On the Ground

The ground segment consists of gateways strategically located around the world. The role of each gateway is to provide access to the satellite constellation and, in turn, to interface with public and private data networks including the Internet. The major elements of the ground and control segment include:

Gateway Earth Stations (GES) consisting of two radomes, with enclosed VHF tracking antennas, one of which is largely redundant, and associated pedestals, controllers and radio equipment, an uninterruptible power source and back-up generator. They link the ground segment with the ORBCOMM satellites. They are located in multiple locations worldwide where they each:

• Track and establish two-way communications with the ORBCOMM satellites,
• Relay messages and telemetry between the satellites and the GCC (see below),
• Monitor the status of local GES hardware and
• Contain two high gain VHF antenna systems, which function independently for additional throughput and redundancy.

Gateway Control Centers (GCC) which process the data and provide the interconnection to terrestrial communications networks. Interfaces to the GCC enable reliable, efficient and cost-effective integration of the ORBCOMM system into existing or new customer information systems. A GCC controls one or more GES located within a licensed region, where they:

• Interface using SMTP and Web-based access via leased line, public or private data networks or the Internet
• Monitor performance of regional GESes and
• Monitor the status of the ORBCOMM message switch and related software.

A Network Control Center (NCC), located in Dulles, VA. In addition to serving as the U.S. GCC, it is responsible for managing the constellation of ORBCOMM satellites. The NCC is staffed seven days a week, 24 hours a day by ORBCOMM certified controllers who use associated tools to command, control and analyze the ORBCOMM satellites and monitor their performance.