Emerging GNSS Resilience Standards – How Good are they Likely to be?

Guy Buesnel, Joshua Stubbs, Paul Crampton

Abstract:	The objective of this paper is to evaluate the current status of Robust PNT standards and specifications from a European perspective. The Radio Equipment Directive (RED) in Europe introduced a mandatory GNSS test on 13 June 2017. New GNSS products that are to be sold in Europe will be required to demonstrate resilience to adjacent band interference as part of the CE marking process. This is the first mandatory requirement in the world related to Robust PNT. This paper will examine two emerging ETSI specifications in Europe and focus on test requirements related to GNSS resilience. Results will be shown from simulated scenarios, where real world interference corresponding to the specified test waveforms will be applied to several generated scenarios representing common use cases where GNSS receivers are used. The impact of the threat in the real world can then be compared to the testing specified by the standard. A concise review of GNSS-specific vulnerabilities is presented including real-world examples where significant disruption has been experienced in a variety of industry sectors. It will be seen that a risk assessment of GNSS products against some of the prevalent threat types is not only desirable but essential to make sure that unexpected device or system behaviour does not occur when a real-world threat is encountered. As well as deliberate instances of jamming and spoofing, the authors will show that unintentional interference events are significant in number and require as much attention as malicious threats. The authors will show that noise in adjacent bands to GPS is also on the rise. Some of this is due to the pressures on governments world-wide to sell off spectrum close to GNSS frequencies for other applications. Also, counterfeit drone control systems have been found that can broadcast close to RNSS frequencies and have the potential to cause interference problems. The authors will also contend that, to date not enough has been done worldwide to put into place coherent systems to Protect Toughen and Augment GPS in the ways proposed by Bradford Parkinson. However, some progress is being made and this paper looks at efforts in the European Union to develop standards that will help to protect and toughen GNSS products. The work in the US on Adjacent Band Compatibility is mentioned in the context of ETSI Standard ETSI EN 303 413 which has been published in Europe and is the first standard in the world to require the developers of GNSS products to carry out testing as part of the CE marking process. The standard contains both an Adjacent Band Compatibility test and an emissions test. This paper will only consider the Adjacent Band Compatibility aspects. The authors will present an analysis of whether the mandated Radio Equipment Directive (RED) GNSS standard will result in improvements in the robustness of GNSS systems. The authors will also consider another ETSI standard – which contains a ranking system for performance including resilience aspects – the authors discuss how this could be used to compare and select GNSS devices for specific applications. Test methodologies and frameworks that allow systems and devices to be evaluated against real world threats have an advantage in this respect. This paper will propose that the two European standards that have been developed have significant advantages in that they do not address the problem by mandating standards for OEMs but are providing common metrics and test frameworks that allow GNSS products to be compared in a manner that allows their suitability for specific applications to be assessed.
Published in:	Proceedings of the 30th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2017) September 25 - 29, 2017 Oregon Convention Center Portland, Oregon
Pages:	1186 - 1203
Cite this article:	Buesnel, Guy, Stubbs, Joshua, Crampton, Paul, "Emerging GNSS Resilience Standards – How Good are they Likely to be?," Proceedings of the 30th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2017), Portland, Oregon, September 2017, pp. 1186-1203. https://doi.org/10.33012/2017.15116
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