IoT Protocols - The Communication Highway

Communication is the key

Internet of Things or IoT are considered smart devices as they are able to autonomously change their parameters based on end user input. This is mainly because of inter communication between devices, as well to the internet. There is also a flow of data packets in large amount and time critical manner, running in the background. This is facilitated with the help of communication protocols. They are considered predefined rules which prevents data loss and enhance security.

How many?

The number of protocols may vary depending upon the use case. For example, to measure energy generated from a solar panel requires a configuration of low power consumption and high security. Now in the case of an ambulance, the data of the patient must be sent before hand to the hospital. Here time is of the essence and security is paramount. However there is not much restriction on energy consumption. The best way to understand this dilemma, is through a framework know as Open System Interconnection (OSI) model. It is divided into 7 layers for easy configuration and flexibility. It moves in a top down order ie from the user application to the Ethernet connection which transfers the data. The different layers are as follows

• Application Layer:  This is the user input layer which contains web app or mobile app used to interact with the IoT device.

• Presentation Layer: Converts the raw data obtained from the application layer into readable format and also provide data encryption. This is done using various mathematical algorithms.

• Session Layer: Before initiating any transmission of data, a session need to be opened between source and destination. A digital handshake is confirmed to make sure the receiver is ready to accept the request.

• Transport Layer: Deals with transmitting data over the network. Consider this layer as delivery trucks containing user data.

• Network Layer: Decides where and how the data stream needs to be passed. Routers are an essential part of this layer, and they act as a post office redirecting mail to the correct addressee.

• Data Link Layer: Deals with error correction in the physical layer and makes sure redundancy of the bits are clearly marked.

• Physical Layer: This is the bottom and final section which contains the hardware peripherals. This include Ethernet cable, mobile towers and network cards.

Now this network topography is not fixed and there can be changes depending on the industry application. Some have five layers while others only four. But the base model is the same. Nowadays there is an additional layer called the Business Layer which integrates with the cloud. This provides additional features like Machine learning and Artificial Intelligence.  

The network layer uses the following protocols for communication

• WiFi

• Bluetooth

• Zigbee

• Thread

• Packet Communication

The Application layer uses the following protocols

• HTTP (Hyper Text Transfer Protocol)

• Simple Object Access Protocol (SOAP)

• Constrained Application Protocol (CoAP)

Though HTTP is widely used in personal electronics, it forms as a constraint in the case of embedded systems. So most developers shy away from using the tech in IoT devices mainly due to power consumption and bandwidth management. 

Final Note

We have covered a basic understanding of the different layers and protocols. However if we dive deeper, there are sub sections related to the same. More on this in the upcoming blog.