Definition and importance of IoT protocols
Internet of Things (IoT) protocols are a collection of guidelines and standards that control how objects on the network communicate with one another. These technologies’ primary goal is to provide seamless communication across various IoT devices, irrespective of platform or vendor. They serve as the basis for data transfer and are essential to the accomplishment of IoT projects. IoT applications would not be able to effectively communicate with one another without these appropriate protocols.
IoT application protocols
A network’s application layer makes it possible for network entities to recognize and communicate with one another.
MQTT (Message Queueing Telemetry Transport)
MQTT is a low-power communication protocol made especially for M2M and Internet of Things applications. It works well in remote settings or for bandwidth-constrained applications. Through the usage of a connection-oriented publish/subscribe architecture, MQTT applications have the ability to either publish (transmit) or subscribe to (receive) topics. Information is passed from the publishing client to the subscribed client via a MQTT broker.
An oil rig, for example, might contain a predictive maintenance sensor that uses the MQTT protocol to identify vibration variations. When the vibration level is above a threshold, the MQTT broker forwards the information to a software program that has subscribed to the topic “vibrations.” The sensor “publishes” the vibration level to the broker.
HTTP (HyperText Transfer Protocol)
The most used protocol for Internet navigation and data availability via REST-APIs is Hypertext Transfer Protocol. Using HTTP for IoT has the primary benefit of allowing web application developers to deliver data to a Webserver using the same method an HTTP POST request.
The fact that HTTP use connectionless request-respond communication means that each message must contain authentication information, which wastes energy and data. However, HTTP may be the best option for use cases where devices already need to call REST-APIs and where there are fewer power and data limitations.
As with MQTT and MQTT over WebSocket, common IoT cloud providers like AWS IoT and Azure IoT support HTTP as one of the protocols.
WebSocket
WebSocket is a bi-directional communication protocol that web applications can use to deliver large amounts of data fast. Every message has a minimal overhead after the initial connection is established since a WebSocket creates a connection between the client and the server. Because servers and devices may send and receive data simultaneously in real-time, this protocol is ideal for Internet of Things applications where frequent connectivity, low latency, and cheap data consumption are all crucial.
AMQP (Advanced Message Queuing Protocol)
Open-source message-oriented middleware (MOM) protocol AMQP. Although not designed for the Internet of Things, it allows communication across systems, gadgets, and apps from different manufacturers. Unlike MQTT, more routing options are offered than just publish and subscribe on topics, however this flexibility increases protocol overhead and application setup complexity. Additionally, Azure IoT supports AMQP for device communication.
CoAP (Constrained Application Protocol)
The Constrained Application Protocol (CoAP) is intended for “constrained” networks, which are lossy, low-power networks. Because CoAP is typically used in conjunction with User Datagram Protocol (UDP), it is very effective and desirable for Internet of Things applications where battery life is crucial. It is frequently utilized in smart meter communications, for instance. As a transport mechanism, CoAP can also employ SMS or TCP.
LwM2M (Lightweight Machine-to-Machine)
Building on CoAP, the Lightweight Machine-to-Machine (LwM2M) protocol offers extremely effective low-power communication. However, LwM2M also outlines device management and provisioning features. Consequently, LwM2M, for instance, provides a defined process to make clear which security technique is employed and how firmware updates are made to devices. LwM2M can be used with SMS, TCP, and UDP for data transfer because it is built on top of CoAP.
XMPP (Extensive Messaging and Presence Protocol)
XML was used to create the Extensible Messaging and Presence Protocol. Originally designed for instant messaging (IM), XMPP includes an overhead for sending presence data and is unsuitable for low-memory devices. However, because XMPP enables the message format to be defined, it can handle highly structured data, uniquely identify a device, and make cross-platform conversations easier. With new IoT-related advancements, this open-source technology is always being improved and is very accessible.
DDS (Data Distribution Service )
For solutions requiring extensive coordination, dependable transmissions, and distributed processing among the devices themselves, the Data Distribution Service protocol is an interoperable, real-time communication protocol. It is more reliable and effective when data is shared directly between peers rather than being sent to a central hub or broker. DDS employs a publish/subscribe system in which devices send to a topic, subscribe to the subject, and then use multicast to disseminate the information to them. TCP and UDP are both acceptable transmission protocols for DDS.
SMS / SMPP (Short Message Peer-to-Peer Protocol)
Through a cellular connection, Short Message Service enables devices and apps to send and receive text messages. To send and receive data to the application or to another peer in the mobile communication network, cellular Internet of Things devices use Short Message Services (SMS).
Through the use of an SMS Rest-API or the Short Message Peer-to-Peer Protocol (SMPP), an application can establish a programmatic connection with a service provider’s Short Message Service Center (SMSC). Telematics companies can remotely provision and configure their devices by using SMPP.
USSD (Unstructured Supplementary Service Data)
The USSD messaging protocol, which is based on the Global System for Mobile Communications (GSM), is often referred to as “Feature Codes” or “Quick Codes.” IoT companies can obtain text-based information from IoT devices (such location, temperature, and other status updates) without a data connection by using USSD. Unfortunately, USSD is going to be outdated soon because a lot of ships are retiring their 2G and 3G networks.
Simple Sensor Interface (SSI) protocol
SSI makes it possible for Internet of Things sensors to send and receive data to and from a terminal, like a computer or mobile device. As the name suggests, SSI communication requires relatively minimal power because the protocol is not particularly complicated. But since 2006, the protocol has not been updated, therefore it might already be out of date.