Environmental Engineering Reference
In-Depth Information
1
Introduction
The rapid growth in demand for computing everywhere has made the com-
puter a pivotal component of human's daily lives [2]. Whether we use the
computers to gather information from the Web, for entertainment, or for
running a business, computers are noticeably becoming more widespread,
mobile, and smaller in size. What we often overlook is the presence of those
billions of small pervasive computing devices around us that provide intel-
ligence integrated into the real world
smart environments
[2] to help us solve
some crucial problems in the activities of our daily lives. While we were asleep
at the switch learning to “plus one” on Google, the Internet of Things (IOT)
just exceeded the number of people that reside on the planet. Beyond just
smartphones and tablets, the number of “things” that connect to the Internet
will only continue to scale as the growing number of connected gizmos and
appliances—and even cows—are coded and catalogued to send messages to
the Web. Dave Evans at Cisco noted that “there are more devices tapping
into the Internet than people on Earth to use them.” How is that possible?
Well, an infographic the firm just published, as shown in
Figure 1.1
, provides
us insight with a visual snapshot of the increase in things connected to the
Internet—and how they will serve us in the very foreseeable future.
By the year 2020, as can be seen in
Figure 1.1
, there will be 50 billion of
these things around us. To achieve this vision of the smart environment with
pervasive computing
, also known as
ubiquitous computing
, many such miniatur-
ized computing devices will be integrated in everyday objects and activities
to enable better human-computer interaction. These computational devices,
which are generally equipped with sensing, processing, and communicating
abilities, are known as
wireless sensor nodes
. When these wireless sensor nodes
are connected, they form a network called the
wireless sensor network (WSN)
,
as illustrated in
Figure 1.2
.
1.1 Motivation of Wireless Sensor Networks (WSNs)
The postmodern era is a world where everything including people is con-
nected like the illustration given in
Figure 1.3
. With surrounding close to
invisibly small smart computing devices and sensors embedded in everyday
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