What does 5G mean for critical comms?

While 5G is on everyone’s lips, its implications for mission-critical users are somewhat unclear. Charlotte Hathway and Sam Fenwick try to cut through the hype

Pushing the boundaries of critical communications is vital in ensuring that public safety agencies are in the best position to effectively respond to an emergency. The current narrowband technologies used by emergency services are a trusted way to transmit voice, but they cannot meet rising demand for data and video capabilities.

Numerous projects are under way across the world to advance public safety communications using mobile broadband. These services are being built around the mission-critical services being standardised in 3GPP but, as 5G develops, there is an expectation they will evolve to take advantage of the capabilities promised by the new standard. It is therefore worth exploring these in detail.

5G is the next generation of mobile broadband. Its key properties can be broadly split into three areas that are commonly illustrated by a triangle (shown below). Its three corners are: enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive IoT (also known as massive machine type communications). These respectively enable the faster transmission of data, fewer interruptions, and connectivity between a vast number of devices and sensors.

The 5G triangle; image credit: ETSI

Of the three, only support for eMBB has gone live with the launch of 5G; the other two corners of the triangle will become available as part of the Phase 2 specification (3GPP Release 16), which is expected to go live in 2020. This means a lot of the promised capabilities are not yet available but, more significantly, public safety agencies are unlikely to meaningfully implement a new technology in its infancy. Ali Helenius, head of strategy, marketing and technology at Airbus SLC, explains the simple reason why public safety will not be “the first adopters” for 5G. “Public safety is not a spearhead [for] new technologies. They want at first to see that the technology is mature enough, and that it is working reliably.”

This does not mean that 5G will remain completely untapped in its early years. Peter Clemons, founder of Quixoticity, believes it won’t be long before public safety users are able to “take advantage of faster downloads”, yet the full benefits of 5G are still years away. When that happens, public safety users will be able to make use of “greater network visibility, enhanced, differentiated quality of service and network slicing”, but this is “unlikely to be available before 2025, except in the very few markets where public safety has been prioritised by governments”.

The first 5G release has already given us an indication of the potential of eMBB, but Clemons adds that its full capability “should enable video calls, faster, more accurate transfer of larger files and multiple eHealth applications for smart ambulances”. In terms of what 5G will eventually bring to critical communications, Adrian Scrase, ETSI’s CTO, sees this breaking down into four areas: high-performance functions, high-precision location services, reliability, and capacity.

The first of these will transform “things like real-time facial recognition, which require very low latency and high performance”. He notes the improvements public safety users can expect from location services; these might already be available, but they are not at “the level of granularity we’d like them to be”. 5G will let you “pinpoint down to less than half a metre”.

On reliability, Scrase explains “this is something 5G is designed to deliver”, which in time will be complemented by landmass being covered “to the best extent possible” using “a truly integrated satellite component”, as opposed to satellite connectivity being “an afterthought”. This will allow remote areas to be reached affordably and without excessive degradation of performance. Low Earth orbit systems will ensure “the delay [is] not too dissimilar to a terrestrial network”.

Preparing for the future
It might be years before critical communications transition fully from existing narrowband services, to LTE, and towards 5G, but mobile network operators (MNOs) can start laying the foundations. Scrase explains that the core network can be set up now so it can be extended as new capabilities and possibilities are realised. “We have 5G phase one delivered [which] enabled standalone and non-standalone operations. You can either attach the new radio to your existing core network or to a new core network, ie, one characterised by a service-based architecture. This need not necessarily be fully virtualised from the outset but is likely to become so over time. It might be 100 per cent virtualised, or it might be partially virtualised, but the new core network is key to delivering the network capabilities that are vital to supporting the requirements of mission-critical users.”

Building a virtualised core network can aid in unlocking all 5G capabilities, as this approach can enable flexibility, allow the use of commodity hardware and enable the faster roll-out of new services. The first 5G cores might be partially virtual before eventually becoming fully virtualised. Quixoticity’s Clemons suggests that, in the future, emergency services will have access to multiple networks and can use the most appropriate depending on the specifics of the incident. He adds that this virtualised environment will help with the introduction of new capabilities, such as mission-critical push-to-talk.

Network slicing
Another area that has the potential to be truly transformative is network slicing. According to ETSI’s Scrase, this is important as it will enable public safety agencies to have “predictability of precise performance”. Network slicing is about ensuring the service provider can deliver the capabilities needed for a specific action that is being undertaken at a certain point in time. Scrase gives the example of a facial recognition session, where there is a need for low latency and high performance. He explains that capability “will be delivered to you by a network slice”; and until you move to 5G, you won’t have this capability of having [a] bespoke network slice delivered to you for the particular [application] you have in mind.”

The reason network slicing is a key issue for critical communications is that any discussion of turning off existing narrowband PMR systems, and relying on mobile broadband, raises the question of whether public networks can unfailingly handle emergency communications. Airbus’s Helenius highlights that how network slicing will service public safety is an unknown area. Yet IHS Markit’s Ken Rehbehn notes that some existing programmes are already moving in this direction. He says: “The mechanisms that support ESN, FirstNet and SafeNet incorporate techniques that are necessary for network slicing, and can be thought of as a precursor for 5G. Network slicing goes beyond the radio operation, which is what we have today, to embrace the challenge of transmission across the core network, as well as operations in the software servers.”

For Rehbehn, the key issue is that network slicing is not viewed as the primary way to make public safety agencies feel more confident about using a public network.

“That confidence has to be established in advance of network slicing. As it stands now, the public safety community has to gain confidence in terms of the operation of the existing LTE mechanisms. Confidence is growing, but I’m not convinced it’s fully established yet as there have been issues in the early days of FirstNet’s roll-out.”

One of 5G’s capabilities is the use of millimetre wave frequencies to provide mobile device users with incredibly high data transfer rates (>1GBps), but it is thought there will be only very specific instances where this will be transformative for public safety agencies. Rehbehn explains that “it’s extremely unlikely that mmWave will play a significant role in critical communications, unless the area of operations is well defined and served by radio assets that can be put in place. At 28GHz, even with beam-forming mechanisms, the propagation is difficult. What is possibly more exciting in terms of coming functionality are the capabilities enabled by [URLLC].”

URLLC is expected to enable mission-critical applications that are sensitive to peak latency. There is a lot of excitement about what those capabilities will mean for public safety users, and Clemons believes these will be vital in “opening up futuristic scenarios such as autonomous vehicles, autonomous drones and remote surgery”. This chimes with Rehbehn’s view that one of the most promising potential applications of URLLC is in using augmented reality to aid firefighters. He explains this would work by taking information from sensors and video, then fusing it to present an augmented field of view inside a firefighter’s mask. That could include information such as outlines of walls, a path to exit, and an indication of the building’s occupancy. This would be an enhanced version of Qwake Technologies’ C-THRU. He cautions such use-cases are unlikely to reach large-scale adoption; this is just an example, if you think about “the art of the possible” with no budget limits.

William Webb, author of The 5G Myth: And why consistent connectivity is a better future, believes URLLC is a “confusing” term given that “low latency and ultra-reliability don’t necessarily go together”. This is because there is far more to reliability than the capabilities granted by URLLC – it won’t remove the need for network sites to be engineered to have no single point of failure, to be hardened against power failure and have multiple backhaul paths. After all, what good is the ability to guarantee the delivery of a data packet under normal operating conditions when your whole network has gone dark?

This disconnection is important when discussing the role of 5G networks in critical communications as reliability is foundational to resilience, whereas “low latency [may not offer] anything for the emergency services”.

Bumps on the road
The blocker in the near term isn’t down to capabilities at all. “The main issue is the lack of coverage,” says Webb. “[It will be a] long time before public safety can rely on 5G being everywhere.”

To put that into context, the UK’s first 4G service went live in a handful of cities in October 2012. Under government proposals released last month, geographic 4G coverage will not reach 95 per cent until 2025. To date, each generation of mobile broadband has developed more quickly than its predecessor, but the gap between a service going live in one area and reaching an acceptable level of geographic coverage will remain a years-long process, and as a consequence public safety agencies won’t be able to build their strategy around a reliance on 5G New Radio in the medium term.

That’s why policies and contracts need to look to 5G but pay closer attention to the standards that are available today. IHS Markit’s Rehbehn, in his Ready for Duty? whitepaper, points out that with LTE capabilities continuing to mature in tandem with 5G development, what is important is that emergency services agencies “incorporate flexible language” so they are free to make use of 5G “if, and when, the technology becomes part of a network operator’s offering”. Here we come back to the question of coverage, as “the economic basis for network operators to support these bands in lower-density population areas is weak”, so agencies “will not have universal access to high-capacity 5G, and operational plans should not assume the capability is available”. Rehbehn says “very high-performance 5G will be constrained in geographic coverage, surrounded by a sea of LTE that is operating at varying levels of capability”.

A decade of progress
5G networking will unlock new possibilities for how the emergency services manage critical situations. Yet in the near term the broader transition from existing radio systems to mobile broadband is the bigger challenge. The shift to LTE will be a more transformative leap, and it can be tackled in a way that will simplify a future move to 5G. Public safety agencies should also note there are limits to 5G. Here ETSI’s Scrase calls for a balanced view. He revisits the 5G triangle, stating that “you cannot have very high broadband, very high reliability, and very low latency” at the same time. To achieve that would require “very extreme network performance”. He clarifies that eventually public safety organisations will need to weigh up which aspect will deliver the greatest step-change in offering a better solution to managing a situation, and ensure that provision – whether around reliability, latency or bandwidth – is included in contract negotiations with the service provider.

Clemons emphasises the need for a realistic outlook, but we can still be optimistic about a safer future on the horizon. He says “the development, installation and operation of radically new solutions is fraught with danger in the short term, so it is probably wise for governments and public safety agencies to keep a close eye on early 5G roll-outs. Mistakes will happen, networks will fail, services will fail and bad things will happen in the early years of 5G. But the long-term promise of 5G, and the hundreds and thousands of highly skilled and committed people and organisations working to make it happen, make me confident that within a decade, by 2030, it should be possible for us to lay the foundations of a better, smarter, safer world.”

Putting 5G to the test
In October, Dense Air and Dublin Fire Brigade completed an emergency response trial demonstration of a river rescue in Dublin’s ‘Smart Docklands’ district using a private 5G network. This involved supplying first-responders with cameras and dispatching connected drones to capture overhead views. Video streams were then viewed in real time by the incident commander who was on-site in the command support vehicle, giving them a more accurate picture of the situation and allowing them to provide better guidance to the team conducting the trial rescue mission.

Edward Emmanuel, project management and governance lead at Smart Docklands, explained that this successful trial highlighted the low-latency benefits of using 5G networking. Compared with using a 4G LTE network, the video streams would simply not provide the same level of “real-time feedback and responsiveness” for the command vehicle and rescuers on the ground. The Smart Docklands district is a testbed for Dublin City Council, and partners are continuing to experiment with how 5G can make the city safer.