Tetrapol must not be confused with the similar sounding TETRA system. Trunked radio systems differ from public mobile radio systems such as GSM or UMTS primarily in terms of their faster call set-up, group calls, priority calls, end-to-end encryption and the possibility of direct calls from mobile station to mobile station without a connection via a base station (this is known as direct mode). All these user groups either have their own private trunked radio system or use the services of a trunked radio systems operator. police, the fire brigade, ambulance services, the army, civil defence, the frontier police, etc.). Potential users of trunked radio systems include closed user groups such as transport services (taxis, Swiss Federal Railways, haulage companies, etc.), airports, energy companies and the emergency services (e.g. It was at this time that the first proprietary digital PMR systems appeared, including ASTRO and iden (both by Motorola), EDACS (Ericsson), SR 440 (Bosch/Ascom) and Tetrapol (Matra Communication). This step was essential in order to increase spectrum efficiency, improve technical reliability and facilitate encryption of the connection. As early as the first half of the 'eighties, initial attempts were being made to seek appropriate solutions for digital PMR systems. In addition, the quality and security of radio systems could be considerably improved using digital technology.
It is therefore possible to fully utilise so-called trunking gain and to increase spectrum efficiency. Unlike earlier conventional analogue fixed-channel systems (a specific radio channel was allocated to each service and each user for the whole time), in the case of trunked radio systems frequencies are allocated dynamically to individual users and services.
TETRAPOL FDMA MODULATION PROFESSIONAL
Digital trunked radio systems are modern radio systems for private and public professional radio applications and for emergency radio applications (PMR/PAMR 2 ). The first customers for Tetrapol were the gendarmerie (mid-1992) and the police (early 1995) in France. Today, Tetrapol technology is supported and is being further developed by two organisations: the Tetrapol Forum (predominantly manufacturers) and the Tetrapol User's Club (user organisations). Tetrapol 1 was originally developed by Matra Communication (now EADS), France. 9ģ Tetrapol Factsheet 3/9 1 Introduction Tetrapol is a digital, cellular trunked radio system for voice and data communications. In Switzerland, the Tetrapol system has been adopted for the POLYCOM national emergency radio network.Ģ Tetrapol Factsheet 2/9 Contents 1 INTRODUCTION DEVELOPMENT IN EUROPE LICENCES IN SWITZERLAND SERVICES TECHNOLOGY FREQUENCIES NETWORKS. The modulation method used is GMSK (Gaussian Minimum Shift Keying) and in Switzerland the channel spacing is 10 khz. Tetrapol is primarily designed for the needs of emergency services and is very successful in this market segment.
Potential users of trunked radio systems include closed user groups such as transport services, airports, energy companies and the emergency services. The first Tetrapol customers were the gendarmerie (mid-1992) and the police (early 1995) in France. Tetrapol was originally developed by Matra Communication (now EADS), France. 1 Federal Department of the Environment, Transport, Energy and Communications DETEC Federal Office of Communications OFCOM Licences and Frequency Management Division Radio Technology Section 14 July 2015 Tetrapol Factsheet Trunked radio system for emergency services Summary Tetrapol is a digital, cellular trunked radio system primarily for voice communications though also for data.
0 kommentar(er)
