Adaptive Kalman Filter for Time Synchronization over Packet-Switched Networks: An Heuristic Approach

The importance of Time synchronization for distributed applications is growing. The most currently used synchronization protocol is NTP [1]. NTP and GPS satisfy the majority of the world's time synchronization needs, although, GPS have limitations [2]. GPS cannot function inside buildings, or in places where there are physical obstructions and high amounts of electromagnetic noise. In addition, GPS is a costly solution. This work proposes a new approach to synchronize time among machines interconnected by computer networks, which minimizes the disturbance introduced by the network with no extra hardware cost. The methodology employs high-resolution clocks and stochastic methods to minimize the error introduced in time measurement carried out across the network. It also uses an adaptive approach to continuously tune the synchronization mechanism to the network traffic characteristics. An increase of time synchronization accuracy of two orders of magnitude, in comparison with traditional estimation methods was obtained as a result.