A Random Priority based Scheduling Strategy for Wireless Sensor Networks using Contiki

In recent years, wireless sensor networks (WSNs) have experienced a number of implementations in various implementations which include smart home networks, smart grids, smart medical monitoring, telemetry networks and many more. The Contiki operating system for wireless sensor networks which utilises carrier sense multiple access with collision avoidance (CSMA/CA) does not provide differentiated services to data of different priorities and treats all data with equal priority. Many sensor nodes in a network are responsible not only for sending their sensed data, but also forwarding data from other nodes to the destination. In this paper we propose a novel priority data differentiation medium access control (MAC) strategy to provide differentiated services called Random Weighted Scheduling (RWS). The strategy was implemented and tested on the FIT IoT-lab testbed. The strategy shows a reduction in packet loss compared to the default CSMA/CA scheduling strategy in IEEE802.15.4 WSNs when carrying data of different priority levels.