IoT protocols and standards are often overlooked when people think about the Internet of Things (IoT). More often than not, the industry has its attention firmly fixed upon communication. And while the interaction between devices, iot sensors, gateways, servers, and user applications are essential components of the IoT, communication would fall down without the right IoT protocols.
With that in mind, we’re going to look at some of the IoT protocols and standards your business may use in 2021.
What protocols do IoT-qualified devices use?
IoT protocols and standards are broadly classified into two separate categories. These are:
- IoT data protocols (Presentation / Application layers)
- Network protocols for IoT (Datalink / Physical layers)
We’re going to start by looking at the former. (The parenthesis is a reference to the OSI network layer model).
IoT Data Protocols
IoT data protocols are used to connect low-power IoT devices. They provide communication with hardware on the user side – without the need for any internet connection.
The connectivity in IoT data protocols and standards is through a wired or cellular network. Some examples of IoT data protocols are:
MQTT (Message Queuing Telemetry Transport)
An MQTT (Message Queuing Telemetry Transport) is a lightweight IoT data protocol. It features a publisher-subscriber messaging model and allows for simple data flow between different devices.
MQTT’s main selling point is its architecture. Its genetic make-up is basic and lightweight and, therefore, it’s able to provide low power consumption for devices. It also works on top of a TCP/IP protocol.
IoT data protocols were designed to tackle unreliable communication networks. This became a need in the IoT world due to the increasing number of small, cheap, and lower-power objects that have appeared in the network over the past few years.
Despite MQTT’s wide adaptation – most notably as an IoT standard with industrial applications – it doesn’t support a defined data representation and device management structure mode. As a result, the implementation of data and device management capabilities is entirely platform- or vendor-specific.
CoAP (Constrained Application Protocol)
A CoAp (Constrained Application Protocol) is an application layer protocol. It’s designed to address the needs of HTTP-based IoT systems. HTTP stands for Hypertext Transfer Protocol, and it’s the foundation of data communication for the World Wide Web.
While the existing structure of the internet is freely available and usable by any IoT device, it’s often too heavy and power-consuming for most IoT applications. This has led to many within the IoT community dismissing HTTP as a protocol not suitable for IoT.
However, CoAp has addressed this limitation by translating the HTTP model into usage in restrictive devices and network environments. It has incredibly low overheads, is easy to employ, and has the ability to enable multicast support.
Therefore, it’s ideal for use in devices with resource limitations, such as IoT microcontrollers or WSN nodes. It’s traditionally used in applications involving smart energy and building automation.
AMQP (Advanced Message Queuing Protocol)
An Advanced Message Queuing Protocol (AMQP) is an open standard application layer protocol used for transactional messages between servers.
The main functions of this IoT protocol are as follows:
- Receiving and placing messages in queues
- Storing messages
- Setting up a relationship between these components
With its level of security and reliability, it’s most commonly employed in settings that require server-based analytical environments, such as the banking industry. However, it’s not widely used elsewhere. Due to its heaviness, it’s not suitable for IoT sensor devices with limited memory. As a result, its use is still quite limited within the world of the IoT.
DDS (Data Distribution Service)
DDS (Data Distribution Service) is another scalable IoT protocol that enables high-quality communication in IoT. Similar to the MQTT, DDS also works to a publisher-subscriber model.
It can be deployed in multiple settings, from the cloud to very small devices. This makes it perfect for real-time and embedded systems. Moreover, unlike MQTT, the DDS protocol allows for interoperable data exchange that is independent of the hardware and the software platform.
In fact, it’s considered the first open international middleware IoT standard.
HTTP (HyperText Transfer Protocol)
We’ve briefly touched on the HTTP (HyperText Transfer Protocol) model before. As mentioned, the HTTP protocol is not preferred as an IoT standard because of its cost, battery life, huge power consumption, and weight issues.
That being said, it is still used within some industries. For example, manufacturing and 3-D printing rely on the HTTP protocol due to the large amounts of data it can publish. It enables PC connection to 3-D printers in the network and printing of three-dimensional objects.
WebSocket was initially developed back in 2011 as part of the HTML5 initiative. Via a single TCP connection, messages can be sent between the client and the server.
Like CoAp, WebSocket’s standard connectivity protocol helps simplify many of the complexities and difficulties involved in the management of connections and bi-direction communication on the internet.
It can be applied to an IoT network where data is communicated continuously across multiple devices. Therefore, you’ll find it used most commonly in places that act as clients or servers. This includes runtime environments or libraries.
Network Protocols for IoT
Now we’ve covered IoT data protocols, we’re going to look at the different network protocols for IoT.
IoT network protocols are used to connect devices over a network. These sets of protocols are typically used over the internet. Here are some examples of various IoT network protocols.
There’s no denying that Wi-Fi is the most well-known IoT protocol on this list. However, it’s still worth explaining how the most popular IoT protocol works.
In order to create a Wi-Fi network, you need a device that can send wireless signals. These include:
That being said, the list goes on.
Wi-Fi provides an internet connection to nearby devices within a specific range. Another way to use Wi-Fi is to create a Wi-Fi hotspot. Mobile phones or computers may share a wireless or wired internet connection with other devices by broadcasting a signal.
Wi-Fi uses radio waves that broadcast information on specific frequencies, such as 2.4 GHz or 5GHz channels. Furthermore, both of these frequency ranges have a number of channels through which different wireless devices can work. This prevents the overflowing of wireless networks.
A range of 100 meters is typical of a Wi-Fi connection. That being said, the most common is limited to 10-35 meters. The main impacts on the range and speed of a Wi-Fi connection are the environment and whether it provides internal or external coverage.
When compared to other IoT network protocols listed here, Bluetooth tends to frequency hop and has a generally shorter range.
However, it’s gained a huge user base due to its integration into modern mobile devices – smartphones and tablets, to name a couple – as well as wearable technology, such as wireless headphones.
Standard Bluetooth technology uses radio waves in the 2.4 GHz ISM frequency band and is sent in the form of packets to one of 79 channels. However, the latest Bluetooth 4.0 standard has 40 channels and a bandwidth of 2Mhz. This guarantees a maximum data transfer of up to 3 Mb/s.
This new technology is otherwise known as Bluetooth Low Energy (BLE) and can be the foundation for IoT applications that require significant flexibility, scalability, and low power consumption.
ZigBee-based networks are similar to Bluetooth in the sense that it already has a significant user base in the world of IoT.
However, it’s specifications slightly eclipse the more universally used Bluetooth. It has lower power consumption, low data-range, high security, and has a longer range of communication (ZigBee can reach 200 meters, while Bluetooth maxes out at 100 meters)
It’s a relatively simple packet data exchange protocol and is often implemented in devices with small requirements, such as microcontrollers and sensors. Furthermore, it easily scales to thousands of nodes. This makes it no surprise that many suppliers are offering devices that support ZigBee’s open standard self-assembly and self-healing grid topology model.
Z-Wave is an increasingly-popular IoT protocol. It’s a wireless, radio frequency (RF) cased communication technology that’s primarily used for IoT home applications.
It operates on the 800-900MHz radiofrequency. On the other hand, Zigbee operates on 2.4GHz, which is also a major frequency for Wi-Fi. By operating in its own range, Z-Wave rarely suffers from any significant interference problems. However, the frequency that Z-Wave devices operate on is location dependent, so make sure you buy the right one for your country.
Z-Wave is an impressive IoT protocol. However, like ZigBee, it’s best used within the home and not within the business world.
LoRaWAN is a media access control (MAC) IoT protocol.
LoRaWAN allows low-powered devices to communicate directly with internet-connected applications over a long-range wireless connection. Moreover, it has the capability to be mapped to both the 2nd and 3rd layer of the OSI model.
It’s implemented on top of LoRa or FSK modulation for industrial, scientific, and medical (ISM) radio bands.