Overview:
Research
effort has been put forth to develop OPNET simulation modules and to test out
proposed network protocols. Below are descriptions of three projects carried
out in 2004. The first two projects were conducted by Computer Engineering
students. The last one was a collaborative effort with Prof. Nirmala Shenoy and
a Computer Science student, and conducted in the Center for Advancing the Study
of CyberInfrastructure - CASCI
(previously known as Laboratory of Applied Computing).
In addition to
research projects, the Computer Engineering Department in RIT has been using
OPNET as its primary network simulation tool in the classroom setting. At its
current stage, the course EECC 694 Introduction to Data and Communication
Networks (which is required for BS and BS/MS students) taught by Dr. Shanchieh Jay Yang
includes Laboratory 00, 01, and 02
from the text “Computer Networks: A systems approach,” by L. Peterson and B. Davie (Morgan Kaufman, 3rd edition,
2003).
Modular Topology Control and Energy Model for Wireless Ad Hoc
Sensor Networks
Niranjan Krishnamurthi (nxk5767@rit.edu),
Shanchieh Jay Yang, (Jay.Yang@rit.edu)
Networked wireless sensors
in a harsh terrain typically are battery operated and, therefore, require
energy efficient network protocols.
In order to ease the analysis of the energy usage of proposed network
protocols, this paper proposes an energy module, implemented in OPNET, to
determine the energy consumption over time during network simulation. Multiple energy consumption modes, such
as transmit, idle, sleep modes are all accounted for. A sensor node will be automatically
turned off (disabled) in the middle of simulation if it runs out of the
user-specified energy. The energy
module provides function calls for network protocols implemented in OPNET, and
therefore allows performance evaluation in terms of the energy efficiency. Among other protocols, this paper
focuses on the topology control schemes, which has individual wireless sensors
determine their own transmission power levels while maintaining network
connectivity. In order to allow the
adjustment of transmission power level having an effect on the transmission
range, this paper investigates necessary modifications on the Closure Pipeline
stage in OPNET. A simple topology control scheme is implemented for validation
purposes. Simulation results will
be presented in this paper to exhibit the effect of the closure stage
modification as well as the energy modules.
The full paper is
accessible here.
Mobile Wireless Sensor
Formation Algorithm Development using OPNET
Mark Seidman ( MSeidman@mail.rit.edu), Shanchieh Jay
Yang( Jay.Yang@rit.edu)
Technology advances in
embedded wireless sensors have enabled the emergence of robust and
cost-efficient networked sensing.
Applications of networked sensing may range from weather monitoring to
military operations. Some of these
applications may require maneuvering and formation of sensors to perform the
sensing tasks. The ultimate goal of
this research is to investigate efficient and robust mobile sensor formation
when the sensors have limited communication capabilities and energy
resources. At the current stage, we
take on an existing theoretical algorithm that forms a circle of nodes, and
implement it in a simulated environment that accounts for physical
communication and movements. The
simulation tool OPNET mimics the practical world of wireless communication and
network protocols, but is limited in modeling the sensing components required
for the theoretical algorithm and sensor networks. This project explores and develops
methods in OPNET to mimic the sensing of neighboring nodes so as to realize and
examine the performance of the algorithm in a real world. The next steps of this work are (1) to
generalize the algorithm in creating other shapes of formation, and (2) to
investigate the use of local communication in making the algorithm more efficient
and more robust in a practical environment.
A poster
presentation is accessible here.
Modeling and Simulation of Gossip-Based Relayed Network for
Ubiquitous and Expanded Access
Sungho Maeung (sxm3011@cs.rit.edu),
Shanchieh Jay Yang (Jay.Yang@rit.edu),
Nirmala Shenoy (ns@it.rit.edu)
The need for ubiquitous
access even in a harsh terrain presents a challenge to provide extended
coverage using lightweight, cost-efficient, and easy-to-deploy wireless
devices. Due to the simplicity of the tasks performed by these devices, it is not justified to dynamically determine
the routes as typical routing protocols do. This paper proposes a lightweight
robust forwarding scheme, called Gossip-Based Relay Protocol (GRP)
that allows information to be relayed across a wireless ad hoc network. One or more forwarding
paths are determined based on probability functions without explicitly
maintaining a routing table. With
the possibility of “not” forwarding a message, it also reduces
unnecessary flooding and collisions are reduced by adopting
a one-time
random back-off medium access before transmission without any retries. A simulation model is
developed using the OPNET Modeler. Performance of GRP is compared against a standard flooding scheme in
terms of the message success rate, end-to-end delay, and message flooded in the
network. This paper discusses the simulation results as well as the issues
associated with topology and network parameters.
The full paper is
accessible here.