Patent ID: 8718038
Filing Date: 2014-05-06
Classification: H04J,H04L,H04W

Abstract:
1. A node system comprising a plurality of nodes that are connected via a transmission line, each of the plurality of nodes including, a clock generator, and a communication controller configured to transmit a frame in a slot assigned based on a microtick generated every time the clock generator generates a first certain number of clocks in a continuously repeated cycle, and to manage an initial value of a cycle microtick count corresponding to a cycle length of the cycle and a rate correction value for the initial value, wherein the plurality of nodes includes: a first node configured to transmit a first frame in a first slot, to repeatedly correct a first rate correction value so that cycles of the plurality of nodes synchronize, to stop transmission of the first frame when an absolute value of the first rate correction value exceeds a certain rate correction limit value, and to transmit the first frame in the first slot based on the corrected first rate correction value when the absolute value is within the rate correction limit value; a second node configured to transmit a second frame in a second slot, to repeatedly correct a second rate correction value so that cycles of the plurality of nodes synchronize, to stop transmission of the second frame when an absolute value of the second rate correction value exceeds the rate correction limit value, and to transmit the second frame in the second slot based on the corrected second rate correction value when the absolute value is within the rate correction limit value; and a supervisory node configued to transmit a third frame in a third slot, to transmit the third frame in the third slot while increasing or decreasing the cycle microtick count, and to determine reduced cycle microtick counts by subtracting or adding the rate correction limit value from or to the cycle microtick count of the supervisory node when reception of the first and second frames stop.