Patent ID: 7184920
Filing Date: 2007-02-27
Classification: H04J,H04W

Abstract:
1. A delay measurement system comprising: a master device including an interface which transmits a delay measuring signal at a fixed timing relative to a synchronous pattern signal in an overhead and transmits a frame signal in which an internal delay time, associated with a frame signal generation, from a delay measurement start timing to a transmission timing of the delay measuring signal is stored in the delay measuring signal as a master offset value, and a delay controller which generates the delay measuring signal; and a slave device including an interface which adds an internal delay time of its own device associated with a frame signal generation to the master offset value after having received the frame signal to make a slave offset value and transmits a frame signal in which the delay measuring signal is updated with the slave offset value, and a delay controller which updates the delay measuring signal; wherein the delay controller of the master device calculating a delay time between both devices by subtracting the slave offset value from a time difference between a timing at which the delay measuring signal within the frame signal transmitted from the slave device is received and the delay measurement start timing.