Site: Space Communications Corporation (SCC)
2-8, Higashi-shinagawa
2-chome, Shinagawa-ku
Tokyo 140, Japan

Date Visited: June 5, 1997

WTEC: C. Mahle (report author), K. Bhasin, R. DePaula, J.V. Evans, N. Helm



Space Communications Corporation (SCC) was founded in 1985 by Mitsubishi Corporation and Mitsubishi Electric Corporation as Japan's first satellite business in the private sector. Today SCC is supported by 28 shareholders from the Mitsubishi Group and is a satellite operator providing space segment capacity to several domestic and international customers. SCC is a domestic and international Type 1 telecommunications carrier in Japan and received an international license in 1995. The company has a paid in capital of approximately $600 million and revenues of approximately $200 million in 1996.

At the time of this WTEC visit, SCC had two satellites in orbit, Superbird A and Superbird B. Superbird C was launched July 27, 1997. Superbird A and B are SS/L FS-130 satellites with 23 Ku-band transponders (36 MHz channel bandwidth, 50 W TWTAs) and 2 Ka-band transponders (100 MHz channel bandwidth, 29 W TWTAs) located at 158 E (Superbird A) and 162 E (Superbird B). The single beam coverage extends from north of Japan to Taiwan and includes Korea. Superbird C is an HS 601 satellite with 24 Ku-band transponders (4 x 54 MHz, 4 x 36 MHz and 16 x 27 MHz channel bandwidth, 90 W TWTAs) and will be located at 144 E. One beam covers Japan and Hawaii, two beams cover Northeast Asia and Southeast Asia and a steerable beam can be pointed at most of the Asia-Pacific region.

Satellite operation is performed from two sites (one north of Tokyo, the second in western Japan), both fully equipped for TTC&M as well as communications monitoring. The facilities also include a network operations center for DirecPC service.

SCC has developed many different service offerings to serve a variety of customers. These include VSAT networks, satellite news gathering (SNG) systems, satellite broadcast and distribution systems and private networks. Services currently performed and/or contemplated in the near future are listed below.


Local Government Network (LASCOM) is a network used to connect approximately 3,000 terminal points (eventually 5,000) all over Japan, carrying TDF (telephone, data, facsimile, 32 kbps), simultaneous command service 32 kbps), packet data exchange (32, 64, 128 kbps), digital video (64.384 Mbps), and analog video service (17.1 MHz, 32 MHz) for emergency and non-emergency local government use. This may be one of the largest VSAT systems.

Satellite interactive TV system is used for remote communications and monitoring (for Tokyo Electric Power Co). This network allows remote observation of construction sites, weather, etc. The remote camera can be controlled from the home office in addition to telephone and facsimile transmissions.

A variable bandwidth (DAMA) system bused for telephone, facsimile, video conferencing and digital TV.

A telemetry/Telecontrol System is used for public utilities such as a gas company and an electric power company. The outbound link is TDM, the inbound link is TDMA, the link quality is monitored and a switch to a terrestrial backup is performed automatically. DAMA is used for ADPCM voice.


SCC offers satellite news gathering services in Japan and also abroad. Both analog and digital techniques (includes video and order wire) are in use. Analog service is expected to diminish. Vehicles with stabilized antennas have been developed that can transmit news coverage while driving.


In 1996 SCC established a new company, DirecTV Japan, in conjunction with Hughes DirecTV International and other Japanese companies. This company will provide approximately 100 channels of digital TV using the MPEG-2 format, and high quality audio (based on the Hughes U.S. offering) using 16 transponders on the Superbird C satellite.

Currently in use is CS broadcasting (DTM) via Superbird called "Skyport TV," cable TV program transmission, a data distribution service for weather data and news (850 kHz transponder bandwidth), a BGM distribution system for department stores (450 kHz transponder bandwidth), and an interactive HDTV distribution system for University Hospitals (forward link 32 Mbps HDTV, return link 6.144 Mbps NTSC, both FEC Rate 3/4). This system is in operation with 8 universities and is expanding.


Private networks are in use for schools (educational TV and on the job training), public utilities (gas company, electric power company) and private companies.

SCC currently provides a DAMA service for customers. DirecPC service (a development by Hughes Network Systems) has also been provided since January 1998. Three types of service are contemplated (packet delivery, multimedia data pipe and Internet/intranet connections). The service will use a 12 MBps data stream via Superbird A into a 45-60 cm antenna.


SCC expects future growth in Ka-band services. Superbird A and B each have three transponders at Ka-band. Central issues affecting Ka-band services are expensive ground equipment, especially the transmitter, and quality issues, especially rain fade. C-band is not considered usable by SCC for service in Japan, as there are too many interference problems (terrestrial) and also no available suitable orbital slots.

SCC prefers to buy only spacecraft with proven designs but does consider using new technology up front. It is focused presently on Japan and has some service outside. One of the new technologies considered desirable is satellite antenna patterns with steeper rolloff as the borders with Russia, Korea, China and Taiwan are very close and are located in a different ITU region. Frequency coordination is a major and difficult issue for SCC.


SCC is a satellite operator with an excellent business base that has a well developed service offering with additional new services coming on line. It will use whatever satellite technology is readily available that can satisfy its customers within the economic constraints of the market. Continued rapid growth of satellite services can be expected.

Published: December 1998; WTEC Hyper-Librarian