METHOD FOR DETECTING DUPLEXED LINK STATES IN ASYNCHRONOUS TRANSFER MODE EXCHANGE

摘要

PURPOSE: A method for detecting duplexed link states in an asynchronous transfer mode(ATM) exchange system is provided to rapidly detect a link error generation and an error recovery to minimize cell losses and system errors caused by link errors in a cell transmission between a duplexed subscriber device and a switch device. CONSTITUTION: If a power of a subscriber device is turned on, an asynchronous transfer mode(ATM) exchange system sets up a reference state signal, a link state signal and a count enable signal as initial values. Whenever a reference cell starting signal which displays a cell start from the subscriber device is applied to a switch device, the ATM exchange system adds a value of the link state signal to a value of the reference state signal. Whenever the reference call starting signal is applied, the ATM exchange system compares the value of the link state signal and the value of the reference state signal. If the value of the link state signal is equal to the value of the reference state signal, the ATM exchange system applies a count enable signal to initialize a count value. Whenever a reference pulse is applied, the ATM exchange system increases the count value. The ATM exchange system constantly keeps a link normal signal which displays a current link state until the count value is counted as a set up value. The ATM exchange system decides that a current link is an abnormal link, and switches the current link with another normal link by the link normal signal.