METHOD AND APPARATUS FOR POWER SUPPLY INTERRUPT DETECTION

摘要

PROBLEM TO BE SOLVED: To prevent misjudge of power interrupt. SOLUTION: A subscriber line terminator 70 transmits a data frame including power state information to an intra-station line terminator 60. The intra-station line terminator 60 detects out of synchronism of data frames to be sent based on power supply state information of m-sets of the data frames among the transmitted data frames. Interrupt of power supply is discriminated, when number of data frames whose power supply state information indicates power interrupt information among the m-sets of data frames when they satisfy a majority decision, based on respective power supply state information of the m-sets of preceding data frames to n-sets of data frames monitored in the past by forward protection processing that is made, when of synchronization is detected.