Research On Typical Energy Efficient Coverage In Wireless Sensor Networks

Recent advances in wireless communication and hardware device have posed a bright blueprint for Wireless Sensor Network (WSN) applications. Sensing coverage is a fundamental problem in WSN. Many applications in WSN, such as forests fire monitoring, military detection and wildlife animal habitat protection, need to provide sensing coverage to a Region of Interest (Rol). However, the energy of sensor is limited, which constrains the quality of sensing coverage. Thus, it is very meaningful to study how to provide required sensing coverage energy efficiently so that the lifetime of network can be prolonged. In this paper, the two typical coverage scenarios in WSN, trap coverage and barrier coverage, are studied.Several basic applications of WSN are introduced in this paper. The results and challenges on sensing coverage are also introduced in this paper, especially on the newly emerging trap coverage and barrier coverage. As for the trap coverage, this paper proposes the minimum weight trap coverage problem based on disc sensing model and designs an effient algorithm for the problem. Localized protocol is also designed for implementation. The concept of trap coverage is also extended to probabilistic sensing model and probabilistic trap coverage is proposed. When the energy optimization problem in probabilistic trap coverage is analyzed, efficient scheduling protocol is designed for the maximum trap lifetime problem which prolongs the lifetime of network significantly. In terms of barrier coverage, this paper transforms the problem of finding the minimum detection probability when intruders cross a barrier of sensors into the minimum cut problem in graph theory. The minimum weight barrier problem is formulated and an approximation algorithm based on maximum network flow is proposed for the problem. The algorithm is proved to perform well in the worst case.Several efficient approximation algorithms and localized protocols are proposed on energy optimization and network lifetime maximization in barrier coverage and trap coverage in this paper. The bounds of approximation ratio of these algorithms are analyzed theoretically. The algorithms therefore can be applied in the sensing coverage of WSN. Simulations are conducted to validate their performances.