NAB: Mobile TV for 700MHz

LG Electronics and Harris Corporation are using this week’s National Association of Broadcasters convention, in Las Vegas, to unveil mobile digital television that will enable as many as 16 different video programs on one television channel. Harris Corporation says their “Scalable Full-Channel Mobile Mode” can send 16 different video programs on the 6 MHz bandwidth utilized by TV broadcasters.

Developed in conjunction with LG Electronics, which gets royalities for their ghost-prone ATSC standard, it devotes most of the 19.4 Mbps bitstream in the 6 MHz TV channel for transmission of mobile programming. Full-Channel Mobile Mode is designed for compatibility with the ATSC A/153 Mobile DTV Standard, adopted last year by the NAB.

While the demonstration is a prototype, “the finished product will require nothing more than a software upgrade” for Harris Mobile DTV equipment owners, according to Jay Adrick, vice president of broadcast technology for Harris Corporation.

“We’re already working with a customer, and there are others operating in the 700 MHz spectrum who plan to launch mobile services that are compatible with the ATSC transmission system,” Adrick said. “We believe that Scalable Full-Channel Mobile Mode transmission will come to market rather quickly, once it is standardized.

Broadcasters, like cellular operators, are only interested in one thing. But Qualcomm’s Media FLO has had little impact on the market. “Mobile TV is just not as big a deal as we all thought it would be,” said Frank Dickson of Instat. Qualcomm has spent almost $1 billion trying to find the Mobile TV sweet spot, notes Rethink Research.

The ATSC-M/H standard (ATSC A/153), delivers a “hardened” bit stream to mobile devices. Unfortunately, the M/H standard will require considerable overhead (pdf). It is expected that only about 18-38 percent of the bits allocated to the service will be available for actual service payloads.

Harris says MPH typically delivers about 1.1 Mbps of payload in a 4.4 Mbps channel (pdf). That’s 25% efficient. So a 20 Mbps channel is capable of about 5 Mbps of mobile television, or about 20 channels of 250 Kbps each. Qualcomm claims to deliver more payload (pdf) on 6 MHz, with their new FLO-EV delivering a 3-5 dB improvement in performance.

While current TV broadcasters are required by the FCC to offer at least one standard-definition digital TV program, owners of other 700 MHz spectrum have more flexibility. A spectrum owner could convert 2-way broadband channels into one-way mobile broadcast television.

The Open Mobile Video Coalition (OMVC) is an alliance of U.S. commercial and public broadcasters formed to accelerate the development and rollout of mobile DTV products and services. The MPH (Mobile-Pedestrian-Handheld) system, jointly developed by LG and Harris, won out in a shoot out with the A-VSB system jointly developed by Samsung and Rohde & Schwarz; and a third system jointly developed by Thomson and Micronas. Harris says they have provided mobile-DTV equipment for about 40 U.S. broadcasters, with 36 of them currently transmitting mobile DTV.

Japan is the largest mobile TV market in the world with over 80 million ISDB enabled handsets shipped. Many countries in South America also follow the ISDB standard. With FLO TV being available countrywide in the United States and a range of receivers being available (FLO TV receivers), this translates into an advantage for this technology for Pay mobile TV services which cannot be easily beaten by competition, say some analysts.

Swapping Qualcomm’s COFDM-based system for an inefficient ATSC-based system may be more about keeping ATSC royalities in-house than providing any useful service.

Posted by Sam Churchill on .

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