More than 20 Million TV Phones Ship in Japan

Shipments of cell phones compatible with Japan's mobile digital TV service have surged to more than 20 million units in fewer than two years since launch, according to industry data released Wednesday.

The 20 million mark was reached in December, thanks to shipments of more than 1 million handsets during the month, the Telecommunications Carriers Association said.

The digital TV service, called OneSeg, delivers a QVGA (320 pixels-by-240 pixels) resolution simulcast of Japan's terrestrial TV networks at no cost to the viewer. The broadcasts don't carry any digital rights management software, so it's been easy for cell phone makers to build recording functions into cell phones. With current phones it's possible to pick a TV show from the electronic program guide sent with each channel and program the phone to record the show onto a memory card for later viewing.

OneSeg launched on April 1, 2006, and the service is now available in much of Japan.

The service isn't popular only in cell phones. Many laptop PCs pack OneSeg tuners, and it's also built into many new car navigation systems, along with other portable devices like music and video players and electronic dictionaries.

The service is favored in portable gadgets over the conventional high-definition digital TV service because the processing power needed to handle the OneSeg signal is significantly lower. The maximum OneSeg data rate is about 416k bps (bits per second) versus about 20M bps for terrestrial HDTV.