Transmitting mobile DTV requires the integration of a wide variety of gear. WGCL-TV, the CBS affiliate in the Atlanta market, chose a Thomson Broadcast mobile DTV transmission system based on the ATSC A/153 standard. Thomson also integrated and commissioned the fully redundant mobile DTV package, which was launched in September 2010 in a cost-effective upgrade to the station's existing DTV transmitter.
To be ready for mobile DTV, Thomson upgraded the station’s existing ADAPT-IV 8-VSB exciters with new software that created full compatibility with the A/153 standard. The ADAPT-IV exciters post process the mobile DTV signal for maximum reception performance and simultaneous ATSC terrestrial and mobile DTV operation.
Thomson’s ATSC Mobile DTV terrestrial broadcast technology is backward-compatible with legacy ATSC transmission systems, allowing stations to use their existing DTV channel and the ATSC 8-VSB modulation scheme. The technology also uses M/H block coding for maximum signal reception.
WGCL-TV also rolled out a mobile video program that delivers news and weather alerts to mobile devices via Mogreet’s MMS system, which delivers video, picture and audio to mobile devices. Viewers subscribe by texting NEWS or WEATHER to 21534, and then receive video news and weather updates as they are created. The advantage is that viewers don’t have to browse the mobile Internet to find the information.
MMS also is widely because subscribers do not need a smart phone or a data plan to view it. Almost every phone shipped in the past three years in the United States is equipped to handle MMS, whereas U.S. smart phone penetration still hovers at less than 50 percent (Nielsen predicts the percentage will top 50 percent later this year).
The station reportedly intends to offer pre- and post-roll advertising within the alerts in the near future. According to the station executives, advertisers already sponsor news and weather alerts on TV and have expressed interest in adding mobile to their portfolio.