Inteligent railway infrastructure: Tehnical solutions for new Divača-Koper line

10. June 2011, author: mag. Boštjan Hernavs, Transport infrastructure
Because of specific geographical situation second railway track between Divača and Koper require new technical and technological equipment for telecommunication and signal interlocking system.

Mr. Sc. Boštjan HERNAVS
GH Holding, d.d.
Tivolska 30, 1000 Ljubljana


Second track Divača-Koper, intelligent railway infrastructure, technical standard of interoperability, ETCS, GSM-R, PTS, ŽAT, transmission system.


The port of Koper as one of the most notable users of freight railway traffic in Slovenia is connected to Slovenian railway network since 1967, when a single track railway from Prešnica to Koper was built. Final decision about construction of second rail track was made at the meeting at ministry of traffic on 2nd of April 2009. Before designing executive projects one must determine and execute all studies and researches which in any way influence the construction of the second track of this railway. Studies of introduction of interoperable intelligent infrastructure are especially important because of specific pathway of the second track.


The existing track Divača – Koper is in the process of modernization of signal-safety devices. Within this phase eight railway stations will be equipped with electronic interlocking devices including stations Koper and Divača. A telecommunication system on the level of data transfer systems will also be upgraded. Automatic announcement of passengers will be introduced as well as SOS system, video supervision system, fire alarm system and two power distribution stations. There will be an upgrade of uninterrupted

IMAGE 1: Expected GSM-R network on existing Divača – Koper track

power supply system and a new track side cabling with all local branches will be performed, which will be necessary for project realization Therefore the project of current track modernization is the basis, on which all solutions for new two-track railway are bounded. Traffic management after modernization will be entirely controlled from the Centre of Traffic Management in Postojna. Nevertheless the stations Divača and Koper freight will still keep the possibility of local management and supervision of railway traffic.


Currently analogue radio system (RDZ) is operative on the track and serves for communication between trains and dispatcher (traffic management center). This system will be replaced with GSM-R system. Predicted GSM-R network on existing track Divača – Koper is shown on image 1. The system is based on dual coverage of the track or full redundancy based on components of GSM-R system. MSC is positioned in Ljubljana and BSC`s are stationed in Maribor and Ljubljana. All network connections will be made through SDH third generation system. Radio system will also be connected with PTS and ŽAT (railway fixed-line telephone) system.


Solution is based on the demand, that the new track Divača – Koper will be designed as ETCS Level 2 track. Besides that we also begin with the fact, that on the section from exit portal of the tunnel T2 in km.15+923.000 to the split of Bivje in km 28+058.015 there is no other traffic points. ETCS L2 system is a system of train supervision, which has a condition of fully operative GSM-R system with availability of 99,995% and level of signal -95 dBm (41,5 dBmV/m).

IMAGE 2: Concept of GSM-R system


The basic part of GSM-R is a central system, composed of various units, which ensure all functionalities, demanded from GSM-R system regarding equipment of the track with ETCS and regarding other functional demands. Central system also ensures connectivity with other systems (data networks, fixed phone line systems ŽAT and PTS, public GSM networks, connectivity with other railway networks etc.) and manages the system of base stations.


Especially important segment in this particular project is the provision of proper signal level on track as well as in tunnels. Technical solutions available for ensuring proper signal level in tunnels are the ones where antennas are positioned on both sides of the tunnel and connected with radio emissive cable through the tunnel. Some typical possibilities are shown on images below and the type of solution also depends on the length of the tunnel.


All positioning of the antennas will be executed in the manner of duplicate coverage with cells. In that case there are two independent systems mounted on the same antenna tower and they ensure double coverage with cells. Systems are physically and logically separated which is shown on image 1.


For the coverage with signal three base stations are built:

  • BTS 1 in km 16.7
  • BTS 2 in km 21.1
  • BTS 3 in km 26.2

IMAGE 3: Example of equipping the 50m long tunnel

IMAGE 4: Example of equipping longer tunnel

IMAGE 5: Example of equipping two small tunnels with small mutual distance

BTS 1 covers the area from the exit portal of the tunnel T2 to the portal of the tunnel T3. BTS2 covers area from exit portal T7 to entry portal T8. BTS 3 covers area from exit portal T8 to the split of Bivje. On each of these locations proper power supply must also be ensured. Power consumption of BTS itself is approximately 1000VA without heating / cooling devices and other devices on the location BTS (entry supervision, video supervision). When building BTS3 and covering area with the signal one must also take into consideration the fact that the track of Divača – Koper freight on the section of exit portal T8 closes to the existing track and then parallel continues to the split of Bivje.


Regarding the position of BTS 1 a part of the tunnel will be covered with signal from this BTS. On the exit portal of T3 the antenna will be mounted. Power supply of this antenna will come from BTS 1.


In the tunnel an emission cable is mounted on the left and the right part of the ceiling. Power supply of emission cable is taken from system place TP 4.4, where all necessary equipment of BTS is mounted. Intermediate amplification is not necessary due to the length of the tunnel. In case that after measurements on field there is such necessity, an amplifier is mounted in the system place TP 4.2, where it is also powered. Typical power consumption of amplifier is 500 VA, precise consumption however is depending on the manufacturer.

TUNNELS T5, T6 and T7

Antenna is positioned at the entry and exit portal. Antenna is powered from BTS in TP 4.4 and BTS2.


In the tunnel an emission cable is mounted on the left and the right part of the ceiling. The cable is powered from BTS 3. To amplify the signal there is a setup of signal amplifier foreseen in the system place TP 8.2 and TP 8.5. Typical amplifier power consumption is 500 VA; precise consumption however depends on the manufacturer.


From the aspect of fall-out of GSM-R system, in case of accident events as well as in the aspect of ensuring quality of services for the passengers it makes sense to ensure the signal of public GSM operators. Based on field measurements the sufficient signal coverage will be determined.


To ensure functionalities of GSM-R, one must execute the connection to the PTS and ŽAT systems. It is a connection through radio interface. Connection will be executed within construction of GSM-R system on the existing track Divača – Koper, so no extra adaptations on PTS system will be necessary.


Functionally the BTS is designed in a way that it functions on the principle of Plug and Play. In real life this means that all equipment of BTS is designed in a way that only connection to the optical cable is necessary to ensure communications (through E1 interface) and a power supply. Within BTS all redundancy demands are also met. Therefore to connect BTS one must ensure optical cable from two ways and a redundancy optical cable. BTS power supply is taken from the power source, from two mutually independent power sources if possible. Typical BTS power consumption is approximately 2000 VA, but it depends on final configuration. It therefore makes sense to foresee 5000 to 6000VA for every BTS by which heating/cooling systems and eventual reserve for powering other operator’s devices. Every BTS has a built-in battery supported uninterrupted power supply.


PTS system is a digital communication system which covers the needs for operative communications on railways. Through the PTS system the following connections or functionalities are ensured:

  • Railway telephone connections (LB, CB, ŽAT, dispatcher)
  • interphones,
  • service and passenger voice notifications
  • radio connection (UKV, RDZ, GSM-R)

PTS system is based on ISDN standard and its composition is modular. For various needs there are various modules built in (CB, LB, S0, audio, line, S2M...). System is connected with ŽAT system, over which all connectivity to other telephone networks is ensured – railway networks and other public networks as well as functionality of direct emergency number calls. PTS system is based on ring topology and SDH network is used for mutual connection. It enables local and remote supervision and programming. On existing track Divača – Koper PTS system is built on locations Divača, Kozina and Koper freight. Intermediate locations have various ports (TK desk, amplification, TK talking points) and for connection a PDH or SDH system is used.

Local units on Divača, Kozina and Koper freight are connected over local cable lines directly on PTS system on particular location. Supervision and management of the system is carried out over central supervision system in Ljubljana with possibility of accessing on local level. Over pTS system all amplifications on existing track are also managed and there is a local utilization over TK desk ensured as well as utilization over the system for automatic train announcement. The latter is valid only for passenger amplification systems. The system for automatic train announcements is on the location of Postojna in CVP and controls all passenger amplification systems on the track Divača – Koper and gets information about trains from electronic interlocking device. PTS system also supports functionality of SOS pillars. SOS pillars are placed on all stations and connected over cable to PTS system (unit – emergency call central) on the stations Kozina and Koper freight. SOS system enables users a double functionality, call of busy operative traffic point to get information about traffic and call in case of accidents or unpredictable situations regarding the traffic.


The system ensures telephone functionalities for business needs. It also ensures complete functionality of connections to external telephone networks, railway and public, including functionalities for direct emergency calls in case of accidents. It is based on ISDN/IP telephone centrals which are mutually connected over SDH systems and over Ethernet network (protocol TCP/IP). Remote modules on smaller stations are also connected over Ethernet. ŽAT centrals are positioned on stations Koper freight and Divača and are connected to the rest of the ŽAT network in ring topology.


On the existing track Divača – Koper there are FMX/SDH and Ethernet transmission systems. Each of the system is a basic part of the whole system of data transfer on the railway network. Configuration is carried out with the topology of rings with which a high level of reliability and availability is ensured.

Connections are carried out through optical cable system. All systems are centrally monitored and managed from the control centre in Ljubljana with availability of local management. Capacity of transmission system should be STM-16 and lead to E1. Configuration of transmission level should be ring which assures maximum level of reliability and availability.

All new configuration of transmission system will be incorporated in present network whit remote maintenance and management access.


Due to great increase of cargo transfer and therefore the needs of the transport on one side and limited space of building the new traffic infrastructure as well as remarkably complicated processes of placing into the actual environment, the systems of intelligent railway infrastructure are becoming more and more important at planning transfer capabilities of railway transport companies. The project of second track of railway Divača – Koper therefore offers the first opportunity of unified planning of increasing transport capabilities of railway tracks with introduction of intelligent transport systems on the national level. Experiences of already implemented systems abroad show, that not only its construction but also adapted ways of railway traffic management, models of maintenance and changed business models of operation of railway sector as a whole are important. But it is mostly up to ourselves, how and how much we will be successful at.


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  • © GH HOLDING, Letališka cesta 27, 1000 Ljubljana
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