IoT Protocols and their Architecture

Now everywhere we are hearing the word IoT. Actually, what it is, how it works and how it simplifies our daily lives we will discuss in this article. Let’s start with the definition of IoT. Multiple electronic devices which are equipped with a unique IP address and communicated with over internet are called the Internet of Things (IoT). In multiple ways, we can define IoT but finally, in this technology, we can control the number of electronic devices through a single device with the help of the Internet. Here, the electronic devices in IoT technology should have the sensors and it should sense the signal through electrically and functions according to it. And the sensed data transferred to the other device through the Internet. IoT will make our life so simple and accurate. Present this technology has huge job opportunities and still there are many developments are going on. Examples for IoT devices like a smartwatch, smart speakers, smart TV’s, Amazon Alexa, Google Home devices are internet-connected devices come under examples of IoT. This article discusses what is IoT, IoT protocols, and architectures.

What are IoT Protocols?

Now the interesting question comes here, how these devices can communicate with each other in IoT? and How IoT works?  Well, how we humans can communicate with each other, same like these devices this can communicate with other devices through protocols which are known as IoT protocols. The protocol is defined as a set of rules and regulation guidelines having how to react for commands from another device. These protocols are very important while in communication devices. The general-purpose protocols like CDMA, WAP, etc are not suitable for this specific IoT technology. This technology needs some more powerful protocols.

Some of the Specific IoT Protocols List

  • MQTT – Message Queue Telemetry Transport Protocol
  • DDS – Data Distribution Service
  • AMQP – Advanced Message Queuing Protocol
  • CoAP – Constrained Application Protocol

Now let’s discuss in detail of IoT protocol overview

1). Message Queue Telemetry Transport Protocol

Machine to machine communication can be with this MQTT. It was developed by IBM. Message queue telemetry transport protocol is a messaging protocol. This protocol collects the data from the devices and forwards to the network. So the connection between the devices and network can be done by this protocol. It’s a simple protocol which sends the data from the sensors to devices and then towards the network. This is the top protocol of the TCP/IP protocol reference model. The three elements in MQTT protocol in IoT. They are subscriber, publisher and dealer/broker. The data can be interchanged between subscriber and publisher. The dealer/broker enables the safety connection between the subscriber and publisher. MQTT runs over the TCP/IP model. Because of this MQTT protocol cannot be used for all types of IoT applications.


2). Advanced Message Queuing Protocol (AMQP)

This advanced message queuing is a suitable protocol for the message-oriented middleware environments. This was developed by John Hara from JP Morgan Chase, London. This IoT communication protocol useful for the exchange of reliable message can be done with this AMQP.

The publisher can communicate with subscriber through AMQP carrier. The messages from the publisher can be store in the carrier of AMQP and as per the message queue and order, they will be forwarded to the relevant subscriber with proper security system line. AMQP has the following three capabilities which make it more reliable and secure. This protocol has the below processing chain.


Exchange: Receives the messages from the publishers and based on priorities they are forwarded to message queues.

Message Queue: Stores the messages until they are properly processed with client software.

Binding: The connection between the exchange and message queue will state by this binding component.

3). Data Distribution Service (DDS)

This protocol is an IoT standard which is developed by Object Management Group (OMG). This DDS can be used in small devices which occupies less area and as well as in the cloud. This is a middleware protocol (lies between operating system and application) and API (Application Programming Interface) which enables the data connectivity between devices. This architecture is best suitable for IoT application. This protocol software is best for interchanging the information and quick data integration in IoT systems. This one supports the major software programming languages. Scalable, real-time and reliable communication can be possible with this Data Distribution Service (DDS).


This DDS standard has two layers. They are:

  • Data-Centric Publish-Subscribe (DCPS)
  • Data Local Reconstruction Layer (DLRL)

DCPS layer delivers the information to all subscribers whereas DLRL providing the interface to the functionalities of DCPS.

4). Constrained Application Protocol (CoAP)

This protocol is an internet utility protocol for the few (restricted) IoT gadgets. It is useful in most of IoT applications. Initially, CoAP is used in the machine to machine communications. CoAP is the alternate protocol for the HTTP. This protocol has an effective XML interchange data format technique. It is a different technique of binary data format has more preferable in terms of space. This could be better than plain text HTML/XML file. CoAP has four different types of messages. They are: non-confirmable, confirmable, reset and acknowledgment. For reliable and secure transmission over UDP confirmable messages are used and the responses can be in the form of acknowledgment. CoAP is a very lightweight protocol and it uses DTLS (Datagram Transport Layer Security) for providing more security and reliable communications.

These are the important protocols of the Internet of Things protocols or IoT protocols.

IoT Protocol Architecture

The most interesting point here is, IoT has don’t have any particular architecture. The researchers proposed different IoT architectures. But in that most proposed architectures three-layer architectures & five-layer architecture.

Three-layer IoT Architecture

This architecture introduced in the early days of research of IoT technology. The three-layers are in IoT architecture is for


Application Layer: This layer is to deliver the specific application to the end-user. The specific applications can be done with this application layer. Example of this layer like a smartwatch, smartphone, smart TV, etc. which is used for a specific application.

Network Layer: Network layer have an important role in IoT architecture. It connects to the other smart electronic devices (smartwatches, servers, etc). The network layer is for transmitting and processing the sensor data.

Perception Layer: It is the physical layer and it gathers the surroundings data by sensing the area with help the of sensors.

Five-layer IoT Architecture

Another architecture which is five-layers IoT architecture is proposed by the researchers who were worked on IoT. In this five-layer IoT architecture, the three-layers which are the application, network, and perception layers are having same architecture like three-layer IoT architecture. Additionally, the Business layer, Transport layer, and processing layer are the new one.


Transport Layer: This layer forward the data from the processing layer to perception layer and vice versa through wireless networks like LAN, 3G, and Bluetooth, etc.

Processing Layer: It is in the middle of the IoT architecture. It’s having an important role in this five-layer IoT architecture. This layer stores the data and process the data which comes from the transport layer. This processing layer able to implement latest technologies like big data, DBMS and cloud computing, etc.

Business Layer: This layer is the head of the IoT architecture. It manages the complete IoT system even applications, user’s privacy, profit models, etc.

The smart home consists of all the devices are connected with a network and communicated with the internet. To develop a smart system like this five-layer IoT protocol stack is the best one.

This concept having more weight in the research area. And there are tremendous changes are happening in IoT technology day today. We can do more research on this IoT protocols and architectures. Here, we have discussed some of the important IoT protocols only. And the few regular protocols like Bluetooth, WiFi, ZigBee, NFC, Cellular, Long ranged WAN and RFID are not discussed here. You can get more data from those on our leprous portal.