method and device for time synchronization in a TDMA multi-hop wireless network

The invention concerns a method for synchronizing clocks of a set of nodes in a TDMA ("Time Division Multiple Access") communication network comprising a plurality of nodes, among which some called time reference (TR) nodes are synchronized to a common time reference through a predetermined out-of-band synchronization mechanism, other nodes being called non-TR nodes, each node comprising an internal clock, characterized in that it comprises the steps of: • transmitting, at the level of at least one of said TR nodes, a broadcast beacon packet during a given time slot of sub-frames, each sub-frame comprising a plurality of time slots ; • propagating among the remaining nodes said beacon packet using the slotted structure of the TDMA protocol, each node being pre-assigned a conflict-free time slot in a sub-frame to broadcast said beacon packet received from another node in a previous slot of said sub-frame; and • updating in at least two of said non-TR nodes the internal clock based on an updated offset estimate, upon reception of said beacon packet. The invention also concerns a communication device in a TDMA communication network.