A TDMA Algorithm for Dual-Hop Energy Harvesting Wireless Sensor Networks

In this paper, we propose a time division multiple access (TDMA) algorithm and system for a dual-hop energy harvesting wireless sensor network. We assume that the network is divided into clusters, where each cluster has a cluster head and cluster members. A cluster head collects data from its respective cluster members and then transmits the data in one packet to the base station. The proposed algorithm first synchronizes the network and then enables each node to transmit over its designated time slot. The proposed algorithm allows each node to synchronize not only based on a synchronization packet from the base station, but also based on a data packet from another node that is within its communication range. Moreover, the proposed algorithm synchronizes clusters individually, i.e., if a cluster becomes out-of-sync, the algorithm only synchronizes that cluster while allowing the remaining clusters to continue normal operation. The proposed algorithm works also for single-hop networks, and achieves network synchronization without the need for acknowledgment packets, which reduces the average energy consumption and average delay by approximately 1.36 and 1.46 times, respectively, compared to the most recent single-hop algorithm.