that a company cannot just use existing high-power transmitters on existing high masts for a successful DVB-H implementation. But the good news is that a dense array of smaller transmitters, like in a cellular network, is not needed. Actual experience in Italy has shown that a DVB-H transmitter network can be set up with only about one-tenth the number of transmitters needed for the typical cellular network.
Wills has launched a DVB-H trial in Las Vegas with the intention of eventually rolling out a DVB-H service nationwide. Wills presented his justifications for being optimistic about the potential for DVB-H broadcasting to be a better business than the unicast video download model as used by cell phone network operators. His company’s research indicates that consumers much prefer to watch continuous long-form streaming video than short downloaded clips. Unicast long-form video does not make economic sense for a telco, but it is imminently suited to DVB-H broadcasting technology.
The Hiwire DVB-H service is planned to provide more than 24 channels of streaming real-time video in 12 MHz of spectrum (2x6 MHz channels). The video will be full 30 fps with high quality and reliability. The trial in Las Vegas utilizes the LG U900 handset and a T-Mobile RF network on UHF channels 54 and 59.
MacAvock emphasized that the DVB Project is instrumental in the enabling of that expanded reach by wide standardization of the technologies behind it.
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