RFS radiating MIMO cable sets world record in-tunnel speed in Norway

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RFS, the global designer and manufacturer of cable, antenna, and tower systems for wireless and broadcast infrastructure, has worked with mobile operators in Norway to successfully break the in-tunnel world record download speed of 560mbps as part of the Follo Line project.

The Norwegian Ministry of Transport is pushing to significantly improve mobile capacity and speeds across the country’s rail network and the Follo Line project, due to complete in 2021, is acting as a test bed to develop the technology.

RFS worked with Telia, Telenor and Bane NOR to deploy in-tunnel infrastructure capable of delivering a mobile broadband connection. The deployment is geared towards delivering a Quality of Experience (QoE) that will allow passengers to use data intensive services with the aim of achieving 5 mbps per user.

The deployment

The testing was conducted inside a 20km abandoned road tunnel in Holmestrand, Norway. Inside the tunnel, RFS deployed its RADIAFLEX radiating cables connected to a radio transmitter with 4G 4×4 MIMO capability. The 2×2 MIMO setup utilised a horizontally polarised radiating cable and a vertically polarised radiating cable. This doubled in the 4×4 MIMO setup.

The results achieved approximately 95 percent of theoretical maximum speeds for 4×4 MIMO in the tunnel.

The results also demonstrate a 100% increase in download rates when going from SISO to 2×2 MIMO and an additional 100% increase in download rates from 2×2 MIMO to 4×4 MIMO.

Tom Kuklo, Global Product Manager In-Building Solutions at RFS commented, “Tunnels are still one of the most challenging environments when it comes to achieving reliable, high capacity mobile broadband. We have a huge focus on developing the technology to extend what is possible when it comes to in-tunnel connectivity. The Follo Line project was pretty unique in bringing all the players; hardware vendors, operators, government together, to push what is possible with in-tunnel mobile broadband to its limits and we look forward to exceeding those as the project continues.”