GAC: Energy-Efficient Hybrid GPS-Accelerometer-Compass GSM Localization

TL;DR

This paper presents GAC, a hybrid localization system combining GPS, accelerometer, and compass sensors to significantly reduce energy consumption on smartphones while maintaining acceptable accuracy levels.

Contribution

The paper introduces a calibration-free, energy-efficient hybrid localization scheme that leverages internal sensors and infrequent GPS use, validated on Android phones.

Findings

Exponential energy savings with linear accuracy loss

Effective in highway and intra-city environments

Parameter tuning impacts energy-accuracy tradeoff

Abstract

Adding location to the available information enables a new category of applications. With the constrained battery on cell phones, energy-efficient localization becomes an important challenge. In this paper we introduce a low-energy calibration-free localization scheme based on the available internal sensors in many of today's phones. We start by energy profiling the different sensors that can be used for localization. Based on that, we propose GAC: a hybrid GPS/accelerometer/compass scheme that depends mainly on using the low-energy accelerometer and compass sensors and uses the GPS infrequently for synchronization. We implemented our system on Android-enabled cell phones and evaluated it in both highways and intra-city driving environments. Our results show that the proposed hybrid scheme has an exponential saving in energy, with a linear loss in accuracy compared to the GPS accuracy. We also evaluate the effect of the different parameters on the energy-accuracy tradeoff.