A method for synchronising a first gateway of a LoRa network, intended to enable the first gateway to function according to the class B communication mode of the LoRaWAN protocol. The method relies on at least one reception of a synchronisation frame by the first gateway, each synchronisation frame having been transmitted by a second class B gateway in the LoRa network, equipped with synchronisation means and designated by a server. The first gateway uses an instant of reception of each synchronisation frame that it receives in order to synchronise beacon transmissions used in the implementation of the class B communication mode with beacon transmissions made by other class B gateways in the LoRa network.