The radio duty cycle (RDC) of wireless sensor nodes can be considered as a crucial factor that determines the wireless sensor network (WSN) lifetime and its service availability. Clustering would be a preferable solution to minimize node radio duty cycle by electing multiple cluster heads (CHs) around the network to schedule node transmissions and collect readings. This paper presents a mesh-under cluster-based routing (MUCBR) protocol that will divide the sensor network into multiple clusters and perform the routing function within the IEEE 802.15.4 platform. MUCBR is implemented via the Contiki operating system (OS). It reschedules the structure of the 802.15.4 standard in order to reduce the RDC of the sensor nodes and minimize the number of collisions. The election of the CHs is density-aware and determined by the routing direction inside the network which in turn reduces the number of hops and minimizes the number of collisions caused by the existence of multiple CHs in a single area. The proposed MUCBR manages to achieve a RDC of 0.08% for non-CH nodes and 1.3% for CH nodes while reducing the impact of collision by 40% as compared to the 802.15.4 standard
