Abstract: The important issue in the wireless sensor network is scalability and stability due to huge number of sensor node, their deployment and density. When the network size increases it become necessary that scalable and energy efficient routing is imperative. With static sink energy hole problem or hot spot is a major problem in WSN. The sensor nodes which are located near to the sink, act as relay for those of the nodes which are far apart from the sink. This causes the lifetime of the network reduced. In this paper mobile sink and heterogeneity of the nodes extends the stability period. Heterogeneous network model gives the three different energy levels of the sensor nodes. In this paper we propose to improve the stability period of the wireless sensor network by using mobile sink based energy efficient adaptive threshold clustering hierarchy algorithm. Here we use hybrid routing protocol APTEEN which gives overall snapshot of the network at periodic intervals and also react to time critical situations. The results obtained from the proposed algorithm have been compared with that obtained from MSIEEP protocol. It can be assessed from results that the proposed algorithm works better than MSIEEP. The simulation result is performed in MATLAB.

Keywords: Mobile sink, stability, energy efficient, Heterogeneous.