Over the course of the next 3 years, the UK's emergency services will be switching over to state-of-the-art handset and vehicle-mounted communication devices, operating on a private 4G network. Part of the Emergency Services Mobile Communications Programme (ESMCP), this new equipment can provide increased resilience and security across all communication channels and navigation devices used by frontline emergency services in the UK. In addition, new services and applications will be launched, which improve the function, efficiency and safety of the emergency services. However, the nature of the security landscape for these technologies and services is evolving rapidly. Their reliance on Global Navigation Satellite Systems (GNSS) to deliver location data to users of the ESMCP leaves them open to outside interference. Unless properly addressed and mitigated, these threats could pose a critical risk.
While physical maps and individual knowledge of local areas allow paramedics to find their way to critical locations, the use of satellite navigation is still used in the vast majority of tactical operations through the on-board vehicle mounted communications systems. What's more, the use of GNSS is likely to become even more integral to everyday missions. Oulu in Finland recently linked a monitoring system between the town's CCTV and central traffic light system with GNSS tracking. This enables emergency vehicles to be ‘green lighted’ through the main urban intersections to an incident anywhere in the municipal area, vastly improving the efficiency and effectiveness of the emergency response call-outs.
However, when such systems fail, the consequences can be severe. In June last year, three different ambulance crews got lost on their way to the Olympic velodrome whilst answering a call. It took the crews 27 minutes to reach the venue because their sat-nav systems had not been updated with new roads since 2012. As a result, it took paramedics three-times the NHS 8-minute response time target to arrive on the scene.
The error resulted from the maps rather than with the satellite navigation systems and the problem could have been prevented with a software update to the on-board system. However, significant vulnerabilities in GNSS-controlled navigation can have the same effect, rendering on-the-ground systems almost inoperable. GNSS satellites orbit the Earth at an altitude of over 20 000 km. By the time this signal reaches the Earth's surface, it is incredibly weak – sometimes imperceptible from the background noise of other transmissions – and so complex algorithms are needed to identify and track them. If additional ‘noise’ is transmitted over the top of a GNSS signal, creating interference, it can stop a receiver from working.
Jamming devices, designed to intentionally achieve this, are available for as little as £30 online and their effects can be severe. To put it in perspective, 10mW jammers for that price can be as small as cigarette packs and could knock out satellite signals across an area the size of a commercial airport. A combination of decreasing prices and ease of accessibility via online vendors has meant that these devices are now becoming more and more prevalent in the UK. Criminals are beginning to use such jamming devices to avoid detection by the police after stealing vehicles fitted with tracking devices. After stealing the cars, they are then parked in a ‘safe location’ with a jamming device inside, which prevents it from being tracked. So pervasive is this kind of interference that the government issued a Home Office report advising manufacturers to secure vehicles against this new wave of crime and ‘ensure they stay ahead of the technological curve’.
As this sort of crime proliferates, so too do the amount of GNSS ‘blind spots’ across the country, affecting any system reliant on satellite signal coverage. Results from the NSL Strike3 Project – an international investigation into GNSS threats funded by the European GNSS Agency – found in one location 400 interference incidents in one week at an airport, 138 incidents on a motorway and 839 in an inner city location.
GNSS blind spots have already been proven to affect emergency service operations. In New South Wales in Australia, it was found that ambulances winding their way through Sydney streets would often fall into geographical ‘black holes’, which disrupted the signal of the satellite tracking systems in the vehicles. Due to ambulances being unable to report their location, dispatchers have been sending ambulances to medical emergencies, unaware that other vehicles were far closer. What's more, the tracking system is also used as a protective function for paramedics. If a crew is attacked on the job they can hit their duress alarm. However, the signal errors have meant that police responding to such alarms are often being sent to the wrong locations.
This is an increasing threat that the UK's emergency services must confront head on if they are to ensure that individual paramedics and ambulance crews are able to carry out daily missions as effectively as possible. If this is disregarded, situations in which emergency services crews fail to find critical locations in time have the potential to become commonplace and lives will be put at risk.
However, the switch-over to the ESMCP's private network provides an opportunity to tackle this issue. Over the next 3 years, new handsets and vehicle-mounted devices will replace those with existing GNSS security vulnerabilities. Anti-jamming technology now exists, which can be introduced to these devices to ensure emergency services, does not fall victim to GNSS interference. Such technologies are able to foil signal interference by using multiple satellite constellations and multiple frequencies (MCMF). In the event of a jamming incident against one signal or constellation, this kind of capability can ensure continuity of service for satellite receivers in ambulance tracking systems and other emergency services vehicles. For a sector that relies on GNSS for life and death situations, these technologies could be a turning point against the increasing threat from interference.
There is now a recognised need to defend systems from GNSS threats. These threats, whether malicious or accidental, have affected the abilities and safety of paramedics on the frontline and are putting patients' lives at risk. If the ESMCP is to ensure complete security and redundancy against all kinds of threats to the emergency services communications technology, then defending position and timing capabilities from interference must be paramount.