The numbers of smartphone users is expected to be 2 billion around the globe by 2016 according to new figure e-Marketer, there is a great need of efficient location tracking system. At the same time the privacy of the users is a prime concern for security. The traditional global positioning system is not able to efficiently track the indoor location of users. This paper is comprehensive survey of various localization techniques and proposes a combined approach of GPS, cellular tower triangulation, Activity recognition, Wi-Fi and Harversine Formula to track the user's location.

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Activity Recognition Cellular Tower Triangulation Mobile Sensors