The document discusses the 4-stage architecture of IoT systems. It begins with sensors and actuators that collect analog data from the physical environment. This data is then sent to an internet gateway that converts it to digital format. Next, edge IT performs preprocessing like machine learning before the data reaches the final stage - the data center and cloud where it is analyzed and stored.

1. IoT Architecture – The Art of
Building Smart Systems
In this article we will discuss IoT Architecture
“Alexa! Turn off the light”, we all know that this task happens in a millisecond,
but only a few of us know what happens behind the scenes. In this article, we
shall try to understand the architecture of IoT as we scale down each layer of
the 4 stage architecture IoT system.
Hopefully, by the end of this article, the next time you ask any virtual assistant
to operate a smart gadget, you will know exactly what is happening in the
background and which stage is performing what role.
The 4-Stage IoT architecture
The most used architecture for the Internet of Things is the 4-stage
architecture which has 4 phases in it. There is no rule stating that only the 4
stage architecture of IoT will be used all the time, but the twist is that these
four stages will always be used no matter how many stage architectures you
use.
By phases, I mean the path that the action traverses. So to achieve a specific
action, be it smart watches, smart homes, driverless cars, or any other
example, the data has to traverse or go through these phases.

2. IoT in itself means an interrelated internet-connected object system that
collects and transfers data over a wireless network without any human
intervention. This brings me to the next topic:
Importance of IoT architecture
In IoT, Data collection is enabled by having devices (or sensors) connected to
the internet via their own IP address. The quintessence of this is to track data
through their sensors, perform calculations and make them available for
consumption to their users.
One of the vital importance of having good architecture is ‘security’. If
penetration is anywhere in the architecture, the data could fall into the wrong
hand and could cause significant damage. Hence these perpetually connected
systems have a secure architecture.
In layman’s language, the IoT architecture is where the data flows from the
“things” to the “internet”! Here, “thing” refers to a machine, sensor, etc., and
“internet” refers to the cloud or server.
The 4 Stages of IoT architecture
Okay, enough talk. Let’s get down to the matter at hand. The four phases or
stages of IoT architecture are:
1. Sensors and Actuators
2. Internet Gateway

3. 3. Edge IT
4. Data Center and Cloud
Let us take a detailed look at each phase and see what happens to the data in
each stage.
1. Sensors and actuators
We all know that IoT revolves around sensors. But do we know why? Well. it
is because they convert information obtained in the outer world into data for
analysis. They include data regarding the process or environmental
surroundings like temperature, fluid flow in the pipe, air quality, and more.
But what are actuators? Well, by definition, actuators can intervene to alter the
physical reality. It sounds mindboggling when you put it like that, but they are
boring. They are just normal machines like fan regulators, switches,
thermostats, valves, air conditioners, etc.
Every IoT device must and will have sensors because it is from this stage that
data is generated and collected. This data will travel through the different
stages of IoT architecture and, finally, the cloud.
2. Internet gateway
The IoT architecture’s second stage works close to the first stage (sensors
and actuators). This stage is the gateway to the internet, or more technically:
data acquisition systems (DAS).

4. The data obtained from the sensors is in analog form. For this data to enter
the cloud and undergo in-depth processing, it needs to be aggregated and
converted to digital signals.
This is precisely what this stage does. It prepares the data from the sensors to
be cloud readable, acting like a gateway to the cloud, thus the name ‘internet
gateway’. Finally, the internet receives this digitized data and routes it to
systems in stage 3.
3. Edge IT
At this stage, the data from the sensors has already been transferred to the IT
world. But there is one problem, the data still requires to be reduced in volume
before it enters the data centers. In technical terms, Edge IT systems perform
enhanced analytics and pre-processing, such as machine learning and
visualization.
The edge IT stage reduces the burden on IT infrastructure. How? Here are
two examples: edge IT systems use machine learning to scan for anomalies
and use visualization techniques to present information into attractive
dashboards, pie charts, and graphs. Here is a bonus fact: this stage sits a little
closer to the sensors in a wiring closet.
4. Data Centre and Cloud
The last and final stage of IoT architecture is not the data centre and cloud but
rather happens in the data centre and cloud. It is where the data is analysed,

5. managed, and securely stored for in-depth processing and follow-up revision
for feedback and future decisions.
This stage can also execute precise analysis by combining data from other
sources, including the digital and physical worlds. These sources can identify
and analyse significant patterns and trends.
With that said, this architecture is the basic fundamental for IoT. However,
before we conclude, let us take a look at some advantages and
disadvantages of IoT.
Advantages of IoT
1. Cost reduction
IoT devices catch problems and bugs very fast when compared to traditional
debugging. It saves not only the cost of repairs but also time.
2. Efficiency
IoT devices are very productive and efficient. One such example is an
automated PDF converter, which removes the hassle of PDF editing and
archiving.
3. Mobility
Thanks to IoT, employees can work from any geographical location, anytime,
without any restrictions.
4. Supports Various Technologies
IoT supports technologies like big data analytics, cloud computing, wireless
sensor networks, embedded systems, and many more.

6. Disadvantages of IoT
1. Security
Since the data travels all over the internet, end-to-end encryption is a must in
IoT. However, as of today, maintaining privacy is a big challenge. It is why we
need better and more secure architectures.
2. Complexity
As much as IoT is good at Fixing bugs, most of the devices still contain some
software bugs. Each IoT device must be able to seamlessly interact with other
devices in the network to which they are connected.
3. Compatibility
One example of why IoT devices are not compatible is that there is no
International Standard for monitoring the equipment.
4. Policies
Governments must impose policies and standards to stop the Black marketing
of IoT devices.
Summary
Now you know exactly what happens every time you say, “Alexa! Turn up the
temperature”. We have now seen the importance of IoT architecture and the
four different phases of it and concluded with some advantages and
disadvantages of IoT.