March 31, 2014
Channel sharing trials recently conducted by Los Angeles television stations KLCS and KJLA have determined that there are few technical barriers to two broadcasters sharing the same 6 MHz channel. The report should serve as good news for the FCC, which hopes to auction off a percentage of broadcast airwaves to mobile carriers in 2015. Key to the FCC’s plan is convincing broadcasters that they can efficiently consolidate feeds onto fewer television channels.
“Working with mobile carrier industry group CTIA, KLCS and KJLA found that it was not only feasible for two TV stations to run two separate 720p HD video feeds over the same 6 MHz channel, but they also could include two standard definition streams in the same bandwidth without having any major impact on video quality,” reports GigaOM. “That’s a key finding because many broadcasters already transmit the HD and SD versions of their programming on the same channel. This shows it’s possible to continue the same practice through channel sharing.”
“The stations went further, testing 3 HD streams and many more combinations of SD and HD programming,” notes the article. “While they were successful in many cases, the reports’ authors warned that there were quality trade-offs. The more complex the digital content, the more a video feed would suffer from a constrained bandwidth — sporting events need more capacity than talking head programs.”
In addition, the trial found that televisions and digital tuners had no problems receiving and parsing different feeds.