Slovenske železnice has its own telecommunications system that is mainly used to manage railway transport and carry out company activities. Slovenske železnice has its own telecommunications system that is mainly used to manage railway transport and carry out company activities. To modernise the telecommunications network, which is mostly analogue and rather outdated, a project to set up a modern digital telecommunication network was launched in 1996. Currently, a total of 567 km of optical cables were suspended from their catenary poles on the main railway cross (an intersection of key north-south and west-east railway lines) to serve as the basis for the digital system and devices. Extensive changes also included a replacement of the entire analogue telecommunications network on the main railway cross with modern ISDN devices, which among other enable the transmission of data, images, and sound. Moreover, outdated telecommunication systems were also replaced at railway stations. The maintenance and control over the whole network is carried out by the Control Centre in Ljubljana. Telecommunications management from a single place gives a better overview of the network while enabling a more cost-effective and faster error detection and correction. Currently, 80% of main railway lines are equipped with radio dispatching communications, which provide communication between the engine driver and the transport dispatcher. Moreover, network-wide upgrades to the GSM-R system are currently on-going. Telecommunications equipment Basic data Lines equipped with digital telecommunications 545 km Lines equipped with radio dispatch connections (RDZ) 324 km Statistical data DŽT and S-ŽAT centrals 37 ŽAT connections 7120 Digital PDH devices 77 Digital SDH nodes 24 Telecommunications systems at stations 37 Modern telecommunications devices at stations 125 Telegraph exchanges 1 Teleprinter connections 34 Optical cables 576 km Line cabless 818 km Air power lines 1274 km Radio dispatcher connections (RDZ): 394 km fixed stations 68 engine stations 164 USW stations: manual stations 644 fixed and relay stations 261 mobile stations 90