PS-LTE (Public Safety LTE) is used as the umbrella term to describe LTE networks with one or more key LTE features – such as mission – critical push-to-talk over LTE (MCPTT over LTE), PPDR (Public Protection and Disaster Relief) over LTE and critical communications over LTE.
The 3GPP community introduced a set of solutions suitable for use in a public safety context with the establishment in 2016 of standards for mission critical communications over LTE networks. Enhancements and additions have been made in subsequent 3GPP standards releases to provide emergency and blue light services.
In Release 14, completed in 2017, 3GPP added functionalities that were increasingly in demand by the MC community. The Release included enhancements to MCPTT including new protocols and improved security. Release 15 was frozen in June 2018, continuing the development of the technology, introducing mission-critical common core enhancements such as server-initiated group a liation and de-a liation, resource management, and priority handling between MC servers. Other developments included enhancements of the MCPTT, MCData and MCVideo features.
Work is underway on Release 16, encompassing further enhancements to MCPTT architecture, MCData, systems migration and interconnection, MBMS APIs for MC Services, enhanced interworking with LMR systems and more work on security aspects.
PS-LTE Deployment Worldwide:
- 10 countries are deploying or have launched PS-LTE networks
- 9 countries plan or are trialling PS-LTE networks
- 78 devices designed for PS-LTE networks
- 42 smartphones or handhelds support PS-LTE functionality
- 35 unique PS-LTE device suppliers
There are 10 countries with PS-LTE networks that are launched or in deployment. This count doesn’t include LTE-R such as that launched by KT. These PS-LTE networks are not necessarily country-wide and some are only at small scale e.g. citywide. Launched or in deployment networks can be public or private.
A particularly notable launch is the American initiative FirstNet which is an independent authority within the US Department of Commerce tasked with developing a public safety network. In March 2017, it commissioned AT&T to build a critical communications network, in part using the Band 14 spectrum set aside for public safety purposes in the US, and to provide public safety communications services using that network. By June 2018, all US states had decided to opt-in to using the AT&T-delivered access network.
In August 2017, Verizon announced its rival plan to build a private 4G-LTE based public safety network. Following this, in March 2018, Verizon announced its Public Safety Private Core was launched. The network utilises Verizon’s existing LTE network on the 700 MHz, 800 MHz, 1.9 GHz PCS, 1.7/2.1 GHz AWS bands to provide priority communication channels for critical communications.
Another national launch has been achieved by Australia’s Telstra-managed LANES PS-LTE network. Its service was introduced in 2016 on a dedicated 166 MHz of spectrum at 700 MHz. The operator has continued to innovate, announcing LTE-Broadcast-enabled MCPTT in March 2017.
The UK is currently in the process of deploying its national critical communications over LTE network called the Emergency Services Network (ESN). In 2015, British mobile telecommunications operator EE was awarded the contract to build and run the network. Motorola Solutions was tasked with providing the user services. The network is slated for completion in 2020. It is planned to cover major and minor roads, specific locations such as underground lines and select buildings and cover 12 miles out to sea as well as air to ground communications.
South Korea is yet to launch its national PS-LTE network. However progress is being made towards it. In June 2018, the government pledged to invest $1.58 billion into a national public safety LTE network through to 2020 when it also plans to launch a maritime PS-LTE network. The start of the project is expected in July 2018. It will be carried out in three phases.
There are also a number of launched private networks around the world. This approach has been prevalent in China where several cities have city-based government-financed PS-LTE networks for emergency services and first responder use.
Brazil, Finland, Thailand, France, Hong Kong, Japan, Mexico, Norway and Singapore are all trialling PS LTE networks. Chile announced that the 700 MHz band would be reserved for public relief in case of catastrophe. France reserved 2×5 MHz and 2×3 MHz of the 700 MHz band for PS-LTE in 2016. Malaysia, Singapore and Thailand have all allocated spectrum in the 800 MHz band for PS-LTE networks.
Sweden has proposed using the 700 MHz band for a critical communications network. It stated that the network would start out as a MVNO with a state- owned evolved packet core (EPC) and will eventually consist of a dedicated radio access network of 7,000 eNodeBs of which 800 will be on green field sites.
India’s telecommunications regulator TRAI has been investigating the potential to build a PS-LTE network.
The progress towards PS-LTE networks has been slow and steady. The intricacies of changing from legacy systems such as TETRA to the newer LTE based public safety systems are complex and time consuming. There are also technical issues with PS-LTE networks that must be overcome, such as ongoing challenges of device-to-device voice communications when users go off-network.