IoT protocols are divided into data and network protocols. They are an integral part of the IoT technology infrastructure. These protocols enable hardware to exchange data so the end-user can extract useful information. The data protocols are responsible for the connectivity of low-power IoT devices, and they deliver communication with hardware on the user end. A standard communication medium between the devices would bridge the gap between protocols and reduce the risk of security threats. Here are some of the important IoT protocols you should know.

1. MQTT
As a lightweight IoT protocol, MQTT (Message Queuing Telemetry Transport) is a Machine to Machine oriented protocol that features a publisher-subscriber messaging model. It allows for a simple data flow between devices. Since its architecture is basic and lightweight, it provides low power consumption. MQTT protocol also works on top of a TCP/IP protocol. It is specifically designed to tackle unreliable communication networks.

2. CoAP
Constrained Application Protocol is an application layer protocol designed to cater to the needs of HTTP-based IoT systems. It relies on the USe Datagram Protocol to establish secure communication between the endpoints. Designed by IETF, it uses a request/response model and supports built-in service discovery. While HTTPS is often too heavy and power-consuming for most IoT applications, CoAP is lightweight with smaller packets. It is traditionally used in applications that include smart energy and building automation.

3. AMQP
Advanced Messaging Queue Protocol is an open standard publish/subscribe type protocol used for transactional messages between servers. Its use is quite limited in the IoT industry due to its heaviness which is not compatible with IoT sensor devices with limited memory, power, or bandwidth network. Its robust communication model can guarantee complete transactions. Due to its security and reliability, it is commonly used in server-based analytical environments.

4. REST
Representational State Transfer is a web standards-based architecture that uses HTTP protocol. It is used to exchange data between applications and integrate applications that belong to different domains. It uses a client/server paradigm composed of clients, servers, and resources. REST is a good model for IoT devices and is also used to create stateless, reliable APIs.

5. XMPP
Extensible Message and Presence Protocol has been widely applied as a communication protocol that uses XML messages. It enables users to send real-time, instant messages and handles users’ status (presence) information. The features of XMPP include:

  • Sending and receiving messages
  • Checking and sharing presence status (online, offline, busy)
  • Manage subscriptions to and from users
  • Manage contact lists
  • Block communications to specific users

6. STOMP
Simple/Streaming Text Oriented Messaging Protocol uses a set of commands such as Connect, Send or Subscribe to manage a conversation. It transmits data across applications and is less complex than AMQP. It is used with message-oriented middleware in IoT, and it enables clients to communicate with message brokers, enabling easy and widespread messaging interoperability.

IoT has rapidly expanded across the globe in various industries, and today it supports dozens of different protocols. Sustainable development of the IoT network requires a clear understanding of the protocols. Experts who provide IoT technologies analyze business requirements and know the advantages or drawbacks of various protocols, allowing them to select the best-suited one for any given use case.