|
|
Type of Document Master's Thesis Author Puccinelli, Daniele Author's Email Address dpuccine@nd.edu URN etd-03212005-110624 Title Mitigation and Exploitation of Multipath Fading in Wireless Sensor Networks Degree Master of Science in Electrical Engineering Department Electrical Engineering Advisory Committee
Advisor Name Title Martin Haenggi Committee Chair J. Nicholas Laneman Committee Member Panos Antsaklis Committee Member Keywords
- routing
- opportunistic schemes
- wireless sensor networks
- multipath fading
- Rayleigh fading
Date of Defense 2005-03-30 Availability unrestricted Abstract The increasing interest in wireless sensor networks can be promptly understoodsimply by thinking about what they essentially are: a large number of small sensing
self-powered nodes which gather information or detect special events and commu-
nicate in a wireless fashion, with the end goal of handing their processed data to a
base station. Sensing, processing and communication are three key elements whose
combination in one tiny device gives rise to a vast number of applications [5, 46].
Sensor networks provide endless opportunities, but at the same time pose formi-
dable challenges, such as the fact that energy is a scarce and usually non-renewable
resource. The minimization of energy expenditure in the sensing nodes is a natural
direction for wireless sensor network research. Reducing the computational load and
minimizing radio power consumption are necessary steps dictated by common sense;
on the radio side, the knowledge of the properties of the wireless medium can help
minimize packet loss. Wireless analytical models are useful, but the oversimplifica-
tions introduced by many of them can lead to wrong considerations and conclusions.
For this reason, it is essential to analyze the wireless medium with real hardware.
Sensor network design should be performed by considering the interactions between
the physical layer and the upper layers: physical layer phenomena should be taken
into account in the development of MAC and routing schemes. In the present work, we consider the impact of multipath fading on sensor networks. Chapter 2 focuses
on the analysis of the properties of multipath fading, and the verification of the
most common models through software simulations and tests based on hardware
implementations. In Chapter 3, we use the properties of multipath fading to pro-
pose a novel, lightweight protocol for the acquisition of data from the nodes in a
wireless sensor network based on the exploitation of mobility and the concept of
opportunistic transmissions. Our protocol aims at the avoidance of packet loss by
the nodes and the minimization of their energy consumption.
While Chapter 3 revolves around the mitigation of the eŽects of multipath fading,
chapter 4 describes a novel idea for its constructive exploitation. We show how
the footprint of multipath fading on the received signal strength can be used for
purposes of motion detection. The present work is completed by an appendix where
extra details specific to our hardware implementations are provided to the interested
reader.
In the rest of the present chapter, we provide an overview of the research efforts in
the field of wireless sensor networks. We start by listing some interesting applications
and research projects currently underway. We then indicate the main peculiarities
of sensor networks to give a feeling and basic understanding of what makes them
unique and to justify the enormous interest in the field that is being displayed by the
community. Finally, we present the most interesting and commonly used hardware
platforms that enable wireless sensor network research.
Files
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access PuccinelliD052005.pdf 1.48 Mb 00:06:50 00:03:31 00:03:04 00:01:32 00:00:07