Exploring IIOT communication protocols

In this blog, we delve into the intricacies of IIoT and IOT communication protocols, exploring their significance, key features, and the impact they have on industrial processes. At the heart of this technological revolution lies the robust and efficient communication protocols that facilitate seamless connectivity between devices, machines, and systems.

Connecting IoT devices

A major aspect of planning an IIoT technology project is to determine the devices’ IIoT protocols—in other words, how the devices connect and communicate. In the IIoT/IoT technology stack, devices connect either through gateways or built-in functionality.

What are gateways?

Gateways are part of the technology of IIoT that can be used to help connect IIoT devices to the cloud. Though not all IIoT devices require a gateway, they can be used to establish device-to-device communication or connect devices that are not IP based and can’t connect to the cloud directly. Data collected from IIoT devices moves through a gateway, gets preprocessed at the edge, and then gets sent to the cloud.

Using IIoT gateways can lower latency and reduce transmission sizes. Having gateways as part of your IIoT protocols also lets you connect devices without direct internet access and provide an additional layer of security by protecting data moving in both directions.

How do I connect IIoT devices to the network?

The type of connectivity you utilize as part of your IIoT protocol depends on the device, its function, and its users. Typically, the distance that the data must travel—either short-range or long-range—determines the type of IoT connectivity needed.

Types of networks

Low-power, short-range networks

Low-power, short range networks are well-suited for homes, offices, and other small environments. They tend to only need small batteries and are usually inexpensive to operate. Eg Ble, Zigbee, wifi.

Low-power, wide-area networks (LPWAN)

LPWANs enable communication across a minimum of 500 meters, require minimal power, and are used for a majority of IoT devices. Eg LoRawan

Understanding IIoT Communication Protocols

IIoT communication protocols serve as the foundation for the exchange of data and information between interconnected devices in industrial settings. These protocols are essential for ensuring reliable, secure, and efficient communication, enabling real-time monitoring, control, and analysis of industrial processes. Several protocols are widely adopted in IIoT environments, each designed to address specific needs and challenges.

Common IOT protocols:

The type of IoT protocol you’ll need depends on the system architecture layer that the data will travel in. The Open Systems Interconnection (OSI) model provides a map of the various layers that send and receive data. Each IoT protocol in the IoT system architecture enables device-to-device, device-to-gateway, gateway-to-data center, or gateway-to-cloud communication, as well as communication between data centers.

Application layer

The application layer serves as the interface between the user and the device within a given IoT protocol.

Advanced Message Queuing Protocol (AMQP)

A software layer that creates interoperability between messaging middleware. It helps a range of systems and applications work together, creating standardized messaging on an industrial scale.

Constrained Application Protocol (CoAP)

A constrained-bandwidth and constrained-network protocol designed for devices with limited capacity to connect in machine-to-machine communication. CoAP is also a document-transfer protocol that runs over User Datagram Protocol (UDP).

Data Distribution Service (DDS)

A versatile peer-to-peer communication protocol that does everything from running tiny devices to connecting high-performance networks. DDS streamlines deployment, increases reliability, and reduces complexity.

Message Queue Telemetry Transport (MQTT)

A messaging protocol designed for lightweight machine-to-machine communication and primarily used for low-bandwidth connections to remote locations. MQTT uses a publisher-subscriber pattern and is ideal for small devices that require efficient bandwidth and battery use.

Transport layer

In any IoT protocol, the transport layer enables and safeguards the communication of the data as it travels between layers.

Transmission Control Protocol (TCP)

The dominant protocol for a majority of internet connectivity. It offers host-to-host communication, breaking large sets of data into individual packets and resending and reassembling packets as needed.

User Datagram Protocol (UDP)

A communications protocol that enables process-to-process communication and runs on top of IP. UDP improves data transfer rates over TCP and best suits applications that require lossless data transmissions.

Network layer

The network layer of an IoT protocol helps individual devices communicate with the router.

IP

Many IoT protocols utilize IPv4, while more recent executions use IPv6. This recent update to IP routes traffic across the internet and identifies and locates devices on the network.

6LoWPAN

This IoT protocol works best with low-power devices that have limited processing capabilities.

Data link layer

The data layer is the part of an IoT protocol that transfers data within the system architecture, identifying and correcting errors found in the physical layer.

IEEE 802.15.4

A radio standard for low-powered wireless connection. It’s used with Zigbee, 6LoWPAN, and other standards to build wireless embedded networks.

LPWAN

Low-power wide-area networks (LPWAN) networks enable communication across distances of 500 meters to over 10km in some places. LoRaWAN is an example of LPWAN that’s optimized for low power consumption.

Physical layer

The physical layer is the communication channel between devices within a specific environment.

Bluetooth Low Energy (BLE)

BLE dramatically reduces power consumption and cost and maintains a similar connectivity range as classic Bluetooth. BLE works natively across mobile operating systems and is fast becoming a favorite for consumer electronics due to its low cost and long battery life.

Ethernet

This wired connection is a less expensive option that provides fast data connection and low latency.

Long-term evolution (LTE)

A wireless broadband communication standard for mobile devices and data terminals. LTE increases the capacity and speed of wireless networks and supports multicast and broadcast streams.

Near field communication (NFC)

A set of communication protocols using electromagnetic fields that allows two devices to communicate from within four centimeters of each other. NFC-enabled devices function as identity keycards and are commonly used for contactless mobile payments, ticketing, and smart cards.

Power Line Communication (PLC)

A communication technology that enables the sending and receiving of data over existing power cables. This allows you to both power and control an IoT device through the same cable.

Radio frequency identification (RFID)

RFID uses electromagnetic fields to track otherwise unpowered electronic tags. Compatible hardware supplies power and communicate with these tags, reading their information for identification and authentication.

Wi-Fi/802.11

Wi-Fi/802.11 is a standard in homes and offices. Although it’s an inexpensive option, it may not suit all scenarios due to its limited range and 24/7 energy consumption.

Z-Wave

A mesh network using low-energy radio waves to communicate from appliance to appliance.

Zigbee

An IEEE 802.15.4-based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios.

A Detail view on standard iiot protocols:

MQTT (Message Queuing Telemetry Transport)

MQTT has gained prominence as a lightweight and efficient publish-subscribe messaging protocol in the IIoT realm. Its low overhead and support for real-time communication make it an ideal choice for applications requiring rapid data transmission. MQTT's ability to operate over unreliable networks and its minimal bandwidth consumption make it well-suited for industrial applications with varying connectivity conditions.

CoAP (Constrained Application Protocol)

Designed specifically for resource-constrained devices and low-power networks, CoAP is a lightweight and RESTful protocol. It enables efficient communication in environments where bandwidth and energy resources are limited, making it an excellent choice for IIoT devices with constrained capabilities. CoAP's integration with web technologies simplifies data transfer and interaction with web services in industrial applications.

OPC UA (OPC Unified Architecture)

OPC UA is a widely adopted communication protocol that provides a standardized platform for secure and reliable data exchange in industrial automation. It ensures interoperability between diverse devices and systems, promoting seamless integration across different vendors and platforms. OPC UA's support for rich data modeling and security features makes it suitable for complex industrial scenarios, fostering a standardized communication framework.

DDS (Data Distribution Service)

DDS stands out as a data-centric communication protocol that prioritizes real-time, scalable, and reliable information exchange. It is particularly well-suited for applications demanding high-performance communication in distributed systems. DDS's ability to support complex data models and its QoS (Quality of Service) mechanisms make it an excellent choice for demanding IIoT applications in sectors such as healthcare, transportation, and manufacturing.

CONCLUSION

The extensive list of IoT protocols outlined, from the application layer to the physical layer, demonstrates the rich array of tools available to developers and engineers. Whether it's facilitating efficient machine-to-machine communication through MQTT, addressing the constraints of low-power devices with CoAP, ensuring interoperability with OPC UA, or prioritizing real-time, scalable data exchange with DDS, each protocol has a unique role in enhancing industrial processes.

Real-world applications of these protocols underscore their practical significance, enabling industries to achieve unprecedented levels of efficiency, reliability, and security. From smart homes and offices to complex industrial automation systems, IIoT communication protocols are the invisible threads connecting the digital fabric of our interconnected world.