Battery charger for the PUMA T2 hand-held radio
Technical Manual
TETRA network overview
P/N: 779-0357/02
Revision 04
OTE Proprietary Information
Page 15
2.
TETRA NETWORK OVERVIEW
A short overview of the TETRA radio-communication system, the reference
standards adopted, the network infrastructures, the user terminals (PUMA T2
included) is reported in this section. The battery charger is one of the accessories
of the PUMA T2 user terminal.
2.1
NETWORK ARCHITECTURE
TETRA stands for TErrestrial Trunked RAdio (Trans European Trunked Radio).
The TETRA standard 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 (unsecure transmission)
•
Transfer rate (secure transmission): up to 19.2 kbits/s
An example of a TETRA system architecture is shown in fig. 2.1.
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).
