Sanjay Talwani /
07.10.2002 12:00 AM
Homeland Security: With Public DTV?
Broadcasters pitching emergency services to Congress
Suppose, in an emergency, information needed to reach homes across America, and cellphone traffic was clogged the way some of it was on Sept. 11.
Public broadcasters say their digital signal should be part of the homeland security equation. They're trying to get Congress on board, saying PBS has the satellite infrastructure to get information from federal authorities to emergency agencies and citizens across the country within seconds.
A new initiative by the Association for Public Television Stations (APTS) would use datacasting technology to send such signals to PCs and, perhaps years down the road, to home set-top boxes and digital televisions. On Capitol Hill in June, broadcasters demonstrated the datacasting technology using the digital signal of Washington's WETA. Advocates of the technology say it goes beyond the traditional Emergency Alert System and text crawls, allowing stations nationwide to seamlessly combine emergency data with local content, deliver it to the right people and provide additional data such as maps and escape routes.
"Osama bin Laden's been spotted in Washington. And he's got a bomb!"
At the demonstration, that was the sample message an APTS staffer called in to WETA. Within seconds, a technician at the station sent the information over the air, where a PC in the hearing room picked it up using a small antenna and a receiver card.
"DTV is really a wireless data distribution system," said APTS President John Lawson. "It's scalable and we don't need additional bandwidth."
When authorities want to communicate only to particular agencies and not to the general public, the system -- dubbed the Homeland Security Communications Network -- would use software developed by Newport Beach, Calif.-based NDS Americas Inc. to encrypt and prioritize the data.
Public-safety applications are among the many trial runs of datacasting technology, which have included several attempts at commercial applications. Datacasters are counting on the ATSC data receivers becoming less expensive as they grow more common, until eventually becoming ubiquitous in PCs. Now, said Lawson, the receiving cards range from less than $50 for those that receive only data, up to $300 or more for cards that can handle high-definition video.
Jonathan Schembor of Princeton, N.J.-based Triveni Digital Inc., which makes datacasting equipment, offers a four-part test for the viability of commercial applications.
First, does it involve rich media and large amounts of data? Second, does the data change frequently? Third, are many receivers, say 75 to 100 or more, going to receive the data? Fourth, is the data going to receivers in out-of-the-way locations unserved by other data links?
"Answer any three of the four 'yes,' and I believe you have a [viable] project," Schembor said.
Triveni has been at the forefront of datacasting. In October 1999 the company collaborated with PBS to demonstrate live data broadcasting to three stations in different regions across the country. Also since 1999, the company has worked with WRAL-DT in Raleigh, N.C., on its DTV Plus datacasting project. Triveni has also worked with PBS and Zenith Electronics on trials of the ATVEF Transport B datacasting and interactive standard. In that project, no return path is required for interactive functions, as all the data required is stored in the user's receiving device. Further ATVEF trials continued in the 2001-2002 season with PBS' Life360 interactive project.
Triveni's SkyScraper three-component system allows flexibility for broadcasters and interfaces with a variety of existing studio equipment, the company says.
In July, APTS hopes to demonstrate the technology in a House hearing as stations continue to seek funds for their digital buildouts. Public broadcasters seek $137 million through the Corporation for Public Broadcasting, with $14 million set aside to digitize content for DTV. They also seek $110 million through the Department of Commerce.
APTS estimates the cost for the digital buildout for all public broadcasters at $1.7 billion.
So far, according to the association, state and local sources have provided most of the funds, totalling $758 million, but some stations have landed little or no local support.