A system that includes a powerline communication network with a reactive routing protocol and at least one gateway comprising a powerline communication interface and one radio-frequency communication interface. A smart electricity meter also includes a powerline communication interface and at least one radio-frequency communication interface: broadcasts an announcement request message on each of its communication interfaces; after reception of one or more announcement messages, selects a relay agent having the lowest route cost for joining a centralised management device; and making a registration request, using the selected relay agent as a proxy. After registration, the routing of messages coming from or going to said smart electricity meter takes place at the data link layer of the OSI model.