MQTT (Message Queuing Telemetry Transport) is a lightweight messaging protocol that provides resource-constrained network clients with a simple way to distribute telemetry information. The protocol, which uses a publish/subscribe communication pattern, is used for machine-to-machine (M2M) communication and plays an important role in the Internet of Things (IoT).
Characteristics of MQTT
Lightweight and Efficient
MQTT is designed for connections with remote locations where network bandwidth is limited. The protocol is incredibly lightweight and ideal for IoT devices, mobile applications, and any application where bandwidth and battery power are at a premium.
MQTT uses a publish/subscribe model, which allows messages to be pushed to clients. This model reduces network bandwidth requirements and can improve message distribution time.
Quality of Service
MQTT supports three Quality of Service (QoS) levels: At most once (0), At least once (1), and Exactly once (2). This allows the sender and receiver to negotiate the best trade-off between network bandwidth and message reliability.
MQTT brokers can retain messages on a topic and deliver these messages to new subscribers when they subscribe to that topic. This feature is useful when new subscribers need to get the last value of a topic immediately after they subscribe.
Last Will and Testament
MQTT allows clients to specify ‘last will and testament’ (LWT) messages that are sent by the broker to other clients when the client disconnects ungracefully. This feature is useful in notifying other clients about the abruptly disconnected client.
Applications of MQTT
IoT and M2M Communication
MQTT is widely used in IoT and M2M communication due to its lightweight nature and publish/subscribe model. It enables devices to send (publish) information about a given topic to a server (broker) that then pushes that information to all devices (subscribers) following that topic.
MQTT’s real-time capabilities make it ideal for real-time analytics. Data can be collected from various sources and then pushed to an analytics engine in real time.
Mobile and Web Applications
MQTT is also used in mobile applications to send notifications and updates and in web applications to update web pages in real time.
Remote Sensing and Control
MQTT is used in remote sensing and control applications where a sensor or controller needs to communicate with a remote server. The protocol’s lightweight nature and ability to work over unreliable networks make it ideal for these applications.
MQTT is a powerful protocol designed for lightweight data transmission. Its characteristics make it ideal for use in bandwidth and power-constrained environments like IoT and M2M communication. As more devices become interconnected, the use of efficient and reliable protocols like MQTT will continue to grow..