German communications supplier Siemens is to equip two Austrian motorway tunnels with a tunnel radio system and a new emergency call system. Voice over internet protocol (VoIP) technology will be used so that voice messages can be sent along with control signals via a single data line. The tunnel radio will provide two FM (VHF) broadcasting channels and narrow-band analog channels for the emergency services by means of 14 repeater stations using fibre-optic cables, 15km of broadcasting cables act as antenna mounted in the ceiling. The work will be carried out with general renovation on the Hiefler and Ofenauer tunnels that have a combined length of 3.6km.
