FAO

IoT protocols are an integral part of the IoT technology stack. Without them hardware would be deemed useless. This is because these protocols enable hardware to exchange data from which useful information can be extracted by the end-user.

Types of protocols

IoT protocols and standards are broadly classified into two separate categories. These are:
1. IoT data protocols (Presentation / Application layers)
2. Network protocols for IoT (Datalink / Physical layers)

Network architecture

The internet of things requires huge scalability in the network space to handle the surge of devices. IETF 6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks-this concept originated from the idea that “the Internet Protocol could and should be applied even to the smallest devices,” and that low-power devices with limited processing capabilities should be able to participate in the IoT) would be used to connect devices to IP networks. With billions of devices being added to the Internet space, IPv6 will play a major role in handling the network layer scalability. IETF’s Constrained Application Protocol, ZeroMQ, and MQTT would provide lightweight data transport.
Fog computing is a viable alternative to prevent such a large burst of data flow through the Internet. The edge device’s computation power to analyze and process data is extremely limited. Limited processing power is a key attribute of IoT devices as their purpose is to supply data about physical objects while remaining autonomous. Scalability is easy because IoT devices simply supply data through the internet to a server with sufficient processing power.

Protocol architectures and Application

1.IoT Data Protocols
These 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:
i.MQTT (Message Queuing Telemetry Transport)
An MQTT is a lightweight IoT data protocol which features a publisher-subscriber messaging model and allows for simple data flow between different devices. (Pub/Sub messaging is a form of asynchronous service-to-service communication used in serverless and microservices architectures. In this architecture any message published to a topic is immediately received by all subscribers to that topic.)
MQTT’s generic 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. 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
ii.CoAP (Constrained Application Protocol)
A CoAP is an application layer protocol designed to address the needs of HTTP-based (Hypertext Transfer Protocol) IoT systems. HTTP is 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 leading to many within the IoT community dismissing HTTP as a protocol not suitable for IoT.
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 which is ideal for use in devices with resource limitations, such as IoT microcontrollers or WSN nodes. It is used traditionally used in applications involving smart energy and building automation.
iii.AMQP (Advanced Message Queuing Protocol)
An Advance Message Queuing Protocol is an open standard application layer protocol used for transactional messages between servers.
The main functions of this IoT protocol are as follows:
1 Receiving and placing messages in queues
2 Storing messages
3 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 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.
iv.DDS (Data Distribution Service)>
DDS 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. It is considered the first international middleware IoT standard.
v.HTTP
This is not preferred as an IoT standard because of its cost, battery life, huge power consumption, and weight issues. However, it is still used within some industries e.g 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.
vi.WebSocket
It 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. There-fore it is used most commonly in places that act as clients or servers. This includes runtime environments or libraries.

2.Netwoek Protocols for IoT
IoT network protocols are used to connect devices over a network. These sets of protocols are typically used over the internet. They include:
i.Wi-Fi
In order to create a Wi-Fi network, you need a device that can send wireless signals e.g Telephones, computers, routers. 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. 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./
ii.Bluetooth
Bluetooth tends to frequency hop and has a generally shorter range. It has however gained a huge user base due to its integration into modern mobile devices as well as wearable technology.
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 2 MHz. 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 requires significant flexibility, scalability, and low power consumption.
iii.ZigBee
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.It’s a relatively simple packet data exchange protocol and is often implemented in devices with small requirements e. g microcontrollers and sensors. It easily scales to thousands of nodes hence many suppliers are offering devices that support ZigBee’s open standard self-assembly and self-healing grid topology model.
iv.Z-Wave
Z-Wave is an increasingly-popular IoT protocol. It’s a wireless, RF cased communication technology that’s primarily used for IoT home applications. It operates within its own range, There-fore suffers from any significant interference problems. Z-Wave is an impressive IoT protocol. However, like ZigBee, it’s best used within the home and not within the business world.
v.LoRaWan
This a media access control (MAC) IoT protocol. It 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 of FSK modulation for industrial, scientific, and medical (ISM) radio bands.