Adaptive assignment of unique words in a communication system

How to assign a unique word in a SDMA (space division point-to-multipoint connection) communications system and a system are provided. A network management system arranges a plurality of cell stations to a plurality of clusters logically, and supervises a high traffic state. If it judges with a high traffic state existing, it is a network management system, 1) Or it moves a cell beyond 21 つ which re-distributes a unique word within one cluster from a cluster of a busy state to a cluster with a comparatively low busy state, create 3 new cluster and move a cell from a cluster of one or more busy states to a new cluster. Thus, a communications system is continuously adaptation-ized so that use of more unique words may be attained at a cell station which has higher communication demand.