A joint optimization of data ferry trajectories and communication powers of ground sensors for long-term environmental monitoring

Recently, various hybrid wireless sensor networks which consist of several robotic vehicles and a number of static ground sensors have been investigated. In this kind of system, the main role of the mobile nodes is to deliver the messages produced by the sensor nodes, and naturally their trajectory control becomes a significant issue closely related to the performance of the entire system. Previously, several communication power control strategies such as topology control are investigated to improve energy-efficiency of wireless sensor networks. However, to the best of our knowledge, no communication power control strategy has been investigated in the context of the hybrid wireless sensor networks. This paper introduces a new strategy to utilize the communication power control in multiple data ferry assisted wireless sensor network for long-term environmental monitoring such that the lifetime of the sensor network is maximized. We formally define the problem of our interest and show it is NP-hard. We further prove there exists no approxiDonghyun Kim Division of Algorithms and Technologies for Networks Analysis, Faculty of Information Technology, Ton Duc Thang University, Ho Chi Minh City, Vietnam. Department of Math. and Physics, North Carolina Central Univ., Durham, NC 27707, USA. E-mail: [email protected], [email protected] Wei Wang ( ) School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, China. E-mail: wang [email protected] Deying Li School of Information, Renmin University of China, Beijing, P.R. China. E-mail: [email protected] Joong-Lyul Lee, Weili Wu Dept. of Computer Science, University of Texas at Dallas, Richardson, USA. E-mail: [email protected], [email protected] Alade O. Tokuta Dept. of Mathematics and Physics, North Carolina Central University, Durham, USA. E-mail: [email protected]