Abstract: Clustering and multi-hop routing can improve the energy efficiency of wireless sensor networks (WSNs). However, when cluster heads transmit their data to a sink via multihop communication, nodes around the sink are burdened with heavy relay traffic and tend to die early, which results in the energy hole and network partition problems. This paper proposed an energy efficient unequal-clustering routing algorithm (UCRA) for WSNs, which consists of a weighted unequal-clustering algorithm (WUCA) and a multihop routing algorithm. WUCA takes into consideration the vote and transmission power of a sensor node when grouping the sensor nodes into unequal clusters. This paper designed the minimum energy consumption (MEC) multi-hop routing algorithm for intercluster communication. It exploits sensor nodes’ location information to determine an MEC routing path. The simulation results show that UCRA balances the energy consumption among sensor nodes and achieves a substantial improvement on the network lifetime.  

Key words: wireless sensor networks, unequal clustering, routing algorithm, energy efficiency