Summary

  • Arcep's 2026 mobile survey included the first territory-by-territory reliability check of newer graded 4G coverage maps in Guadeloupe, Martinique, French Guiana, Saint-Barthélemy and Saint-Martin.
  • The regulator says the field check sometimes led operators to correct their maps locally. Its release gives neither the patches nor a count of corrections.

A coverage map is a promise drawn before the customer drives the road. Arcep has now taken new graded 4G maps across the French Antilles and Guiana out to meet the road. Its 22 October results say the regulator checked the reliability of operator-supplied maps at each territory's scale and that the checks sometimes led to local corrections. The cheerful block of colour on a screen had to answer to measurements on the ground.

The wider May-to-July campaign made more than 465,000 mobile-service measurements in Guadeloupe, Martinique, French Guiana, Saint-Barthélemy and Saint-Martin. It tested calls, SMS and internet uses, including page loads, video and speeds. Map verification was one component of that work. Arcep does not state how many of the overall measurements fed the map check, or which particular areas were repainted. The interesting fact is the correction loop itself: a simulated coverage claim was checked against service observed in the field, and the public-facing claim changed in places.

These maps are made by operators through digital simulation. Arcep's explanation of its mapping tool describes four grades of mobile-internet coverage, from none to very good, alongside a separate layer of measured service quality. A theoretical map answers where a network is expected to work; a field test answers what a handset could actually do at tested points. One colour cannot settle both questions. That is why a local correction matters more than a prettier legend.

The original Arcep release also says the 2026 test devices could use 2G, 3G, 4G or 5G, with 5G measurement expanding to Guadeloupe and Martinique. That describes the service survey; the newly audited maps concern graded 4G mobile internet. Readers choosing a service, councils planning around coverage and anyone trying to understand a stubborn blank spot all need the map to say what the ground supports.

Arcep has published the survey results and the data through its public map and open-data links. The next useful disclosure is a record of the corrected 4G areas and how field evidence changed their grades. Until that map history is visible, the regulator's announcement establishes the mechanism and its local effect, not a count of errors.

Sources