This paper proposes LeSS-TDMA, a novel approach for scheduling TDMA activity in a sensor network, where nodes create their own schedules by learning from previous activity. The protocol uses routing information to establish a schedule appropriate for periodical data gathering, which is the main traffic type in sensor networks. The schedule is determined by examining patterns that arise from data being sent in an incipient CSMA/CA, RTS/CTS phase. No extra control packets are needed, as is the case with existing TDMA solutions, so the power consumption is reduced. Tests show a high data throughput and fast schedule establishment, in tree-like topologies with relatively small neighborhoods. © 2008 IEEE.