What is MQTT protocol?

MQTT protocol is way for sending low size messages between devices or machines with low resources.

This protocol is based on publish-subscribe method and is a key feature for machine to machine communications in the Internet of Things.

MQTT protocol is designed with the following things in mind:

  • Simplicity of implementation
  • Low size
  • Suitable for unstable communication networks with low bandwidth
  • Ensure the sending and receiving of data

Key Features of the MQTT Protocol

MQTT protocol is light and binary. Data transfer is an array of bytes to transmit high-reliability data between clients with limited resources, it is much better than the common protocols in the web such as HTTP. This protocol has the smallest overhead.

Due to its simple implementation and low volume, it is a very good protocol for devices with limited computing resources which want to exchange information with other devices in the Internet of Things, just like Niligo Smart Lights.

Comparison between MQTT and HTTP protocols

To better understand this protocol, we’ll compare it with the HTTP protocol. The main difference between these two protocols is their work pattern.

As you know, HTTP is a request-response protocol between two sides, one side in the client relationship, and the other in the role of the server.

The client sends its request to the server and the server sends an answer to the client after receiving and processing it.

During this operation, the communication line between the server and the client must be maintained. Otherwise, this connection will be lost.

The MQTT protocol for resolving the problem has transformed the request-response pattern into a publish-subscribe pattern. In such a way that two clients are not connected directly to each other and their connection is established through a broker.

The benefits of the publish-subscribe pattern

The sender and receiver of the data are independent of each other and are not dependent on existence or non-existence and in fact they have no information of the nature of each other.

The independence of the data transmitter and receiver increases the reliability of the entire system. Because by disconnecting a client, only one branch is connected to the broker, but the system continues to work.

The MQTT protocol does not require that the communication link between the client and the broker be maintained, and only when the data needs to be transmitted, this connection is established.

For example, if a recipient client disconnects with a broker, it is still possible to re-establish this connection and receive data from the sender’s side, and the data sender can also disconnect from the broker after sending the data to that.

The benefits of this disconnection can be to increase the safety factor and less power consumption in that client, for example a smartphone.

This issue has many advantages over the style of the protocol, such as the low battery consumption of smartphones and its suitability for social networks.

The MQTT is a data-centric protocol, while the HTTP protocol is document-driven. This means that the HTTP protocol is suitable for transmitting documents and web services and MQTT is more suitable for transmitting short messages.

The MQTT protocol is about 93 times faster than the HTTP protocol in terms of measurements performed on 3G networks.

For example, Facebook recently used MQTT protocol in its messenger. The reason for this is not only to keep the smartphone batteries charged while exchanging messages, but also to quickly and efficiently exchange messages despite the uncertainties in the Internet.

The Amazon Web Services (AWS) also supports the MQTT protocol alongside HTTP so that the ability to connect IOT objects to the cloud is also provided.

The MQTT protocol ensures a high degree of delivery to the recipient through the quality of service or Quality of Service, and therefore suitable for unstable networks.

The MQTT has a very short heather and the smallest package of messages is 2KB. While the HTTP protocol is capable of sending long messages and messages using a text format.

This issue in the MQTT protocol makes it possible to read messages and, on the other hand, this volume of message generally responds to the transmission of information between devices with limited resources in the Internet of Things.

At the end, it can be said that the MQTT protocol is for transferring low-volume data into unsteady networks and is in a higher priority when response times, lower battery consumption, bandwidth, and efficiency is more important.

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