Critical Networks

The Terrestrial Trunked Radio (or TETRA) standard is defined by the European Telecommunications Standards Institute (ETSI).

This bi-directional professional digital mobile radio system (walkie-talkie style), allows one or more groups of users to use the same network while using completely independent equipment. Thus, each user can use his own device by pressing a button (PTT: Push To Talk) to talk or transmit data to a group to which he belongs.

Specially designed for official services such as police forces, ambulance and fire brigades, public transport services and for the army, these private networks are very efficient and offer fast communication establishment, priority calls and group calls.

DMR (Digital Mobile Radio) is a digital mobile radio standard of the European Telecommunications Standards Institute (ETSI) to which most private radio networks comply.

It integrates voice and data services to increase operational efficiency and support a wide range of applications. In addition, with native encryption, it protects the network from eavesdropping. Through the integration of digital technology, the standard enables the unification of inter-DMR and terrestrial networks through routers and gateways.

3 levels are thus defined :
– Level 1 : Intended for use without a license (446 MHz), and supports consumer products and low-power commercial applications.
– Level 2 : Covers conventional licensed radio systems, mobile and portable devices using the PMR frequency bands (66 to 960 MHz).
– Level 3 : Covers shared resource operations (66 to 960 MHz).

Concretely, PMR is suitable for fleet management, monitoring or remote control of sites, or locating people or vehicles by GPS. In addition, it offers superior audio quality over long distances while eliminating background noise and interference. Finally, users of radio technology can send messages over the same network internally.

DMR is thus used by industry, construction sites, administrations and local authorities and more generally by large companies. It isperfectlysuited to use in civil security.

Tier 1 – intended for use without a license, where the basic mode is point-to-point walkie talkie type mode. Two other modes are available :

– Conventional relay mode – which allows walkie-talkie calls to be switched by creating a cell,

– Network relay mode, where several “cells” are interconnected in IP.

Tier 2 – is a protocol that includes TDMA allowing a single channel to carry both “outgoing” and “return” channels – It allows :

– More extensive cell coverage,

– More elaborate voice services (group calls, digital listening quality),

– Data services.

Tier 3 – provides in addition :

– Even more sophisticated voice services,

– Interconnections with computer applications, such as geopositioning, data collection,etc.

– Interconnections with other voice servers (IPBX/PSTN).

TETRAPOL is a secure mobile radio communication system, mainly intended for security professionals and security forces. Our partner Airbus is at the origin of the development of the technology, which today represents nearly 850,000 users spread over 83 networks.

TETRAPOL standards are reserved for AOSS (Autorités Chargé du Sauvetage et de la Sécurité) such as the French Navy, the Gendarmerie, the Fire Brigade and the National Police within the same infrastructure (INPT).

eDMR is a professional digital TDMA (Time division Multiple Access) radio data management system. As the developer of the technology, eDMR offers analogue and digital operating modes in all VHF frequency bands.

The solution allows existing analogue radio terminals to be used with new digital mobile equipment. Thus, radio network operators who wish to migrate their analogue infrastructure to digital can do so smoothly and gradually.

eDMR can be adapted to any type of need as it allows the implementation of a single or multi-site radio system, interconnected locally, regionally or nationally via an IP infrastructure. Thanks to this flexibility, it ensures the configuration, control, administration and maintenance of the system(s), and allows supervision and management for agencies and/or multiple users.

As a variant of GSM, the GSM-R network (Global System for Mobile communications – Railways) is a wireless communication standard, specially developed for railway applications and communications.

It offers voice communication services and transmits railway signalling to the train driver’s cab. Trains can thus communicate with rail traffic control stations; drivers, train crews and maintenance staff can also communicate with each other in conference mode (group calls).

The GSM-R network also allows trains to travel freely between countries within Europe and supports data applications such as ETCS (European Train Control System).

P25 (or Project 25 or APCO 25) standard is a set of telecommunications standards for digital radio in the North American security field, whether for police or firefighters. P25 was initiated by the Association of Public-Safety Communications Officials (APCO), the largest and oldest organization in communications for public safety professionals. The standard is comparable to the European TETRA system.

It allows public safety officers to communicate, within a common infrastructure, with any professional in the event of an emergency or a request for assistance.

P25 has been entirely designed from a user perspective to meet the specific needs of public safety professionals. It thus guarantees the permanent availability of specific services related to their activity. The standard also include an analogue operating mode that is compatible with existing FM radio equipment, making it easy to migrate with existing equipment.

VHF (Very High Frequency) band is the band of the radio spectrum extending from 30 MHz to 300 MHz, i.e. from 10 to 1 m in electromagnetic wavelength.

UHF (Ultra High Frequency) band is the term for radio frequencies between 300 MHz and 3,000 MHz, i.e. wavelengths from 1 m to 0.1 m. The upper part belongs more generally to the technical domain of “microwaves” which extends from 1 GHz (1,000 MHz) to 1,000 GHz. Its use developed with the saturation of the VHF band for fixed or mobile radiotelephony and television applications, as suitable components became available.

LTE mobile networks are marketed as 4G by operators in many countries. LTE terminals can be telephones (smartphones), tablets, USB modems or any other type of fixed or mobile equipment (GPS, computer, video screen, etc.). LTE offers two main advantages compared to its predecessor (GSM): higher download speeds and faster data transmission.