Energy-aware Routing in Internet of Things (IoT)

In contrast to wireless sensor networks (WSN), Internet of things (IoT) applications are supported by global IP connectivity and two-way data communication between low power wireless sensor nodes of lossy area networks. The Internet Engineering Task Force (IETF) has proposed the routing protocol for low power and lossy area networks (RPL). The RPL constructs a destination oriented directed acyclic graph (DODAG) that is grounded at the root node. The DODAG is constructed by using an objective function (OF) to compute the rank of each sensor node. The IETF has proposed two objective functions that are OF0 and MRHOF. Subsequently, with the help of the rank of nodes, a parent-child relationship is established between nodes to construct the DODAG. In this paper, we have proposed an OF named `EEQ' that protects the node which has already excessively consumed its energy for forwarding sensed data towards the root node. The EEQ computes the rank of a node using three energy related parameters: i) expected number of transmissions, ii) consumed energy, and iii) active queue length. Under low and high intensity traffic loads, we have simulated various scenarios for OF0, MRHOF, and EEQ. The simulation results show that for high intensity traffic, EEQ has less overhead of control messages as compared to OF0 and MRHOF, resulting in energy conservation.