The 6km long Södra Länken tunnel complex opened in 2004 after a lengthy six year construction period and provides four main routes into Southern Stockholm. Zenitel Radioteknik supplied and implemented the analogue radio coverage when the tunnel first opened and has now been awarded the contract for establishing radio coverage using the new Swedish TETRA based public safety network, known as RAKEL. The tunnel complex handles over 60,000 vehicles per day.
The Radioteknik system employed by the tunnel today facilitates underground emergency communications for police, fire brigades, ambulance and other rescue services, and utilizes FM radio broadcast with voice intervention. To allow emergency communications to continue throughout the digital implementation phase and subsequent transition period, the analogue MRTS repeater amplifier system, connected via optical fibres, is required to run in parallel with the new digital infrastructure for a given period of time. Moreover, certain redundancy demands were put forward in the tender material, increasing the level of system complexity but helping to safeguard the communication in the traffic tunnels, escape routes and other facility areas.
Zenitel, founded by King Leopold II, has over 100 years experience in radio technology and 25 years specializing in confined areas. Since 1981 alone, over 100 tunnels in Norway operate using Zenitel Radioteknik designed solutions. With new demands, the first fibre-distributed communication system was delivered in 1992, the first channel selective repeater in 1994, the communication system for the 24,5 km long Laerdal tunnel in 2000 and then in 2005, a band selective TETRA repeater was designed which is now being applied by the Kleistunnel, Police Amsterdam, Haarlem and more.
Zenitel Radioteknik will deliver the new Södra Länken system before the end of 2006 and implement the project in parallel with the roll-out of the RAKEL infrastructure. As such, Zenitel Radioteknik must follow an extensive and detailed project plan. We speak with Mariusz Gerlach, country manager of Zenitel Radioteknik about this project win. "The Öresund Link was our first confined area project within the RAKEL TETRA network and we are delighted to be associated with another, local and historic project. Zenitel has vast digital experience right across Europe and is a forerunner in the migration of radio systems from analogue to digital. Together with partners, Zenitel actually implemented the first commercial TETRA network in 1997 in the airport of Oslo, Norway!"
Mariusz continues "The entire system and solution for Södra Länken is based on Zenitel in-house building blocks and know-how. Site surveys in order to determine essential RF environment characteristics are already underway with full implementation, by Zenitel Radioteknik confined area specialists, due to be completed later this year. The complete solution we offer is professional, competent, reliable and assured." Certainly, the TETRA implementation on the Öresund Link tunnel and bridge complex, which was also through the RAKEL network, received very positive customer feedback, both concerning the actual system design and the RF performance of the entire solution experienced since implementation.