Cell towers in Saint-Ouen-l'Aumone (Val-d'Oise)

2 camouflaged "tree" pylons and 16 pylons and 10 buildings carry the commune's antennas.

Masts stand at Les Belles Vues, 23 Rue des Frères Capucins, Le Clos du Roi, 11 avenue du Vert Galant, Le Clos Borgne and avenue du Gros Chêne.

Systems from 1996 are still on the register. Bouygues Telecom switched on the first 5G here in November 2020; Free Mobile followed in December 2020, SFR followed in September 2021. 2015 was the busiest year, with 36 new systems, most of them 4G.

Over the past 12 months ANFR recorded 30 new systems here. Approved additions not yet in service are pending on 8 existing masts, for example Bouygues Telecom (5G, including 5G at 3.5 GHz) at Le Clos Borgne, Bouygues Telecom (5G 3.5 GHz) at 11 avenue du Vert Galant and Free Mobile (4G and 5G, including 5G at 3.5 GHz) at 3 Rue Louis Delage. 20 Bouygues Telecom 5G transmitters are listed as technically operational — installed, but not yet declared commercially in service.

ANFR lists a 49 m building at Le Clos du Roi as the tallest structure. The median height of measured supports is 27 m.

9 supports carry only Bouygues Telecom.

Among the 43 Val-d'Oise towns with at least five masts, Saint-Ouen-l'Aumone ranks 5th by mast count. With 28 masts for 25,578 residents, or 11 per 10,000, it has more masts per inhabitant than the median for those towns (6).

On 3.5 GHz, the fastest 5G band: Bouygues Telecom on 9 of its 12 masts, Free Mobile on 8 of its 9 masts, SFR on 8 of its 9 masts and Orange on 4 of its 7 masts.

Nearby, Eragny (3.4 km to the south-west) has only 9 masts.

Figures above cover installations declared to ANFR as in service or technically operational, as of October 2026; approved projects are not counted.