TETRA(Trans European Trunked Radio)

TETRA profile

TETRA (Trans European Trunked have, now has been changed to Terrestrial Trunked have) digital trunking communication system is based on digital TDMA (TDMA) professional technology of mobile communication system, this system is the European telecommunications standards institute (ETSI) in order to meet European countries professional departments for mobile communication needs and design, formulate unified openness system. Commenced input, now has become European standards, also as GSM, as obtain - including the United States outside Europe countries and regions adopt, quite has the development potential.

TETRA digital trunking communication systems available in the same technology platform provides command scheduling and data transmission and telephone service, not only does it provide much of the group scheduling function, and can also provide short data information service, packet data services and digital full-duplex mobile phone services. TETRA digital trunking system also support the powerful mobile station off nets straight-through (DMO) way, can achieve jian power, the air interface encryption and end-to-end encryption. TETRA digital trunking system but also has a virtual private network function, can make a physical network for irrelevant multiple organizations service. TETRA digital trunking system possesses abundant service function, higher frequency utilization rate, high quality and flexible communication network mode, many new applications (such as vehicle positioning, image transmission, mobile Internet, database query, etc.) are already in TETRA in implemented. Therefore, nearly two years TETRA digital trunking system in Europe and even world obtained fast development.

TETRA business

According to ap different TETRA basic business can be divided for carrying business and user terminals business.

TETRA support user terminal business includes: single call (point-to-point), a group called (point-to-multipoint), response group called, radio call (one-way point-to-multipoint) and above all in Ming words or secret words.

TETRA support bearing business includes: packet data, circuit data.

Bearing business with the following user bitrate:

· unprotected voice or data 7.2 KB/s (tiptop 28.8 KB/s);

Low protect degrees, the data is 4.8 KB/s (tiptop 19.2 KB/s);

High degree of data protection, 2.4 KB/s (tiptop 9.6 KB/s).

TETRA support of supplementary services include: professional scheduling type supplement business and phone type supplement business. Professional scheduling type supplement business includes: access priority, or take first, priority call, Tolerance call, and dynamic transfer, later into; DiaoDuTai verification of call, monitor, protected reliably against detective, Regional choice; Shrinkage bits addressing, Speech recognition, Dynamic reconfiguration, etc. Telephone type supplement business includes: list search call, and call forwarding, call limit, call report, call waiting, call hold, caller/called recognition display, caller/called recognition shows limitation,

To busy users/to no answer call finish, Billing announcement; Call reserved etc. Gotone suitable for most carrying business and user terminals business.

TETRA manufacturers

The current major TETRA system manufacturers are EADS and Motorola corporation;

The current major TETRA terminal manufacturers are Sepura, EADS and Motorola company.