AlanDick Gets Tunnel Vision in Malaysia

AlanDick says that it has developed and installed a unique cellular, emergency service and maintenance radio solution for a motorway tunnel system in Kuala Lumpur, Malaysia, that duals as a massive storm drain during flash floods. The company has developed two separate radio communications systems for the Storm Water Management and Road Tunnel (SMART), being constructed by the Government of Malaysia. It is installing an emergency services and maintenance communications system in the city road tunnel in Kuala Lumpur, along with a multi-operator 2G and 3G cellular communications system for traffic using the motorway.

The SMART tunnel is a unique undertaking, incorporating both a 9.7km storm water tunnel and a 3km motorway thanks to an ingenious three-level design.

Motorway traffic travels along the top two levels of the tunnel during normal operation while the bottom level is used for water bypass. Amazingly, in storm conditions, the double-deck carriageway is cleared of vehicles and used to divert floodwater from a catchment area upstream of the nearby Klang River, thus alleviating the problem of flash flooding in Kuala Lumpur. The two communications systems therefore had to be both waterproofed and optimised for tunnel conditions.

The first tunnel contract, for the design and deployment of a 2G and 3G ready mobile communications system within the tunnel, was awarded by DiGi Telecommunications and will provide combined antenna systems for all three Malaysian operators - DiGi, Celcom and Maxis.

The communications system uses antennas mounted inside the tunnel and fed by fibre optic cables sealed into the tunnel wall. The antennas were specially designed for the tunnel, explains Rudi Fiedler, Vice President for Business Development at AlanDick. "New antennas had to be designed to work under heavy water pressure for this environment," he says, explaining that the devices are sealed units, designed to IP68 standards (dust-tight with protection against complete, continuous submersion in water). Antennas are placed at multiple points and hand-off signals between traffic as it passes along the tunnel.

The emergency communications contract, awarded by joint venture contractors MMEC-Gamuda, required a system operating at FM, VHF, and UHF 450 and 800Mhz frequencies. AlanDick chose a single tuned radiated mode leaky feeder cable as the transmission medium, facilitating the transmission of all the frequency bands. Seven radio channels in the 160Mhz and 800MHz band will be provided for police, fire brigade and ambulance services. They will be broadcast along the cable using channel selective air interface repeaters to eliminate unwanted programmes in the tunnels. The 450Mhz band will be used for the tunnel maintenance system.

According to Fiedler, the communications systems will be ready to support the tunnel within the next year, contingent on the completion of buildings designed to serve the tunnel."

Posted to the site on 31st March 2006