Prioritising public safety in MNOs' LTE and 5G networks

Prioritisation on LTE and 5G networks is technically feasible, but there are a number of legal issues that need to be carefully addressed.

Public safety authorities in many countries are moving, or considering moving, their public safety broadband services to public mobile networks using 4G/LTE today and 5G in the near future. However, prioritisation of public safety (PS) traffic on mobile networks is more than a technical issue.

There are a number of prioritisation and pre-emptive mechanisms available in LTE, and further mechanisms are planned in 5G, to make this possible. The experience of a number of countries has demonstrated that LTE and 5G are perfectly capable of handling PS traffic. However, both government legislation and MNO operations have to be configured properly for it to work.

MNOs need to be able to ensure three things to support PS applications: network availability, performance and security. In many jurisdictions, MNOs may not be set up properly to meet these requirements, or legislation is getting in the way.

Network availability varies from country to country, but many still have areas of insufficient coverage to support broadband video from a body cam, for example. Backhaul, core network functions, power supply: all need to be fully redundant and physically secure.

MNOs also need to ensure that the RAN is redundant by ensuring national roaming is implemented. Push to talk (PTT) is supported on LTE, but MNOs may not have ensured that their PTT service interworks with the existing public safety PMR or LMR system.

On the network performance side, 3GPP mission-critical standards support prioritisation and country legislation has mandated that it be implemented — but the implementation isn’t actually optimal. For example, should first responder calls be given absolute priority over commercial calls?

In some countries, legislation has assigned the full capacity of the network to PS in case of emergency. But in a major incident, it will also be helpful for commercial users to be able to make calls because they provide valuable information for situational awareness, among other things. MNOs can divert commercial calls to 2G/3G layers or other 4G/LTE bands while still ensuring that PS requirements are met. In this case, the legislation, which is intended to be helpful, is a hindrance.

End-to-end security is a priority for all PS authorities and 4G/LTE have a number of well-established security solutions available. Again, the question is how well have MNOs implemented security and does government help or hinder? Many MNOs will forgo security in areas of the network because of the cost. But the network is only as secure as its weakest link and the solution has to be holistic. Have national security services weakened security protocols or inserted backdoors that provide unintended entry for rogue parties?

Some PS authorities are proposing to create a hybrid situation with some private LTE being used to supplement MNO infrastructure. This may be necessary wherever MNO coverage is insufficient — using deployable LTE solutions for instance. The PS authority might also leverage private LTE networks, such as those being implemented in hospitals, factories, harbours, airports and mines, when required.

Current trends in public safety planning suggest that there will be significant growth in LTE. The needs of national public safety are, therefore, a big opportunity for MNOs. However, it is critical that they make the investment in setting up their infrastructure to ensure that they can meet the network availability, performance and security requirements of public safety authorities. Governments and regulators can play an important role in ensuring this, while being careful not to create policies that hinder performance or undermine security.

The good news for public safety is that prioritisation on LTE and 5G networks is technically feasible. MNOs can handle PS traffic requirements as long as they take the necessary steps to meet the availability, performance and security needs. There are a number of legal issues that need to be carefully addressed and regulators, working closely with MNOs, will need to ensure that, without getting in the way, legislation helps to make this a success.

For more information about public safety prioritisation on commercial networks, see the TCCA white paper: Nokia.ly/TCCA.