How to Choose MQTT Broker For Your IoT Project

If you think digital technologies have already changed your life, think again. The IoT can revolutionize today’s world. IoT helps people work and live smarter and get complete control over their lives and homes. Apart from offering smart devices for home automation, IoT is essential to a vast majority of business domains. We need to start with the basics to understand better what MQTT is and how it’s used for IoT projects.

MQTT for IoT

With the technical advancements and automated processes in the manufacturing industry, smart sensors and devices are increasing. The systems need to collect and receive various data collected by such devices. Here’s comes the IoT (Internet of Things) extremely easy. The following concept can solve the problems of interaction of a large number of devices and compilation of devices into one network.

While being parts of the same network, such devices need to interact with each other through various interfaces and data transfer protocols. Since we are talking about the industrial application of the IoT concept, which should use industrial equipment with its own protocols and hardware, let’s call it the IIoT (Industrial Internet of Things) concept. The IIoT is a new step towards the full automation of manufacturing processes.

Devices utilize various messaging protocols to communicate with each other, and MQTT is probably the most widely-used protocol.

What Is MQTT?

MQTT or Message Queue Telemetry Transport is a lightweight, compact and open data exchange protocol designed to transfer data to remote locations with low bandwidth networks and those with high latency. The following protocol works with application-specific data.

The main features of the MQTT protocol:

• Bi-direction communication
• Lightweight and efficient
• Small packets
• Support unreliable networks
• Three defined quality of service levels
• Easy scalability

The exchange of messages in the MQTT protocol is carried out between the client, which can be a message publisher or subscriber, and a message broker (for example, Mosquitto MQTT).

The publisher sends data to the MQTT broker, indicating a specific topic in the message. Subscribers may receive different data from multiple publishers depending on their topic.

MQTT Use Cases

MQTT is widely used in IoT and IIoT due to consuming minimal bandwidth. As you know, IoT devices have quite limited resources. Thanks to its lightweight and efficiency, it’s often a wise choice for the IoT industry. Here are the most common MQTT use cases:

• Collecting and transferring data from sensor nodes to the server
• Sending critical data from a sensor directly to a user device
• Configuring smart devices remotely
• Bulk sending configuration data from a single app to all devices
• Updating devices in the network via OTA
• Monitoring patient health parameters
• Eliminating duplicating or lost messages

What is an MQTT Broker?

An MQTT broker is the heart of any subscribe/ publish protocol. It’s the server that distributes the information to the parties involved. In other words, An MQTT broker acts like a real estate broker. It checks the background of the interested clients and assures that the relevant rules are enforced, the broker starts the transaction. An MQTT broker does a similar thing but handles message transactions instead of money transactions. All messages go through an MQTT broker before they can be delivered to the subscribers.

Such brokers need to handle thousands of transactions and connected MQTT clients, so while choosing what broker to integrate, you need to consider its scalability, integration, failure-resistance, and monitoring capabilities.

Types of MQTT Brokers

Generally, we can define two types of MQTT Brokers: self-hosted brokers and managed brokers.

Self-hosted brokers

Unlike managed brokers, self-hosted brokers cannot work without the installation on your own VPS or a server with a static IP. The installation process isn’t too complicated, but its securing, managing, and scaling of self-hosted brokers require a particular skill set and a deep understanding of the IoT system.

Managed brokers
While utilizing managed brokers, you don’t need to set up anything on your server to set up MQTT communication. They are out-of-the-box solutions. There are particular managed broker services to let you use their hosted brokers like AWS IoT Core.

Top Five Alternatives to an MQTT Broker

There are plenty of alternatives to MQTT brokers on the market. There are some of the most popular options:

• Mosquitto. It’s an open-source message broker that works with low-power single-board computers and full servers.
• AWS IoT Core. It’s a managed messaging protocol that enables you to connect devices to AWS services and other devices. It allows for connecting IoT devices and routing billions of messages without managing the infrastructure.
• EMQX. It’s more than just a distributed MQTT broker. EMQX is a cloud-native IoT messaging platform. It supports multiple protocols, including CoAP, MQTT, WebSocket, and others.
• VerneMQ. A distributed MQTT broker with scaling to support a high number of concurrent consumers and publishers. It is a good choice for a reliable IoT hub.
• HiveMQ. It can help connect, collect, and move data to and from connected devices. HiveMQ is designed for cloud-native deployments. Thanks to the open API, it’ll be much easier to integrate IoT data into your existing enterprise systems and pre-built extensions.

All the above-mentioned brokers have their own pros and cons that you need to consider and discuss with your IT service provider. Some of the mentioned brokers are a perfect fit for large-scale apps with billions of transactions, while others were architected for small-scale projects. For example, HiveMQ was initially designed for cloud-native deployments and easy scalability of the system.