A two-levels hierarchy for low-energy adaptive clustering hierarchy (TL-LEACH)

Abstract

Wireless sensor networks with thousands of tiny sensor nodes are expected to find wide applicability and increasing deployment in coming years, as they enable reliable monitoring and analysis of the environment. In this paper we propose a modification to a well-known protocol for sensor networks called Low Energy Adaptive Clustering Hierarchy (LEACH). This last is designed for sensor networks where end- user wants to remotely monitor the environment. In such situation, the data from the individual nodes must be sent to a central base station, often located far from the sensor network, through which the end-user can access the data. In this context our contribution is represented by building a two-level hierarchy to realize a protocol that saves better the energy consumption. Our TL-LEACH uses random rotation of local cluster base stations (primary cluster-heads and secondary cluster-heads). In this way we build, where it is possible, a two-level hierarchy. This permits to better distribute the energy load among the sensors in the network especially when the density of network is higher. TL- LEACH uses localized coordination to enable scalability and robustness. We evaluated the performances of our protocol with NS-2 and we observed that our protocol outperforms the LEACH in terms of energy consumption and lifetime of the network.