Mobile TV: The Next Big Thing?
April 18, 2008
The NAB Show’s Broadcast Engineering Conference started with a tutorial on ATSC-M/H, the proposed ATSC mobile/handheld standard. Throughout this week’s show in Las Vegas, presentations directly or indirectly related to M/H broadcasting addressed antenna, building penetration loss, propagation, single frequency networks and many other topics.
Engineers looking for a “winner” in the Independent Determination of Viability (IDOV) were disappointed. Sterling Davis. vice president of engineering for Cox Communications and in charge of the Open Mobile Video Coalition’s Technology Advisory Working Group, discussed IDOV procedures and results at Monday’s OMVC breakfast, “Mobile TV Opportunity at 100 MPH,”, but did not disclose results for specific systems.
He did report on the key findings of the IDOV, the most important being that both systems tested in San Francisco and San Jose, Calif., (A-VSB and MPH) worked, mobile reception was possible up to 40 miles from the transmitter site, and the systems did not interfere with normal DTV broadcasting. The Thomson system was not available for testing in San Francisco. Measurements in Las Vegas were completed just before the 2008 NAB Show and results were not available.
Saturday’s tutorial highlighted the technology behind the A-VSB, MPH and the Thomson–Micronas systems. Sunday’s Broadcast Engineering Conference session did not provide as much detail as proponents used the session to position their system as the best one for broadcasters, offering claims that some of which I, and I’m sure others, questioned. Samsung claimed the A-VSB system was the only one that could be deployed in 2009, playing on the need for broadcasters to roll out this service as soon as possible. LG, however, was displaying working hardware using IP transport operating on cell phones capable of working with the two major cellular systems and stated they were ready to roll out their MPH system as well. Harris, LG’s partner, has even arranged financing for stations wanting to add MPH equipment to their transmitter.
I was disappointed at a slide in one of the MPH presentations listing “no requirement for spectrum sharing” as an advantage. I took this as a slight of one of the benefits offered by the Thomson–Micronas proposal. While not a requirement, Thomson–Micronas allows broadcasters to split data with another broadcaster in the market and achieve frequency and to varying extent, space diversity on the transmission side. As Thomson showed Saturday, this diversity provides a significant improvement in reception, but it isn’t a system requirement.
You may remember that MPH proponents cited “no need for single frequency network or diversity reception” as an advantage last year. A-VSB did not require a single frequency network or diversity, but had the option of using them to improve coverage. A-VSB proponents demonstrated a single frequency network and diversity reception at NAB2007, but it was absent from this year’s NAB Show, and among the various receivers in cell phones, MP3 players, and portable media devices in the A-VSB Initiative booth, only one had an antenna.
It seems to me the option to take advantage of spectrum sharing, diversity and single frequency networks would benefit any of the systems, and I expect at some point they will be an option in whatever system or combination of systems ATSC selects for the ATSC-M/H standard, if not in Version 1.0, in a later version.
I didn’t see or hear anything that would prevent OMVC from achieving its goal of having a mobile/handheld standard and devices ready to market next year. Most of the broadcasters I talked to are excited about the opportunity to use their broadcast spectrum to do more than reach a minority of viewers and feed cable headends. This was evident in the interest in the technologies needed for a successful rollout of broadcast mobile/handheld services.