GPS error caused 'havoc' for companies

Several companies were hit by hours of system warnings after GPS satellites broadcast the wrong time, according to time-monitoring company Chronos.

The company observed problems last week, after noticing some GPS time signals were 13 microseconds out.

Such a discrepancy is considered severe and several Chronos telecoms clients faced "12 hours" of system errors.

Previously, the GPS errors had also been blamed for disturbances with BBC radio broadcasts.

According to the US Air Force, which manages the GPS satellite network, problems began when a satellite named SVN 23 was decommissioned.

'Escalating alarms'

"Our support manager was rung at [02:00]," said Chronos chief executive Prof Charles Curry.

"He was called from his bed by a network operations centre."

"What we saw was about 12 hours of problems," he told the BBC.

Prof Curry said telecoms companies relied on the accuracy of time measurements to control the flow of data through their networks.

The bits and bytes of a telephone call, for example, might be synchronised based on the time as reported by GPS satellite signals.

That signal was constantly monitored for accuracy.

And when the 13 microsecond error had been detected, it resulted in thousands of system warnings being activated at some companies.

"The alarms were escalating," said Prof Curry.

"One particular network we have, which is a global network, [was] seeing alarms from all over the place, all over the world."