Tokyo - Targeting a service launch in the spring of 2004, Mobile Broadcasting Corp. has developed a second-generation chip set and a compact prototype mobile video receiver capable of picking up S-band audio, video and data from a satellite.
The company, known as Mbco, is expected to be granted a license from the Japanese government in the next month or so as virtually the sole broadcaster focusing on mobile reception in Japan. The company ordered a satellite from Space Systems/Loral Inc. in August 2001 and plans to launch it in October.
Power consumption of the six-chip set-built in a 130-nanometer process by Toshiba Corp., one of Mbco's founders-is 2 watts. When the chips are paired with the prototype receiver, the figure rises to 4 W. That level will restrict the Mbco system, at least initially, to relatively large consumer electronics boxes such as portable TVs, PDAs and cars. "For a mo-bile-phone implementation, we need to integrate these chips and lower the power consumption," said Masashi Suenaga, vice president of Mbco. For cell phones, the goal is to merge the six devices into one using 90-nm processes sometime in 2005 or later.
"In Korea, TV broadcasting to mobile phones has already started," Suenaga said. "But TV reception through a mobile-phone network costs a lot. Once our LSI chip set is implemented in a mobile terminal, users can receive broadcasting at a low flat rate as a receiving fee."
The distribution of audio, video and data to mobile systems is a potentially big market for existing TV broadcasters, mobile-phone carriers and other operators like wireless-LAN providers. Mbco intends to take the lead in preparing the infrastructure to make that happen.
Founded in 1998 by Toshiba and several other companies, Mbco's original mission was to broadcast video content based on MPEG-4 technology. Toshiba owns a 38 percent share of its capital of about $222 million, and South Korea's SK Telecom is the second largest shareholder. Toyota, NTT Data and Nippon Television are also listed as large shareholders among the 63 investors.
Mbco's broadcasting system consists of one satellite and so-called "gap fillers" that are designed to fill the radio wave gaps in places like tunnels and behind buildings, where the 2.6-GHz short waves cannot reach. "Gap fillers are less expensive than launching another satellite to cover those gaps," said Suenaga. Mbco is now actively installing gap fillers in Japan, starting in metropolitan areas.
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The Japanese firm intends to deploy its broadcasting system, which receives signals without a parabolic antenna, by 2004.
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Suenaga said that in field trials, the Mbco prototype receiver, which has a built-in antenna, succeeded in receiving signals on the bullet train running at 167 miles an hour. The broadcasting system, which has a data rate of more than 7 Mbits/second, uses MPEG-2 for baseband multiplexing, MPEG-2 AAC for audio coding and MPEG-4 Visual for video coding.
The company expects to complete construction of its uplink station by June. The station sends a time-division multiplexed (TDM) signal in the Ku band to the satellite. The satellite converts this to a code-division multiplexed (CDM) signal in the 2.6-GHz S-band frequency, amplifies that signal and sends it to the ground for direct broadcasting.
In parallel, the satellite relays the Ku-band TDM signal to each of the gap fillers. They in turn convert the signal to CDM for delivery to each mobile receiver within the gap filler's coverage area.
Mbco's six-chip set forms the receiver's core. One device handles CDM and forward error correction, another handles conditional access and a third is the decoder. Orthogonal detection uses two ICs. The sixth chip is a twin phase-locked loop, which is used for the RF tuner.
The CDM/FEC chip demodulates the mobile-broadcasting signal, preventing interference of the same-frequency signals from the satellite and gap fillers.
