International Journal of Computer Networks (IJCN) Volume 2, Issue 4

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International Journal of
Computer Networks (IJCN)
Volume 2, Issue 4, 2010
Edited By
Computer Science Journals
www.cscjournals.org

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Editor in Chief Dr. Min Song
International Journal of Computer Network
(IJCN)
Book: 2010 Volume 2, Issue 4
Publishing Date: 30-10-2010
Proceedings
ISSN (Online): 1985-4129
This work is subjected to copyright. All rights are reserved whether the whole or
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Publishers. Violations are liable to prosecution under the copyright law.
IJCN Journal is a part of CSC Publishers
http://www.cscjournals.org
© IJCN Journal
Published in Malaysia
Typesetting: Camera-ready by author, data conversation by CSC Publishing
Services – CSC Journals, Malaysia
CSC Publishers

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Editorial Preface
The International Journal of Computer Networks (IJCN) is an effective
medium to interchange high quality theoretical and applied research in the
field of computer networks from theoretical research to application
development. This is the fourth issue of volume second of IJCN. The Journal
is published bi-monthly, with papers being peer reviewed to high
international standards. IJCN emphasizes on efficient and effective image
technologies, and provides a central for a deeper understanding in the
discipline by encouraging the quantitative comparison and performance
evaluation of the emerging components of computer networks. Some of the
important topics are ad-hoc wireless networks, congestion and flow control,
cooperative networks, delay tolerant networks, mobile satellite networks,
multicast and broadcast networks, multimedia networks, network
architectures and protocols etc.
IJCN give an opportunity to scientists, researchers, engineers and vendors to
share the ideas, identify problems, investigate relevant issues, share
common interests, explore new approaches, and initiate possible
collaborative research and system development. This journal is helpful for
the researchers and R&D engineers, scientists all those persons who are
involve in computer networks in any shape.
Highly professional scholars give their efforts, valuable time, expertise and
motivation to IJCN as Editorial board members. All submissions are evaluated
by the International Editorial Board. The International Editorial Board ensures
that significant developments in computer networks from around the world
are reflected in the IJCN publications.
IJCN editors understand that how much it is important for authors and
researchers to have their work published with a minimum delay after
submission of their papers. They also strongly believe that the direct
communication between the editors and authors are important for the
welfare, quality and wellbeing of the journal and its readers. Therefore, all
activities from paper submission to paper publication are controlled through
electronic systems that include electronic submission, editorial panel and
review system that ensures rapid decision with least delays in the publication
processes.
To build its international reputation, we are disseminating the publication
information through Google Books, Google Scholar, Directory of Open Access
Journals (DOAJ), Open J Gate, ScientificCommons, Docstoc and many more.
Our International Editors are working on establishing ISI listing and a good
impact factor for IJCN. We would like to remind you that the success of our
journal depends directly on the number of quality articles submitted for
review. Accordingly, we would like to request your participation by

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submitting quality manuscripts for review and encouraging your colleagues to
submit quality manuscripts for review. One of the great benefits we can
provide to our prospective authors is the mentoring nature of our review
process. IJCN provides authors with high quality, helpful reviews that are
shaped to assist authors in improving their manuscripts.
Editorial Board Members
International Journal of Computer Networks (IJCN)

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Editorial Board
Editor-in-Chief (EiC)
Dr. Min Song
Old Dominion University (United States of America)
Associate Editors (AEiCs)
Dr. Qun Li
The College of William and Mary (United States of America)
Dr. Sachin Shetty
Tennessee State University (United States of America)
Dr. Liran Ma
Michigan Technological University (United States of America)
[
Dr. Benyuan Liu
University of Massachusetts Lowell (United States of America)
Editorial Board Members (EBMs)
Dr. Wei Chen
Tennessee State University (United States of America)
Dr. Yu Cai
Michigan Technological University (United States of America)
Dr. Ravi Prakash Ramachandran
Rowan University (United States of America)
Dr. Bin Wu
University of Waterloo (Canada)
Dr. Jian Ren
Michigan State University (United States of America)
Dr. Guangming Song
Southeast University (China)
Dr. Tian-Xiao He
Illinois Wesleyan University (United States of America)
Dr. Jiang Li
Howard University (China)
Dr. Baek-Young Choi
University of Missouri – Kansas City (United States of America)
Dr. Fang Liu
University of Texas at Pan American (United States of America)
Dr. Lawrence Miller
The University of Toledo (United States of America)
Dr. Enyue Lu
Salisbury University (United States of America)
Dr. Chunsheng Xin
Norfolk State University (United States)
Associate Professor. Wenbin Jiang
Huazhong University of Science and Technology (China)

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Associate Professor. Xiuzhen Cheng
The George Washington University (United States)
Dr. Imad Jawhar
United Arab Emirates University (United Arab Emirates)
Associate Professor. Lawrence Yeung
The University of Hong Kong (Hong Kong)
Dr. Yong Cui
Tsinghua University (China)
Dr. Wei Cheng
The George Washington University (United States of America)
Dr. Filip Cuckov
Old Dominion University (United States of America)
Dr. Zhong Zhou
University of Connecticut (United States of America)
Dr. Mukaddim Pathan
CSIRO-Commonwealth Scientific and Industrial Research Organization (Australia)
Associate Professor. Cunqing Hua
Zhejiang University (China)

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Table of Content
Volume 2, Issue 4, October 2010
Pages
173 - 180
The Design of a Simulation for the Modeling and Analysis of Public
Transportation Systems as Opportunistic Networks
Rotimi Iziduh, Jamahrae Jackson, Howard Sueing, A. Nicki
Washington, Robert Rwebangira, Legand Burge
181 - 189
Queue Size Trade Off with Modulation in 802.15.4 for Wireless
Sensor Networks
Sukhvinder S Bamber, Ajay K Sharma
International Journal of Computer Network (IJCN) Volume (2): Issue (4)

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Iziduh, Jackson, Sueing, Washington, Rwebangira & Burge
The Design of a Simulation for the Modeling and Analysis of Public
Transportation Systems as Opportunistic Networks


Rotimi Iziduh




riziduh@howard.edu
Department of Systems and Computer Science
Howard University Washington,
DC 20059 USA

Jamahrae Jackson





j_m_jackson@howard.edu
Department of Systems and Computer Science
Howard University Washington,
DC 20059 USA

Howard Sueing






hsueing@howard.edu
Department of Systems and Computer Science
Howard University Washington,
DC 20059 USA

A. Nicki Washington




a_n_washington@howard.edu
Department of Systems and Computer Science
Howard University Washington,
DC 20059 USA

Robert Rwebangira





mugizi@howard.edu
Department of Systems and Computer Science
Howard University Washington,
DC 20059 USA

Legand Burge






lburge@howard.edu
Department of Systems and Computer Science
Howard University Washington,
DC 20059 USA


Abstract

Vehicular ad-hoc networks, when combined with wireless sensor networks, are used in
a variety of solutions for commercial, urban, and metropolitan areas, including
emergency response, traffic, and environmental monitoring. In this work, we model
buses in the Washington, DC Metropolitan Area Transit Authority (WMATA) as a
network of vehicular nodes equipped with wireless sensors. A simulation tool was
developed, to determine performance metrics such as end-to-end packet delivery delay.

Keywords: Opportunistic networks, Vehicular networks, Simulation, Network simulation



International Journal of Computer Networks (IJCN), Volume (2): Issue (4)
173

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Iziduh, Jackson, Sueing, Washington, Rwebangira & Burge
1. INTRODUCTION
Mobile ad hoc networks (MANET) have provided technological connectivity in areas where various
constraints, including environmental, financial, cultural, time, and government prohibited the
establishment of infrastructure-based networks. Nodes may be static or mobile, leading to a dynamic
network topology. Routing of data occurs as nodes relay information to each other. Traditional ad hoc
routing protocols assume the network is fully connected. In addition, the end-to-end source-destination
path is assumed to be known prior to transmission.

The need for increased connectivity extends from urbanized areas to remote and rural areas previously
unreachable via standard telecommunication networks. In either of these cases, the establishment or use
of an infrastructure-based network is not always feasible, due to various constraints, including time,
financial, cultural, government, and environmental. In addition, certain catastrophic events can render
infrastructure networks useless.

Opportunistic or disruption tolerant networks (DTN) are special types of MANETs where no end-to-end
path exists between source and destination nodes, due to a number of potential factors, including node
mobility, physical obstructions, etc. Packet transmission occurs in a store-and-forward fashion, where
nodes relay packets to neighboring nodes as they come in contact with each other, until the packet
ultimately reaches its destination. As a result, packets must endure longer delays.

Vehicular ad-hoc networks (VANETs) are a special type MANET where cars or buses are equipped with
devices that allow them to communicate with each other and any stationary equipment they may pass.
These vehicles, referred to as nodes, are restricted to movement on streets or designated paths. In a
major metropolitan area, public transportation systems can be utilized to provide opportunistic routing and
delivery of data via buses. When equipped with wireless sensors, these networks can be used for a
number of purposes, including health, environmental, habitat, and traffic monitoring, emergency
response, and disaster relief [4, 10, 11, 15, 16, 20, 22].

In this work, we develop a simulation tool for modeling and analyzing a DTN comprised of buses in a
public transportation system. Using real bus information and schedules, the simulation provides a realistic
model of the entire network. This tool can be used to study various routing protocols and network
performance metrics, such as end-to-end packet delay, packet copy distribution, and more. In addition,
we provide a web-based front-end, using the Google Maps API, that provides a user-friendly interface for
updating the network to account for a number of parameters and conditions, including inclement weather,
traffic congestion, and other adverse conditions.

We note that, while this work uses the Washington Metropolitan Area Transit Authority (WMATA) system,
the simulation can model any public transportation system that subscribes to the defined specification. It
is the ultimate goal that this simulation will be used not only to study the use of the public transportation
systems of cities for various societal and research purposes, but also to provide a means for any
organization or individual to utilize this tool to gather relevant data.

The remainder of this work is organized as follows. In section 2, we discuss related work on DTN
simulation models. In section 3, we present the network model. In section 4, we present the simulation
model and web-based front end. In section 5, we present numerical results and a snapshot of our
simulation application. In section 6, we conclude our findings.


2. RELATED WORK
Opportunistic or delay tolerant networks (DTN) have been suggested as a viable solution for a number of
non-traditional mobile ad-hoc networks. These include providing connectivity in rural or remote areas,
wildlife tracking and monitoring, and military battlefields, to name a few. A large majority of the work has
focused on the development and analysis of routing protocols to measure a number of performance
metrics, including end-to-end delay and packet copy distribution.
International Journal of Computer Networks (IJCN), Volume (2): Issue (4)
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