July 16, 2020

An eye on the future of in-tunnel connectivity

How do operating metro services meet the consumer need for high and reliable connectivity?

Axel Schroeder, Product Line Manager, In-Tunnel Solutions

Consumer expectations when it comes to connectivity are higher than ever before. Perhaps the most unreasonable expectation of all is for flawless mobile coverage on metro services. Despite being literally 100s of feet underground, in some of the most challenging environments possible when it comes to RF propagation, end users simply demand high speed, reliable connectivity. So how do those operating metro services meet this particular consumer need?

A global footprint

At RFS we have a long history when it comes to solving in-tunnel connectivity conundrums. In 1972, our teams developed the world’s first radiating coaxial cable which enables consistent, reliable, easy to install connectivity in tunnels for the first time and since then our RADIAFLEX cable has been used across the globe to deliver in-tunnel connectivity.

Connectivity demands have moved on significantly since 1972 and so has the original RADIAFLEX cable. Evolving with every generation of mobile communication, RFS been at the forefront of providing high-tech in-tunnel solutions; working on projects which include, EuroTunnel, St Petersburg metro and the Follo Line in Norway, which set the world record for in-tunnel download speeds in 2018.

Baked-in futureproofing

One of the biggest focuses when developing solutions at RFS has always been to have one eye on solving the challenge in front of us, but also having one eye firmly on the future. Particularly when we look at tunnel deployments, the difficulties of installation, the cost of both making infrastructure alterations, and the disruption it causes means we need to deliver solutions that will stand the test of time.

Futureproofing is a key focus for our R&D teams which means the latest generation of Ultra Broadband RADIAFLEX radiating cables work with no stopbands. This means they can adapt to work on any frequency between 610 – 2700MHz. As network technologies evolve and different frequency bands needs to be utilized, there is no need to rip and replace the cable, it can simply adapt and evolve with customer demands.

Cable in action

One of the latest examples of RADIAFLEX in action is with the Grand Paris Express project. Nokia and ENGIE have been selected to deliver this deployment and RFS was recently selected by Nokia as a technology supplier for what is currently the largest transport project in Europe with plans to lay 200 kilometers of new rail lines and build 68 new stations. As part of the project, The Société du Grand Paris (SGP) is planning to build a private LTE network to support voice, data and video services, onboard trains and in stations including location capabilities.

The project will see RFS’s RADIAFLEX deployed in dual-cable MIMO configurations. This means that end users, with ever increasing connectivity expectations, will benefit from an ultra-high-bandwidth radio network with enhanced throughput everywhere along the new rapid transit lines.

Safety First

Not only does this deployment, like all of our in-tunnel installs deliver when it comes to connectivity, the equipment also meets the highest fire safety standards to ensure even in an emergency, communication is possible. For our customers, knowing that even if the worst happens their critical communication channels remain available is vital. This means we have a keen focus on making sure RFS cables meet highest fire safety requirements, including European Construction Product Regulation (CPR) and UL Certifications to ensure communication when it is needed most.

 What’s next?

The RADIAFLEX cable is an RFS innovation that has and will continue to deliver connectivity in the most challenging of spaces. However, in order to keep serving the growing need for connectivity, the R&D teams at RFS will continue to push the potential of the technology forward to ensure that metro operators and service providers will always be able to meet customer connectivity demands, regardless of how challenging those demands become.

 To find out more about our global in-tunnel deployments click here.