Patent ID: 7433312

Claim:
A dynamic bandwidth allocation circuit which is provided in a single optical line terminal of a P2MP system in which a plurality of optical network units and the single optical line terminal are connected, and which shares bandwidth in an upstream direction between the plurality of optical network units, comprising: a target data size calculation section which, upon each cycle and for each of the optical network units, calculates target data sizes (target j,k ) which are targets for allocated data sizes in one cycle (allocated j,k , where j is a number of an optical network unit and k is a cycle); an ideal allocated data size calculation section which calculates ideal allocated data sizes (ideal j,k ) according to ideal j,k =target j,k −(α/(1−α))·excess j,k−1 , where τ is an exponential weighted moving average time constant, and α=(τ−1)/(τ+1); an excess allocated data size calculation section which calculates excess allocated data sizes (excess j,k ) for one cycle according to excess j,k =α·excess j,k−1 +(1−α)·(allocated j,k −target j,k ); and a bandwidth allocation calculation section which does not grant bandwidth allocation, if the ideal j,k <0.