5G: Vodafone wants to close dead spots in tunnels with innovative antennas

Better mobile phone reception even in tunnels: Vodafone puts new 5G antenna for car and train tunnels into operation.

Mobile network operator Vodafone wants to improve mobile phone reception in car and train tunnels with windproof and cone-shaped multiband antennas from network equipment manufacturer Ericsson. As its first project, the company has equipped the 1400-metre-long Arlinger Tunnel near Pforzheim with stable 5G radio coverage. Five cone antennas are being used for this. The plan is to expand 20 further tunnels.

Cone-shaped antenna specially designed for 5G network expansion in long tunnels

According to Marc Hoelzer, Head of Network Development at Vodafone, plugging dead spots in tunnels is particularly challenging for structural reasons. This is because "passing cars and trains set large masses of air in motion in tunnels, which can lead to vibrations in the antenna technology and thus impair the transmission and reception performance of mobile radio antennas". The requirements for the wind resistance of the antennas used and their installation are correspondingly high.

The cone-shaped design of the installed antennas makes them "particularly wind-resistant and therefore robust". It supports all frequency ranges and ensures particularly high bandwidths in the 5G network. "Drivers and passengers will experience fewer dropped calls and more stable data rates thanks to the new generation of antennas," says Hoelzer.

Vodafone plans to use cone antennas in 20 more tunnels

The network operator explains that there are over 270 road tunnels with a total length of 270 kilometers on federal highways in Germany. On rural, district and urban roads, there are 420 tunnels with a total length of over 350 kilometers. The Deutsche Bahn network also includes 761 tunnels with a total length of more than 600 kilometers.

However, these cone antennas are not required for every tunnel. For smaller tunnels, for example, antennas at the entrances and exits are sufficient to provide mobile phone reception. In deeper and longer tunnels, optical repeaters are used to forward the mobile phone signal to the antennas installed in the tunnel and transmit the signal back to the mobile phone cell.

To create the tunnel infrastructure for the 5G network, cables have to be laid and base stations installed. This construction work usually requires closures in the tunnels operated by Deutsche Bahn and Autobahn GmbH. Network expansion in mobile phone tunnels is usually carried out as part of renovation or maintenance work, explains Vodafone.

Due to the effort involved, not every mobile network operator has to install its own cables and technology. Instead, the network operators have divided the tunnels among themselves and make the infrastructure available to the other providers.

The expansion of the 5G network in Germany is making progress, according to a report from October 2024, which stated that around two thirds of railroad tunnels are already equipped with mobile technology. As far as the general 5G network expansion is concerned, Vodafone wants to reach 95% of German households by the end of the year, Deutsche Telekom 99%. O2 Telefónica is pursuing similar goals.

(mma)