France Télévisions and TDF test 5G broadcast of Diagonale des Fous

For the mountain ultramarathon Diagonale des Fous, TDF has rolled out a 5G broadcast trial in partnership with France Télévisions, Antenne Réunion, and Web TV Grand Raid.

During the Grand Raid de la Réunion, also called La Diagonale des Fous, runners cross the volcanic island of La Réunion, encountering ever-changing weather conditions, tropical forests, and UNESCO World Heritage valleys.

5G-Broadcast-2-scaled.jpg (2).webp — TDF's deployment in Réunion meant the 5G network could be tested within a complex environmental and topographical setting

To cover the event, a broadcasting zone was launched in Réunion, operating from TDF’s sites at Saint-Pierre-Hyacinthe and Saint-Denis-La Montagne. In doing so, the team were able to transmit live audiovisual streams on smartphones without SIM cards, Wi-Fi, or mobile data.

During the event, programming from France Télévisions – including competition footage provided by Réunion La 1ère, as well as content from Antenne Réunion and Web TV Grand Raid – was made accessible via 5G broadcast within the coverage area.

Following trials in Paris, Reims, Bourges, Le Havre, Nantes, and Vannes, this deployment in an overseas territory marks a step in the ongoing evaluation of the technology under real-world conditions and across challenging terrain, according to the partners.

TDF reportedly deployed the technology to demonstrate the effectiveness of terrestrial broadcasting in addressing the challenges posed by large-scale public gatherings. In making this point, the organisation asserted that the method ensures consistent image quality with zero latency, regardless of how crowded the venue becomes.

Karim El Naggar, CEO, TDF, stated: "With this new milestone in Réunion during the Diagonale des Fous [a major ultramarathon], 5G broadcast proves its value in supporting large-scale sporting and public events. Delivering live coverage from France Télévisions to mobile devices – without the risk of network congestion and with open access – perfectly illustrates the added value of modern terrestrial broadcasting. Our ambition remains constant: to build – step by step, in collaboration with content providers and the entire ecosystem – a robust, sovereign, and complementary solution to bring live content to every screen.”

Adrian Pennington recently investigated how the 2026 Accelerator Project, Network Control, deployed standardised network APIs to make 5G predictable for broadcasters. Discover more here.