Energy Savvy Network Joining Strategies for Energy Harvesting Powered TSCH Nodes

Abstract

This article presents methods that enable batteryless energy harvesting powered time-synchronized channel hopping (TSCH) wireless sensor nodes to join a network with less energy wastage. Network joining of TSCH nodes is very power hungry yet inevitable process to form a working wireless sensor network (WSN). Since the energy level from energy harvesting is scarce, energy passive methods are essential. A duty-cycled network joining process in combination with an appropriate capacitor size is proposed here as they are among the factors that can be easily controlled without extra energy. When a node joins the network in a duty-cycled manner, other nodes may join the network during the gap time, which reduces energy wastage of the nodes in waiting. With an appropriate capacitor size, the capacitor can be charged up within a reasonable time and power up the node for a sufficiently long time, which increases the probability to complete the network joining process of the node. With the combination of a join duty cycle of 50% with a 100-mF capacitor, a WSN was successfully formed by two energy harvesting powered wireless sensor nodes in one network joining attempt.