1. A satellite communication system operative with at least one existing terrestrial communication system for carrying communication traffic, comprising: a constellation of satellites in earth orbit, each of said satellites transmitting one or more links containing said traffic to one or more terrestrial users; one or more terrestrial gateways, said gateways being linked to one or more satellites in said constellation for carrying said traffic, each of said gateways associated with a geographically limited cell; a computing center, operatively associated with said communication system; and a communication link allocation system within said computing center for calculating optimized available resources and for allocating said traffic according to said optimized resources for a specific cell, said communication link allocation system comprising: a first computer module constructed to generate and store a geographic definition of a cell including the communications resources available thereto and the power constraints related to said resources; a second computer module constructed to generate and store a user traffic model based on historic user demands related to said cell over time, including data relating to channel changes for connected links; a third computer module constructed to generate and store an optimized performance objective in the form of a barrier function which penalizes allocations which cause channel changes to links in said cell over time; and wherein said communication link allocation system calculates a solution for optimum traffic allocation for traffic within a cell at a particular time, at least in part based on said data in said first, second, and third computer modules; and a traffic allocation module comprising: a tiling module for defining multiple subdivisions within said cell; a diversity implementation module for receiving and storing a selected diversity policy; and a subdivision adjustment section for adjusting the definition of a subdivision in accordance with said diversity policy and said user traffic model, thereby balancing the signal to noise ratio among links in said cell.