While he hasn't yet seen a stampede of broadcasters to launch Mobile DTV service, Scott Barella, VP of technology and business development at Larcan, says several interlocking technical issues related to the new service will be widely discussed at the NAB Show. Among the most important will be the relationship between quality of service delivered and the revenue model employed for Mobile DTV; power efficiency; the future of main antenna versus distributed transmission via a single-frequency network (SFN); and a growing chorus of broadcasters who will question the fairness of being forced by the government to restrict Mobile DTV modulation to ATSC A/153.
To Barella, the quality of service broadcasters seek to achieve with Mobile DTV will depend on how important it is to them that they protect the content they are delivering.
“Subscription, advertising or a combination of both will determine the mechanism of capital expenditure for RF when it comes to mobile,” he said.
Mobile DTV deployment based on a subscription model may require broadcasters to add a higher level of RF redundancy.
But quality of service issues don't end with redundancy, he said. Ultimately, broadcasters may need to consider deploying SFNs to augment their current antenna. As they do, Barella said, they likely will explore whether it makes sense to reduce power out of their main antenna in favor of powering up a network of low-power transmitters in an SFN.
While these issues will be front of mind, they likely will be overshadowed by the bigger concerns raised by the FCC's National Broadband Plan and its implications for Mobile DTV, Barella said. Increasingly, broadcasters will ask why they are being asked to relinquish spectrum rather than being given the freedom to employ other modulation techniques such as CMMB or DVB-T2, which could position them to deliver free-to-air TV and meet the goals laid out in the National Broadband Plan, he said.
