FREQUENCY ERROR ESTIMATING APPARATUS USING RX DELAY IN PTP

摘要

The present invention relates to a frequency error estimating apparatus using RX delay in PTP which analyzes the trend of differences between transmitting time of a transmitting packet and receiving time of a receiving packet and estimates a frequency error so as to estimate a frequency error faster and more accurate than the existing way. The frequency error estimating apparatus of the present invention comprises: a delay detection unit which detects delays between transmitting time of a sync packet transmitted from the master server of PTP and receiving time of a slave device; a modified median filter which extracts a delay in a certain order among delays detected by the delay detection unit and the transmitting time of a packet having the corresponding delay; a delay average unit which calculates an average value of the extracted delay and the transmitting time extracted by the transform median filter; and a frequency slope estimating unit which estimates a frequency error by using the average value of the delay and the transmitting time calculated by the delay average unit.