Driving standardisation of mission critical LTE

The TCCA’s Critical Communications Broadband Group is helping to shape the introduction of mission critical functionality into the 3GPP LTE standard. James Atkinson gets a progress report from CCBG chair Tero Pesonen

Driving standardisation of mission critical LTE

In April 2012, the TCCA (TETRA + Critical Communications Group) set up the Critical Communications Broadband Group (CCBG) to help drive the development and adoption of a common mission critical broadband LTE standard.

Critical communications is a niche industry, so it came as an agreeable surprise when the mobile phone industry, which is largely focused on meeting the needs of mobile network operators and their billions of consumer subscribers, agreed to incorporate mission critical functionality into the 4G LTE broadband standard via the international standards writing body 3GPP.

3GPP set up a new Working Group, SA6 – Mission Critical Applications, to write the mission-critical standards and, in October 2013, CCBG’s influence on the process was given a major boost when it was invited to become a market representation partner to 3GPP, enabling it to provide direct input into the standards revision to ensure the needs of critical users are fully met. 

So far, SA6 has concentrated on establishing the Mission Critical Push-to-Talk (MCPTT) functional architecture for voice applications, which were included in LTE Release 13, finalised in March 2016. 

Tero Pesonen, chair of CCBG (pictured), says the group’s number one priority is to ensure the functionality required by the mission critical community largely already addressed in the mission critical narrowband PMR standards such as TETRA, Tetrapol and P25 ends up in the 3GPP LTE standard. ‘If it does not get in there, then it will very difficult to achieve the global standardisation we want,’ he says.

That said, Pesonen observes: ‘It is sobering to recognise that 3GPP is doing a lot of great work for a very important niche market. There is a lot of work going on behind the scenes, as there are so many strands that need pulling together.’

Information sharing

He adds that one of CCBG’s roles is to share information about the 3GPP process with the critical communications end users and industry. But 3GPP standards writers speak their own language, which is different from a firefighter. CCBG is able to ‘translate’ the different languages and provide a dialogue between end users and industry on one side and the specialist standards writers on the other.

‘That is why CCBG exists,’ says Pesonen. ‘CCBG includes public safety agencies, end users of all kinds and industry. That includes traditional TETRA vendors, plus all the major LTE vendors, and now more application developers are also joining CCBG too. Having that mix of representation enables us to have fruitful discussions and ensures we have the relevant competencies in place.’ 

One other thing CCBG has manged to achieve is to develop a process by which it can accommodate the speed of 3GPP’s work. ‘In the traditional critical communications world the
typical turnaround time from government agencies for information and decision making is slow,’ explains Pesonen. 

‘They are not used to providing feedback within the time that 3GPP generally requires it, but we have put a process in place so that generally we get our input ready in time and that’s almost unheard of in the government sector!’ 

Work items

As to the work items for this year, more functionality will be added to the new MCPTT specification in Release 14, which is due for completion in March 2017. However, the key work items are developing specifications for mission critical video (MCVideo) and mission critical data (MCData).

There are also three new work study areas. One study is addressing enhancements for the use of MBMS (Multimedia Broadcast Multicast Services) for mission critical services (for example in areas such as service continuity, MBMS resource usage optimisations, QoS).

A second is looking at enhancements to allow for a mission critical services user to obtain services from a partner system (migration) and for communication between different mission critical systems (interconnect).

The third one is focusing on specifications for interworking between LTE mission critical systems and non-LTE systems, such as P25, TETRA and legacy PMR systems. This is a good example of where CCBG has been able to influence 3GPP proceedings.

‘There was a proposal to leave an essential part of interworking out of the study,’ recalls Pesonen, ‘but we managed to bring it in with fairly wide support among 3GPP members. We argued that enabling short data services between PMR systems such as TETRA, for example, and LTE,  is actually quite important. So, we were successful in also getting this requirement approved and, moreover, directly as a dedicated section into the MCData TS (Technical Specification).’

Pesonen reveals that the CCBG is working on a paper for the Hybrid Business Case, which is due for publication in early 2017. ‘We recognise that hybrid public and dedicated broadband networks are likely to be the case in a number of countries,’ he says, so ensuring a standardised approach to interworking between the two is vital. Clearly there will also be a significant period of time of narrow band and broadband parallel use thus that will also need to be addressed.’

Testing and certification

CCBG is also looking at the issue of testing and certification. Personen points out that TETRA is an excellent example of a global multi-vendor standard. ‘We own the interoperability process. We issue certificates on our testing systems and that is the starting point for network-specific function testing.

‘We are investigating what things need to be done specifically for broadband critical communications,’ says Pesonen. ‘It is clear that the situation for consumer broadband products is sorted. If I buy a consumer LTE phone from any retailer it will work. But we need to be able to test and certify mission critical functionalities also and have a way to ensure interoperability of terminals and other equipment.’ 

CCBG is therefore working with ETSI to set up an MCPTT plug-fest next June to test devices and servers. ‘Critical communications is a niche market, but the more we can ensure standardisation, the more we can have open interfaces for information exchange, and that encourages innovation and creativity – and that creates an enormous opportunity,’ argues Pesonen.

He points out that the world view of the latest generation entering the public safety and wider critical communications sector is quite different from those who served in public safety organisations before the era of smart mobile phones.

Thanks to new technology, this latest generation is used to a more information-centric way of working and that, believes Pesonen, is likely to revolutionise mission critical operational procedures. ‘It will be more data centric and less voice centric,’ he says, ‘so we need to pull this together and incubate it. It is a great challenge for us, but a big opportunity at the same time.

‘So, if we can bring everyone together as we work on the global standards it will benefit everyone,’ he continues. ‘And we should do so in such a way that railways, utilities and other critical communications users can adopt it too. That way we can all operate on shared networks as the Nordic countries already do with TETRA.’ 

User requirements

CCBG has also been undertaking various studies on user requirements and asking what are the things that prevent agencies from harvesting the best from modern technology. One hindrance is that existing legislation has not caught up with the digital way of doing things, which is holding back migration in some areas. Finding harmonised spectrum for mission critical use is another challenge, while net neutrality issues could also make difficulties.

‘If all users and their data should be treated equally that can be interpreted as saying data from a fireman, which could save your life, should be treated with the same priority as a child accessing information on an iPad. As a parent, do you want a life to be saved or your child’s video session not to be interrupted?’ asks Pesonen.

He notes that the rate of changing laws and regulation usually takes plenty of time,  so the industry needs to raise the issue and highlight the hazards to policy makers, so that they can change the legislation by the time critical communications broadband services are being rolled out, to enable optimum use of the new technology. 

For now, CCBG has created and submitted its view for MCVideo and MCData prioritisation in order to maximise the value of Release 14 content. It also intends to continue embracing more and more different critical communications sectors in order to consolidate their needs into the 3GPP process.

At the same time, it intends to take a more significant role in addressing the on-top-of-the-3GPP-standard topics that are required to reach true open market and multi-vendor supply, as well as encouraging competition in the critical mobile broadband communications market.

Looking further ahead, Pesonen points out that LTE Release 15 will address the key technology concepts being proposed for 5G such as ultra-low latency and ultra-reliable networks – features that are familiar to any existing mission critical network user.

‘The 5G work is very good for our community,’ enthuses Pesonen. ‘In that sense I am quite thankful to the automobile industry and others that are driving these 5G developments that need critical communications; it is helping to drive industrial convergence.’

Summing up, Pesonen notes that incorporating mission critical technology into the LTE standard is, of course, important, but he points to a much more general,
but hugely important factor. ‘I would say that in the critical communications sector the killer app is trust. The end user has to know he can rely on everything to work when he needs it and in every possible layer.’

Key tasks and study items for 3GPP LTE Release 14 (close date:
9 June 2017)

  • Enhancements for mission critical push-to-talk           
  • Common functional architecture to support mission critical services
  • Mission critical video           
  • Mission critical data           
  • Study on mission critical system migration and interconnect between MCPTT systems           
  • Study on mission critical communication interworking between LTE and non-LTE systems
  • Study on MBMS usage for mission critical communication services.

 

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