ABSTRACT
Inmarsat-C is an all-digital text/data system which operates between the mobile earth station (MES) and a ‘gateway’ or land earth station (LES). The principal advantages of the system when compared with Inmarsat-A, are that it is low cost, small and uses a very small omni-directional antenna. Its main disadvantage is, of course, that voice communication is not possible. It should be remembered however, that information transfer by voice communication is very slow and generally requires more bandwidth per carrier than data communications.
