Nodes in wireless sensor networks (WSNs) are battery powered and oftentimes deployed in remote and hostile locations. Energy conservation is, therefore, one of the primary goals of MAC protocols designed for these networks. Contention-based protocols employ static or variable duty cycles to minimize energy dissipated in idle listening. TDMA-based protocols, on the other hand, use reservation and scheduling to minimize energy loss. Further energy savings may be obtained by taking the nature of the network traffic into consideration. Several WSN applications such as surveillance applications and habitat monitoring applications generate bursty traffic. In this paper, we combine the advantages of contention-based and TDMA-based protocols to form Advertisement-based Time-division Multiple Access (ATMA), a distributed TDMA-based MAC protocol for WSNs, that utilizes the bursty nature of the traffic to prevent energy waste through advertisements and reservations for data slots. We provide detailed comparisons of the ATMA protocol with contention-based protocols (S-MAC, T-MAC and ADV-MAC), a TDMA-based protocol (TRAMA) and hybrid protocols (Z-MAC and IEEE 802.15.4) through extensive simulations and qualitative analysis. The simulation results show that with bursty traffic, ATMA outperforms these existing protocols in terms of energy consumption with reductions of up to 80%, while providing the best packet delivery ratio (close to 100%) and latency among all the investigated protocols for several simulation scenarios studied.

Peer Reviewed