Trusted dissemination of a reference time scale to user terminals

A non-transitory computer-readable medium storing instructions for implementing a Reference Time Scale (RTS) Dissemination System (RTS-DS) that are executable by a processing device, wherein the Reference Time Scale (RTS) Dissemination System (RTS-DS) includes (i) a RTS Dissemination Data Provider (RTS-DDP), and (ii) a User Terminal (UT), wherein the RTS Dissemination Data Provider (RTS-DDP) is equipped with a Radio Receiver, and the User Terminal (UT) is equipped with a Radio Receiver and a Clock Device, wherein execution of the instructions by the processing device causes the processing device to:

• receive radio signals at the RTS Dissemination Data Provider (RTS-DDP) with the Radio Receiver and compute a RTS-DDP Computed Time Scale based on the received radio signals;
• receive radio signals at the User Terminal (UT) with the Radio Receiver, compute a UT Computed Time Scale based on the received radio signals, lock the Clock Device to the UT Computed Time Scale, and provide a UT Local Time Scale resultingly locked to the UT Computed Time Scale;
• receive a Reference Time Scale (RTS) at the RTS Dissemination Data Provider (RTS-DDP);
• compute with the RTS Dissemination Data Provider (RTS-DDP), at a RTS-DDP Computed Time, Time Quantities indicative of a difference between the RTS-DDP Computed Time Scale and the received Reference Time Scale, including (i) a Time Scatter indicative of a difference between the RTS-DDP Computed Time and a corresponding Reference Time, and (ii) a Time Offset indicative of a mean value, computed over a timespan, of a number of differences between RTS-DDP Computed Times and corresponding Reference Times;
• transmit with the RTS Dissemination Data Provider (RTS-DDP) RTS Dissemination Data containing the computed Time Quantities, the RTS-DDP Computed Time when the Time Quantities are computed, and the RTS-DDP Computed Time when the RTS Dissemination Data is transmitted;
• receive at the User Terminal (UT) transmitted RTS Dissemination Data,
• compute at the User Terminal (UT), at a UT Computed Time corresponding to the RTS-DDP Computed Time when the Time Quantities are computed (i) a first quantity indicative of a difference between the UT Computed Time and a corresponding UT Local Time, and (ii) a second quantity indicative of a difference between the Time Scatter and the Time Offset contained in the received RTS Dissemination Data;
• and
• check at the User Terminal (UT) whether a validation criterion is met by the first and second computed qualities, wherein:
• if the validation criterion is determined to be met:
• compute a UT RTS-Aligned Time Scale in time alignment with the Reference Time Scale based on the Time Offset contained in the received RTS Dissemination Data, and
• expose the UT RTS-Aligned Time Scale, along with an indication that the exposed UT RTS-Aligned Time Scale is in time alignment with the Reference Time Scale and an indication that the exposed UT RTS-Aligned Time Scale is trusted;
• and if the validation criterion is determined not to be met:
• expose the UT Local Time Scale to the UT, along with an indication that the exposed UT Local Time Scale is not in time alignment with the Reference Time Scale and an indication that the exposed UT Local Time Scale cannot be trusted.