Supporting mobile operators working on Norway's Follo Line project, RFS radiating cables helped achieve an in-tunnel world record download speed of 560 Mbps.

The Norwegian Ministry of Transport is pushing to significantly improve mobile capacity and speeds across the country’s rail network. 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 allowing passengers to use data intensive services, with the aim of achieving 5 Mbps per user.

Demonstration Results

• Testing was conducted inside a 20 km abandoned road tunnel in Holmestrand, Norway.
• Inside the tunnel, RFS deployed its RADIAFLEX radiating cables connected to a radio transmitter with 4G 4 x 4 MIMO capability. The 2 x 2 MIMO setup utilized both horizontally polarized and vertically polarized radiating cables, which were doubled in the 4 x 4 MIMO setup.
• The results achieved approximately 95 percent of the theoretical maximum speeds for 4 x 4 MIMO in the tunnel.
• The results also demonstrate a 100 percent increase in download rates when going from SISO to 2 x 2 MIMO and an additional 100 percent increase in download rates from 2 x 2 MIMO to 4 x 4 MIMO.

“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.” — Tom Kuklo, global product manager of in-building solutions at RFS