IoT Architecture, devices, Building Blocks, and Layers

IoT Architecture, devices, Building Blocks, and Layers

IoT is a revolutionary technology that dates back to the 1990s. It is a model that connects everyday things in a network of all kinds. The interconnection of the elements in your home or office connects seamlessly to the Internet and communicates with each other for increased efficiency, cost savings, and simplified management. IoT is not only useful for home users, but it offers huge benefits, such as high efficiency, to large organizations.

It is estimated that there will be 20 billion connected devices by 2020. Research companies such as Gartner and IDC, as well as technology companies such as Cisco, have space estimates connected IoT devices and they also agree that connected devices will offer a number of challenges by the end of decade.

Before getting into the details of IoT architecture , lets take a look at some of the devices in IoT domain which are already in market to grab an idea of IoT applications.

A Quick Overview of IoT Devices:

Below is an overview of most remarkable IoT devices:

1. Belkin WeMo Switch & Motion:  This is a Belkin home automation product that lets you control your home virtually from anywhere in the world. Just plug the device into Belkin switch and enjoy remote control and monitoring of the plugged in device.

2. SmartThings –  Knowing and controlling your home: Just like Belkin switch, it allows us to convert any device into a smart device. At $ 99, this is a smart hub compatible with a large number of devices. It also comes without monthly fees.

3. iSmartAlarm: This is a complete smart security kit for your home. This is a very intriguing, intelligent home security device that anyone can use.

5. Philips Hue connected bulb: Want to use your lighting remotely? The Philips Hue connected bulb should be your first choice. It can automatically change its color based on the preferences you have set for your home.

6. August Smart Lock: This tiny smart lock can be opened only using your smartphone. It allows you to manage multiple users with the access control you specify. But this can be a pretty expensive security device.

What do we mean by an IoT Architecture?

By IoT architecture, we mean the technologies involved including protocols, standards and approaches necessary to build a complete working IoT system. Think of an Apartment and a Bungalow. What makes us call that they are different in their architecture? if we take certain things out from a beautifully built Bungalow, we will alter the architecture and it will certainly not be considered a bungalow.

An IoT Architecture consists of the following:
1. Peripherals, which we call “things”.
2. Sensors attached to these things to gauge and transmit their data and information.
3. Network connection through which data is transmitted (wireless or wired).
4. Remote Cloud to which data is transmitted by the system.

Building Blocks of IoT:


Sensors are the frontend of IoT devices. As the name suggests, they perform the function of ‘sensing the environment’. Their main task is to extract the necessary real-time data from the surroundings and then transmit that to processing systems – Microcontrollers.

Usually, Sensors are connected directly to microcontrollers through a wired connection. In a complete IoT product like the ones described above, both microcontrollers and sensors are mounted on a single printed electric board and packed together to form a product.

Sensors must be able to be uniquely found from their assigned network addresses as they are considered to be a basic element in the large network of other devices.


In computer and other electrical systems, processors play a vital role in data processing. The main task of the processors – which we call microcontrollers in IoT due to their small size – is to process the real-time data collected by sensors and either process it locally or transmit to the cloud – a server on the internet – via an IoT Gateway for in-depth analysis and processing.

Microcontrollers are easily controllable by end-user applications, and they also perform the most important task of securing data. They perform encryption and decryption of data.

While prototyping large IoT projects at a small level, we use a complete IoT development board that features a specific microcontroller along with other necessary electrical components. The world’s famous IoT development board Arduino Uno – also known as Genuino Uno – contains an ATMega controller at its core.


Gateways facilitate data communication. An IoT gateway is something that sits between cloud services and microcontrollers to enable the transfer of data and information between the two.

Main task of gateways is to take processed data from the microcontroller and transfer it to an appropriate network or IoT platform by utilizing various communication protocols such as WLAN, xBee, 3G/4G, and WiMAX, etc. for further analysis in order to generate meaningful insights and analytics. This IoT platform is a server in the cloud and may use machine learning and AI technologies to generate advanced analytics from collected IoT data.

Nowadays most IoT development boards already have microcontrollers and gateways built-in. So you just need to program the board (actually programming the onboard microcontroller) in a plug and play fashion. A Famous example is IoT NodeMCU development board containing ESP WiFi Chip as a communication device.


Applications are considered as endpoints of IoT systems. Applications provide an interface for users to interact with data. These applications can be web based or mobile applications serving one or both of the following purposes.

1. Displaying sensors data collected by microcontroller
2. grab the processed information from cloud IoT platform and display to user in a meaningful way.

 Applications are user-controllable and also known as delivery points of particular services. They can also be used to control particular IoT devices or send instructions to microcontrollers.

SmartThings provides a mobile app to monitor and control all the connected things at home.

Now that you have grabbed an idea of all the Four building blocks of IoT, let’s move further and understand how all the blocks combine to form a big picture of an IoT system.

How do IoT Systems work?

If we summarize the elements of IoT architecture, we can say that the real-time data collected by sensors are transferred to the integrated processors known as Microcontrollers. These microcontrollers transform raw data into meaningful information and then transfer it again to remote cloud applications – also known as an IoT platform – through the connectivity of gateway device for further processing and to generate analytics. The processed information is transferred to applications for users to display and interact.

Layers of IoT Architecture:

Keeping in view the Building blocks, Internet of Things system is based on three fundamental layers.

iot architecture and iot layers
Image Source: IEEE

Physical layer:

Physical layer consist of gateways, sensors and actuators. In IoT systems, this layer serve the purpose of collecting raw data by using sensors ,to send gathered data from sensors to higher layers and to process control signals for actuators to function accordingly.

Think of a Temperature sensor and an actuator –  We have already defined sensors above , actuators can be defined as something that cause a measurable change in environment such as an LED, a bulb or a Fan – sensor is continuously reading temperature and feeding it to microcontroller. Microcontroller decides to turn on the LED as a caution if temperature exceeds a certain limit.  Both components – sensors and actuators- interact with the physical world and thus they form physical layer of IoT Systems. Physical layer is also known as perception layer.

Communication Layer:

This is the middle layer where communication takes place. We have already discussed about gateways and communication channel. In order to Keep the concept simple that this layer handle all the protocols involved in communication. Whether they are communication protocols such as Wifi (802.11), Zigbee (IEEE 802.15.4) or messaging protocols such as MQTT and CoAP, whenever we talk about protocols , we have been talking about communication layer.

This layer is responsible for managing sessions, security and error control. Some researchers also state this layer as Resource layer and divides it further into access layer, internet layer and service management layer for the sake of simplicity.

Application layer:

Application layer is the top most layer of the IoT architecture and have a close resemblance to the application layer of OSI model in computer networks. This is where information is utilized for useful purposes to form IoT use cases for example, smart home, smart grid and enterprise IoT solutions.


As the protocols and standards gaining maturity, IoT is going to cause a major impact in each sector. However, Challenges are still there in development of a complete and adoptable IoT framework in order to utilize the full potential of internet of things.

This Post Has 2 Comments

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    1. admin

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