Distributed medium access control for broadband access systems

A distributed scheduler for frame based communication between a plurality of terminals and a master controller, comprises a plurality of concentration elements for local scheduling of upstream data, the plurality of concentration elements and the plurality of terminals being partitioned over a plurality of cells distributed on a multiple hierarchical level star topology, each cell belonging to a hierarchical level N, where N is comprised between a top level, corresponding to a single cell to which the master controller is assigned, and a bottom level; at each cell at level N one concentrationelement being the master element for the cell and the remaining concentration elements and terminals in the cell being slave elements of the master element for the cell; each master element in a cellatlevel N being in turn a slave of the master element in one of the cells at level N+l , the master element at the top level being the master controller; each master element at level N comprising means for collecting uplink ag