PUMA T2
Technical Handbook
General information
P/N: 779-0306/01
Revision 03
OTE Proprietary information
Page 3
1.2 TETRA NETWORK OVERVIEW
A short overview of the TETRA radio-communication system, the reference
standards adopted, the network infrastructures, the user terminals is here reported.
TETRA stands for TErrestrial Trunked RAdio (Trans European Trunked Radio).
The TETRA standard, it relies on a thoroughly digital technology and it is able to
offer services and performances not yet available on alternative technologies. By
using TETRA Networks it is possible to obtain a greater data transmission rate,
that is to say that you can send more information in a shorter time. This means that
you can send longer messages to vehicle drivers or that a greater number of
mobile users can be served under the same system resources. A typical TETRA
application is the managing of a great number of mobile means, where voice and
data communications can be required as well. On TETRA systems Voice and Data
transmission services are supported by a radio transmission interface which has
the following main parameters:
• Channel spacing: 25 kHz or 12.5 kHz
• Modulation: π/4 DQPSK
• Gross channel rate: 36 kbits/s (25 kHz channels) or 18 kbits/s (12.5 kHz
channels)
• Access mode: TDMA with 4 timeslots (25 kHz) or with 2 timeslots (12.5 kHz)
• Transfer rate: 7.2 kbits/s per timeslot
• Max transfer rate: 28.8 kbits/s (unsecured transmission)
• Transfer rate (secure transmission): up to 19.2 kbits/s
An example of a TETRA system architecture is shown in Fig. 1.1.
The main system elements are:
• Radio base stations (covering the whole network).
• Switching and control units.
• Network management system.
• User terminals divided in:
- hand-held;
- vehicular (or motovehicular);
- fixed (desktop).
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