Developments in mobile satellite communications

Over the past few years there have been very significant developments in the field of mobile communications, in particular in the development of terrestrial based cellular systems. The 1st generation cellular systems which are still being deployed are primarily analog. The 2nd generation systems which are being deployed at a breathtaking pace are primarily GSM, D-AMPS and PDC. The requirements and features of more advanced systems are currently being addressed at the ITU and at the ETSI, the FPLMTS/IMT2000 and UMTS systems respectively. For the first time these 3rd generation systems will have a satellite component which will make them truly global mobile communication systems. The developments which have being taking place in mobile satellite communications are addressed with particular reference to the system currently under implementation at ICO. The ICO system will be the first such system to use the frequency band allocated for the satellite component of FPLMTS. For MSS, most of the systems proposed or currently under development are outlined in tables