Hoping to boost the appeal of digital television, News Corp.'s Fox Group unit and Philips Research announced a new technology Wednesday that they say would deliver perfect digital TV signals to more homes through indoor antennas.
The technology resulted from three years of research into digital TV reception in Los Angeles and three other major metropolitan areas. The companies' study found no fundamental problems with the way stations broadcast digital TV; instead, the shortcomings were in the digital TV receivers inside people's homes.
The work by Fox and Philips is just the latest in a series of efforts across the television industry to improve indoor reception, one of several issues slowing the transition to digital TV. Such improvement is critical for viewers who use antennas but can't have or don't want one on their roof, particularly those in densely developed cities or hilly neighborhoods.
Even homes with cable or satellite TV frequently rely on antennas for one or more of their sets, such as a small TV in the kitchen. Researchers have found that up to 40% of all viewers receive some television through an antenna.
The study by Fox, the Australian National University and Philips Research, an arm of Royal Philips Electronics, found that the biggest difficulty for digital receivers is distinguishing between the original broadcast and the echoes bouncing off buildings and hills. On a conventional analog TV, such echoes cause ghosts, or multiple images. But on a digital TV, those reflections can wipe out the entire picture.
Andrew G. Setos, president of engineering for Fox, said the team studied the reflections in hundreds of locations around the four cities, using newly developed tools to capture and analyze the echoing signals.
"It turns out everyone had made bad assumptions" about the reflections and their effect, Setos said. Using computer models of the most severe conditions, the researchers developed software that microchips in digital receivers could use to filter out the reflections far more effectively, he said.
"This is really wonderful news," analyst Richard Doherty of Envisioneering Group, a technology consulting firm in Seaford, N.Y., said of the Fox announcement. The reception problems in early digital sets "really did raise eyebrows and keep wallets closed for the past four years."
The Federal Communications Commission ordered broadcasters five years ago to switch from analog to digital transmissions, which promised flawless reception, richer pictures and cinema-quality sound. But the public has been slow to make the leap.
Although more than 3 million sets capable of displaying high-resolution digital pictures have been purchased, most of those models have been outfitted only with analog receivers and need separate equipment to tune in a digital signal. Meanwhile, fewer than 1% of U.S. households have bought the digital receiver needed to tune in the broadcasters' new digital channels.
Hoping to speed up the transition, the FCC recently ordered set manufacturers to put digital receivers in all TVs, starting in 2004 with big-screen models.
The Fox-Philips news comes just four weeks after Linx Electronics Inc. of Palatine, Ill., announced new microchips for digital TV receivers that also are designed to address the problems caused by echoing signals. President Robert M. Rast said Linx's technology was able to tune in digital channels 88% of the time in the toughest environments in Chicago, compared with 17% for a 2-year-old receiver and 50% for a top current model.
The Fox-Philips team claims an 85% success rate overall in areas that receive a strong enough signal. Their technology could make it into digital receivers this year, and Linx's chips will start appearing in receivers next year.
Rast praised the Fox-Philips work, saying, "They're addressing a very clear need in the industry.... They've collected a great database, and that database will hopefully be available for the benefit of the industry."
John Taylor of Zenith Electronics Corp., a key patent holder in the field of digital broadcasting, maintains that the biggest shortcoming for today's digital receivers is tuning in weak signals, not weeding out echoes.
But that issue is being addressed too as manufacturers develop increasingly sensitive receivers and better antennas, and more broadcasters shift from low-powered experiments on their digital channels to fully powered digital stations.