Store-and-forward data communications using small terminals and microsatellites

While most interest in constellations of satellites in low Earth orbit has been for systems providing global mobile or fixed broadband communication services, there is also a role for small, inexpensive systems providing specialized services. At the smallest level this is represented by a single microsatellite offering a “store and forward” or messaging service for users who require regular low to medium volume data transfers. We describe the major characteristics of a typical store-and-forward system and outline some of the technological challenges that designers face. We provide a justification for using on-board buffering and focus on the selection of an appropriate channel multiple access scheme that offers certain advantages over conventional Aloha random access