A Novel Economic Barrier Coverage using wireless networks

Wireless sensor networks are networks that consist of a large number of nodes that communicate using a wireless medium. Sensors may be attached to nodes to measure properties of the environment. One of the fundamental research issues in WSNs is barriercoverage. Barrier coverage aims at detecting intruders that attempt to cross the monitored region. It requires a chain of sensors with overlapping sensing areas. Each independent chainof sensors is called a barrier and acts as a trip-wire to detect intruders. Barrier coverage has a great importance in military and homeland security applications however the high cost of both nodes and sensors limits its practical usage.The main goal of this research is to present a novel economic technique for building barrier coverage systems using wireless networks. The system is deployed without sensors to reduce the cost. The proposed system depends on the phenomenon of radio irregularity that witnesses changes in the presence of a human in the network. This change could be measured from the communication channel characteristics, such as Received Signal Strength Indicator (RSSI) and Link Quality Indication (LQI) which are affected by radio irregularity. The basicidea of the protocol is to measure the change in channel characteristics at each node, when receiving data from its neighbors, due to intruder’s movement. An exploration period is applied without intruders in the system then when an intruder passes the change is recorded.Some practical experiments were made in real outdoor fields to test the proposed protocol.The proposed system is then compared to a real system with actual sensors. Thecomparison showed that the proposed technique will require less or same number of nodes to cover the same area. Also the system will use slightly less energy than the actual sensors system.Finally, a simulation program was developed to model the network and determine the number of barriers that could be formed from a given nodes distribution. The idea behind theprogram is to use the maximum flow in graph theory to determine the barriers in the network.This program is also needed in the proposed protocol to determine nodes neighbors’ in the barrier.Keywords: Wireless sensor network, barrier coverage, intrusion detection, RSSI, energy consumption.