Next-generation infrastructure for public protection and disaster relief organizations

The number of events that involve regional-scale public safety and security (PS&S) concerns, and which have the potential to evolve into large-scale cross-border disasters, is increasing and thus putting more pressure on the agencies and organizations responsible for PS&S. Public protection and disaster relief (PPDR) networks are used by public protection entities, police forces, firefighters, medical emergency responders, as well as other public safety agencies and some utility organizations to respond in a timely and adequate manner to these events. The groups involved with the PPDR activities therefore need to cooperate with one another, to align their procedures, to share the necessary information, and to be interoperable.

Existing PPDR technologies are based on mature private mobile radio (PMR) infrastructures, and they include the Terrestrial Trunked Radio (TETRA), TETRAPOL, and Project 25 (used specifically in North America) approaches. Although these narrowband methods are suitable for voice communications, they are inappropriate for the transfer of large data volumes. Indeed, PPDR users predict that they will require—in addition to the currently used voice and short data services—extensive mobile broadband capabilities in the future. For example, video and high-resolution images, as well as real-time access to databases, are of growing importance to police and law-enforcement users. Firefighters also need real-time access to building plans and data, as well as to sensors (e.g., IR cameras and through-the-wall motion detectors). Moreover, ambulance and emergency medical services agencies require high-resolution images—in combination with real-time medical telemetry—for remote assistance and in-transit interventions.

Commercial long-term evolution (LTE) technology is generally accepted as a good baseline candidate for a broadband carrier in PPDR services. Standards bodies—including the Third-Generation Partnership Project and European Telecommunications Standards Institute—are currently working to enhance LTE specifications with additional functionalities that will be able to address the particular needs of PPDR users. For instance, these functionalities include group working (i.e., ‘one-to-many’), direct-mode operation (device-to-device, outside network coverage), and additional resilience in case of infrastructure failures or disruption. Although it seems clear that LTE will replace TETRA and TETRAPOL in the next few years, it is still unclear how the transition between the use of traditional (focused on voice applications) and new PPDR terminals will be realized.

In this work,¹ we present the design of a next-generation communication infrastructure for PPDR organizations, with which we can fulfill several requirements, e.g., the need for secure and seamless end-to-end communication and for interoperable information exchange within the networks. With our approach—known as security and interoperability in next-generation PPDR communication infrastructures (SALUS)²—we consider the fact that multiple phases will exist when the existing PPDR networks are transferred from simple cooperation (i.e., with LTE commercial operators, for non-mission critical interworking) toward a full mission-critical LTE PPDR-owned or shared network. In particular, we consider a case in which current PPDR technologies and LTE coexist for a long period of time. Several available references^3–11 provide more information about the future evolution of PPDR communications, and we provide additional details on potential migration roadmaps in our Intermediate Business Analysis for SALUS.¹²

For the design of our SALUS approach, we considered several different aspects, such as strategic, organizational, regulatory, technological, operational, and economic factors. We based SALUS on an enterprise architecture (EA) of PPDR organizations, which is used to enable the required alignment of procedures and the design of interoperable systems. We used the Open Safety and Security Architecture Framework (OSSAF) to design both our EA and our system architecture. The OSSAF—created by PS&S agencies—provides a framework and approach for coordinating the perspectives of different types of stakeholders within a PS&S organization. We complement our use of the OSSAF by also utilizing the NATO Architecture Framework meta-model to represent the different OSSAF views and perspectives.¹³

In the SALUS approach (illustrated in Figure 1), we make use of the critical voice and data protocol, as well as TeamLink gateways, to ensure interworking between PMR technologies and LTE. Our high-level system architecture for SALUS is also presented in Figure 2. The command and control center (CCC) is a central piece of the system's architecture. This is where meaningful data is collected, processed, and relayed to the appropriate recipients.

Figure 1. Schematic illustration of the SALUS (security and interoperability in next-generation public protection and disaster relief communication infrastructures) solution for interworking between private mobile radio (PMR) technologies—such as Terrestrial Trunked Ratio (TETRA) and TETRAPOL—and long-term evolution (LTE) technology. The critical voice and data protocol (CVDP), TeamLink gateways, and the dispatcher and management station are used to ensure successful interworking among these technologies. SALUS can interface with the digital TETRA switch (DXT) and complies with the latest third-generation mobile network (3G) standards, including support for mission-critical push-to-talk (MCPTT). EPC: Evolved packet core.

Figure 2. Illustration of the high-level SALUS system architecture. In this case, it is assumed that a future public protection and disaster relief communications network is deployed as a mix of multiple technologies, i.e., LTE, TETRA, TETRAPOL, and wireless Internet (Wi-Fi), and that it includes the deployment of multiple enodes (eNBs) and base stations (BSs). Each technology has its own extensions, e.g., an emergency mobile ad hoc network (eMANET) that can be deployed using IEEE 802.11 (Wi-Fi) point-to-point links. Alternatively the Wi-Fi can be used to create a medium-range fast-deployable mesh network. PMR stations (MSs) can also be deployed as over the top (OTT) solutions for LTE and Wi-Fi networks. Sensor data from multiple sources, e.g., user equipment (UE), wireless body area networks (WBANs), or cameras, is collected at the command and control center (CCC), at which a common operational picture of real-time events is created. Novel applications are also enabled through the use of broadband, e.g., the access of highly detailed maps with dynamic push-and-pull key points of interest (KPI) for emergency operations. The interoperability is achieved through the use of gateways (GWs) and relays, and security is ensured by a cluster of authentication, authorization, and accounting (AAA) entities. QoS: Quality of service. ID: Identification.

With SALUS we can enable the next generation of PPDR networks, i.e., which will be dominated by data-driven applications (as well as voice and video support, including group calls). Applications of our approach include streaming—in real time—the location of PPDR operatives from their handheld terminals to the CCC. In addition, SALUS can be used to provide terrain characteristics and to report the measurements to remote geographical information systems, and it will be possible to determine (through necessary data processing) whether a PPDR operative is incapacitated (e.g., they have fallen to the ground). Such applications of SALUS are (by their nature) distributed, i.e., some run on PPDR handheld terminals, whereas others run on computers at various locations (ranging from the CCC to vehicles). Furthermore, the communications enabled by SALUS will necessarily be secure (and will protect the privacy of its users) because its applications will often involve processing of personal data.

In summary, we have designed a next-generation communication system for PPDR organizations as part of the SALUS project. Our proposed approach enables interworking between legacy PMR networks (e.g., TETRA and TETRAPOL) with LTE, and effectively permits a smooth transition toward the next generation of PPDR communications systems. SALUS can also address the information flow and communication requirements for PPDR cross-border operations. By making use of a broadband technology, we have demonstrated key applications of SALUS that have the potential to improve the reaction time and effectiveness of public safety forces in emergency situations. In our future research we will seek to further improve the interworking with TETRAPOL and to exploit the new opportunities that will be provided by LTE Proximity Services.