A Novel Approach Based Wireless Intrusion Detection System K.Suresh 1 , A.Sarala Devi 2 , Jammi Ashok 3 1,3 Dept. of CSE, 2 Dept. of IT Guru Nanak Institute of Technology ,Hyderabad Abstract-Intrusion detection in Wireless Sensor Network (WSN) is of practical interest in many applications such as detecting an intruder in a battlefield. The intrusion detection is a mechanism for a WSN to detect the existence of inappropriate, incorrect, or anomalous moving attackers. In this paper, we consider this issue according to heterogeneous WSN models. Furthermore, we consider two sensing detection models: single-sensing detection and multiple-sensing detection. Our simulation results show the advantage of multiple sensor heterogeneous WSNs. 1. INTRODUCTION A Wireless Sensor Network (WSN) is a collection of spatially deployed wireless sensors by which to monitor various changes of environmental conditions (e.g., forest fire, air pollutant concentration, and object moving) in a collaborative manner without relying on any underlying infra-structure support .Recently, a number of research efforts have been made to develop sensor hardware and network architectures in order to effectively deploy WSNs for a variety of applications. Due to a wide diversity of WSN application requirements, however, a general-purpose WSN design cannot fulfill the needs of all applications. Many network parameters such as sensing range, transmission range, and node density have to be carefully considered at the network design stage, according to specific applications. To achieve this, it is critical to capture the impacts of network parameters on network performance with respect to application specifications. Intrusion detection (i.e., object tracking) in a WSN can be regarded as a monitoring system for detecting the intruder that is invading the network domain. 1.1 PROBLEM DEFINITION The intrusion detection application concerns how fast the intruder can be detected by the WSN. If sensors are deployed with a high density so that the union of all sensing ranges covers the entire network area, the intruder can be immediately detected once it approaches the network area. However, such a high-density deployment policy increases the network investment and may be even unaffordable for a large area. In fact, it is not necessary to deploy so many sensors to cover the entire WSN area in many applications, since a network with small and scattered void areas will also be able to detect a moving intruder within a certain intrusion distance. In this case, the application can specify a required intrusion distance within which the intruder should be detected. Fig 1: Intrusion detection in WSN As shown in Fig. 1, the intrusion distance is referred as D and defined as the distance between the points the intruder enters the WSN, and the point the intruder is detected by the WSN system. This distance is of central interest to a WSN used for intrusion detection. In this paper, we derive the expected intrusion distance and evaluate the detection probability in different application scenarios. For example, given an expected detection distance EðDÞ, we can derive the node density with respect to sensors’ sensing range, thereby knowing the total number of sensors required for WSN deployment. In a WSN, there are two ways to detect an object (i.e., an intruder): single-sensing detection and multiple-sensing detection. In the single-sensing detection, the intruder can be successfully detected by a single sensor. On the contrary, in the multiple-sensing detection, the intruder can only be detected by multiple collaborating sensors .In some applications, the sensed information provided by a single sensor might be inadequate for recognizing the intruder. It is because individual sensors can only sense a portion of the intruder. For example, the location of an intruder can only be determined from at least three sensors’ sensing. In view of this, we analyze the intrusion detection problem under two application scenarios: single-sensing detection and multiple-sensing detection. According to the capability of sensors, we consider two network types: homogeneous and heterogeneous WSNs. We define the sensor capability in terms of the sensing range and the transmission range. In a heterogeneousWSN some sensors have a larger sensing range and more power to achieve a longer transmission range. In this paper, we show that the heterogeneous WSN increases the detection probability for a given intrusion detection distance. This motivates us to analyze the network connectivity in this paper. K. Suresh et al, / (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 3 (4) , 2012,4666 - 4669 4666