Emergency roadside telephone – design, implementation, maintenance

Communication between traffic participants and emergency services is achieved through a telephone call system, which consists of a central unit at the control panel, roadside or tunnel telephone call devices, and telecommunication cables (fiber optic or copper) or wireless infrastructure (GSM).

Emergency roadside telephones are evenly distributed along the highway (approximately every 2 km on open highways or 120-150 m in tunnels).

Once the connection is established, the operator on duty has the ability to transmit information about an accident to the relevant services via a public telephone line or directly connect the call device to the public telephone network.

Road tunnel public address systems – design, implementation, maintenance

Tunnel public address system is designed to provide information or instructions to tunnel users, who may be stopped inside the tunnel in the event of an incident.

The system is designed in such a way that all parts of the tunnel are adequately covered with sound, ensuring clear and intelligible speech so that instructions from the operator can be heard by users even if they have not turned off their engines.

The operator in the control building selects the speaker groups through which they want to provide information.

The tunnel public address system consists of equipment located in the tunnel control building (control terminal, PA central unit) and equipment installed inside the tunnel (tunnel sub-centrals, speakers, low-voltage cable distribution).

Passenger Information Systems in railways – design, implementation, maintenance

Passenger information includes visual and audio information about train traffic, as well as accurate time information.

Visual passenger information includes all information boards connected to a unified LAN network. It consists of information boards in waiting areas and platform information boards. The information boards provide detailed information about the timetable (scheduled departure/arrival time, train category, route, platform, track, train delay time, etc.).
In addition to information boards, visual information also includes the installation of WiFi hotspots through which passengers can receive all relevant information regarding train departures and arrivals.

The audio information for passengers consists of an internal and external speaker system. The internal system includes speakers installed inside waiting areas and passenger restrooms. The external system consists of speakers installed on the facade of the station building and on the platforms.

To provide accurate time information to passengers, clocks are installed in the waiting area, ticket office, on the facade of the station building, and on the platform information board.

The clocks should be equipped with high-precision quartz movement and have the capability for radio-controlled time correction.

Relocation and protection of existing TK installations – design

During the construction of a new road, there is often a collision between its route and existing TK installations. Therefore, as a measure to protect the existing installations, either their protection on the existing route is planned, or their relocation to new locations with the application of additional protective measures (HDPE pipes and cable chambers).

Installation works include:

  • Cable testing

  • Underground cable installation

  • Cable pulling into conduits

  • Production of cable connectors

  • Dismantling of cable connectors

  • Required sorting and testing

Construction works within such interventions involve excavation of trenches for pipes and cables, as well as pits for manholes and junction boxes.

Removal or relocation of existing utility installations by other users is carried out by specialized companies according to specific projects or technical conditions for the respective type of work.

Telecommunication cable ducting – design, implementation

Telecommunication cable ducting represents a network of underground pipes and manholes used for distribution and protection of telecommunication cables.

In addition to protecting telecommunication cables, cable ducting enables quick and easy replacement of existing cables, seamless expansion of the telecommunication network, and promotes environmental preservation and cost-effectiveness in network construction and operation.

The number and dimensions of pipes, as well as the size and type of manholes, are determined based on the planned number, type, and capacity of cables to be installed in the ducting.

Fiber optic cable (underground and self-supporting) – design

Thanks to its good properties (low attenuation, wide frequency range for signal transmission, immunity to interference, error-free transmission over long distances, high data transmission capacity, ease of installation, etc.), optical technology has become indispensable for secure transmission of large amounts of data at high speeds.

Along roadways, fiber optic telecommunication cables are installed to connect traffic management and control devices, transportation networks, video surveillance systems, SOS systems, remote control systems, and other security and communication systems.

A non-metallic fiber optic telecommunication cable is installed, which is protected against moisture and designed for installation in cable ducts. The arrangement of cable fibers and their termination points is determined during the design phase, according to the specific requirements defined by the designers of individual systems.

Along electrified railway lines, it is common to install a self-supporting fiber optic cable, which is suspended on the outer side of the supporting structure of the overhead contact line poles. It also includes protection against damage from birdshot.

Low-frequency balanced cable – design, connection, measurements

In telecommunications systems, along with optical fibers, low-frequency balanced cable is used as the transmission medium for information and telecommunication infrastructure. It is used as the main cable with a construction of 15 pairs, while the connection cables have 3 or 5 pairs.

Impedance terminations are installed on both ends of the transmission path, consisting of passive elements, to achieve the required transmission quality. If necessary, bridging modules are installed.


To protect the cable, personnel, and equipment from the influence of power lines and atmospheric discharges, cables with improved sheath reduction factors are used.