Iridium is the world’s only truly global mobile satellite network company, with voice and data solutions covering every inch of the Earth’s surface. That’s why Yellowbrick uses it, to make sure our trackers work absolutely everywhere.
The Science bit…
The Iridium constellation has more satellites than any other commercial constellation. The 66 Iridium satellites are in a near-polar orbit at an altitude of 485 miles (780 km). They fly in formation in six orbital planes, each comprising 11 satellites, evenly spaced around the planet. Each Iridium satellite completely circles the Earth once every 100 minutes, traveling at 16,832 miles per hour, traveling from horizon to horizon across the sky in about ten minutes.
When an Yellowbrick sends a position report, that device connects to the Iridium satellite that happens to be overhead. The traffic is routed among Iridium satellites around the globe to reach the satellite above the Earth gateway, which downlinks the data and transfers it to the Yellowbrick servers in Dallas, Texas and London, England. Because the Iridium constellation comprises Low Earth Orbit (LEO) satellites, data delays are typically so minimal they are virtually unnoticeable (normally under 2 seconds from transmission to receipt)
Each Iridium satellite is cross-linked to four other satellites – two in the same orbital plane and one in each adjacent plane. These links create a dynamic network in space. Data is routed among Iridium satellites without touching the ground, creating a reliable connection. Iridium’s satellites are virtually impervious to natural disasters, such as hurricanes, tsunamis and earthquakes, that can damage ground-based wireless towers and terrestrial wires.
Iridium is the only connection available to many parts of the world. Even in urban and suburban environments, Iridium data solutions increasingly provide reliable backup for business communications transmissions.
Global support and control
The Iridium ground network comprises the system control segment and gateway that connects into the terrestrial data and phone systems. The system control segment supplies global operational support and control services for the satellite constellation, delivers satellite tracking data to the gateways, and controls termination of Iridium messaging services. This segment has three components – four telemetry tracking and command/control (TTAC) stations, the operational support network, and the satellite network operation center (SNOC). Feeder links and cross-links throughout the satellite constellation supply the connections among the system control segment, the satellites and the gateway.
Gateways house ground-based antennas and electronics that provide voice and data services, messaging, prepaid and postpaid billing services, and other customer services. They are responsible for supporting and managing mobile subscribers and for interconnecting the Iridium network to the terrestrial phone system.