What are the IoT protocols that are at the base of the Internet of things? Before answering this question, it is useful to have an overview about IoT.
Internet of things is gaining appeal and the most important players are investing in IoT. Internet of things promises to be a technological revolution that will invest every area: industrial, transportation, energy everyday life and so on. As we have seen in previous posts there are several IoT definitions highlighting different aspects and there are many solutions to implement IoT projects.
IoT promises to connect all the devices together and enable them to exchange information like wearable, home devices, smart objects. All this information is gathered and analysed to improve our life.
But how these devices send and receive data? We all know HTTP protocol that makes possible to browse the net, opens web pages and so on. Is this protocol still useful for IoT?
Well, the answer is yes but there are other IoT protocols that can be more efficient and suitable for low power devices.
Below, you will find a list of the most “important” IoT protocols used in IoT ecosystem:
The most important IoT data protocols, you must know to build IoT projects Click To Tweet
MQTT stands for Message Queuing Telemetry Trasport . It is a publish/subscribe message lightweight protocol. It is a M2M (Machine to Machine) oriented protocol. Now it is an open standard maintained by OASIS group. The reference architecture is very simple and it is based on client/server. The client is generally a sensor that “publish” the information to the server (broker) that receives the information and dispatch it to the subscribers. The underlying communication is based on TCP.
Generally speaking, MQTT protocol uses a many-to-many paradigm and the broker decouples the publisher to the subscriber and acts as a message router. This protocol implements QoS, secure communication, persistence and so on. There is another version of this MQTT IoT protocol called MQTT-SN (or MQTT-S) that stand for Sensor network. Eclipse has released an open source implementation of MQTT called Mosquitto.
COAP stands for Constrained Application protocol. This protocol was designed by IETF and it is a M2M protocol. This protocol is defined by RFC7252 and it is web transfer protocol. This protocol is very similar to HTTP and it is based on the document transfer paradigm. It uses request/response model and supports built-in service discovery. Respect to HTTP protocol, COAP is lightweight with smaller packets.
COAP uses UDP as underlying network protocol. It is basically a client-server protocol where the client makes a request and the server sends back a response as it happens in HTTP. The methods used by COAP are the same used by HTTP.
AMQP stands for Advanced Message Queue Protocol. It is maintained by OASIS as MQTT. AMQP is an open standard to exchange messages between applications (M2M). In other words, it is a message oriented protocol that provides features like routing and queuing. The key factors of AMQP are:
- It is open
- It is interoperable
- It is secure
- It is reliable
We al know Rest protocol. It stands for (Representational state transfer). It is used to exchange data between applications and to integrate applications belonging to different domains. It uses HTTP as based protocol. Rest uses client/server paradigm. It is widely used not only in IoT ecosystem. We discussed how to use Rest to integrate arduino with Android.
XMPP (Extensible Messaging and Presence Protocol) is an open standard for presence and messaging. This protocol uses XML messages The XMPP-IoT is designed specifically for IoT environment. Basically, this protocol enables users to send real-time messages and handles the user presence (Online, Offline, Busy). The IoT version enables users to send and receive messages from machines. Moreover, it is eXtensbile easily. The key factors are:
- Open standard
Stomp is a text oriented messaging protocol. It is very easy to use. Clients connect to a message broker to exchange messages.
At the end, you gained an overview about IoT protocols and what are their key points.