Improving QoS in query-driven WSN using a cross-layered handover algorithm

Quality of Service (QoS) provisioning in Wireless Sensor Networks (WSNs) presents an open research issue within the scientific community because the rapid development of microelectronics proliferates new applications for WSNs. These applications often require a connection of end-to-end delay and high reliability for various communication models. Within this scope, a special class of WSNs are query driven WSNs where each node sends a query to the network sink, which expects a response to the query. As the application of query driven WSNs becomes versatile, the need to establish QoS support becomes intensely expressed, particularly for medium and high traffic loads. An experimental validation for query-based communication in a star configuration topology for various numbers of nodes and packet generation interval is performed within this paper. In existing WSNs, the QoS deteriorates upon increased traffic load due to congestion and the shared medium. This paper proposes a cross-layered handover algorithm in order to improve deteriorated performance and the QoS by means of multi-channel redundancy. Measurement results show that the proposed algorithm improves the delivery ratio by 25% and the RTT by 40% in the worst-case scenario. However, it underperforms upon the heavy traffic load where the trade-off is shown accordingly.