The Design, Implementation and operation of the JPL OnEarth WMS Server

An access control method to control access to a communication channel of a plurality of units coupled to it, each unit having a first and a second own priority assigned to it, includes a first step of comparing and withdrawing units, based on the first own priorities of said units, and for these units that have not withdrawn after the first step, this first step is repeated but using the second own priorities of these remaining units. A method to control access to a communication channel interconnecting a multitude of pluralities of units coupled to it, includes the mentioned steps for a single plurality for at least one plurality amongst said multitude.