JSAT Satellites Table

Equipped with state-of-the-art facilities, the JSAT Yokohama Satellite Control Center (YSCC) is located close to Nakayama Station on the JR Yokohama Line. Satellite control operations are carried out 24 hours a day to ensure consistently reliable satellite communications services. Generally satellite control operations mean Satellite Operations and Network Operations.

YSCC, JSAT's main satellite control facility, and its backup station, the Gunma Satellite Control Station (GSCS), are located approximately 130km apart to ensure that natural disasters and other contingencies do not disrupt the operation of both facilities at once.

In the event that an event disrupts operations at YSCC or GSCS, either facility can remotely control equipment at the other facility via dedicated digital lines. Satellite control operations remain unaffected as a result.

JSAT delivers highly reliable services using a total of 19 parabolic antennas facilities. These antennas consist of two types -limited-motion antennas, which are adjustable within a limited range in the direction of the orbital position of each satellite, and full-motion antennas, which can track satellites anywhere in the sky.

	Satellite operations entail monitoring the condition of satellites and controlling the orbital position of satellites. JSAT uses geostationary satellites to provide telecommunications and broadcasting services. These satellites appear stationary from a position on Earth, but actually circle the planet once every day. Geostationary satellites are positioned 36,000 km above the equator, where the centrifugal force generated by the satellite's movement around the Earth precisely balances the gravitational pull of the planet. Left alone, satellites are displaced from geosynchronous orbit due to many factors, including the gravitational influences of the sun and moon. Satellite control is needed to adjust the orbital position and attitude to correct for these displacements. Control also involves closely monitoring the temperature, voltage, current and other variables of each section of a satellite to ensure that vital functions remain normal at all times.

Telemetric satellite monitoring (confirm that temperature, voltage, current and switches are normal)

Uplink commands (command signals) to satellites

Measure ranges from Earth to satellites

Execute corrective maneuvers to control satellites (correct orbit and attitude of satellites by firing small jets on board satellites)

Network operations involve monitoring and controlling satellite networks that employ transponders on communications satellites. Satellite networks must be constantly monitored as they can be disrupted by numerous factors. These include anomalies in the satellite network, conflicting signals due to ground-station malfunctions or control errors, or when incorrect transmission output or frequency settings are employed in uplink access tests from fixed, portable and vehicle mounted earth stations.

Monitor the condition of satellite networks 24-hours a day.

Perform uplink access tests when using fixed, portable and vehicle mounted earth stations for the first time to ensure normal transmission at all times.

Manage the use of satellite networks by processing requests for transponder use from customers with ongoing service contracts and other means.

Completed in 1987, the current YSCC building incorporates the expertise of U.S.-based Hughes Space and Electronics Company (now a division of Boeing). This building has played a significant role in the growth of JSAT's satellite telecommunications business.

Today, JSAT's fleet consists of 9 satellites, including a backup satellite. JSAT looks to expand satellite control operations and antenna facilities in line with its growing volume of business. However, this will require more room for equipment as well as larger workplaces, creating the need to construct a new building on the premises of the YSCC. The first phase of construction was completed in December 2002, and succesive grand open of the new facility was December 2004.

These actions will take the YSCC to its next stage of evolution, in terms of roles and facilities. Currently performing satellite control operations and network operations, the YSCC will add the new role of satellite relay station when work is completed.

Services made possible by the new YSCC facility will include an expanding range of video transmission services, for which demand has been growing in recent years. To relay transmissions from overseas broadcasters to their offices in Tokyo and to Japanese broadcasters, JSAT plans to install facilities for receiving transmissions from JSAT and other satellites at the new YSCC facility.

This will give JSAT the ability to provide a comprehensive service whereby a wealth of video content from around the world is received by the YSCC and delivered to local broadcasters via JSAT's media center in Tokyo. Conversely, images from Japan will be sent to overseas broadcasters via facilities at the YSCC. As Asia prepares for the start of digital multi-channel broadcasting services, new facilities at the YSCC will allow JSAT to broadcast Japanese anime, music, serial dramas and other forms of content that are in high demand throughout Asia. The new YSCC facility will also be equipped with facilities for transmitting the JC-HITS program distribution service for cable TV operators and demonstration equipment for the SAO service, a low-cost VSAT service.