Solutions · Highways and tunnels
In a tunnel, the signal drops. Our job is to make sure it doesn’t.
We design, install, and maintain the radio coverage and monitoring systems for Autostrade per l’Italia, SITMB, SAV, RAV, Asti-Cuneo, and many other concessionaires. Over more than twenty years we have equipped more than 500 km of routes and over 100 tunnels.
The three challenges highway operators face.
What a concessionaire must guarantee every day, on the open road and in the tunnel.
Service continuity
The operational radio networks, along with those of the Polizia Stradale and the 118 emergency service, must stay live in every tunnel bore. A short circuit caused by a fire, or an open line from a faulty connector, leaves the tunnel without communications exactly when they are needed.
Safety for road users
Anyone driving through the tunnel must be able to call 112 and receive emergency instructions without installing any app. That takes cellular coverage verified around the clock and alert messages broadcast straight to the car radio.
Longevity of the investment
The system has to last for years and be maintained without closing the route. What counts is component quality, technical documentation, and scheduled work carried out overnight.
How radio coverage in a tunnel is built.
An equipped bore seen in cross-section: the base station in the technical room at the portal, the radiating cable that distributes the signal along the tunnel, and the backbone to the concessionaire’s control room.
- Radiating cable
- The radiating cable runs along the sidewall of the bore and distributes the radio signal throughout the tunnel, where the signal from outside does not reach. Line amplifiers compensate for the attenuation along the run.
- TP-CCV2 and TP-RFX
- TP-CCV2 flags short circuits and open lines on the radiating cable. TP-RFX checks the radio carriers present in the tunnel.
- Technical room at the portal
- The technical room at the portal houses the base station, the monitoring equipment, and the tunnel power distribution boards.
- Backbone and alarms
- The optical fiber backbone or the microwave radio link connects the technical room to the control room: the equipment alarms travel over the same link.
What a system for a highway route includes.
The systems we build along a route and what each one contains, from the radiating cable in the tunnel to the crews’ radio fleet.
Radiating cable and in-tunnel coverage
- Radiating cable run along the sidewall of every bore, at the height set by the design
- Couplers, splitters, termination loads, and line amplifiers housed in the wall niches
- Antennas at the portals and in the cross passages between bores, where the radiating cable does not reach
- TETRA, DMR, VHF/UHF, and cellular telephony distributed over the same line
- Continuity, attenuation, and standing wave ratio (SWR) measurements before commissioning
Radio sites along the route
- Base stations and repeaters installed in the technical rooms and shelters along the route
- Site antennas on masts and lattice towers, with the azimuth and tilt set by the design
- DMR Tier II networks in simulcast (same-frequency) configuration, TETRA trunking, and VHF/UHF links
- Duplexers, combiners, filters, and feeder cables, so that several networks can share the same site
- Alignment and synchronization of the simulcast sites along the whole route
Control room and radio rooms
- Operator positions in the control room and in the radio rooms, with dispatch consoles and the Respondr platform
- Operational radio networks and those of the Polizia Stradale, the 118 emergency service, and the Vigili del Fuoco fire service brought together in a single interface
- Audio recording of communications, with the date, time, and channel of every call
- GPS location of the road-maintenance crews and man-down alerts
- Call tests on every channel in service, run together with the control room staff
System monitoring
- TP-CCV2 in the base station cabinet: it flags short circuits and open lines on the radiating cable
- TP-RFX in the tunnel: it checks the TETRA, DMR, FM, and DAB carriers present in the bore
- TP-CELLX in the bore: it verifies the mobile operators’ 2G, 3G, and 4G coverage
- Track-TP as the supervision platform: it collects the status of every device along the route
- Notifications to the control room by email, SNMP traps, WhatsApp, and Telegram
Radio in the tunnel and alerts on car radios
- Rebroadcast of FM and DAB+ programming in the tunnel with TP-DAB
- Digital distribution over optical fiber from the central unit to the remote units installed along the bore
- Interruption of the programming and broadcast of the emergency message to car radios, with independent zones per bore
- Verification of the rebroadcast signals with the spectrum analysis built into the unit
Power supply and earthing
- Distribution boards, protection devices, and lines dedicated to the radio equipment
- Power supplies, uninterruptible power supplies, and buffer batteries sized for the required autonomy
- Bonding of equipment, racks, and antenna supports to the earthing system
- Surge arresters on the RF lines and on the power lines
- Test of the installation running without mains power
Links and integration
- Optical fiber backbones between the technical rooms, the radio sites, and the control room
- Point-to-point and point-to-multipoint microwave links where fiber does not reach
- Network equipment, PoE power supply, and patch cabinets in the technical rooms
- Connection to the tunnel SCADA and to the operator’s platforms via SNMP, relay contacts, and APIs
The crews’ radio fleet
- Supply of portable and vehicle terminals to the road operations and maintenance crews
- Programming of channels, talkgroups, and user profiles
- Batteries, chargers, and accessories delivered together with the terminals
- Communication tests along the route and verification of emergency calls
What happens when there’s an accident in the tunnel.
A real case: a rear-end collision in a tunnel bore, from the emergency call to the return to normal.
The emergency call goes through
A driver involved in the collision calls 112 from their phone. The call connects because the DAS carries the mobile operators’ signal into every tunnel, and TP-CELLX checks that it is available around the clock, day and night.
The control room coordinates the response
The operator manages the incident from the Respondr console: calling the road-maintenance crew on the route’s radio network and talking to the Polizia Stradale and the 118 service, whose radio networks reach the tunnel over the same radiating cable.
Drivers in the tunnel are warned
TP-DAB interrupts FM and DAB+ programming and broadcasts the emergency message straight to the car radios of passing vehicles, all along the tunnel: slow down, stay in your lane, do not turn around.
The incident stays documented
Once the emergency is over, the operator can reconstruct how the incident was handled: the radio communications are retained by Respondr’s built-in recording system, with the date, time, and channel of every call.
The systems we put in the field.
Each solution has its own in-depth page: here you will find only what it does for a highway route.
- Control room
Control rooms and dispatch
We build concessionaires’ radio centers with Funktronic consoles and the Respondr platform: managing the route’s radio networks, GPS location of crews, and man-down alerts from a single operator position.
- Operational radio
DMR and TETRA radio networks
We design and build the route’s operational radio networks: DMR Tier II systems in simulcast (same-frequency) configuration, TETRA trunking, and VHF/UHF links, from design to maintenance.
- In-tunnel coverage
DAS and radiating cable
We design and install multiband DAS and radiating cable systems, carrying TETRA, DMR, VHF/UHF, and cellular on the same line: it is the solution we have used to equip over 100 tunnels.
- Radiating cable continuity
TP-CCV2
A patented Teleproject system that flags short circuits and open lines on the radiating cable in real time, before the tunnel loses radio coverage.
- Cellular coverage
TP-CELLX
Continuously checks cellular coverage in the tunnel and alerts the control room when 112 and 118 can no longer be reached.
- Spectrum monitoring
TP-RFX
An outdoor spectrum analyzer that watches the TETRA, DMR, FM, and DAB carriers in the tunnel: it detects radio signal degradation before it becomes a service outage.
- Alerts on car radios
TP-DAB
It rebroadcasts FM and DAB+ signals in the tunnel and, in an emergency, interrupts the programming to send the alert message straight to car radios, all along the tunnel.
- Traceability
Communications recording
Audio recording systems for operational and emergency radio communications: every call stays documented and available to reconstruct events.
- Sensors and monitoring
LoRaWAN solutions
LoRaWAN networks and sensors for monitoring environmental and infrastructure parameters along the route, with the data collected on the Track-TP platform.
- Site-to-site links
Microwave radio links
Point-to-point and point-to-multipoint microwave links to connect the route’s radio sites and control rooms where fiber does not reach.
- Radio terminals
Radio fleet supply
Supply, programming, and maintenance of the crews’ radio terminals: we are authorized resellers for Motorola Solutions, Hytera, and Kenwood, and the exclusive Funktronic distributor for Italy.
- Before the tender
Radio coverage study
Propagation models, link budgets, and system sizing: the technical documentation you need to design the coverage and present the project in a public tender.
Learn more.
DABDAB+ and FM Coverage in Tunnels: Radio Systems for Road and Highway Tunnels
How to bring FM and DAB+ signal inside tunnels, how the VBI emergency break-in system works to reach vehicles in transit, and what Directive 2004/54/EC and Legislative Decree 264/2006 require for tunnels on the trans-European network.
MonitoringHow to Monitor Radiating Cables in Critical Infrastructure
Why continuous monitoring of radiating cables in tunnels and large infrastructure is essential: risks of an unmonitored system, components of the Teleproject-patented TP-CCV2, and how electrical continuity monitoring works without interfering with radio signals.
DABThe FM and DAB+ Break-In System in Tunnels
How the VBI (Voice Break-In) system interrupts in-vehicle radio to broadcast emergency messages inside tunnels: intelligent amplifier architecture, automatic activation via API/SNMP and manual activation via SIP VoIP, DAB+ text and image support, and regulatory obligations under EU Directive 2004/54/EC and Legislative Decree 264/2006.
Frequently asked questions.
The questions we are asked most often about this type of system.
What is the difference between radiating cable and antennas for covering a tunnel?
The radiating cable radiates the signal along the entire path it is laid on, so it spreads coverage evenly inside a long, enclosed bore, where a single antenna would only cover the stretch in line of sight, as far as the first curve. Antennas remain the right choice at the portals, in the cross passages between bores, and in short tunnels, where a continuous line is not needed. In practice the two solutions coexist in the same installation: which one to use, and on which stretch, is decided by the coverage study.
What happens to radio coverage if the radiating cable is damaged?
The damaged stretch stops distributing the signal, and in that portion of the bore the tunnel is left without radio communications, often with no one noticing the fault until the moment a call is needed. There are two failure modes: a short circuit, caused for example by a fire or by the cable being crushed, and an open line, caused by a break in the cable or by a faulty connector. This is why line continuity has to be checked continuously: TP-CCV2 detects both cases and flags them in real time, so the maintenance crew can set out immediately.
How long does a tunnel’s radiating cable last, and when does it need replacing?
There is no declared lifetime that holds for every installation: the radiating cable is a passive component and, as long as it stays intact, it works for years without losing performance. What degrades it is moisture getting in through joints and connectors, mechanical damage, and fires. Replacement, whether of the whole line or of a single stretch, is decided on the measurements: when attenuation and standing wave ratio (SWR) fall outside the design values, or when faults keep recurring on the same stretch, it is worth rebuilding that section of line instead of continuing to repair it.
In a tunnel, is cellular coverage delivered by the concessionaire or by the mobile operators?
As a rule the distribution infrastructure inside the tunnel, meaning the radiating cable or the DAS with its amplifiers, is built on behalf of the infrastructure operator, while the mobile operators bring their own signals as far as the injection points. The exact split depends on the agreements between the concessionaire and each operator and has to be defined before the design work starts, because it determines which bands the line must carry. After commissioning, the presence of the signal has to be verified over time, with field measurements and with the monitoring equipment installed in the bore, which flags the loss of coverage as soon as it occurs.
Our systems integrate with the equipment you already have.
No closed systems: we use open protocols, let different technologies coexist on the same infrastructure, and hold the certifications that public tenders require.
Multi-protocol on the same cable
TETRA, DMR, and VHF/UHF coexist on the same radiating cable: existing investments stay valid even when the radio technology changes.
Integration with the tunnel SCADA
The monitoring systems interface with the tunnel SCADA and with the operator’s platforms through SNMP, relay contacts, and APIs.
Certifications and qualifications
Teleproject is an ISO 9001:2015 certified and SOA OS 19 qualified company. The Respondr and Track-TP platforms are designed in compliance with the NIS2 directive and the ISA/IEC 62443-3-3 standard.
Request a proposal for your highway route.
Feasibility analysis, radio coverage study, and project planning, tailored to your requirements.