In Australia, as we move closer to a Public Safety Mobile Broadband Network (PSMBN) which will be underpinned by 4G (LTE) and soon 5G broadband technologies for its communications, it is important that standards-compliant solutions are used by everyone to ensure an emergency response is not compromised by lack of interoperability between agencies.
The Australian Government wants to deliver a PSMBN that is Smarter, Stronger and Faster
These are the 11 National Objectives that the Government have set out:
- Be delivered through national cooperation and tailored to meet each jurisdiction’s needs and
- Support the services and applications that Australia’s PSAs need to use.
- Have coverage where Australia’s PSAs need it.
- Ensure that those communications which matter most will get through first.
- Have the capacity to manage the volume of communications required and to expand as needed.
- Be available when Australia’s PSAs need it.
- Be secure.
- Enable interoperable public safety communications.
- Be accessible on any fit-for-purpose device.
- Complement and, where appropriate, be integrated into existing public safety communications systems.
- Be based on open standards to ensure the technology can evolve and is more cost effective and efficient.
Interoperability needs to be enabled at several levels, including among networks, agencies, multivendor devices, applications and software. Interoperability at all these levels ensures fast and efficient teamwork at the scene of an incident. With the lack of interoperability, it could hamper effective joint emergency response management and could potentially pose a risk to life.
If agencies select standards-compliant solutions, then these groups could avoid being locked into a proprietary product from a single supplier. By doing so this ensures they have the second source of security and are not dependent on a supplier that might end support a product after it reaches its end-of-life date or does not wish to satisfy the requirements of small user groups.
A multivendor environment creates competition, which helps price competition, encourages innovation and encourages a shorter development cycle for new products. A standardised testing and certification process ensure compliance with the standard and interoperability between vendors’ equipment.
Transition to 4G LTE / 5G
As public safety agencies begin to migrate to 4G/5G broadband technology, it is vitally important that this kind of multivendor, open standards approach is continued because this will ensure interoperability among networks, equipment and public-safety agencies is maintained at all levels.
One of the biggest interoperability tasks facing the public safety environment is enabling the successful integration of push-to-talk (PTT) and mission-critical push-to-talk (MCPTT) services across multiple 4G and soon 5G networks, plus how will they integrate existing emergency services mobile radio networks.
MCPTT refers to the standard specification drawn up by the Third Generation Partnership Project (3GPP).
To achieve interoperability, it is necessary for network operators, MCPTT client application providers, device manufacturers and app developers to adopt open standards, namely 3GPP’s MCPTT, mission-critical data (MCData) and mission-critical video (MCVideo) specifications. However, some threats to interoperability are emerging.
*The Future of MCPTT
Currently, in the United States, AT&T, the 2nd largest mobile operator in the US is building the First Responder Network Authority (FirstNet) nationwide public-safety broadband network. AT&T has plans to introduce a 3GPP standards-compliant MCPTT service in 2019. AT&T also offers its Enhanced PTT (EPTT) service using technology from Kodiak, a Motorola Solutions company. That technology is based on the Open Mobile Alliance Push-to-Talk over Cellular (OMA-PoC) standard. AT&T also supports over-the-top (OTT) PoC providers that are certified on the FirstNet network.
Verizon, the largest US mobile operator also offers carrier-integrated PTT services, again based on Kodiak technology, and supports OTT PoC providers.
Sprint, the 4th largest mobile operator in the US launched its Direct Connect Plus solution, again using Kodiak PTT technology, earlier in 2018.
No testing has been conducted to ensure AT&T’s PTT customers can talk to other carriers’ PTT users.
Over-the-top (OTT) PTT solutions operate independently of carriers’ wireless networks. There are two types: basic OTT PoC provides a PTT service using the carrier’s wireless network as the data transportation provider, and advanced OTT PoC offers PTT plus enhanced quality of service (QoS) solutions provided by the carrier. Some PTT platform providers offer both types of services.
* In the past most of the major US carriers used and embraced the Kodiak platform and actively tried to procure the Kodiak company, Kodiak was purchased by Motorola. Motorola aggressively pursued FirstNet and AT&T, with SPRINT and Verizon both actively looking to replace Kodiak in their core networks with another solution.
The danger is that first responder agencies may choose MCPTT services that are compliant or non-compliant or proprietary PTT products that may not be interoperable. Also, network carriers may not allow
PTT products to be interconnected even if they are compatible.
This lack of seamless MCPTT communications between carriers is a political rather than technical issue and should be resolved if the goal of inter and intra agency interoperability is to be achieved. However, the issue is not confined to interoperability between carriers but also between users of different PTT solutions on the same carrier.
As an example, a network integrated MCPTT solution based on 3GPP standards will provide users with access to the full suite of mission-critical services. But those using a non-MCPTT carrier-integrated PoC service or one or more different OTT PTT products will not be able to access full network solutions.
This could create interoperability issues between network-integrated MCPTT users and OTT PTT users at both transport and application levels, as well as between users of different MCPTT/PTT products if they are not compliant to 3GPP standards.
There is also a variety of other delivery models in between full network integration and an OTT application, such as the mobile virtual network operator (MVNO) approach. The United Kingdom is adopting for its Emergency Services Network (ESN). In the UK EE (a division of BT) is providing the network, while Motorola Solutions is providing the MCPTT services, again using Kodiak technology, which Motorola own.
Another issue to be considered is the possible complication that a mission-critical services provider does offer an MCPTT-compliant solution but locks users into its way of applying MCPTT with proprietary “upgrades.” End users are therefore locked into using this specific MCPTT client application to enable their devices to access the mission-critical application server on the network.
Thus, leaving them very little choice when it comes to this client application or a later release of it.
The Importance of Compliant MCPTT Client Apps
If the supporting network and/or separate MCPTT platform provider allow users to deploy the MCPTT client application of their choice (if it’s compliant with the 3GPP standard) this would open the ecosystem to a multivendor environment and avoid locking customers into a single MCPTT solution in a way that would not compromise interoperability with other end users.
This would be very important as end users need to understand the benefits of developing a true multivendor standards-compliant MCPTT broadband market rather than electing a numerous proprietary solution. The public safety environment should encourage the development of standards-compliant solutions by multiple suppliers to take advantage of the choice, lower prices and innovation a competitive multivendor environment provides. Agencies can then select and purchase standards-compliant solutions that suit their requirements and change the client at any time to another MCPTT compliant client.
It is also helpful if MCPTT client and application developers work to a single standard, so their products can be used across different carriers and devices.
MCPTT – LMR
MCPTT will co-exist as a complementary technology with traditional LMR networks for some years. That means there must be a standardised way of interworking between the two technologies to ensure users of one technology can talk to the other.
3GPP, together with the European Telecommunications Standards Institute (ETSI) and Alliance for Telecommunications Industry Solutions (ATIS), are developing the interworking standards, but it remains to be seen whether vendors will implement the standards and, more urgently, whether carriers will do so and, if so, at what cost to users. The first responder and other allied communities also need to devise an MCPTT testing and certification regime to ensure devices, solutions and apps are compliant with 3GPP MCPTT, MCData and MCVideo.
Interoperability will drive a multivendor ecosystem, as well as furthering competition. It will also save a great deal of time and money because device and app vendors can avoid having to submit their products to individual test and certification with any network operator providing a mission-critical service.