Cell towers in Montmorency (Val-d'Oise)

Place names on the register include 11 avenue Charles de Gaulle, 7 rue de la Poterne, 1 rue de Verdun / 12 rue Galliéni, 8 Avenue de la Fontaine Rene, 66 rue du Général de Gaulle and 5 Rue Henri Dunant.

ANFR has approved one new site that is not live yet, plus additions on 2 existing masts. New: SFR (4G and 5G, including 5G at 3.5 GHz) at 10 Bis Rue Saint Valery. 10 Bouygues Telecom 5G transmitters are listed as technically operational — installed, but not yet declared commercially in service.

2015 was the busiest year, with 16 new systems, most of them 4G. Bouygues Telecom switched on the first 5G here in November 2020; Free Mobile followed in April 2021, SFR followed in June 2021. The oldest transmitter still listed here goes back to 1998.

11 of the 11 masts are rooftop-mounted. The tallest support is 31 m at 14 rue Racine (building). The median is 21 m, slightly below the Val-d'Oise median of 25 m.

3.5 GHz 5G is declared by Bouygues Telecom on all 5 masts, Orange on 4 of its 5 masts, Free Mobile on 3 of its 4 masts and SFR on all 2 masts.

Nearby, Groslay (413 m to the south-east) has only 6 masts.

Of the 11 masts in the commune, Bouygues Telecom is the only carrier on 3 masts.

At 5 km² with 21,763 residents, the commune is dense enough that most antennas sit on rooftops rather than pylons. It is part of the CA Plaine Vallée intercommunal grouping.

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