A time & energy efficient topology discovery and scheduling protocol for wireless sensor networks

TDMA-based MAC protocols are considered an energy efficient solution to prolong wireless sensor network lifetime. The topology learning and collection process, together with the used scheduling scheme, are essential parts in the design of such MAC protocols. Previous MAC and multihop scheduling protocols rely completely on CSMA to exchange topology scheduling information. However, for large or dense sensor networks, CSMA may lengthen the time it takes to reach a state in which enough information has been collected to build a highly conflict free multihop schedule. In addition, due to the nature of CSMA, collisions may occur during packet transmission. These factors cause energy waste in an environment where energy resources are scarce. In this paper, we propose PROGRESSIVE, a time and energy efficient topology discovery and multihop scheduling protocol that progressively schedules nodes as their topology information becomes available at the sink. The proposed protocol controls the time during which CSMA is used for control message transmission, and hence, energy consumption is reduced. Simulation results show that PROGRESSIVE is able to schedule a large number of nodes in less time and energy compared to DRAND.