TETRA-LTE gateways: Best of both worlds

Laurence Doe hears from the key players enabling TETRA users to easily communicate with a wide variety of co-workers and volunteers 

Picture this scene: it's 3am and a police chief wakes up to the distinctive ping of the push-to-talk app on his smartphone, which is connected via a gateway to the local TETRA network. His deputy's voice is shaky. Something monstrous has happened. Despite the hour, the chief's mind is racing. How did they do this? Why my city? Then his long years of experience take over. Still in his pyjamas, he starts to bring order to the chaos, pulling his teams together, channelling their outrage and fear into something he can work with. The losses are unthinkable, but lives can be saved and there's still time. Time to find the people responsible for this atrocity and stop them before they can strike again.

This scenario may be extreme but it's a good example of what can happen thanks to integration between TETRA and LTE. In today's cost-sensitive world it's often not economically feasible to issue TETRA handsets to everyone who may need them. There's also the high cost of building and running a dedicated network and it may not be possible to provide blanket coverage across an entire country. 

"If it is completely mission-critical it makes sense to keep the radio, but if you are out of coverage or have people from management without a radio it is much more flexible to use your smartphone," explains Kaveh Hosseinzadeh, managing director and owner of software company TASSTA. Its gateway T.BRIDGE extends the PMR network by connecting mobile device users from any network. 

However, gateways can only be as good as the networks they're running on. Niklas Lagerblom, solution business manager at Airbus Defence and Space, points out that the extent to which his company's hybrid networks solution, the Tactilon Suite, can be used for mission-critical applications depends on the reliability and availability of the cellular and broadband service it is running over. 

One factor adding to the appeal of an interoperable approach is the timescale for truly mission-critical LTE. With 3GPP Release 13 imminent at the time of writing it will still  take 18 to 24 months before its standardised mission-critical features [see our interview with 3GPP's Erik Guttman - Ed] find their way into devices. The time it will take for procurement and deployment also needs to be considered. 

Additionally, several countries such as Germany and Norway have recently invested in large and modern TETRA systems and no doubt wish to get the most out of their spend. 

"This transition period is going to be long so we feel that interoperability between both [TETRA and LTE] domains is going to be very important so that our customers can deploy existing and new capabilities with broadband," says Lagerblom. 

Hosseinzadeh is also very clear on the subject. "We are not asking the customer to turn off their radio solution, we always recommend a hybrid approach," he says. "The demand is there because customers have made investments in TETRA and don't want to think about changing to another technology yet, so a hybrid solution is the best option. The other need comes from customers who require a future-proof system - with a universal gateway their investment is safe." 

"Different approaches will take place," says Lagerblom. "Some customers will follow an evolutionary approach to extending what they already have. That's the case for many of Airbus' customers; they're upgrading existing TETRA networks and gradually introducing broadband capabilities. 

"The key benefit with the Tactilon Suite TSA is to enable TETRA services on smart devices. Users can then communicate to radios, dispatch services and control centres on the TETRA side, and TETRA services can be extended with many other broadband data applications on the smart device," he adds. 

International organisations using TETRA for public safety, public transport, military and security operations have expressed interest in hybrid systems and purchased TASSTA's universal gateway products. 

"It's much more flexible, you don't need to stay with any vendors, and you can change whatever you want at any time because there are so many low cost, rugged smartphones available," explains Hosseinzadeh. 

TASSTA has also supplied its solution - via its partners - to regional departments of Greece's police. They and other public safety users have found TASSTA's gateway of use when expanding networks to improve co-operation between volunteers and relief organisations, given the costs associated with private networks and radios. Applications that have been particularly popular among these users are individual and priority calling, group communications, GPS tracking, geo- fencing, messaging and file sharing. 

Motorola Solutions' offering in this area is its WAVE Mobile Communicator application, which connects smartphones through LTE push-to-talk (PTT) without network restrictions. 

It is being used in the village of Shipton Bellinger, which is the community most at risk of flooding in Hampshire [see our article "DMR and LTE: a bridge over troubled waters" in the November issue of Land Mobile - Ed]. With support from Motorola Solutions the village deployed a WAVE system to link resilience team members on MOTOTRBO digital mobile radios (DMR) with other organisations that are using smartphones. This makes it easier to manage wider multi- agency teams in an emergency. It also allows team members who may be out of the area to stay in touch. 

"The benefit of having WAVE in the mix is interoperability," says Steve Bluff, parish councillor and Shipton Bellinger community resilience response team leader. "We can dynamically set up talk groups over DMR, TETRA and connected smart devices. If people come into the area and do not have radio handsets they can be given a smartphone with WAVE Communicator downloaded from the app store. We can set up a new talk group, and they can securely speak over our network." 

Bluff, Penton Bellinger councillor Philip Lashbrook, and Test Valley Borough Council are in discussions to use WAVE to secure interoperability at Gold and Silver Command. That would provide a direct link with local police and fire services so resources can be deployed when and where they are most needed. 

Andrew Gill, MSSSI VP, growth and alliances at Motorola Solutions says that the first WAVE deployment for a utility in Germany, EWR Netz (EWR), reflects a trend whereby existing TETRA managed service customers will choose additional services over broadband to extend the "user footprint" and diversify workforce communications. 

EWR employees and partners such as public utility companies, municipalities and local distributors can use mobile devices equipped with the WAVE application to access pre-defined TETRA channels. The TETRA network is used to monitor parts of EWR's electricity, gas and water networks, as well as to transfer the information gathered on customers' smart meters back to EWR for monitoring and billing. 

In emergencies or breakdowns staff can access pre-defined TETRA communications channels using their mobile devices. Internal and external users are still able to leverage the benefits of TETRA technology, but can also set up group calls through public radio networks. This is enabled by the MOTOBRIDGE IP-based solution, which establishes communications between different systems. 

EWR has found that when control room and office-based personnel can use their own smart devices to communicate on TETRA voice channels collaboration with radio-equipped field teams is faster, leading to improved response times. 

However, human interference is still an issue and procedures beyond encryption are still required for true end-to-end security. Initiatives like 'bring your own device' could threaten applications such as WAVE. 

"Some of the rules of security in the radio world have to extend to this new world where you start to bring in other devices on other networks," explains Gill. "You still need to have a level of control over those devices, hence why you will have to have a fairly high level of mobile device management and security protocols around that. 

"You cannot expect to add other networks and get the same level of security you get on a private network, but you can put things in place to create those levels of security, such as having hardware with a crypto-chip on it." 

There is an alternative approach to TETRA-LTE integration, which in some respects is more traditional than the gateway/smartphone method. Finmeccanica, which recently won the ICCA Best Innovation Award for its PUMA T4-TLE (dual mode TETRA-LTE Enhanced) handset [see our coverage of the ICCAs here - Ed], is working to provide users with a device featuring on-board sensors either in a bandwidth-constrained environment or multivector radio.

 

Finmeccanica's PUMA T4-TLE handset supports both TETRA and LTE 

Finmeccanica believes that some of the barriers to the use of LTE for professional applications, such as spectrum availability and the costs of providing sufficient RAN (radio service coverage), may be resolved through the use of new business models involving public operators. 

Like Hosseinzadeh and Lagerblom, Finmeccanica anticipates that current TETRA networks will continue to have an important role in the near- to mid-term. It also notes that dual-mode TETRA-LTE devices will allow the progressive introduction of broadband capability on a need-to-have basis. 

Regardless of who supplies the gateway or handset that integrates TETRA with LTE, ultimately what matters to the end users is that it works when needed. Given the challenges facing public safety officials, particularly those in a Europe that's struggling to cope with the twin issues of terrorism and mass migration, it may be some comfort to know that if an incident happens they will hear the bleep of PTT and be able to deal with the situation then and there. It certainly beats facing the media backlash for addressing it too late.        

Both the original and print versions of this feature incorrectly referred to the Puma T4-TLE as T4-LTE. This has been corrected in this version.