MQTT, CoAP and other IoT based protocols

Published On - July 13, 2023

Avinash Sharma Technology

MQTT (Message Queuing Telemetry Transport) and CoAP (Constrained Application Protocol) are both communication protocols commonly used in the Internet of Things (IoT) domain. Let’s break them down:

  1. MQTT (Message Queuing Telemetry Transport):
    MQTT is a lightweight publish/subscribe-based messaging protocol designed for constrained devices and low-bandwidth, unreliable networks. It follows a client-server architecture, where MQTT clients publish messages to a central broker, and other clients subscribe to receive those messages. The key features of MQTT include:
  • Lightweight: MQTT is designed to be efficient in terms of network bandwidth and resource usage, making it suitable for resource-constrained devices such as sensors or embedded systems.
  • Publish/Subscribe model: MQTT uses a publish/subscribe messaging pattern, where publishers send messages to a specific topic, and subscribers receive messages by subscribing to one or more topics.
  • Quality of Service (QoS): MQTT supports three levels of QoS, ensuring reliable message delivery based on the importance of the message and the network conditions.
  • Retained messages: MQTT brokers can retain the last message published on a specific topic, allowing new subscribers to receive the most recent value immediately after connecting.
  • Widely supported: MQTT has become a widely adopted protocol in the IoT domain, and there are numerous libraries, frameworks, and tools available for implementing MQTT-based solutions.
  1. CoAP (Constrained Application Protocol):
    CoAP is another lightweight protocol designed for IoT devices operating in constrained environments such as low-power, low-memory, and lossy networks. CoAP is inspired by HTTP and provides similar request/response interactions but with reduced overhead. Key features of CoAP include:
  • RESTful design: CoAP follows a Representational State Transfer (REST) architectural style, making it easier to integrate with web-based systems and leverage existing HTTP infrastructure.
  • Resource-oriented: CoAP treats resources as identified targets that can be read, written, observed, or executed using simple methods like GET, POST, PUT, and DELETE.
  • Low overhead: CoAP minimizes message size by using compact binary encoding and offers options for efficient data transfer, making it suitable for constrained networks.
  • UDP-based: CoAP is based on the User Datagram Protocol (UDP), which provides lightweight transport without the complexities of TCP, making it more suitable for resource-constrained devices.
  • Proxy support: CoAP can be used in proxy architectures to bridge CoAP-based IoT devices with HTTP-based web servers, enabling seamless integration with existing systems.

Other IoT-based protocols:
Apart from MQTT and CoAP, there are several other protocols commonly used in the IoT domain, including:

  • HTTP (Hypertext Transfer Protocol): Although not specifically designed for IoT, HTTP is widely used for IoT applications that require compatibility with existing web infrastructure, especially in scenarios where devices have sufficient resources.
  • AMQP (Advanced Message Queuing Protocol): AMQP is a messaging protocol that supports reliable message queuing, routing, and interoperation between different systems, making it suitable for IoT scenarios where message reliability and interoperability are critical.
  • Zigbee: Zigbee is a wireless communication protocol widely used in home automation and building control systems, offering low-power and low-data-rate wireless connectivity for IoT devices.
  • LoRaWAN: LoRaWAN is a long-range, low-power wireless protocol designed for wide-area networks, enabling long-range communication with low data rates, making it suitable for applications such as smart cities and agriculture.
  • Bluetooth Low Energy (BLE): BLE is a power-efficient wireless communication protocol commonly used for short-range communication between IoT devices and smartphones or gateways.

These are just a few examples of the many protocols used in the diverse IoT landscape, each with its own strengths and areas of application. The choice of protocol depends on factors such as device constraints, network conditions, interoperability requirements, and specific use-case needs.