Enabling Multi-Hop Communications through Cross-Layer Design for Hybrid WSNs with Transmit-Only Nodes

Simple yet cost effective hybrid Wireless Sensor Networks (WSN) with both standard nodes and transmit-only nodes are promising for their great potential as the "edge" of the "Internet of Things". However the lack of receivers at many transmit-only nodes in the hybrid network renders most existing MAC protocols invalid. Our previous efforts showed the benefits of this hybrid architecture for building single-hop efficient and reliable hybrid WSN cluster for QoS aware applications. This work explores the capability of building multi-hop communications in a hybrid WSN with multiple clusters (where each cluster consists of a sink as well as a certain number of standard nodes and transmit-only nodes) via a cross-layer protocol design. The proposed M-QoMoR protocol and HPAssist scheme are built based on the resource information from the underlying MAC layer. Through the analysis and extensive simulations, we showed that the hybrid WSN architecture can efficiently support multi-hop communications across multiple hybrid clusters. It also achieves certain performance boost that is not viable in the previous single hybrid WSN clusters.