|
|
RADIOCOMMUNICATION
 |
|
|
|
Networks : SPECIFIC
SYNCHRONOUS networks
Synchronous networks use a dedicated frequency pair and comprise several relay sites each equipped with a duplex relay and a relay controller. The relays are managed by a synchronous transmission technique and work with a microwave radio link.
The control computer is equipped with a supervisor workstation and a management interface linked to the MUX/DEMUX of the HF links of all the relays. This management interface provides the external channel manager with LF access (with a transmitter input and a receiver output), an input for transmit/receive control and an output for carrier detection.
The network consists chiefly of :
Automatic relays, each controlled by a relay controller which deals with radio field measurement, encoding/decoding pilot tones, data transmission to databases (ST 1382 standards) and input/output contact management (on-site remote control and signalling, etc).
Interfaces with radio beams connecting all the LF channels of each site on HF links or specific lines.
Management interface, supervisor workstation and audio console; this equipment is installed in the control room and used to coordinate the dialogue with the relays, analyse the field measurements of the LF sound received from the relays, select the best site, display site alarm and relay alarm status and automatically switch the LF relay in communication (Hand Hover).
Synchronous network with INTER SITE link
Transmission by portable equipment: the PC and all the network portable units listen in over the entire cover zone (all the relays retransmit the best signal from the best relay)
ISO FREQUENCIES
Example of radioelectric cover produced by our services with a special preference software program for France :
|
|
