| 摘要 |
A clock synchronization method is described for a system including N clocks, at least three and at most N-1 of which are master candidate clocks. A start message is broadcast from the fastest master candidate clock. From each of the master candidate clocks, a response message including the local time of receipt of the start message according to the clock in question is broadcast. Using the information representing the times of receipt of the start message, the median master candidate clock is selected and becomes the master clock. The master clock determines the clock synchronisation error for each master candidate clock, using the information representing the times of receipt of the start message. If any such clock synchronisation error is excessive the master clock declassifies the clock in question as a master candidate clock and classifies another clock as a master candidate clock. This is achieved by broadcasting a classification message identifying which of the N clocks are to be classified as master candidate clocks. Next, the master clock broadcasts a synchronisation message including the local time of receipt of the classification message according to the master clock. Each of the other N-1 clocks is then synchronised with the master clock using that information and the local time of receipt of the classification message according to the clock in question.
|
