GPS rollover in 2019 poses risks for global time services

On 6 April 2019 the GPS system, used by many organisations for critical infrastructure, will perform a rollover. The rollover is the result of a legacy GPS navigation message which gives a Week Number (WN) as a ten bit parameter. As a result, the WN parameter in the GPS navigation message needs to reset to zero every 1024 weeks.

For many organisations running up-to-date systems, this should not be a problem. However, there is the possibility of problems for older receivers or those that have not been receiving firmware updates. More information about the possible effects of the GPS rollover on time services is available here.

PTP and time accuracy 

Given the importance of accurate time to critical infrastructure ranging from communications, power and industrial processes to banking, finance and emergency services, it is important to consider running a redundant backup for time services. If milliseconds matter to your business, it is worth learning more about alternative time services, such as those using Precision Time Protocol (PTP). PTP is used by industries ranging from banking and financial services to telecommunications, transport and the energy sector. For any organisation that needs to ensure the highest level of time accuracy and does not want to depend solely on GPS, PTP offers robust and reliable traceable time. 

Netnod’s PTP service 

Netnod’s PTP service offers traceable time over a dedicated fibre which enables organisations to time stamp to the highest degree of accuracy. It provides guaranteed redundancy for organisations that are using GPS, which is important given the fact that GPS is susceptible to interruption due to weather conditions, rollover problems and security issues.

More information is available about Netnod's PTP service is available here.