  Advances in Wireless Sensor Network Technology (WSN) have provided the
availability of small and low-cost sensor with capability of sensing various
types of physical and environmental conditions, data processing and wireless
communication. In WSN, the sensor nodes have a limited transmission range, and
their processing and storage capabilities as well as their energy resources are
limited. Triple Umpiring System (TUS) has already been proved its better
performance on Wireless Sensor Networks. Clustering technique provides an
effective way to prolong the lifetime of WSN. In this paper, we modified the Ad
hoc on demand Distance Vector Routing (AODV) by incorporating Signal to Noise
Ratio (SNR) based dynamic clustering. The proposed scheme Efficient and Secure
Routing Protocol for Wireless Sensor Networks through SNR based dynamic
Clustering mechanisms (ESRPSDC) can partition the nodes into clusters and
select the Cluster Head (CH) among the nodes based on the energy and Non
Cluster Head (NCH) nodes join with a specific CH based on SNR Values. Error
recovery has been implemented during Inter cluster routing itself in order to
avoid end-toend error recovery. Security has been achieved by isolating the
malicious nodes using sink based routing pattern analysis. Extensive
investigation studies using Global Mobile Simulator (GloMoSim) showed that this
Hybrid ESRP significantly improves the Energy efficiency and Packet Reception
Rate (PRR) compared to SNR unaware routing algorithms like Low Energy Aware
Adaptive Clustering Hierarchy (LEACH) and Power- Efficient Gathering in Sensor
Information Systems (PEGASIS).
