• Tunnelfunk

DAB+ & FM Tunnel Voice Break-In (or In-house)

Industry leading technology and field proven DAB+ and FM Tunnel Voice Break-in devices for emergency situations in tunnels or buildings.
We provide both digital (DAB+) and analog (FM) emergency voice break in devices.

Why should you choose PrecisionWave VBI devices?

Our VBI devices not only offer many unprecedented features such as up to 12 ensembles in a single unit (DAB+) or 32 FM channels with fully customizable RDS messages, but they are industry's lowest power consuming and smallest devices, saving substantial cost both in installation and over the total lifetime.

Plus: we are more than happy to customize and incorporate your requirements. Contact us!

Our Features

Small in size, low in power and large in features:

easy to configure, highly versatily DAB+ or FM-Voice Break-In (Einsprechfunk) solution will have your needs covered - guaranteed!
  • Repeater and Voice Break-In mode
  • Scalable, up to 12 ensembles or 32 FM channels on a single unit
  • No GPS reception needed!
  • Automatic gain control (AGC) and precise RF input level measurement
  • Automatic reconfiguration on changes in the DAB/DAB+ ensembles
  • Low power consumption (less than 20W typ.)
  • Intuitive control software for device management and monitoring
  • Various interfaces, alarm outputs for signal loss or customizable inputs/outputs
  • Full RDS support with completely customizable messages during break-in
  • Compact, rugged module or 19” device available
  • High reliability, MTBF
  • All-in-one hardware solution
  • Field proven systems
  • Industry leading performance (ask us for independently made measurement results) and highest density
  • Future ready: modulator/demodulator fully embedded in hardware, yet programmable (FPGA)
We further offer buy-in options (you only pay what you really need)
  • Dual RF output and individual selection of the mode (voice break-in/repeater) for two tunnel tubes with a signle unit
  • 24hr monitoring service
  • Repeater only>
  • Second RF receiver available for in-tunnel RF signal monitoring on a full redundant setup
  • Two audio inputs for individual voice break-in on RF output 1 & 2
  • SNMP message service for remote monitoring or break-in activation
  • Pre-recorded (mp3/wav) messages for break-in
  • UKW Voice Break-In
  • Additional ensembles / FM channels
  • OEM service - our device, your casing, your brand

How does Voice Break-In work and why is it needed?

Read the Funktionsbeschrieb (German) or the note on synchronization (English) Blockschema


The VBI hardware is based on our versatile embedded software radio platform with precision DAB+ or UKW/FM front-ends. Thanks to its modularity it is customizable for your needs: whether you need different frequency bands, additional storage, a GSM connection or something else - talk to us, we're happy to implement even the most advanced ideas.
VBI Electronics
Rugged, custom fully milled aluminum case for absolute EMI protection and maximum RF performance in a potentially dirty environment. We offer both these small modules for customer integration or pre-fitted in standard 2HU cases including power supply (90-240V).
Original casing
19 inch rack
2-HU build


You have full control over the device via our intuitive "WebControl" application. It allows easy setup of ensembles and real-time RX-power monitoring as well as customization of I/O and transmitted messages. It is your hub for audio control or RDS and constantly shows system health status and alarm message history. Blockschema


Product brief DAB+
Read all information about our innovative DAB+ Voice Break-In solution.
Product brief FM
Read all information about our innovative FM Voice Break-In solution.
Funktionsweise VBI
What is Voice Break-In and how does its work? (German)
DAB+ Synchronization
Some notes on synchronization (English)

Live Demo

Gotthard Tunnel Demo

Video demonstrating live DAB+ voice break-in in Gotthard road tunnel. First, the break-in message is received and then the seamless switch-over to the standard program happens.