Orbcomm space segment for mobile satellite system (MSS)

In this paper is introduced the Orbcomm space segment as a wide area packet switched and global two-way data transfer network providing satellite communication, tracking, monitoring and logistics services between mobile, remote, semi fixed or fixed Subscriber Communication Units (SCU) in Mobile Satellite Service (MSS) and Gateway Earth Stations (GES) or Gateway Control Centres (GCC) accomplished via LEO satellites and Network Control Centres (NCC). Orbcomm Global, L.P., from Dulles, Virginia, USA equally owned by Teleglobe and the Orbital Sciences Corporation, provides global services via the world´s first LEO satellite data and messaging communications system. The US Federal Communications Commission (FCC) granted Orbcomm system a commercial license in October 1994 and the Commercial service began in 1998. Orbital Sciences was the prime contractor for the design project of Orbcomm satellites. The Company owns and operates a network consisting in 36 Little LEO satellites and several GES deployed around the world, connecting small, low-power and commercially proven SCU terminals to private and public networks, including the Internet. Orbcomm delivers information to and from virtually anywhere in the world on a nearly realtime basis to the Terrestrial Telecommunication Network (TTN). The Orbcomm space segment has subscriber transmitters (Tx) that provide a continuous 4.8 Kb/s to 9.6 Kb/s stream of downlink packet data to the receivers (Rx), and vice versa.