skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Search for: All records

Creators/Authors contains: "Ashraf, Khadija"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Sensing and communication technology has been used successfully in various event monitoring applications over the last two decades, especially in places where long-term manual monitoring is infeasible. However, the major applicability of this technology was mostly limited to terrestrial environments. On the other hand, underwater wireless sensor networks (UWSNs) opens a new space for the remote monitoring of underwater species and faunas, along with communicating with underwater vehicles, submarines, and so on. However, as opposed to terrestrial radio communication, underwater environment brings new challenges for reliable communication due to the high conductivity of the aqueous medium which leads to major signal absorption. In this paper, we provide a detailed technical overview of different underwater communication technologies, namely acoustic, magnetic, and visual light, along with their potentials and challenges in submarine environments. Detailed comparison among these technologies have also been laid out along with their pros and cons using real experimental results. 
    more » « less
  2. The increasing use of light emitting diodes (LED) and light receptors such as photodiodes and cameras in vehicles motivates the use of visible light communication (VLC) for inter–vehicular networking. However, the mobility of the vehicles presents a fundamental impediment for high throughput and link sustenance in vehicular VLC. While prior work has explored vehicular VLC system design, yet, there is no clear understanding on the amount of motion of vehicles in real world vehicular VLC use–case scenarios. To address this knowledge gap, in this paper, we present a mobility characterization study through extensive experiments in real world driving scenarios. We characterize motion using a constantly illuminated transmitter on a lead vehicle and a multi–camera setup on a following vehicle. The observations from our experiments reveal key insights on the degree of relative motion of a vehicle along its spatial axis and different vehicular motion behaviors. The motion characterization from this work lays a stepping stone to addressing mobility in vehicular VLC. 
    more » « less