IoT Architecture

What is IoT?

The IoT is a paradigm that allows various smart devices and gadgets to connect with each other. These devices will have sensors and actuators that communicate real time data and decide the course of action to be taken depending upon the situation. The Internet of Things (IoT) aims to embody an intelligent world that encompasses the physical, the digital and the virtual. The IoT will be built upon a complex network connecting billions of devices and humans into a multi-technology, multi-protocol and multi-platform infrastructure. Idealistically, IoT will allow billions of disparate devices to communicate with each other, exchange data, and make meaningful use of the data. Take a hypothetical case where a person wants to go the office. As soon as the person opens his / her apartment door, a sensor alerts the car, which auto starts and warms the engines. The garage door too senses the owner approaching it, and swings open automatically. Once the car leaves the garage, the garage door shuts down automatically. Meanwhile, the car plays the owner's favourite radio channel automatically, and advises the best possible route to take in order to avoid traffic jams. At the office, the biometric system recognizes the person, greets him / her by name, and allows entry. It also alerts the air conditioning in the cabin to start cooling the room just like the owner prefers. This is just one example of how IoT will change our lives for better.

IoT is already providing solutions across a broad spectrum of domains including healthcare, agriculture, security, etc. One of the first sectors that gauged the potential of IoT was the industrial manufacturing sector. Industrial IoT or IIoT is nothing but the tenets of IoT applied to industrial production. Indeed, IIoT will be an integral part of manufacturing in the near future. 

IoT solutions are getting popular in many countries like India, Singapore, US, and others because of the benefits it offers. Specialised software like Kepware and IoT development platforms like ThingWorx are accelerating the adoption of IIoT in these countries.

IoT Architecture
Broadly speaking, it is the engineering and integration of hardware systems. Hardware architecture is identification of the physical components and their interrelationships in order to provide stable and scalable infrastructure. As products grow increasingly complex, the hardware design and configuration plays a key role in interoperability. Hardware architects provide software component designers valuable information that allows them to choose the right protocols and platforms for software development and integration. A hardware architect is responsible for hardware architecture, hardware specification, external hardware module specification and the hardware implementation, integration and evaluation concept. Hardware architecture plays a pivotal role in IoT solutions. The key features of IoT include artificial intelligence, connectivity, sensors, active engagement, and small device use. The IoT architecture is purely conceptual, and is majorly built from three pillars relevant to interconnection of smart objects that includes identification, communication, and interaction of ‘things’. The IoT architecture helps developers visualise how the ‘things’ interact with each other, and what their hierarchy is. The IoT stack or architecture can be described in many ways since it is an abstract concept. In this article, we will cover the IoT architecture in three different ways that are most popular. 

IoT Device Layer: This is the layer where the connected devices with embedded sensors / actuators reside. These 'things' are connected objects that are not only capable of transmitting system environment data, but can also receive communication. In other words, there is a two way communication between their corresponding gateways or data acquisition systems, and also between each other in order to gather and share information and collaborate in real time to leverage the value of the whole deployment.

Kepware's KEPServerEX® from PTC is one example of a secure connectivity server that enables users to connect diverse automation devices and sensors to a wide variety of IoT solutions. 

IoT Gateway: The data from all the end nodes (The devices or the 'things' of the IoT) is collected, aggregated, and transmitted via IoT gateways. It can be either software, hardware or combination of both. An IoT gateway serves as the connection point between the cloud and controllers, sensors and intelligent devices. It is needed to perform the pre-processing of information in the field, before they’re sent to the data center. This is because the sensors or actuators are 'dumb'; all they do is transmit and receive data. On their own, they are not equipped to take intelligent decisions based on this data. In addition, some sensors, especially in a complex IIoT scenario, generate humongous real time data (Big Data). This big data needs to be pre-processed locally at the edge before sending it on to the cloud. Such pre-processing also includes message filtering and aggregation. Unless IoT gateways pre-process such data, it would significantly affect the response time and increase network transmission costs of the cloud. In short, the IoT gateway acts as the control tier, where data is streamlined intelligently. 

The IoT Platform: The IoT platform is responsible for providing a pathway that connects clients and operators. It is responsible for delivering application specific services to the user. The IoT platform stores, controls and displays data flow, controls edge devices, runs diagnostic tests, and manages and updates devices. It defines various applications in which the Internet of Things can be deployed. One example of a sound IoT platform is ThingWorx from PTC. The ThingWorx platform is a complete, end-to-end technology platform designed for the industrial Internet of Things (IIoT). It delivers tools and technologies that empower businesses to rapidly develop and deploy powerful applications and augmented reality (AR) experiences.

There are two other popular ways of classifying IoT architecture; the 3 layered and the 5 layer architecture. 

The 3 layer IoT architecture conceptually consists of:

The perception layer: Also called as the recognition layer, it is the lowest layer of the conventional architecture of IoT. It is a physical layer, responsible for the collection of useful information / data from things or the environment, and transforms them in a digital setup. The perception layer of an IoT system hosts most of the application and business domain functions.

The network layer: is the core of conventional IoT architecture. This layer’s main responsibility is to help connect to other smart things, network devices and servers (like the KEPServerEX) and secure data transmission between the application and perception layer of IoT architecture. The network layer acts as a bridge or gateway; it collects information and delivers to the perception layer. In other words, this layer is a convergence of internet and communication-based networks.

The application layer: is considered as the top layer of conventional IoT architecture. The application layer is responsible for delivering personalized application specific services to the user. Its main responsibility is to link the major gap between the users and applications. The application layer is also responsible for high-level intelligent applications type solutions like health monitoring, logistics, etc. 

As IoT solutions progressed, researchers and academicians realized that the 3 layers do not cover all the IoT architecture functionality adequately. They therefore added two more layers to the IoT architecture, making it a five layered architecture. 

The perception layer: as above

The transport layer: The transport layer transfers the sensor data from the perception layer to the processing layer and vice versa. The two popular IoT transport layers are TCP and UDP. TCP provides the concept of a logical connection, acknowledgement of transmitted packets, but is not needed for embedded systems, which typically use the UDP protocol.

The Processing layer: The processing layer is also known as the middleware layer. It stores, analyzes, and processes huge amounts of data that comes from the transport layer. It can manage and provide a diverse set of services to the lower layers. It employs many technologies such as databases, cloud computing, and big data processing modules.

Business layer: The business layer manages the whole IoT system, including applications, business and profit models, and users’ privacy. It is concerned with the process of data management as applied to the business logic.

Application layer: as above

In addition, there is one more IoT architecture model that is 7 layered that adds a global infrastructure layer and bifurcates the business layer into applications and people & processes. However, the 5 layered IoT architecture is sufficient to understand the basic skeleton on which the IoT solution will be built.

Summary
From Singapore, India to other countries, IoT and IIoT is gaining traction. To understand IoT in a better manner, it is essential to understand its architecture. The IoT architecture can be classified in several ways; we have covered the most popular architectures in this article.