I
NTERNET
-
OF
-T
HINGS
35
June 2014
Over the past two decades, the Internet has
evolved rapidly and completely changed our
way of life. The initial phase, the so-called
Web 1.0, enabled the user to access information
that a small number of players have provided.
The second phase, often called Web 2.0, at the
turn of the year 2000 was no longer only
about distributing and presenting existing
static content. It rather enabled the user to
generate new, individual content and to easily
share it with a selected audience. Now, broad-
scale Internet usage moves into its third decade
enabled by new technologies such as IPv6.
The key difference is that content is now auto-
matically generated and/or consumed. So un-
like in the previous waves of Internet usage,
one or both parts of the communication can
now be machines. Therefore, this third Internet
usage paradigm is often called the Internet of
Things (IoT). In such a scenario, users will be
able to directly access data related to the
current situation, followed by calculations in
real time and the intelligent control of actuators.
The necessary networks built of sensors, actu-
ators and processors can be composed and
flexibly modified according to the actual user
requirements. In the process, data storage and
processing can be done locally or within a
cloud-based infrastructure (Infrastructure as
a Service – IaaS). The following 3 examples
illustrate the concept:
Sensors measure energy consumption and au-
tomatically create a website visualising status
and trends (content creation by machine, con-
tent consumption by human). User instructs
the heating system over the Internet to raise
the temperature to comfort level ahead of re-
turning home (content creation by human,
content consumption by machine). Wireless
sensors measure outdoor and room tempera-
ture which together with the current weather
forecast will be used by the home automation
system to calculate the required heating (con-
tent creation and consumption by machines).
Having a large network of sensors, actuators
and control units all interacting with each
other and the user can bring several distinct
benefits. More input (sensor) data usually
yields a better insight into the system status.
This additional information allows a better
decision-making process considering a broad
range of criteria. Unlike the standard approach
of one or more sensors being connected to a
central control unit, an Internet of Things al-
lows the sharing and reuse of available infor-
mation between different partners. Thus, the
system collects data only once but uses the in-
formation for several applications.
Current control systems are usually local; for
example sensors, control unit and actuators
are often in close proximity and directly con-
nected with each other (wired or wireless). An
Internet of Things no longer requires such
proximity. It even allows outsourced computing
resources, thus driving down infrastructure
cost. Besides this, the IoT allows dynamic cre-
ation of control networks which can be formed
or dissolved flexibly based on time, location
or other parameters.
All required base technologies for such network
already exist today – sensors, actuators, local
or cloud-based control units and IPv6 to con-
nect all of them together. The major challenge
now is how to deploy large numbers of sensor
and actuator nodes and connect them in a
suitable way. The answer is by wireless (ease
of installation and scaling), self-powered (main-
tenance-free, zero cost of operation) sensor
and actuator nodes that can be accessed via
IPv6 protocol. Freeing sensors from external
power, making them self-powered, opens up
unlimited processing and monitoring applica-
tions where cables or batteries represent an in-
surmountable hurdle. These features make en-
ergy harvesting wireless technology the ideal
solution to easily and reliably interconnect
thousands of individual devices in a system
and with the Internet. Nowadays solutions
predominantly use three energy sources: mo-
tion, light and temperature differences. The
key challenge with all these energy sources is
that they provide very small amounts of energy.
Energy-harvesting wireless sensor
nodes for the Internet of Things
By Matthias Kassner,
EnOcean
Energy harvesting wireless
is just starting to unfold
its potential. The rapid improvement
of components will open up
new applications in many aspects
of life. Together with the Internet
moving towards IPv6,
the battery-less approach
can even form the foundation
for an Internet of Things.
