Getting onboard MQTT

Akira Hirakawa
Red Dot Drone
Published in
5 min readApr 28

Exploring the uses of MQTT for drones.

MQ Telemetry Transport or MQTT for short, is a protocol for data transport. It is a lightweight publish/subscribe messaging protocol designed for constrained devices and low-bandwidth, high-latency or unreliable networks.

It follows a publish and subscribe model and allows for simple communication between multiple devices. MQTT is especially reliable in situations with constrained devices and low bandwidth and a useful communication protocol for Internet of Things (IoT) applications.

What are the key features of MQTT?

  • Lightweight: It has a small code footprint and requires minimal network bandwidth
  • Publish/Subscribe model: Devices subscribe to topics and receive messages published on those topics
  • QoS (Quality of Service) levels: It provides three QoS levels to ensure message delivery reliability
  • Retained messages: It allows for the last published message on a topic to be retained and sent to new subscribers
  • Session management: It maintains the state of a client’s subscriptions and messages even if the client is disconnected
  • Last Will and Testament (LWT): It allows clients to define a message that is sent to subscribers if the client disconnects unexpectedly.

What does MQTT allow you to do?

MQTT uses a publish/subscribe model, where a client subscribes to a topic and a publisher publishes messages to that topic. The broker acts as a mediator, receiving messages from publishers and forwarding them to all subscribers of that topic. The QoS level determines the reliability of message delivery, and retained messages are used to store the last message published on a topic.

MQTT Concepts

Publish and Subscribe

Device publishes on a topic, devices subscribed to the same topic in which the first device is publishing in, receives the message.


Topics are the way you register interest for incoming messages and how you specify where you want to publish your messages. Topics are represented with strings separated by slashes “/”. Slashes indicate the topic level.

MQTT Broker

The broker is responsible for receiving, filtering and publishing the messages to all subscribers. The broker can queue messages for disconnected subscribers. Subscribers can also publish messages to the Publisher. For example, to tell the publisher to adjust the temperature.

Efficiency of MQTT

  • MQTT messages are lightweight of a few bytes and requires minimal network bandwidth, making it ideal for IoT devices
  • It supports a publish/subscribe model, which simplifies communication between devices
  • MQTT clients are decoupled and managed by a broker
  • Devices do not need to be connected to each other
  • Communication over MQTT is stable and reliable
  • It allows for session management and retained messages, ensuring messages are delivered even if a client is disconnected
  • Scalability of connectivity to thousands of devices
  • It has a large ecosystem with many open-source and commercial implementations available.

MQTT over Websocket

  • Allows the browser to leverage on the MQTT features
  • Able to communicate with mobile web applications
  • Display information live from device or sensor
  • Receive push notifications
  • View current status of devices

How does MQTT compare to other messaging protocols, such as HTTP and CoAP?

MQTT is more lightweight than HTTP and CoAP, and is designed specifically for constrained devices and low-bandwidth, high-latency or unreliable networks. Unlike HTTP, it supports a publish/subscribe model, which simplifies communication between devices. Compared to CoAP, it has a larger ecosystem with more available implementations and is more widely used.

Why MQTT for Drones

Drones are required to operate under constraining network conditions with limiting network bandwidth. IoT applications are expected to run on mobile devices even with restricted bandwidth and power supply.

MQTT can be an excellent protocol for drones because it is lightweight and designed for constrained devices and low-bandwidth networks. MQTT can help to increase efficiency, reliability and scalability in drone operations. It can be a useful protocol for drones, allowing for reliable and efficient communication between the drone and other devices, enabling real-time monitoring and control, low overhead, and supports safety-critical applications.

Here are some ways MQTT can be used with drones

  1. Control and telemetry: MQTT can be used to send control commands to the drone and receive telemetry data from it. For example, the drone can publish its GPS coordinates, altitude, battery level, and other sensor data to an MQTT broker, which can be subscribed to by a ground control station or other devices. Similarly, the ground control station can publish control commands such as takeoff, land, or change altitude, which the drone can subscribe to and act upon.
  2. Unmanned Traffic Management (UTM) System: MQTT can be used to manage a fleet of drones, such as tracking their locations, battery levels, and other status information. This information can be published to an MQTT broker and subscribed to by a fleet management application.
  3. Image and video streaming: While MQTT itself is not designed for streaming large amounts of data, it can be used to publish small commands or metadata related to image or video streams. For example, an MQTT message could be used to trigger the drone to start recording video, or to provide information about the video stream, such as resolution and frame rate.
  4. Edge computing: MQTT can be used to send data from the drone to an edge computing device, such as a Raspberry Pi or a Jetson Nano, where it can be processed in real-time.

Why use our Drone MQTT?

Easy, flexible management

Managing users, topics on the Dashboard easily, you will be able to host an MQTT instance in more than 10 regions around the world in minutes.

Secure connection

You are able to use SSL connection without the extra cost.

Log storage

With the Advanced plan, you will be able to download stored MQTT messages whenever you need.

Affordable pricing

Affordable compared to doing it yourself or other products. Hosting a dedicated instance on DroneMQTT starts from $19 with various functions such as WebSocket, SSL Connection etc.




Akira Hirakawa
Red Dot Drone

Co founder of Red Dot Drone