Linkedclocks for a robust solution of GNSS timing receivers

GNSS is vulnerable due to the low power satellite signal reception that can be easily jammed with domestic equipment (accidental and malevolent local events). With this disadvantage in mind and at least 17 of 21 types of infrastructures classified as critical by government authorities require timing information, most of them by GNSS timing receivers. There are a requirement of make the time obtained more robust against jamming. The way to make the reception of GNSS time can now be done linking the time signals from scattered sources (as GNSS receivers located at medium distance from each other). This solution is scalable in the number of GNSS receivers that can be redundantly used and the distance (up to 100Kms) between them. Its regular self-calibration functionality facilitates its deployment providing a full and accurate time integrity solution. Our approach is based on IEEE1588v2 and can take advantage of high accuracy profiles as White-Rabbit to enhance the scalability and robustness of the solution. This allows time-critical nodes to access a distributed timing network linking three or more GNSS receivers without affecting significantly the time accuracy in the time transfer stage.