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Journal of Computer Networks and Communications
Volume 2013, Article ID 136213, 13 pages
Research Article

ECOPS: Energy-Efficient Collaborative Opportunistic Positioning for Heterogeneous Mobile Devices

1University of Missouri-Kansas City, 546 Flarsheim Hall, 5110 Rockhill Road, Kansas City, MO 64110, USA
2Texas A&M University, Fermier Hall 008, 3367 TAMU, College Station, TX 77843, USA

Received 16 June 2012; Revised 12 October 2012; Accepted 19 November 2012

Academic Editor: Lingjia Liu

Copyright © 2013 Kaustubh Dhondge et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The fast growing popularity of smartphones and tablets enables us to use various intelligent mobile applications. As many of those applications require position information, smart mobile devices provide positioning methods such as Global Positioning System (GPS), WiFi-based positioning system (WPS), or Cell-ID-based positioning service. However, those positioning methods have different characteristics of energy-efficiency, accuracy, and service availability. In this paper, we present an Energy-Efficient Collaborative and Opportunistic Positioning System (ECOPS) for heterogeneous mobile devices. ECOPS facilitates a collaborative environment where many mobile devices can opportunistically receive position information over energy-efficient and prevalent WiFi, broadcasted from a few other devices in the communication range. The position-broadcasting devices in ECOPS have sufficient battery power and up-to-date location information obtained from accurate but energy-inefficient GPS. A position receiver in ECOPS estimates its location using a combination of methods including received signal strength indicators and 2D trilateration. Our field experiments show that ECOPS significantly reduces the total energy consumption of devices while achieving an acceptable level of location accuracy. ECOPS can be especially useful for unique resource scarce, infrastructureless, and mission critical scenarios such as battlefields, border patrol, mountaineering expeditions, and disaster area assistance.