Audio Video News

An Asian telecommunications company has successfully transmitted uncompressed HDTV and SDTV video between Japan and the US using fiber optic cable. The results prove the superiority of fiber optics over satellite transmission, the company claims.

Asia Global Crossing (AGC) and its affiliate Global Access, Ltd. announced the outcome of the tests February 22, in which uncompressed HDTV and SDTV video signals were sent trans-Pacific at high bit rates. The tests indicate that "fiber optic cable is a less expensive, more reliable, higher quality alternative to satellites for real-time video transmission," according to a company press release. During the tests, uncompressed and slightly compressed HDTV and SDTV video content was transmitted more than 20,000 kilometers between Tokyo to Seattle "with insignificant delays, resulting in outstanding broadcast quality," according to AGC. The tests used "STM-4C" circuits to transmit SDTV at 270Mbps and HDTV at 1.5Gbps. The event was the first time STM-4C has been used for trans-Pacific or domestic video transmissions.

Satellite broadcasts have long been believed to be the most efficient method of signal transmission, because the beam from one satellite has a "footprint" that can cover an entire continent or oceanic region. Asia Global Crossing claims that satellite feeds have bandwidth limitations that reduce the resolution of transmitted video. Standard-definition television (SDTV) signals need a 270Mbps data rate to attain broadcast quality output, but satellite SDTV transmissions are typically compressed to 45Mbps for transmission, reducing picture quality. There are no such bandwidth limitations with fiber optics, AGC engineers assert, and fiber optic transmissions aren't affected by weather. "Uncompressed video transmissions using high-bandwidth fiber optic systems will enable more stability when broadcasting high-quality video data, such as overseas major league sports broadcasts, in real-time," said Darryl Green, president of Asia Global Crossing Japan.

"Using fiber optic cables instead of satellites will allow broadcasters to transmit HDTV and SDTV video signals without compression, thereby maintaining video quality in a way that is both more reliable and cost-effective than satellites," AGC chief executive John Legere explained. AGC, a Microsoft partner, operates the only independent ring-configured fiber optic system connecting Japan and the US. Asia Global Crossing expects to begin offering commercial video transmission services as early as March 1, 2001.