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Satellite CommunicationsAndronics Ltd utilize a constellation of Low Earth Orbit satellites to transmit data to and from remote sites. The benefits of this approach are:
The ORBCOMM system provides global, two-way, data communication services to a wide variety of applications. Subscriber communicators (SCs) pass data messages to and from Gateway Control Centers (GCC) over ORBCOMM satellites and GCCs route messages to users over the internet or dedicated delivery lines. SCs are highly versatile communications devices available in a variety of configurations to suit different applications. They can support relatively simple, fixed-site, prescribed-content, interval-based messaging as well as complex, mobile, sensor-integrated, event-driven reporting. Common to all SCs is the VHF communication interface to ORBCOMM satellites. SCs communicate directly with satellites using ORBCOMM’s packet-switched protocol, and the system offers full transmission acknowledgement. The satellites provide SCs with system information and serve as the communication link between SCs and the ORBCOMM terrestrial network. Messaging traffic flows between the satellites and a GCC through tracking stations called Gateway Earth Stations (GESs) that connect with satellites as they pass overhead. When a satellite is not connected to a GES, it can still support SC messaging in a store-and-forward mode. The system’s space segment consists of 30 operational satellites distributed around the globe in a low Earth orbit (LEO) constellation, with a license for up to 47 satellites in seven orbital planes at an altitude of 825 km (515 miles). There are currently 13 GES facilities on four continents, maintaining satellite-GCC connectivity and near-real-time messaging capabilities for users throughout much of the world. Message traffic passed down to the GESs is directed over dedicated lines to GCCs for processing and delivery to end users. |