Method of random access communication using subbanding and variable length messages

A method of communication between earth terminals and satellites, comprising the steps of:

• providing a plurality of satellites, each satellite having at least one receiver tunable to a selected frequency;
• providing a plurality of earth terminals adapted to send messages to, and receive messages from, the plurality of satellites;
• defining at least one subband of the frequency spectrum, said subband not being non-mutually exclusive of other subbands;
• assigning at least one subband to each satellite receiver to accommodate a plurality of regulatory constraints and requirements for one or more countries;
• assigning each earth terminal to one of the satellite receivers;
• dynamically selecting a center frequency for the communication channel for each receiver within the subband assigned to that receiver;
• tuning each satellite receiver to the communication channel selected for that receiver;
• informing at least the listening earth terminals of the communication channel selected for the receiver to which each earth terminal is assigned;
• compensating for differential frequency and time of arrival arising from low-Earth Orbit spacecraft dynamics;
• transmitting messages from the earth terminals to the respective, assigned satellite receivers at the selected communication channel for each receiver.