Mobile DTV: Gear for Getting in on the Ground Floor

Correspondent Carl Lindemann takes a look what suppliers are talking about at the NAB Show.

In case you somehow missed it, this is the year mobile digital television (mobile DTV) takes to the airwaves. Early-adopter stations are gearing up for what promises to be the biggest broadcaster bonanza since the arrival of FM radio. Already, the first 50 or so stations are up, with the initial wave of consumer devices poised to hit retail shelves. The first wide-scale deployment is set for May 3 in Washington, DC, with nine stations broadcasting more than 20 program streams.

Mobile DTV isn’t an upgrade of existing services, like the transition from SD to HD. It amounts to an entirely new service that piggybacks on the DTV signal. At its most basic implementation, it is a means to port a station’s signal to a profusion of attractive consumer-electronics devices. What’s even more interesting are the many ways this flexible platform offers for connecting with audiences.

Mark Rushton, senior director of broadcast sales for Roundbox, a vendor of mobile-DTV equipment, sees it as the gateway to a new Golden Age for television-station operators.

“TV stations know how to make money, and mobile DTV is an extension to their standard business,” he points out. “It gives them the ability to reach viewers like they haven’t in 20 years by way of traditional over-the-air means.”

Embedded in a Station’s Signal
One of the more attractive aspects of mobile DTV is the relatively inexpensive get-in price : as little as $100,000 for a station to get started on an entirely new broadcast operation. A basic setup requires a pre-processor/multiplexer plus postprocessing at the exciter.

Such manufacturers as Rohde & Schwarz, Axcera, and Harris are eagerly pursuing what is fast becoming a burgeoning market.

Every mobile-DTV setup is built around a multiplexer that embeds IP data into a station’s standard DTV MPEG-2 stream. Basically, this is a “ruggedized” signal loaded with forward error correction to make it able to withstand the rigors of mobile use. Each equipment manufacturer has its own approach to implementing the MDTV spec, and many stations are shopping at the 2010 NAB Show to decide what’s best for their specific needs and budget.

Software Is the Ticket
According to Denis Hagemeier, product management headend for Rohde & Schwarz, the basic difference among manufacturers is whether the multiplexer box is software- or hardware-based. At R&S, software is at the heart of its AEM100 ATSC-M/H emission multiplexer.

Denis Hagemeier, Rohde & Schwarz

“Software-based implementations are more flexible and open to upgrades and improvements,” says Hagemeier. “Whatever system you look at, stability is crucial. These must run 24/7. The software advantage is that no shutdown is necessary for upgrades, unlike [with] hardware-based versions. Software is also easy to integrate with existing equipment and to fit within existing monitoring systems.”

Axcera, too, has opted for a software-based solution with its ATSC mobile DTV multiplexer.

“Ours is purpose-built rack-mounted broadcast-quality gear,” says Richard Schwartz, VP of Engineering & Product Management for Axcera. “We don’t want to get into a ‘spec-mashup’ with competitors. Suffice it to say that we are in compliance with the spec and have tested this with some 20 different consumer devices.”

At NAB’s MDTV pavilion in Las Vegas Convention Center’s South Hall, interest and excitement has been building since the show opened.

Richard Schwartz, Axcera

“Every U.S. broadcaster that has come by has wanted to know about MDTV — even low-power guys,” says Schwartz. “The Open Mobile Video Coalition [OMVC] expects about 140 installations this year.”

The Hardware Option
At Harris, selling full-blown MDTV systems at NAB is the end of a long road. “We’ve been at this for at least four years,” says VP of Broadcast Technology Jay C. Adrick. “We have more experience than anyone else, and LG [a key MDTV consumer-electronics manufacturer] is our technology partner.”

Unlike the R&S and Axcera implementations, the Harris MDTV multiplexer is hardware-based or, more precisely, is built around FPGAs (field-programmable gate arrays), basically flashable firmware.

Jay C. Adrick, Harris

Why go this route? “This is the heart of the mobile-DTV system, the last link from your station to the transmitter,” says Adrick. “All our competitors trust this to a PC. Why would you want that?”

Other key differentiators for the Harris Mobile DTV solution, he suggests, include a “data carousel,” providing added robustness that keeps the system on-air even if there’s a network failure. Add-ons and enhancements include conditional-access capabilities through a deal with Nagravision as well as the Roundbox Server, an exclusive program-guidance and datacasting package to enhance station services.

“We built the cake, and Roundbox is the icing on that cake,” says Adrick.

It proved a hands-down winner in the initial rollout, with more than 50 installations up-and-running to date, according to Adrick. He says that Harris is busy working through the backlog of orders at a rate of about two stations a week.

Getting Going, Then Going Great
Besides the mobile-DTV multiplexer, stations also will need to add special postprocessing as well. For some with older DTV exciters, that may mean a replacement. For newer units, a firmware upgrade can do the trick.

Whatever the initial costs, the larger expense down the line will involve creating and producing unique content and services. But going live with mobile DTV is just the start of what many hope will be the key to keeping TV broadcasters alive and kicking for the future.