Shortest Path Priority-based RPL (SPPB-RPL): The Case of a Smart Campus

Wireless Sensor Networks (WSN) is the network of embedded and resource-constrained nodes, that forms the foundation of the Internet of Things (IoT). These networks are designed to sense, aggregate and transport sensed data to locations that may be local or remote to the sensory field, for immediate or stored for later use. In most cases, WSN generates heterogeneous data that conveys information of varying priorities which may be real-time (RT) or non-real-time (NRT). However, the de facto routing protocol; Routing Protocol for Low-power and Lossy Networks (RPL) is not optimized for heterogeneous data routing. Likewise, routing schemes proposed in the literature have not proffered a lasting solution. In this paper, we proposed the Shortest Path Priority-based RPL (SPPB-RPL). The SPPB-RPL scheme not only routes data with varying priorities but also does so with optimal network performances. Its application in a smart campus is used as a case study. The scheme uses the mechanism of class of service (CS) to classify and prioritized data into various priority classes. Subsequently, the standard RPL DIO base object was improved upon to accommodate the prioritized data classes, and finally, the Dijkstra Algorithm (DA) was adopted to generate the optimal shortest routing path leading to the destination node which is guided by the priority of the data. Benchmarked with related schemes, SPPB-RPL performed optimally with a 99.98% packet delivery ratio with the least latency. This enhanced the network performance for a prolonged operational lifetime.