Posted by Dr Nigel Davies, QinetiQ · January 09, 2017 5:54 PM
On January 26th last year a GPS satellite orbiting the earth named SVN23 caused hours of systems warnings in companies across the world as well as disruptions and outages to the BBC’s digital radio service in multiple areas.
The BBC quickly learnt that its downtime was caused by the US Air Force decommissioning the outdated satellite. As it was removed from service, an incorrect time was accidentally uploaded to a series of connected satellites. The error took the satellites, including the ones the BBC relied on, out of sync by 13 microseconds. This error was propagated to a host of timing services which rely on the signals transmitted by GPS as their source of high precision time. Those timing services are fundamental to a broad array of infrastructure providers such as communications, banking and power distribution. In the case of the SVN23 anomaly, the time drift was enough to cause a technical error which took the BBC’s digital radio service offline.
Satellite navigation networks such as GPS allow the BBC to provide a global service that, for the most part, runs with incredible efficiency. These same satellite navigation networks are used and depended upon by telecommunications providers globally. The network outage in January reveals the worrying fact that these systems are far from infallible, with disruption occurring in other areas too. On May 25th in 2015, O2 suffered nationwide outages due to a fault in its networking equipment that prevented it from correctly processing mobile phone traffic.
This issue of network fallibility poses a major problem as more and more people adopt smart phones and 4G networks. The UK’s digital communications are dependent on Global Navigation Satellite Systems (GNSS) such as the Global Positioning System (GPS) and Galileo. Atomic clocks in GNSS satellites create precise timing signals that are beamed down to telecommunications networks, keeping cell towers synchronised so calls and data can be passed between them.
Time discrepancies between these signals can render a network inoperative, resulting in downtime and outages – it took a 13 microsecond divergence to affect the BBC’s digital radio. For industries relying on GNSS, such as telecoms, this poses a problem. The satellites which transmit GNSS signals orbit the Earth at an altitude of over 20,000km. By the time the signals reach the Earth they are weak and virtually indistinguishable from background noise, requiring complex algorithms to identify and track them. The high level of timing accuracy required to generate the GNSS signals also makes GNSS highly vulnerable to disruption.
The cause of the disruption can be both within the GNSS system itself (such as the one affecting the BBC) or external interference with the signals. This external interference can be both accidental (such as from poorly isolated communications antennas) or from malicious actors trying to cause harm to the users of GNSS services. Jamming is one such threat that is able to down a network by transmitting additional ‘noise’ over a signal, drowning it out and preventing receivers from working properly.
The effect that these devices can have on satellite signals has serious implications for an industry which relies on the continuity of GNSS services in order to remain operative. A jamming incident in the vicinity of a telecommunications relay could, with relative ease, shut down a network for a whole area in the UK.
This is not merely a hypothetical scenario. In 2014 Jason R. Humphreys was fined $48,000 for operating a localised jammer in his car (a so-called personal privacy device). The effect of the jammer meant that telecommunications provider Metro PCS suffered network failings in one of its mobile phone towers every morning and evening as Humphreys drove to and from work.
The implications of widespread down-time to telecommunications providers are severe. In October 2012, in non-GNSS related event, Blackberry suffered a four-day global outage of its messaging service, starting in London and quickly spreading to mainland Europe, Africa and eventually the United States. The down-time cost the company $54 million. Equally as damaging is the effect on company reputation. O2’s outage in May 2015 was plastered over social media, with negative coverage increasing as high-profile figures vented their frustration.
GNSS dependent industries must be secured on a global scale. A recent report from Chatham House’s International Security Department on threats to space infrastructure advises industry stakeholders to work towards international cooperation and collaboration when it comes to developing technologies and regulations that secure satellite systems. Such collaboration would include “individual scientists, the corporate sector and the military; address technical, political, economic and social interests.”
Already collaboration in the UK between the corporate sector, government and military is developing new technologies that can reduce threats to GNSS-dependent industries. One example includes GNSS receivers that can utilise multiple satellite 'constellations' and frequencies, enabling systems on the ground to jump between satellites in the event that one is forced offline or is unable to communicate its signal. For an industry that relies on business continuity to provide the best customer service these technologies will be highly useful. Telecommunications providers must therefore take an active role in engaging with the space security and satellite navigation industries if they are to ensure they have the right technologies and security policies to meet their needs. Ultimately, as the Chatham House report comments, “ensuring security in space must correspondingly be a common ambition for all concerned players.”
Increased collaboration between industries involved in satellite services is spurring the development of important technologies that will make headway in fortifying these vulnerabilities. Over the coming years, this will ensure that the telecommunications industry has the ability to secure itself against the damaging financial and reputational effects of network disruptions it has previously been unable to defend against.