Patent ID: 9379877
Filing Date: 2016-06-28
CPC Classification: H04J,H04L,H04Q

Claim Text:
1. A communication system comprising: a first device; a second device; and a communication line connecting the first device to the second device; wherein the second device is configured to: measure a transmission delay time of reciprocation between the first device and the second device, calculate a first correction value based on the transmission delay time of reciprocation, and transmit the calculated first correction value to the first device; wherein the first device is configured to, after receiving the first correction value from the second device: generate a predetermined frame, calculate a transmission time for transmitting the predetermined frame to the second device based on a reception time of receiving the first correction value on a basis of a first time information stored on the first device and a process time in the first device calculated based on a clock of the first device, calculate an expected arrival time of the predetermined frame on the second device based on the calculated transmission time and the first correction value, and transmit the predetermined frame including the calculated expected arrival time, to the second device; wherein the second device is configured to, after receiving the predetermined frame: calculate a second correction value to transmit to the first device, based on difference between a reception time of receiving the predetermine frame on a basis of a second time information stored on the second device and the expected arrival time stored on the received predetermined frame; and wherein the first device, after receiving the second correction value, is configured to correct the first time information stored on the first device based on the second correction value.