Three countries worldwide are pioneering public safety solutions using LTE, all for quite different reasons and using different approaches. Other countries are looking and learning, waiting to determine their own strategy. It seems likely that in the long term, LTE will win out, but there are a few issues to be resolved.
Public Safety or Emergency Services Networks are used by first responders such as police, fire and ambulance services. Coverage, resilience, robustness are all extremely important – both of the network service and the handsets themselves.
More demanding services such as CCTV can also be included in the scope.
There are three major elements to the end-to-end service:
- Applications, highly tailored to the needs of each country and organisation
- National wireless network, with very high geographic coverage
- Handsets and terminals, often specially designed and robust to withstand heavy outdoor use
UK Emergency Services Network (ESN)
Airwave (a Motorola subsidiary) operate the current TETRA network which uses 450MHz band, including specialist applications.
Francis Maude, a government minister in 2010, thought that there were huge cost savings to be made by using commercial LTE networks instead of the dedicated TETRA system in place. The high cost of TETRA in the UK was partly due to it being privatised, resulting in high fees compared to publicly owned networks elsewhere in Europe. It’s also due to the specialist nature of handsets used. He initiated a project which is now coming to fruition, managed by a department of around 350 Home Office staff.
EE, now part of BT, won the network contract. Airwave will deliver the applications. I understand that specialist handset orders are not yet placed but standard LTE handsets/devices would be compatible.
In principle, any of these three elements (applications, network, handsets) could be swapped out in future for a different provider. It’s similar to an MVNO arrangement, wholesaling network capacity, but with several important additional features embedded in the network.
EE have expanded their geographic coverage significantly in recent years, providing service both for regular users and public safety. They’ve also invested in over 30 mobile vehicles which can drive almost anywhere for immediate area coverage. The Home Office has invested directly to support a few hundred additional macrocell sites for coverage in areas that would otherwise not be commercially justified. Any operator would have access to use any of these sites for their own equipment should they wish.
The overall timescale is to migrate users region by region between end 2017 and end 2020. Extensions to continue to operate TETRA if there are delays are possible but likely will prove expensive.
Full public safety services are to be supported including voice, text and data. New LTE features such as group calling were introduced in 3GPP standards release 12 and 13. To use these, new handsets with compatible hardware will be required (the feature is not embedded in today’s commercial handsets) as well as network wide support. In the short term, these feature can be provided using Apps.
Existing licensed spectrum and existing cell towers are used. Priority access will be given to public safety users, who could automatically pre-empt service for ordinary customers.
South Korea SafeNet
A completely separate LTE 700MHz network is being rolled out throughout South Korea for public safety. This was triggered by the Sewol ferry disaster in 2014, when response efforts were hampered by lack of interoperability between different agencies. Announced in July 2014, the project was scheduled for completion in 2017.
Samsung announced they had won supply for both network and devices in April 2016. They plan to make full use of the latest 3GPP standards, specifically Release 12 and 13 features such as Group Call and Push to Talk.
I’ve heard that coverage continues to improve as new basestations are rolled out, but the South Korean commercial LTE networks are all exceptionally good so may still have some advantage.
Many small towns throughout the US operate their own private public safety systems, typically based on P25 and using Motorola proprietary technology. These are comparatively expensive and lack interoperability. As long ago as 9/11, moves were afoot to deploy a national network. FirstNet, a government agency, was established and awarded 20MHz of 700MHz frequency plus $7 Billion in funds to build one out. AT&T won the contract last March and will also make use of their existing towers. Individual states can opt out and build their own radio networks, but all will be managed through a common core, use the same types of handsets/devices and be capable of fully interworking.
Some specialist handset vendors have suggested to me that initially FirstNet may initially used only for data services, but again it seems quite feasible to make use of Apps for group calls and other specialist features. It will be effectively a private LTE data network, improving security and resilience. Today, many police cars are already equipped with several radios including LTE provided through commercial networks. The trunk of a police car looks like a cross between an armoury and an electronic equipment room.
Tactical LTE coverage
One of the newer concepts for Public Safety use is to provide localised coverage onsite at an incident. Examples include train derailments, where hundreds of people are suddenly in urgent need of communication services in a remote area. Another is simply enhancing service coverage and capacity at the site of a fire or major incident.
We’ve previously reported on COWS (Cells on Wheels) which are portable basestations built into a standard 4x4 vehicle, airborne LTE small cells in drones and heli-kites. Satellite backhaul can be used in more remote areas, otherwise connection to a nearby donor macrocell may be used. Automated configuration, using SON, allows such sites to be up and running within minutes.
If these can also provide service to regular users, at a lower priority than public safety staff, then it also allows victims to contact friends and family which relieves stress for all concerned.
Complementing the macrocell networks which provide wide area coverage, Small Cells are ideal for tactical and fill-in rural and remote coverage.
What will be required in commercial products is support for the relevant frequency band, a roadmap to support any 3GPP public safety features and greater automation for self-configuration supported by the network itself.
Some countries will want their own dedicated spectrum and network equipment for their Public Safety Networks, but I could see that if the UK ESN project is successful then the lower cost of piggybacking on an existing commercial network would be attractive elsewhere.