Orbcomm Ground Segment Components

The ground segment, which has most of the intelligence of the ORBCOMM system, is comprised of:

Gateway Control Center (GCC), Gateway Earth Station (GES) and ORBCOMM's Network Control Center (NCC) which is located at ORBCOMM's headquarters in Dulles, VA. The NCC also serves as North America's GCC. 

Additionally, within the US, there are four GESs located in Arizona, Georgia, New York State and Washington State.

Gateway Control Center (GCC)
Located in a territory that is licensed to use the ORBCOMM system, the GCC provides switching capabilities to link mobile SCs with terrestrial-based customer systems via standard communications modes including X.400, X.25, leased line, dial-up modem, public or private data networks, and e-mail networks including the Internet. Interfaces to the GCC enable reliable, efficient and cost effective integration of the ORBCOMM system into existing or new customer MIS systems. 

Gateway Earth Station (GES)
ORBCOMM's GESs link the ground segment with the space segment and will be in multiple locations worldwide. The GESs provide the following functions:

• Acquire and track satellites based on orbital information from the GCC

• Transmit and receive transmissions from the satellites

• Transmit and receive transmissions from the GCC or NCC

• Monitor status of local GES hardware/software

• Monitor the system level performance of the satellite "connected" to the GCC or NCC

The GES is redundant and has two steerable high-gain VHF antennas that track the satellites as they cross the sky. The GES transmits to a satellite at a frequency centered at 149.61 MHz at 56.7 kbps with a nominal power of 200 watts. The GES receives 3-watt transmissions from the satellite at 137-138 MHz range. These up and downlink channels have a 50 KHz bandwidth.

Network Control Center (NCC)
The NCC is responsible for managing the ORBCOMM network elements and the U.S. gateways through telemetry monitoring, system commanding and mission system analysis. It provides network management of ORBCOMM's satellite constellation and is staffed seven days a week, 24 hours a day by ORBCOMM-certified controllers.

The NCC provides the following functions:

• Monitor real-time and back-orbit telemetry from the ORBCOMM satellites

• Send real-time and stored commands to the satellites

• Provide the tools and information to assist engineering with resolution of satellite and ground anomalies

• Archive satellite and ground telemetry for analysis

• Monitor performance of the U.S. Gateway Earth Stations (GESs)

  Monitor status of the ORBCOMM U.S. Message Switch (OMS) and related software

• Provide daily and weekly performance totals

See also
Orbcomm Appoints African SPs
Telital Makes Orbcomm Terminals
Explanation of LEO, MEO, GEO satellite systems
Mobile satellite Services
Glossary of satellite terms