Why the hype behind PNT?

In 1962, Arthur C. Clarke famously wrote “Any sufficiently advanced technology is indistinguishable from magic”.

For most people, satnav is magic. They know it has something to do with satellites, and that any time they need it a little icon appears on their screen. It provides precise location, anywhere in the world, any time. And the real kicker is that it’s free.

Of course, we know there is much more to it than that, and that - maybe disappointingly - it’s not magic! GPS (or now GNSS, Global Navigation Satellite System) is one of the engineering wonders of the world and was conceived only fifteen years after the first manmade satellite went into orbit. Back in 1989, Trimble one of the pioneering companies called GPS the next utility and this remained Trimble’s advertising slogan for several years.  How right they were, GNSS has become ubiquitous and synonymous with Position, Navigation and Timing (PNT) that is an anchor of our mobile, connected, data driven society.

In the UK alone, the Government estimates that “PNT services … directly support ~£254bn (13.4%) of the UK economy. Its importance is so crucial that it’s estimated a loss of space-based PNT services would cost the UK economy ~£1bn per day”[1]. A recent review suggests that, since it was published in 2017, the number has increased to ~£1.7bn per day.

Of course, that reliance on PNT, and GNSS in particular is not without risk. That risk is exacerbated by the inherent vulnerability of these systems: low power signals, broadcast using an open specification, transmitted from ~20,000km above the Earth. Interference, jamming, spoofing, cyber attacks, and natural disasters can all impact their performance, their reliability, and their integrity.

The threats to the use of space based PNT are well documented and real. Twenty years of published research, government policies, and high profile demonstrations, have shed light on the scale of the threat. But that is not the subject of this article - the subject of this article is what to do about it.

While a major outage of GNSS (for any number of reasons) would be a nuisance for the general public, even a local outage can cause nightmare scenarios for Critical Infrastructure. PNT (and it’s often the T (Timing) that causes the biggest impact) is so embedded in Critical Infrastructure operations that outages can impact communications networks, power distribution, logistics, emergency services, public transport, defence, finance, and more.

The good news is that:

• The problem is well understood – We know what the threats are, we know what tools are available, we know what can be done and what the impact can be.
• Mitigations are available – Technical, procedural, and legal mitigations can be put in place to reduce the risk to an acceptable level for almost any use case, and generally the cost is not prohibitive.

So why are we still talking about this?

Because despite all of the warnings, all of the research, all of the investment, all of the working groups and lobbying, to date very little has actually been done.

And why has nothing been done? Well that’s simple:

• There are very few examples of bad things happening – examples of jamming and spoofing are everywhere, but there are very few examples of real impact.
• Awareness is low – users of GNSS (and PNT more broadly) are not generally aware of the threat, the scale and scope of the threat, or their vulnerability to the threat.
• There are more immediate concerns – Pandemics, cyber attacks, shareholders, IT transformation; they all shift priorities to urgent, short term survival.
• Identifying the Risks is challenging – while we understand the problem well, an individual business or system can find it very challenging to identify where PNT is used throughout a complex system‑of‑systems, or what the impact and chain reaction might be.

Surely the world has learnt the lesson that we shouldn’t wait for the emergency to unfold, we need to plan to mitigate impact of the threats however low the risk may seem. So what do we need to do?

First, we need government intervention. Many governments, in particular the US and UK, have published policies and studies over the last twenty years that have shed light on the problem, and inspired limited action. Most recently, the US PNT Conformance Framework[2], two NIST Tech Notes[3],[4], and a UK PNT Strategy (still to be published) have set a clear technical direction for mitigating the threats, and for developing mitigation systems at a national and even international level. However, further government action is now needed to compel Critical Infrastructure operators to address the risks they face, and make them responsible for demonstrating an acceptable level of mitigation (as they do for other risks such as those related to cyber attacks).

Second, we need to put PNT in the context of successful business delivery. We need frameworks that allow us to express and quantify the risk in a consistent and coherent manner that shows business level outcomes. And we need to be able to demonstrate (by implementing through‑life assurance – testing, monitoring, standards, good practice) how bounded investment in mitigations can reduce risk exposure to an acceptable level and deliver positive benefits for business and shareholders.

And third, we need robust and resilient technology and services that can be delivered directly to customers. The majority of Critical Infrastructure operators are not in the business of innovating their security systems. Security (and make no mistake, this is a security problem at heart) is a necessary evil for most organisations, and (unless they have truly unique challenges) they want to buy off‑the‑shelf products and services that make the problem go away. By analogy, no company approaches Symantec and asks them to deliver a new or customised antivirus – you buy the software that they sell.

There is a wide recognition that the time has come for PNT security. Action is now being taken across the world to implement alternative PNT technologies and back‑ups to diversify the source of PNT and introduce redundancy and resilience of supply. Governments are starting to put appropriate policies in place. Now we need to communicate the need and the solutions to users. One way or the other, it will happen. As Baron West of Spithead (former head of the Royal Navy and member of House of Lords) recently said in an interview with GPS World “Let’s hope the wakeup call is something short of a national disaster.”

Author: Richard Bowden