A transmission method for transmitting a fragment of an IP packet from a first node device to a third node device through a second node device. The first and second node devices are configured for communicating by powerline and by radio frequency. The second and third node devices can communicate only using a single communication medium from powerline and radio frequency. A first fragment sent by said first node device either by powerline or by radio frequency is received. An acknowledgement message is sent by to said first node device using a second communication medium selected from powerline and radio frequency so that it is different from said single medium. Then said first fragment is transmitted to said third node device using said single communication medium.

A transmission method for transmitting a packet from a first node device to a second node device of an electrical supply network, the transmission method includes the following steps performed by the first node device: transmitting the IP packet by radio frequency in the case where a level of use by the first node device of the transmission by radio frequency calculated on a sliding time window with respect to a maximum use time is below a first threshold, the first threshold being below a second threshold beyond which any transmission by radio frequency is interrupted; transmitting the IP packet by powerline otherwise, and, in the case where the powerline transmission fails, transmitting the IP packet by radio frequency in the case where the level of use is below the second threshold.