中文说明：无线传感器网络（wirelesssensornetworks，WSNs）是由成千上万个能量受限的传感器节点组成的协作网络
English Description：
Wireless Sensor Networks (WSNs) are comprised of thousands of sensor nodes, with restricted energy, that cooperate to accomplish a sensing task. Various routing Protocols are designed for transmission in WSNs. In this paper, we proposed a hybrid routing protocol: Zonal-Stable Election Protocol (Z-SEP) for heterogeneous WSNs. In this protocol, some nodes transmit data directly to base station while some use clustering technique to send data to base station as in SEP. We implemented Z-SEP and compared it with traditional Low Energy adaptive clustering hierarchy (LEACH) and SEP. Simulation results showed that Z-SEP enhanced the stability period and throughput than existing protocols like LEACH and SEP. KEYWORDS: Zonal, Stable, Election, Protocol, Wireless, Sensor, Networks.