# Crescendo: An Infrastructure-free Ubiquitous Cellular Network-based Localization System

## TL;DR

Crescendo is a novel, infrastructure-free outdoor localization system that uses cellular network data and computational geometry to achieve median accuracies of around 150-220 meters, outperforming classical methods.

## Contribution

It introduces a calibration-free, infrastructure-free cellular localization approach leveraging Voronoi diagrams and pairwise site comparisons.

## Key findings

- Median accuracy of 152m in urban areas
- Median accuracy of 224m in rural areas
- Improves classical techniques by at least 15-18%

## Abstract

A ubiquitous outdoor localization system that is easy to deploy and works equally well for all mobile devices is highly-desirable. The GPS, despite its high accuracy, cannot be reliably used for this purpose since it is not available on low-end phones nor in areas with low satellite coverage. The application of classical fingerprinting approaches, on the other hand, is prohibited by excessive maintenance and deployment costs. In this paper, we propose Crescendo, a cellular network-based outdoor localization system that does not require calibration or infrastructure support. Crescendo builds on techniques borrowed from computational geometry to estimate the user's location. Specifically, given the network cells heard by the mobile device it leverages the Voronoi diagram of the network sites to provide an initial ambiguity area and incrementally reduces this area by leveraging pairwise site comparisons and visible cell information. Evaluation of Crescendo in both an urban and a rural area using real data shows median accuracies of 152m and 224m, respectively. This is an improvement over classical techniques by at least 18% and 15%, respectively.