Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Electrical Engineering and Computer Science

First Advisor

Myounggyu Won


A traffic monitoring system (TMS) is an integral part of Intelligent Transportation Systems (ITS) for traffic analysis and planning. However, covering huge miles of rural highways (119,247 miles in U.S.) with a large number of TMSs is a very challenging problem due to the cost issue. This paper aims to address the problem by developing a low-cost and portable TMS called DeepWiTraffic based on COTs WiFi devices. The proposed system enables accurate vehicle detection (counting) and classification by exploiting the unique WiFi Channel State Information (CSI) of passing vehicles. Spatial and temporal correlations of CSI amplitude and phase data are identified and analyzed using a deep learning technique to classify a vehicle into five different types: motorcycle, passenger vehicle, SUV, pickup truck, and large truck (a vehicle with more than three axles according to the FHWA classification). The principal component analysis (PCA) technique is exploited to reduce the dimension of the subcarriers and remove the device specific noise. The CSI phase data of a received signal are preprocessed by applying a linear transformation and the correlations of CSI phase information of multiple subcarriers are taken into account for effective vehicle classification. A convolutional neural network (CNN) is designed to extract optimal features of the preprocessed CSI amplitude and phase data. A huge amount of CSI data of passing vehicles as well as ground truth video data are collected for about 120 hours to validate the performance of the proposed proof-of-concept system. The results show that the average detection accuracy of 99.4%, and the average classification accuracy of 91.1% (Motorcycle: 97.2%, Passenger Car: 91.1%, SUV: 83.8%, Pickup Truck: 83.3%, and Large Truck: 99.7%) can be achieved with a very small cost of less than $1,000.

Library of Congress Subject Headings

Traffic monitoring.
Vehicle detectors.
Wireless communication systems.


Includes bibliographical references



Number of Pages



South Dakota State University



Rights Statement

In Copyright