Safe Estimation of Time Uncertainty of Local Clocks

The Reliable and Self-Aware Clock (R&SAClock) is a new software clock aimed at providing resilient time information. It uses and exploits the information collected from any chosen clock synchronization mechanism to provide both the current time and the synchronization uncertainty, intended as a conservative and self-adaptive estimation of the distance from an external global time. This paper describes an algorithm that uses statistical analysis to compute the synchronization uncertainty with a given coverage. Simulations are presented that show the behavior of the algorithm and its effectiveness.