RFS (Radio Frequency Systems), the wireless infrastructure specialist, has secured a major contract to provide an in-tunnel radio-frequency Commercial, TETRA, and Security wireless communications sub-systems for Line 3 of the Shenzhen Metro.The prestigious three-year project follows hard on the heels of a similar multi-topology contract for Beijing Metro Line 4 and will ensure that wireless communications are available to metro personnel, passengers and police, rescuer workers, fire brigade on the Shenzhen Metro.

According to Bin Zhang, RFS' country sales director for China, the wireless installation - which was won thanks to the company's reputation for supplying high quality and reliable wireless RF coverage systems on schedule and within budget - will enable wireless communication for everyone in the underground environment.

"Our reputation for outstanding technical design, working cooperatively with all concerned and, of course, our firm business relationships with third-party wireless vendors, other suppliers and intermediaries, stood us in good stead in bidding successfully on this project," he said.

Zhang added that RFS has already started work on the project, which involves the deployment of the three sub-systems -consisting of  RADIAFLEX®  Radiating cables and connectors across the entire 32 kilometres of Metro Line 3, which includes 22 stations.

Diversity of stations

The diversity of stations on Line 3, says Roy Guo, Sales Manager with RFS, is keeping the company's engineers firmly on their toes, as the 22 stations comprise six subway sites, one half-subway site and 15 light rail stations."The environment is highly challenging, as my team of engineers are working in very cramped tunnel conditions alongside third-party engineers who are prepping the Line 3 project for opening next year," he said."Construction of Line 3 is now well underway, and will interconnect with Line 1 at Guo Mao and Gouwu Gongyuan, and run out to Longgang in the North-East of the city," he added.

According to Guo, the use of lower frequencies by the essential Terrestrial Trunked Radio (TETRA) communication system allows metro personnel and the operation headquarters to stay in contact across greater distances than with conventional GSM cellular services. That, added to the fact that Tetra transmissions are encrypted, means that the metro personnel and operation control can be assured of staying in contact at all times whilst on the Line 3 system.

"That's not to say that deploying a Tetra communications system underground is any easier than installing a GSM transmission system. Far from it, as the greater distances between Tetra base stations and radiating cables make for some interesting challenges, especially when signal propagation is involved," he explained.

RFS' Bin Zhang, meanwhile, said that this is where the company's pedigree in installing wireless transmission systems in and on subways plus light rail systems across the Asia-Pacific region - and around the world - comes into play.

"We truly understand the way wireless signals propagate and interact with other RF signals, especially in subway tunnels. This complete understanding allows our engineering staff to plot - with great precision - where base stations and radiating cable are needed, without the need for major on-site tweaking which, given the cramped conditions in the tunnels, would be difficult," he said.

Trademarks: RADIAFLEX®, Radio Frequency Systems® and RFS® are registered trademarks of Radio Frequency Systems. All other trademarks are the property of their respective owners.