Unequal-radius clustering in WSN-based IoT networks: energy optimization and load balancing in UDCOPA protocol

The internet of things (IoT) is an exponentially growing network of physical objects equipped with sensors, software and network connectivities to collect, process, transmit and receive data. Wireless sensor networks (WSNs) play an essential role in supporting the IoT. These networks, made up of nodes with the ability to monitor their environment, enable the collection and transmission of specific data in real time, offering enhanced applications and services within IoT networks. This symbiosis between WSN and IoT can be defined as WSN-based IoT. The complexity of WSN-based IoT lies in the effective management of these varied devices, each with its own distinct capabilities. Clustering is a popular technique for reducing the communication load, conserving energy, aggregating data and optimizing the performance of WSN-based IoT systems. Once the cluster heads (CHs) are chosen, conventional clustering algorithms typically use a single radius of clustering (RC) to group devices into multiple clusters. However, this approach may not be optimized for WSN-based IoT networks, as devices may have different features, for example, the residual energy ( \(R_{\rm Enrg}\) $R_{\mathrm{Enrg}}$ ) and the distance to the base station (DistBS). In a previous work, we proposed the DCOPA (a distributed clustering based on objects performances aggregation for hierarchical communications in IoT applications) protocol for clustering in WSN-based IoT networks. DCOPA applies the same clustering algorithm to the elected CHs, without considering their distinctions in terms of \(R_{\rm Enrg}\) $R_{\mathrm{Enrg}}$ and DistBS. The proposed new approach, called unequal-DCOPA (UDCOPA), allows us to define for each CH its adaptive radius of clustering (ARC) which will be sensitive to the local criteria of \(R_{\rm Enrg}\) $R_{\mathrm{Enrg}}$ and DistBS of the CH concerned. The ARC is modeled as a multicriteria system applied to each CH. Simulation results show that our new UDCOPA approach outperforms DCOPA and LEACH protocols for energy management, load balancing, scalability and network lifetime. UDCOPA increases lifetime by (62.61%) over LEACH and by (32.72%) over DCOPA.