LEAP: A Low Energy Assisted GPS for Trajectory-Based Services

Heitor S. Ramos, Tao Zhang, Jie Liu, Bodhi Priyantha, and Aman Kansal


Trajectory-based services require continuous user location

sensing. GPS is the most common outdoor location sensor

on mobile devices. However, the high energy consumption

of GPS sensing prohibits it to be used continuously in many

applications. In this paper, we propose a Low Energy Assisted

Positioning (LEAP) solution that carefully partitions

the GPS signal processing pipeline and shifts delay tolerant

position calculations to the cloud. The GPS receiver only

needs to be on for less than a second to collect the submillisecond

level propagation delay for each satellites signal.

With a reference to a nearby object, such as a cell tower, the

LEAP server can infer the rest of the information necessary

to perform GPS position calculation. We analyze the accuracy

and energy benefit of LEAP and use real user traces to

show that LEAP can save up to 80% GPS energy consumption

in typical trajectory-based service scenarios.


Publication typeInproceedings
Published in13th ACM International Conference on Ubiquitous Computing (UbiComp)
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