Cell towers in Osny (Val-d'Oise)

Declared supports include 1 water tower, with buildings making up most of the remainder.

Declared locations include rue de la Raviniere, Stade Municipal Christian Leon, Chaussée Jules César, 126 Chaussée Jules César, Rue du Petit Albi (bassin de Retention) and Cd 195 - Auchan.

2021 was the busiest year, with 36 new systems, most of them 5G. Free Mobile opened 5G here in December 2020; Bouygues Telecom followed in June 2021, SFR followed in December 2021. The oldest transmitter still listed here goes back to 1994.

11 systems were switched on in the past 12 months. Approved additions not yet in service are pending on 2 existing masts, for example Orange (4G 700 MHz) at Ccal de l Oseraie and SFR (5G 2100 MHz) at Chaussée Jules César. 13 Bouygues Telecom 5G transmitters are listed as technically operational — installed, but not yet declared commercially in service.

The tallest structure is a 56 m water tower at Chaussée Jules César. The median height of measured supports is 24 m.

3.5 GHz 5G is declared by Bouygues Telecom on 6 of its 8 masts, Orange on all 5 masts, SFR on all 5 masts and Free Mobile on 4 of its 5 masts.

3.9 km to the south, neighbouring Cergy has 44 masts, more than here.

Of the 15 masts in the commune, 7 of the 15 masts host at least two operators.

Most declared azimuths point outward, along a corridor or valley rather than at the centre.

By mast count, Osny is 15th of the 43 Val-d'Oise towns that have five or more. With 15 masts for 17,954 residents, or 8 per 10,000, it has more masts per inhabitant than the median for those towns (6).

Source: operator declarations to ANFR, as of October 2026. Projects that are only approved are left out of the totals.