"NTT Mobile Communications Network Inc. (NTT DoCoMo) said on March 9 that it has applied to the Ministry of Posts and Telecommunications for approval to add a packet transmission service to its Satellite Portable/Marine Phone service.
"The company expects to begin the service toward the end of March.
"NTT DoCoMo will release special phones to accommodate the packet data service, aiming to sell 4,000 by 2004. Regular voice communications over the satellite phone service began in March 1993 and there are already about 25,000 subscribers.
"For terrestrial-based mobile phones, NTT DoCoMo offers the "iMode" and "DoPa" packet transmission services. The iMode service provides a maximum data transmission speed of 9,600bps, while the DoPa service features speeds of up to 28.8kbps.
"In comparison, the satellite packet transmission service will offer upstream speeds of 4,800bps and downstream speeds of 64kbps, making it much faster than terrestrial-based packet transmission.
"The technology used is the same for both types of transmissions, but because there are fewer subscribers to the satellite-based service, its transmission speed can be raised.
"The coverage area for the new service will encompass the entire Japanese archipelago plus surrounding waters out to a distance of 200 nautical miles.
"NTT DoCoMo will offer four kinds of payment plans. The "Satellite Dual Service" plan providing both voice and packet data transmission will be priced starting from 9,500 yen per month. The "Satellite Single Service" for packet data transmission only will be priced from 10,000 yen. (107.01 yen = US$1)
"A cellular phone handset that supports the service is scheduled to go on sale toward the end of March.