Cell towers in Le Thillay (Val-d'Oise)

Masts stand at Les Grands Champs, Les Glirettes, avenue des Violettes, Avenue des Violettes Bp42, Chemin de Saint-Denis and 29 rue Louis de Broglie.

Systems from 1999 are still on the register. Bouygues Telecom opened 5G here in November 2020; Free Mobile followed in December 2020, SFR followed in November 2021. 2020 was the busiest year, with 12 new systems, most of them 4G.

Approved additions not yet in service are pending on one existing mast, for example SFR (5G 2100 MHz). 5 Bouygues Telecom 5G transmitters are listed as technically operational — installed, but not yet declared commercially in service.

ANFR lists a 35 m pylon at Avenue des Violettes Bp42 as the tallest structure. The median height of measured supports is 25 m.

Among the 43 Val-d'Oise towns with at least five masts, Le Thillay ranks 32nd by mast count. With 8 masts for 4,560 residents, or 18 per 10,000, it has more masts per inhabitant than the median for those towns (6).

On 3.5 GHz, the fastest 5G band: SFR on all 3 masts, Bouygues Telecom on 2 of its 3 masts, Orange on all 2 masts and Free Mobile on its only mast.

3.3 km to the east, neighbouring Roissy-en-France has 18 masts, more than here.

4,560 residents over 4 km²: supports are mostly pylons, not rooftops.

Supports split between 7 pylons and 1 building.

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