GPS glitch could hit power grid and trading systems

Devices that rely on the timing signal delivered by GPS are potentially at risk due to an arcane feature that will see the entire system experience a type of reset at 1 am on Sunday.

GPS was conceived in the 1970s, with the first satellite launched more than 40 years ago. As a result, its data capabilities for tracking weeks are limited to just 10 bits per message. This means the system’s integrated counting mechanism has to roll back every 1,024 weeks, or 19.6 years. According to the UK’s National Physical Laboratory (NPL), the upcoming reset on Sunday could affect technology that is not prepared for the timing reset.

“The effect of the rollover is truly unpredictable,” said Peter Whibberley, senior research scientist at NPL. “When GPS was first created, the processing power of computers was not what it is today, and limiting the week number to just 10 bits helped to keep down the amount of data that had to be transmitted. Now we rely on precise timing in more and more applications, and naturally, we need reliability to match.”