FEEDBACK CONTROL METHOD AND DEVICE IN ATM EXCHANGE

摘要

PROBLEM TO BE SOLVED: To provide a concrete ABR control function to realize an ABR (available bit rate) service in an ATM exchange system. SOLUTION: A subscriber line processing unit 106 is provided with a function to calculate a cell round delay time based on a time till a cell is reflected in a terminal equipment and returned. A congestion detection function is provided to a switch section 101 or a multiplexer/demultiplexer 108, a rate calculation means 104 calculates a transmission rate corresponding to an outgoing path and writes it to a cell and a rate revision means 105 changes properly the transmission rate depending on a degree of occurrence of congestion. Furthermore, the rate revision means 105 measures number of communicating connections and predicts the number of the communicating connections possibly in existence for a prescribed time based on the number of the communicating connections in a time shorter than the prescribed time by means of a prescribed method. Furthermore, a coefficient is decided based on the predicted number of the communicating connections and the actual number of the communicating connections and the number of the communicating connections is predicted for succeeding prediction to be a more proper number by using the coefficient.