PARIS The futuristic notion of watching TV on a cell phone or iPod, or in cars or high-speed trains, is no longer so farfetched. Europe's homegrown specification for mobile digital video broadcast, DVB-H (for "handheld"), is already in field trials, and commercial services are scheduled to go live in 2005.
Most carriers and industry analysts in the United States remain dubious about mobile TV, and openly wonder if anyone would watch. Allen Nogee, principal analyst for wireless technology at In-Stat/MDR, questioned not only consumer interest but also whether "carriers even want this, especially [using] a form that transmits over the air" instead of via their own cellular networks.
Europeans think otherwise. Rather than add only an existing analog or digital TV tuner to mobile handsets, they are creating a converged platform built on a 2.5G/3G cellular network and a digital terrestrial TV broadcast infrastructure. Europe, which led the world mobile-communication revolution with the GSM standard, believes it has now devised a winning formula for the next stage by marrying DVB-H with Internet Protocol (IP) datacasting.
DVB-H promises to deliver multimedia content"encapsulated in IP packets"by means of terrestrial digital TV to large audiences at low cost, without clogging a cellular network. Proponents say the spec creates opportunities for mobile operators, through their billing mechanisms, to carry and charge for the new broadcast services.
"Sixty thousand people in a soccer stadium, for example, will be able to see an instant playback of a goal scored, broadcast by DVB-H, on their mobile phones," without shorting out an entire cellular network, said Ulrich Reimers, professor at the Technical University of Braunschweig, Germany. The network platform is designed to decide intelligently between a terrestrial DTV network and a mobile net to deliver the soccer highlight to each DVB-H terminal.
Many chip vendors and consumer systems houses hungry for the next big thing are already putting their money on DVB-H. Philips Semiconductors, for example, makes no secret of its efforts to develop a low-power silicon tuner, low-power channel decoder and low-power baseband decoder optimized for handheld TV applications.
"TV has been migrating into a number of consumer products," said Steve Turner, business development manager responsible for Europe at Philips Semiconductors. "TV will become a significant feature in a major mass consumer device"which obviously is a mobile phone."
STMicroelectronics, meanwhile, is transferring Nomadik processor cores, originally developed by its mobile-phone group, to portable set-top-box applications. For ST, TV-on-mobile extends to in-car applications and to gadgets such as iPod-style MP3 players, said Chris Carter, marketing manager of the satellite and terrestrial business at ST's set-top division.
Xceive Corp., a Silicon Valley startup developing RF-to-baseband receiver ICs, this week will announce a complete silicon tuner for ultrasmall analog and digital terrestrial and cable receivers. "Within the next five years, TV will become a commonly accepted feature on mobile handsets," said Jordan Du Val, vice president of sales and marketing at Xceive, just as a camera is now integral to many handsets.
Cell phone giant Nokia, meanwhile, has developed a device called the Nokia Streamer, billing it as the first mobile IP datacast receiver. It will attach, like a battery pack, to the Nokia 7700 media phone. That combination will get a trial for video broadcast to mobile devices in Berlin and in Helsinki, Finland.
Not all U.S. cellular operators dismiss the idea out of hand. Sprint Corp. has launched a subscription-based service, MobiTV, beaming a live television program in a continuous stream, although only at a few frames per second, using a CDMA 1X network.
MobiTV "is a fantastic idea, but they are using the wrong technology," said Jukka Henriksson, research fellow at Nokia Research Center. Henriksson is chairman of the ad hoc technical module responsible for developing the DVB-H specifications at the DVB Project, an industry-led consortium designing global standards for digital television and data services.
Instead of resorting to cellular networks, DVB-H applies an improved version of the radio spec in the DVB-T (terrestrial) standard to deliver TV programs as IP data packets to low-power handhelds. The DVB-H spec is specifically aimed at lower-power TV reception with a high-speed mobility feature.
"With DVB-H, telecom operators, for the first time, can offer something consumers already know about; they know what it is and how to use it," said Ari Beilinson, director of business development at Nokia Ventures. According to Nokia, most of those who watch up to 2.5 hours of TV daily also use mobile phones about 10 minutes a day. "We just want to give the possibility for them to spend 10 minutes of their TV-viewing time on a mobile handset," said Beilinson. If the average tube-watching phone owner tunes in for 10 minutes of handset TV every day, it would instantly double mobile-phone usage time, he added. "This is a goal easily achievable."
It's unclear if DVB-H will remain strictly a European phenomenon. "Certainly some regions of the world potentially have a better chance at this [mobile TV] than others," In-Stat/MDR's Nogee said. "In areas where public-transportation commutes are long, it's a possibility." He argued, however, that "LCD portable TVs have been around for years, and I have never seen a large use of these products."
Nonetheless, "Nothing stops U.S. operators from embracing DVB-H," said ST's Carter, noting the absence of a mobile TV spec that can compete with DVB-H in the United States. DVB-H, in fact, is coming to the U.S. market this year in a trial led by Crown Castle, a company that delivers turnkey infrastructure and network services to broadcasters and wireless operators. Crown Castle is quietly launching the three-site Single Frequency Network in Pittsburgh using DVB-H technology.
Because of the flexible network infrastructure designs DVB-H allows, it's possible to multiplex DVB-H services in an existing terrestrial digital TV network based on DVB-T. It's possible, too, to launch DVB-H services on a newly dedicated DVB-H network, independent of a terrestrial DTV network. In a DVB-H rollout, U.S. carriers would not have to use ATSC, the U.S. terrestrial digital TV standard, whose vestigial-sideband (VSB) modulation scheme is considered unfit for mobile-TV transmission.
European industry leaders have long toyed with the idea of offering mobile applications via DVB-T, claiming the orthogonal frequency-division multiplexing it uses is more inherently resistant to multipath and fading problems than ATSC's 8-VSB and thus is ideal for mobile use. The DVB Project, however, has concluded that DVB-T "does not do the job" for mobile, according to Nokia's Henriksson. Power consumption was the main problem.
To develop DVB-H, the DVB Project introduced features, modifications and options to DVB-T's technical specifications, seeking lower power, more robust mobility and better quality-of-service in portable-TV reception. Among the key optimizations are time slicing and multiprotocol-encapsulation forward error correction (MPE-FEC).
Time slicing, which is required in DVB-H, transmits information to a portable device by organizing data in 1- to 2-Mbit bursts, making it possible to "switch off the radio for a majority of the time" between slices, said Philips' Turner. The DVB group claims that time slicing can achieve a power savings of up to 90 percent in video streaming. The target is to enable the DVB-H delivery chain"including tuner, channel decoder and back-end processing"at less than 100 milliamps, Turner said. In comparison, today's DVB-T requires 500 to 800 mA, he added.
The DVB-H spec also offers additional error correction, MPE-FEC, for improving mobile performance and tolerance to impulse noises. "You need to add another layer of extra error correction for much more robust signals for portable reception," said Turner. A rooftop antenna designed for DVB-T-based TV sets, for example, can easily pick up primary TV signals without interference from signals coming in over the next channel or from reflecting signals, Turner said.
On the other hand, a mobile TV receiver zooming down the autobahn or on a train whizzing by at 300 to 400 km/hour must pick up signals from multiple sources while staying connected.
Another optional feature in DVB-H's physical layer is the so-called 4k mode and 4k symbol interleaver for air interface enhancement. (Strictly speaking, "4k" means a 4,000-point fast Fourier transform, but in TV jargon it stands for the modulation scheme.) Nokia's Henriksson said DVB-H's flexible network architecture "offers a lot of options including 2k, 4k and 8k mode." In the 4k mode, mobility doubles over the 8k, he said. Use of 4k also allows a doubling in the maximum single-frequency network size over what's possible with 2k. If more robust demodulation is needed, operators can use quadrature phase shift keying. An option for 16QAM or 64QAM modulation is also available, Henriksson said.
The spec's new Transmission Parameter Signaling bits, meanwhile, can tell mobile devices that an incoming signal is DVB-H and if it's using MPE-FEC. This ensures faster signal acquisition and better support for handover, the developers say.
In designing DVB-H handsets, phone manufacturers might share a "display, battery, battery charger, user interface and audio/video decoder" with other designs, said Bill Krenik, wireless-advanced-architecture manager at Texas Instruments Inc. "But the commonality stops there. One needs to integrate a DVB-H tuner and a channel decoder." Two radios are mandatory so that TV broadcasts can be interrupted for incoming phone calls.
Krenik predicted a higher demand for a signal-processing chain in DVB-H-based mobiles than with other handset types. He also pointed out that DVB-H will be the first mobile technology in which performance differences on handsets "will be very apparent to users." Two users could easily compare TV picture quality on their handsets by standing side by side.