IoT Communication Models
IoT allows the connection of multiple devices (things) to communicate with each other. So, There are four basic types of IOT communication Models, as given below
1. Request-Response Model
In IoT, The client device sends a request to the server. The request may be an upload or transfer of data. The Server responds to the request. The server may be remote or local and can handle the requests of multiple clients. The server receives the request, processes (decides) the response to that request, and fetches the data from resources (i.e., database).
Note: The Request-Response model is stateless, independently handling each request.
2. Publisher-Subscriber Model
There are three essential elements in the publisher-subscriber Model, as given below.
- Publisher: It transfers data to the broker. Publishers don’t know about consumers.
- Broker: It accepts publisher data and sends it to the appropriate subscriber.
- Subscriber: It consumes the topics that the broker manages.
A detailed diagram of the publisher-subscriber model is given below
The broker holds the table of information as shown below
For example, if a person uploads an article on a particular website and any third person reads that topic from the website, then the article up-loader will be the publisher; the website is a broker. The third person will be a consumer.
3 Push-Pull Model
There are three essential elements in the Push-Pull Model, as given below
- Publisher: It pushes the data into Message Queue
- Message Queue: it is a buffer that stores data pushed by a publisher
- Subscriber: It pulls data from the message queue.
Publishers and Subscribers are unaware of each other. The Push-Pull Model is explained under
4. Exclusive Pair
It is a bi-directional (full duplex) combination model. In an exclusive pair, the client establishes a connection with the server by sending a request, and this connection remains open until the client sends a request to close the connection. A detailed diagram is given below.