The future evolution of critical communications systems is exercising plenty of minds within the industry at the moment. That many public safety organisations will eventually migrate from narrowband technology to some form of broadband 4G LTE technology seems fairly certain.
How that transition is made and what form it will take in terms of network architectures and business models is far less certain. Also open to question is how many other sectors that rely on narrowband radio systems for their voice communications will want to follow public safety into the 4G broadband world.
And where does all this leave traditional PMR technologies and their vendors? Should they be panicking or will they survive the predicted shift to broadband?
Phil Godfrey, chair of the TETRA + Critical Communications Association (TCCA), issues a word of caution. ‘Those of us who are close to what is going on, such as the TCCA, the communications industry and a few end users and press, are talking a lot about 4G broadband because it is the future. But the danger is we think everyone will go that way and will do so in the short term. I don’t think either of those statements is true.’
He points out that the standards body 3GPP is working to add mission critical applications into the LTE standard, but key voice functions such as push-to-talk (PTT) over LTE are not due to be included until LTE Release 13. Furthermore, the work of getting all the applications in will probably not be finished until Release14, which is approximately three years away.
‘I am told that the typical time between the end of standards work and standards compliant products coming out is another two years, so we are at least five years away – in 2020 – before things really start,’ says Godfrey. ‘Also, there is no absolute guarantee that all the functionality that people are used to from TETRA, Tetrapol and P25 technology will be included in the LTE standard,’ he warns.
‘The critical communications community may want that to happen, but although 3GPP has been very supportive, the wider 3GPP community – and there are a lot more of them (mostly cellular mobile operators and suppliers) – may want other things to happen.'
He notes there is another major change that also needs to take place in the professional mobile radio (PMR) world. ‘The current figures show that around 70% of private mobile radio (PMR) is still analogue, so they haven’t even switched to digital PMR yet. Thus, we shouldn’t assume everyone will transition to LTE in any hurry.’
As far as emergency services go, Thomas Lynch, associate director for the critical communications group at research organisation IHS, agrees. ‘There are two sides of the coin right now for the future of mission critical communications and you’re either one or the other.
‘The UK will switch off its Airwave TETRA network and be operating a 4G LTE system on a commercial mobile network for its emergency services by 2017. But others say this is not the way to go.’
IHS’ position is that there will be a timely and phased approach to transitioning to LTE. ‘We think TETRA, P25, DMR and LTE will all co-exist, as PTT over LTE comes in, but there is a lot to be done before everybody moves to 4G,’ says Lynch.
He points to the partnerships between Chinese narrowband manufacturers and major cellular broadband OEMs such as Huawei and ZTE, which have developed what they call ‘2+4’ – PDT (Police Digital Trunking, a Chinese variation on the DMR narrowband standard) working with a proprietary versions of mission critical LTE.
‘The message here is: you can operate your DMR and LTE networks on the same base station – to an extent anyway,’ reports Lynch, although he adds that the Chinese Government is still installing narrowband PDT systems for one million police officers.
Many end users will be wary of adopting proprietary systems, so may wait for open standards to be written. In the meantime, IHS research forecasts that shipments of narrowband technologies will continue to rise across the board, including DMR, dPMR, NXDN and PDT. In fact, they will still be showing above double digit CAGR growth up to 2020.
‘Even now we’ve seen that these technologies are still being adopted and driving the market, as the much larger competitive environment has brought prices down,’ observes Lynch. ‘Plus, there are tiered solutions now, so different segments of users can get different levels of capacity, functionality and price.
‘We are seeing a lot of interest in these technologies from commercial users. I think many of these users will still like the idea of PMR rather than PTT over LTE as a service, but some will go for it, providing the basic PMR functionality is there.’
Looking at the longevity of PMR technology, Sheridan Nye, senior analyst, Frost & Sullivan, says: ‘The big question is: what is the lifespan of narrowband technologies such as TETRA, especially in Europe?
There’s still a lot of new investments going into PMR in Europe, such as new nationwide TETRA networks in Germany and Norway, and there is still a lot of use of these technologies elsewhere.
‘But if you look at the roadmap of commercial mobile technology and where LTE-A and 5G are going, PMR doesn’t want to miss the train. PMR vendors have had a very comfortable ride in the public security sector with its long buying cycles. It’s been a good life up to today, but now there is a tricky transition period coming. How do they maintain the cash cow?’
Nye points out that a switch from narrowband to broadband exposes traditional PMR vendors to a lot of new competitors already well established in the broadband technology market. ‘It is now all about apps and intelligence around the apps. There is a sweet spot there for the likes of IBM who can see a big opportunity,’ says Nye.
Companies such as IBM, Oracle, HP and SAP have a great deal of experience in IP applications. And given the extent to which the market is horizontal, they can apply the same processes to other sectors such as public safety as it moves into the IP world.
But at the same time, Nye observes that public safety is a less attractive proposition because of the specialist knowledge and types of applications required. So, the IBMs and HPs are establishing partnerships with traditional public safety vendors who have the operational knowledge they need to break into the sector. And it works the other way too.
The big PMR vendors have already made the move to team up with the leading 4G broadband OEMs to get access to eNodeB (the 4G base station) technology: Motorola Solutions with Ericsson; Airbus Defence & Space with Alcatel-Lucent; Thales with Cisco and others. But where does that leave the smaller PMR players?
‘I think it looks tricky for the other traditional PMR vendors,’ says Nye. ‘There have been big alliances established between PMR and LTE, and then there is the BYOD (bring your own device) scenario with cellular devices, which is also a competitor in a way to PMR.
‘Mobile operators are also getting into the scene by launching PTT services; Ericsson has a hosted solution for MNOs, which might be attractive to SMEs. Devices need the broadest capabilities now, so the lifespan of PMR terminals is a bit more limited, although this is less the case for the infrastructure.’
Nye also points out that the decline in the importance of voice in some sectors is also a factor in driving the current evolution of critical communications.
‘We take for granted the importance of voice, but look at the Uber-isation of taxis. Field workers in utilities and other sectors might seem to value voice as much as public safety does, but with more automation coming in this may no longer be the case. There are very profound changes going on,’ says Nye.
Private LTE networks
The big question then becomes: will private LTE local area networks replace PMR ones? Cisco for one is betting they will. It has developed what it calls its Premium Mobile Broadband LTE offering, which offers the core elements of carrier-grade virtualised EPC (evolved packet core) and small cells to provide a virtual private network (VPN).
Luc Imbert, public safety and security lead for Cisco EMEAR, says: ‘We are trying to be the enabler here. We are not necessarily offering an overall product, but we work with partners to offer an end-to-end solution to public safety organisations.’
He adds: ‘We have a consumer technology and public safety players do not deploy their communications architecture in the same way as consumers. But they can still benefit from consumer technology and then add the resilience requirements they may have.
‘There are three different approaches, which end up with the same result,’ says Imbert. The first is to simply overlay the broadband service on top of a commercial mobile operator’s network using VPN technologies.
‘It is not resilient,’ he acknowledges, ‘but we can offer better service level agreements than the mobile operator and the necessary security. So, quality of service, yes; resilience, no.’
The second approach is where the end user has no dedicated spectrum, but implements tactical LTE deployments in the form of very small, local LTE islands.
‘These might be implemented by professional organisations to provide coverage at specific sites using mobile base stations with satellite backhaul,’ says Imbert, who points to key power assets as an example.
'It might be in the interest of a utility to orchestrate a dedicated core LTE network that can then connect to something bigger via an MVNO. Two different models are being discussed here: roaming across commercial networks; or MNOs releasing control of spectrum to enterprises for dedicated spectrum,’ says Imbert.
The third approach is to provide dedicated licensed spectrum to public-safety organisations and other critical verticals such as utilities. Imbert cites countries in the Middle East, which have both the available spectrum and the money to implement countrywide dedicated networks.
‘My personal opinion is that we need to wait for the market to develop as all three of these approaches are only just starting,’ says Imbert.
Whatever the model, the availability of LTE spectrum is going to be crucial, and this will vary across the globe depending on historical allocation of spectrum and regulatory regimes.
Philippe Devos, Head of Portfolio & Business Evolution Secure Land Communications at Airbus Defence & Space, says: ‘We don’t see LTE replacing TETRA and other similar standards for some 10 years yet, and you have to consider the fact that LTE spectrum availability, or the lack of it, is a big issue in some regions.
‘If you take the DMR standard, especially on the VHS bands, it provides a very wide coverage with low density of usage. It works well and I don’t see that being replaced in a hurry either,’ he says.
However, he acknowledges that the industry has to meet the challenge that there is a growing need for broadband data. ‘LTE is very good for data, but not good for voice or small data transmission yet,’ asserts Devos.
‘LTE is really designed for a big pipe as it uses big 5MHz channels. You cannot allocate 5MHz to every user, so that makes it challenging to allocate to smaller organisations. On top of that, we still have the LTE mission critical standardisation challenge.’
In the interim, like Cisco, Airbus sees hybrid models emerging using the same architecture with two layers. ‘You use LTE on a commercial service provider as a start, because they have the LTE coverage. Customers use that service for non-critical data applications. They get used to broadband with the non-PMR core managing these applications.
‘You can then start to put in dedicated access,’ Devos continues. ‘You have a PMR core plus TETRA narrowband access, but you also expand the service over a commercial LTE provider. You then connect your dedicated LTE service using tactical cell deployments, a small LTE eNodeB on a truck, for example, so you can bring your own coverage with you.’
This creates a hybrid model with three pillars: mission critical voice on narrowband access; you then extend voice and data to the commercial broadband network; and then add specific, dedicated LTE coverage when justified for critical or business case reasons.
‘The beauty of using MNO access is that they have coverage already – so it is a cheaper solution than building a dedicated private LTE network. Users get the wider access they require via the commercial LTE network, but also the mission criticality functionality and security associated with TETRA networks,’ explains Devos.
Future critical comms landscape
So what does the future critical communications landscape look like? ‘In 20 years’ time, PMR will look like the analogue market now – a slim pickings, replacement market,’ predicts IHS’ Thomas Lynch.
‘For a PMR vendor to achieve good revenues, margins and growth, you need to be in the new technologies, providing that everything connected environment with remote workforce management and all the other efficiency applications that the IP world can bring. In the new age of communications PMR vendors cannot rely on what is available today.’
However, Lynch is fairly positive that the narrowband market will not be heavily impacted by LTE for at least another five years. ‘There will be a mixed use phase before it turns into a single horse race, but those vendors that get into LTE early will get a return on investment over the next five years,’ argues Lynch.
Frost & Sullivan’s Sheridan Nye points out that one of the key benefits of PMR solutions is that end users have control of their own infrastructure and spectrum, either directly, or as a dedicated managed service. They are not dependent on MNOs for spectrum, coverage and capacity.
‘Theoretically there is no reason why you couldn’t allow customers such as public safety ones to have local control of the mobile network,’ says Nye. ‘An MNO could give them more control to allocate bandwidth coverage, prioritisation and make changes on the fly in terms of capacity. It depends how keen MNOs are about allowing this.
‘There is a lot going on in the critical communications sector and there are big changes coming. But for big trends to develop things need to happen at an operational level first. These customers have long buying cycles and it will take time for new trends to work through,’ concludes Nye.
The TCCA’s Phil Godfrey agrees. ‘The conclusion I’ve come to is that there is a strong demand for broadband data services, particularly among the public protection and disaster relief (PPDR) community. There are many benefits available from broadband data, but I think existing technology will be used for a lot longer than people might be suggesting at the moment, but MNOs do have a role in providing broadband overlays.
‘However, the difficulties of mission critical voice have not yet been fully realised. So, I think most organisations will stick with existing voice technology, but probably won’t build their own 4G networks. Instead they will make use of commercial networks.’
Cisco’s Luc Imbert feels that there is a new momentum in public safety to adopt consumer-driven, global market technology, but with a differentiated architectural scheme. He believes the majority of countries will maintain existing technologies and develop new ones in parallel.
‘This will give us a better idea of the use cases, as it is not fully defined across the world yet what kind of broadband services will become critical. And we need to recognise that there are different ways of getting there, so everyone needs to look at everything. My view is: start looking at broadband LTE service as soon as possible, even if it is just on a small scale, but test the end-to-end solutions,’ advises Imbert.
‘Voice is mission critical, but whether data is mission critical is confused at the moment,’ says Philippe Devos of Airbus. ‘A data link to back office systems and records is helpful, but not mission critical. Managing the incident and then managing the information flow are two different aspects.’
LTE security issues
He also points out that the security aspects of LTE are not yet clear. ‘There is a lot of open-source software, such as Android, that has to be dealt with. The rules and standards are not clear yet for such sensitive users as public safety organisations and cyber security is becoming a big issue,’ he warns.
Nonetheless, 4G LTE (or perhaps 5G) will be the main choice of bearer for emergency services communications from the mid-2020s on once the standards are in place and a sufficiently developed product ecosystem has developed.
How many other sectors will follow public safety remains to be seen. Lack of spectrum is going to be a huge limitation for those looking to replace private PMR local area networks with LTE ones in many parts of the world, such as Europe.
A mining company in Western Australia might see the benefit of making such a move. Other business critical radio users might yet keep at least some of the PMR standards going for longer than many might think.
Governments may allocate dedicated spectrum, or alternatively, licensed spectrum holders – generally mobile network operators – might be persuaded to provide spectrum with guaranteed SLAs and perhaps localised spectrum management for key sectors such as utilities and transport.
Finding (harmonised) dedicated broadband spectrum for PPDR
Finding dedicated spectrum for PPDR (public protection and disaster relief) and other critical communication end users is no easy task. However, there is an opportunity coming up at the ITU’s WRC-15 (World Radio Congress 2015) in November, according to Jeppe Jepsen, the TCCA board member leading the charge to lobby for dedicated spectrum for PPDR.
It will decide whether 700MHz spectrum in ITU Region 1 (Europe, excluding Russia, Africa and Middle East) should be reallocated for mobile services. Some countries use this spectrum for digital terrestrial television (including the UK), so these would have to be moved off and found another home. If 700MHz is reallocated for mobile services, there is a chance some might be reserved for PPDR broadband services.
Jepsen says: ‘The big question is: how do we find a way to reconcile the demands of the PPDR user community, which is adamant that it needs a resilient, always-available, guaranteed service – one they think can only be delivered by dedicated spectrum; and the regulatory world, which prefers to auction off all spectrum; and the broadcasting world, which wants to protect its spectrum at any cost?
‘At WRC-15 we have the opportunity to decide on future PPDR spectrum – such opportunities happen rarely – so we must capitalise on this chance as much as we can this year.’
Jepsen points out that what the WRC can do is ensure harmonisation of the spectrum band usage (for mobile services or whatever), whereas the question of whether any of that spectrum is reserved for dedicated PPDR use has to happen later on a country by country basis.
‘If one can force or convince MNOs to take on the liabilities and functionalities of mission critical networks, it makes sense to buy it as a service,’ argues Jepsen. ‘At the TCCA, we’ve created a White Paper looking at service level contracts for PPDR in other countries, highlighting what the extraordinary legal conditions are that most normal MNOs wouldn’t expect to have to guarantee.’
He adds: ‘I am relatively optimistic that WRC will reach a conclusion on harmonisation for 700MHz and 800MHz for PPDR. But we should note that the European Commission has relatively few powers over spectrum as it is a national resource, but we are convinced we have an ally in the EC that will back us.’
What is needed, according to Jepsen, is a global common approach and adoption of common standards, as far as possible. But already he notes that the Chinese have decided to use 1.4GHz for their PPDR and have allocated spectrum for utilities in 1.8GHz. The US is pushing ahead with its FirstNet broadband first responder network in 700MHz.
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