Method for detecting faults in a local area network by a fault detection device, the fault detection device being connected to the local area network by means of a wide area network, the local area network comprising a device for conditioning and processing data (41a, 41b), the method comprises the steps of: - obtaining, by the data conditioning and processing device, from the fault detection device, a data-processing reference frame describing the connections between the stations and the nodes and data describing the connections between nodes of the local area network, a station being a fixed or mobile item of equipment using the resources of the local area network via the nodes of said local area network, and a node being an item of equipment offering connectivity capabilities and constituting part of the local area network, - demanding the collection of the data and aggregating into groups of data, by the data conditioning and processing device, the data describing the connections between the stations and the nodes and the data describing the connections between the nodes, the data-processing reference frame comprising information indicating that the data must be aggregated, - calculating, by the data conditioning and processing device, a severity score for each group of data and for each type of anomaly and calculating a total severity score for each group of data from the severity scores calculated for the group of data if the data-processing reference frame comprises information indicating that the severity scores must be calculated, a group of data comprising, during a period of use of one and the same frequency band, of one and the same channel and of one and the same communication protocol used, the data obtained for the frequency band, the channel and the communication protocol used, an anomaly type being a radio coverage type or a noise level type or a channel change type or a node change type, - transferring, by the data conditioning and processing device, collected data or aggregated data or severity scores in accordance with the processing reference frame to the fault detection device for generating recommendation messages or corrective actions. - obtaining, by the data conditioning and processing device, from the fault detection device, a data-processing reference frame describing the connections between the stations and the nodes and data describing the connections between nodes of the local area network, a station being a fixed or mobile item of equipment using the resources of the local area network via the nodes of said local area network, and a node being an item of equipment offering connectivity capabilities and constituting part of the local area network, - demanding the collection of the data and aggregating into groups of data, by the data conditioning and processing device, the data describing the connections between the stations and the nodes and the data describing the connections between the nodes, the data-processing reference frame comprising information indicating that the data must be aggregated, - calculating, by the data conditioning and processing device, a severity score for each group of data and for each type of anomaly and calculating a total severity score for each group of data from the severity scores calculated for the group of data if the data-processing reference frame comprises information indicating that the severity scores must be calculated, a group of data comprising, during a period of use of one and the same frequency band, of one and the same channel and of one and the same communication protocol used, the data obtained for the frequency band, the channel and the communication protocol used, an anomaly type being a radio coverage type or a noise level type or a channel change type or a node change type, - transferring, by the data conditioning and processing device, collected data or aggregated data or severity scores in accordance with the processing reference frame to the fault detection device for generating recommendation messages or corrective actions.