Critical communications

Safety Communications

Technology must be up to expectations in emergency situations where security and reliability are required

Motorola Solutions is already working on the use of mobile broadband in the concept of civil protection, public security or catastrophes

Security is an essential component for the organization of cities and for professional and industrial activities. Whether it is cybersecurity or “classic” security that includes the police, ambulances, fire brigades or any other rescue services, communications play a key role in operating efficiency when tackling situations in which the normal use of urban spaces or the physical integrity of citizens are at stake.

In emergency situations, security forces must be coordinated and be able to engage in a common strategy, even if the different operational groups are scattered around the city. Besides, several security bodies are usually involved in critical situations: the police, the fire brigades and ambulances must be coordinated and ready to share information and messages. In professional or industrial scenarios, communication systems are also necessary, and technology should be up to expectations if the application area is particularly critical. For example, means of transport such as the underground and trains, facilities such as airports, mining plants or complex factories require reliable and efficient communication networks that make it possible to put in contact all the professionals involved in a matter of seconds. A life may depend on these seconds; avoiding an attack against public order or public security may also be a matter of seconds, as is the case when working to avoid an accident.Motorola Communications

Commercial communication systems devoted to mobility surroundings could be considered an option to tackle the problem, but availability of such networks is not guaranteed, neither does its maintenance depend on public organisms or the state. Coverage is not guaranteed either, and places where huge amounts of people gather -concerts, demonstrations, or any other event- commercial networks collapse right when most needed.


The first approaches to the creation of a communication system suitable for critical situations and emergencies were taken at the start of the 1990 decade. In particular, by the French company Matra Communications, which is now part of EADS (European Aeronautic Defence and Space). Their goal was to design a digital, secure communication system for the French Gendarmerie (police body). The chosen technology to design Tetrapol was that of a terrestrial trunked radio, which uses a conventional radio system but includes a digital control system of communications so that several of them may share the same frequency. In this way, the wavelength spectrum may be more efficiently used, and digital “toying around” is feasible in order to create channels, groups, or even identify those taking part in a conversation and encrypt communications. In fact, intercommunication equipment may be cancelled if interfered with or stolen. The service was launched in France in 1998, and it is currently being used in 80 networks from 34 countries. When the ETSI (European Telecommunications Standards Institute) decided to define a standard for secure professional communications, they chose to develop TETRA, and Tetrapol mainly remained as an emergency-focused technology in countries as Spain, where it is used under the name SIRDEE (Sistema de Radiocomunicaciones Digitales de Emergencias de Estado; “Digital Radiocommunication System for State Emergencies”). It is used by the police, the Guardia Civil (a police corps), the Unidad Militar de Emergencia (“Emergency Military Unit”), the Armada (“Spanish Navy”) and the Casa de S.M. El Rey (The Spanish Crown), as well as local administrations in a sporadical manner.

TETRA has been approached, from the very beginning, as a standard with open specifications, so that terminals and equipment may be designed and marketed by several companies, such as Motorola, Sepura, Teltronic or even EADS, while terminals and equipment for Tetrapol are being manufactured by Matra (currently EADS) or Siemens.

Despite the technological similarities in both systems, they are different enough to be used in different application fields. Tetrapol has a largest action radius than TETRA, which makes it easier to display its infrastructure, which currently covers the whole country. Less base stations are required, which makes it easier to reach larger zones than those reached with TETRA. On the other hand, it is less efficient in data management, and it is not possible to transmit data while doing voice communication. TETRA is a technology that was adopted as a standard, which means it is cheaper to adopt not only by state security forces or rescue services, but also by private companies wishing to have a professional, highly-available radio communication system (typically above 99%). Sectors such as transports, energy or infrastructure and Public Works projects have adopted the TETRA system for their mobile communications in critical scenarios. A critical scenario is that in which no commercial communication systems may be depended on, or where availability is not guaranteed. TETRA offers a better data management system than Tetrapol, although its features are not outstanding if compared to 3G or LTE networks. They work on the same frequencies -typically between 80 and 400 MHz- but differences in modulation involve a lower reach in TETRA.

Right now, such mobile professional radio systems (PMR or Professional Mobile Radio) are being questioned because of their poor data transmission velocity. Nowadays, a higher transmission and reception velocity is expected than that designed in the 90s, but it is not just a matter of choosing an LTE technology and leaving TETRA or Tetrapol behind. The security of a city cannot depend on a somewhat fragile, unpredictable network such as mobile 3G or LTE. Investments done in critical communication systems are important enough to make them as profitable as possible before moving to other technologies, not to speak about the difficulties arising from the migration of all systems used by hundreds of thousands of professionals all over the world.

Collaborative Devices


Recently, Motorola introduced its solutions to tackle the challenges in critical communications and professional mobile radio systems (PMR) to be faced in the next few years. The way to face emergency, security or corporate scenarios is increasingly and inevitably linked to the use of data communications. The PMR sector has 42 million users worldwide, most of them in public security, but the number of users in the industrial or transport sectors is increasing steadily. Most PMR systems are still analogical, but they tend to shift towards digital PMR systems. Moreover, according to a study by the consulting company IHS, public data connections are already being used as a complement to PMR systems for geopositioning or image transfer. Nevertheless, the use of such applications outside the PMR system is limited, due to strict policies on security, reliability and resilience. TETRA designed an improved system in the data transmission field, called TEDS (Tetra Enhanced Data Service), which has theoretical maximum transfer rates of about 500 kbps, but even in the best conditions such transfer rates are not compatible with really smart functionalities integrated in integral city management systems, such as the one already working in Rio de Janeiro (which was developed by IBM Intelligent Operations Center).

The current approach by organisms, institutions and technological companies is to combine PMR existing infrastructure -solutions such as TETRA, Tetrapol, P25 or DMR- with broadband data systems such as LTE. Motorola has been working for years, from its Motorola Solutions division, searching for solutions for an increasing necessity: using mobile broadband in the context of civil protection, public security or taking action after a catastrophe.

There seems to be a consensus regarding the choice of the 700 MHz band with two 10-MHz channels reserved for this kind of applications. Both the United States and Europe are taking the right steps to keep this spectrum band preserved in the context of critical communications.

Interoperability between different systems is not an issue. Despite the fact that the display of communication networks is usually clustered around the most popular choices, operation centres working as a hub to coordinate several organisms, security forces, logistics, health or transports have gateways to keep all the systems and technology that intervene in an incidence connected. These are digital systems, and as such it is just a matter of development to make them “talk” to each other. Besides, quality of service policies (QoS) may be introduced in the network, so that the right priority is given to the most urgent kind of traffic at every given moment.

While waiting for a consensus in the assignment of frequencies for security scenarios, companies are introducing LTE private networks, although they use terminals that may also be connected to commercial mobile networks if needed. From the infrastructure point of view, solutions that combine TETRA technology with LTE for base stations are already available, such as MTS4L from Motorola Solutions, in the 800-MHz frequency. To date, Spain is waiting for the spectrum to be free after relocating TDT emissions to other frequencies. The 800-MHz band is also awaiting a bidding process for operating companies, which are trying to complete their 4G display in the band, an optimum one to ensure a continuous coverage radius for their clients.

Research and development: Motorola

Motorola, in reponse to the current trend towards the use of critical communications of data, recently opened the Mission Critical Solutions Centre in its European headquarters located in Basingstoke (United Kingdom). The initial investment was 1M euros, and it focuses on developing solutions in the area. Several possible situations are rehearsed in the centre, such as the response to a bomb threat from a terrorist group; hands-on emergency protocols are combined with the required technology to make processes reliable, agile and safe by combining TETRA and TEDS with LTE (both private and public) as well as Wi-Fi networks.

During the visit to the centre we could witness one of such displays, which combined information from cameras, pictures obtained on the ground by patrols, vehicle tracking, video and picture processing that included facial recognition systems, geo-positioning on real mapping, as well as quality of service policies (QoS) about LTE and priority management in case of network overload.

Real time Information

Smart solutions for Smart cities

Security and resilience are key for a city to be “smart”. Both parameters depend on the correct choice of technologies on which to base the different solutions for emergency management, police coordination, fire brigades, civil protection or ambulances, or for the protection of the integrity of goods and people by using police intelligence networks with a local or international scope.

There is a global trend to use data as an essential tool, and the new technology generations for critical missions should take into account the use of mobile broadbands to achieve that. LTE is the safest bet, especially in the 700-MHz band and two 10-MHz channel reserve. With such an assignment, there would be enough to build standards for data critical communications, in parallel to those of commercial communication networks. Right now, there is no choice but to use mixed solutions that combine TETRA/TEDS with private LTE and LTE from communication operators. However, in a few years, a well-defined technology will have to be deployed, aside from commercial technology.

Links of Interest


Motorola Solutions



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