Digital TV Cell Phone Test Drive
Digital terrestrial broadcasting for mobile phones is scheduled to begin in Japan by spring 2006 and both Vodafone and KDDI had demonstration models up and running on the first day of the NHK Science and Technical Research Labs open house yesterday. An annual event open to the public, this year’s show focused once again on digital TV broadcasting with three floors of cameras, servers, receivers and handheld devices. Mobile receivers drew packed crowds herded into Disneyland-style long lines waiting their turn to handle an 801SH Vodafone/Sharp CDMA Qualcomm handset. No bigger than a conventional cell phone, the 801SH has a hybrid split-screen displaying images on the upper half with the bottom reserved for scrolling data feeds and Web links to programming, etc. Exclusive from Wireless Watch Japan!
A separate display area showcased Vodafone and a new KDDI/au prototype by Sanyo running live TV feeds through wall screens displaying images from both handsets simultaneously. This year’s wide-screen KDDI model has lost the clunky antenna seen on last year’s clunky Hitachi prototype. Projected side-by-side, each had sharp, clear reception of incoming live TV signals as data rolled inexorably underneath. Neither handset was equipped with a mini hard drive, something we would like to see as these TV phones take on greater significance as mobile communication/entertainment/information centers.
Mobile receivers will also have GPS functionality to handle location-specific data broadcast with the digiTV signal.
Mobile receivers will incorporate AVC/H.264 video encoding protocols; screens should have 320 horizontal lines and either 240 or 180 vertical lines at a maximum of 15 frames per second. Bit rates will differ depending on the broadcaster but will probably be in the 128- to 192-kbps range. This is pretty slow and often results in picture distortion — something NHK admits they and partners at Fujitsu Laboratories are still working on.
One solution to improve imaging is detecting areas where an image is most likely to degrade (faces in particular) and then prioritizing processing on those areas.
WWJ’s report last year touched on NHK’s determination to bring the Emergency Warning System onto mobile handsets. At that time their EWS efforts proved too draining to cell-phone batteries. Engineers had been using FFT (Fast Fourier Transform) processing, commonly used for digital terrestrial broadcasting reception. By slotting the signal into a different band, engineers found they could leave the circuit on standby, waiting for activation without eating into battery power. Should an emergency occur, EWS will ping mobile phones in stand-by mode, cuing users to turn on the phone and tune in to live NHK emergency broadcasts.
NHK is considering installing this EWS technology into other devices including TV remote controls that could automatically activate if an emergency occurs.
Political and corporate Japan, two elements in this country’s famous “iron triangle,” have often skipped merrily along hand-in-hand towards common goals and the digital terrestrial broadcasting initiative is no different. Development of digital TV handsets by the telecos in conjunction with NHK Science and Research Technology Labs has given the whole project de facto government backing.
And it’s not just NHK; all major Japanese TV broadcasters are rushing to adapt content and programming to mobile viewing — and buying. For manufacturers, content providers and marketers alike, the TV/cell phone duo is a sweet deal. As consumers move into a never-away mode for TV viewing, broadcasters and advertisers can use live feeds and hot links right on the cell-phone screen to drive program interest and audience participation — not to mention boosting impulse buying to a whole new level.
— Gail Nakada