|Tunnel Radio System
For the best communication in tunnels ,Radio communications serve both mobility and safety. However, natural propagation in tunnels prevents the reception of signals and interrupts the flow of communications. Aztech Solutions has combined over 20 years of experience with tunnel radio communications to develop a special product that extends all modern radio systems into tunnels.
Signals from the radio network outside the tunnel are received and transferred without interruption into and out of the tunnel to guarantee uninterrupted radio connections for rescue and road repair teams.
Tunnel radio systems also allow for radio and mobile radio reception in tunnels, and permit the direct transmission of reports via USW radio programs in the event of accidents.
Connections to existing networks
Aztech Solutions tunnel radio equipment is connected to existing free field networks to ensure that radio transmission inside the tunnel functions just as efficiently as outside the tunnel.
Different connections to existing networks can be used. Low frequency or high frequency links to/from mobile communications relay stations are possible, and are realized by Aztech Solutions depending on the specific requirements of each project and customer.
The system in detail
The radio signals are fed from the outdoor site into special tunnel antennas – so-called beaming cables – over master stations, which include both transmitting and receiving equipment. The beaming cables are coaxial cables with openings in the outer conductor, through which the cable uncouples the electromagnetic waves in the tunnel. The tunnel radio system can transmit all required radio channels on a parallel basis without reciprocal interference.
Modular systems architecture and programmable system components permit the development of customer-specific solutions.
The master station is linked to the tunnel antenna via a coaxial feeder line or an optical transmission route. This is connected in a radial pattern from the master station to the individual tunnel stations. If desired, the connection can also be redundant.
Aztech Solutions has also developed modules to monitor these glass fiber routes as well as optical transmitter and receiver modules. Linear amplifiers are used in the tunnel stations to compensate for cable loss in the feeders or beaming cables, or to concentrate the signals in the optical receivers.
In order to meet future demands on tunnel radio communications, Aztech Solutions has developed a new concept. It provides both increased input for the many new private radio services as well as multi-bearer services for the new digital trunked radio technologies in tunnel radio systems. This concept also reflects the growing demand for fail-safe performance in the event of damage. The equipment is not only more reliable and less expensive but it also requires less maintenance and supports a broader spectrum of radio services in tunnels.
Continuous monitoring of functions
In order to ensure the greatest possible reliability, equipment operations are monitored continually. The radio system master station and tunnel amplifier are controlled constantly for breakdowns, the individual sections of the tunnel antennas for
cable damage and, where necessary, the optical routes are examined for errors. This procedure guarantees maximum system