IPv6, the most recent internet protocol version, is mostly used in IoT for data transfer and communication. Each Internet of Things device has an IP address, therefore networking is an important part of the Internet of Things. The network layer is served by the communication layer. In this article, we’ll go through the most prevalent communication protocols used in the IoT in depth.

IoT Communication Protocols

Protocols for the Link Layer

Ethernet, Wifi, WImax, Low rate WPAN, and mobile communication such as 5G, 4G, and 3G are the top five protocols in the Link Layer. This layer is used by the PHY and MAC protocols.

Protocols for the Network Layer

This is a crucial layer. IPv4 (previously used), IPv6 (which accepts 128-bit addresses), and 6LoWPAN are the protocols used in this tier. The adaption layer is known as 6LoWPAN.

Protocols for the Transport Layer

The transport agents are contained in this layer. TCP (Transmission control protocol) and UDP (Uniform Datagram Protocol) are the two main protocols used in this tier.

TCP (Transmission Control Protocol) is a highly reliable protocol that includes error control, control flow, and congestion control. There is no packet loss because each packet sent anticipates a response. When the receiver adjusts its size and delivers packets based on the window, this is known as flow control.

a. UDP — This protocol is very easy to use. Audio and video data are typically delivered over UDP. Because all packets are sent from the same parent, acknowledgment is not required in this protocol. It is compatible with the Internet of Things.

Protocol for the Application Layer

The most crucial protocol is this one. The users are served by this layer. It provides the user with information. This layer is necessary since it can meet the user’s requirements. For example, suppose a user wishes to know about his smart refrigerator’s temperature flow. This layer determines the messaging capacity and wraps up the service’s performance. In comparison to the pre-IoT period, these layers mainly fit within the IoT standard.

The following are the most popular protocols in this layer:

a. Message Queuing Telemetry Transport Protocol (MQTT) in IoT

MQTT is ideal for vehicle-to-vehicle communication in the automobile industry. It is now practiced in the majority of European countries. It is based on client-server technology and uses a publishers-subscriber approach. MQTT gateways are servers that run MQTT.

As a result, there are four key components in this model.

The message is published, or rather, a topic is subscribed to by the publishers.
The incoming message is managed by the MQTT server, which then sends it to the subscriber clients.
The broker serves as a storage component, storing all messages received from subscriber clients.
Each topic is identified by a label. The client then sends the relevant subscription, which may include one or more topics.
MQTT control packets are used in the subscriber/publisher technique.

b. Transport of Secure Message Queue Telemetry (SMQTT)

The MQTT protocol has been enhanced with this protocol. It is based on attribute encryption that is light in weight. It improves the MQTT protocol’s security characteristics. Encryption turns your data or information into a particular code that prevents hacking and unauthorized access to your personal information. Because data is constantly transmitted in IoT devices, this is a necessary function. SMQTT is a protocol that ensures secure data transfer between two devices, such as clients and servers.

Initialization, encryption, publishing, and decryption are all part of the algorithm.

c. Application Protocol with Restricted Access (CoAP)

The Confined Application Protocol is a web transfer protocol that is utilized in constrained networks and nodes, as the name implies. They’re commonly found in fields like smart energy and building automation.

It is based on the client-server protocol, which is also used in HTTP. The client sends a request, and the server responds, much like in the HTTP protocol. GET, POST, PUT, and DELETE are all HTTP methods that are relevant in CoAP.

Client-to-client, server-to-client, and client-to-server via proxy communications are all possible. A proxy acts as a conduit for messages between the server and the client.

A smart “thing” in CoAP can operate as both a server and a client. A method code is used by a client to send a request for a server resource. A reply code is returned by the server.

d. Query Protocol for Advanced Messaging (AMQP)

The AMQP protocol was born out of the need to solve basic technologies. AMQP’s fundamental purpose is to be practical, dependable, and useful. Its goal is to disseminate message-oriented middleware throughout the world. It brings together users and vendors to solve all of the existing, common issues. We usually call AMQP “Internet Protocol for Business Managing” so that end-users feel connected to technology without feeling excluded.

On one hand, we have the clients, and on the other hand, we have the service. The services communicate over an AMQP bus, with the majority of the code written in C++ or Java.

1. Exchange gets communications from published sources and forwards them.
2. Queues stores these messages before forwarding them to the subscriber.
3. Binding serves as a link between the queue and the exchange. It establishes a link between the exchange and the intended queue.

e. Data Distribution Service (DDS)

Because DDS is a broker’s design, it differs from the others listed above. DDS’ architecture is based on a publish-subscribe communication model. The DDS is run by the Object Management Group (OMG).

There are two sorts of messages in its message model:

1. DCPS (Data Centric Publish Subscribe): The DCPS layer allows for messaging. It is the foundation of DDS.
2. Data-local Reconstruction Layer (DLRL): The DLRL is an optional layer that is not always used. It oversees application integration and, on occasion, offers sophisticated functionalities.

The DDS delivers excellent performance across a variety of transport protocols and platforms. Google, IBM, and Microsoft are among the companies that employ it.

f. RPL (Research Project License)

RPL, or Routing Protocol for Low-Power Lossy Networks, is a conditional long-distance routing protocol (Destination-oriented acrylic graphs). It’s a sort of graph that doesn’t have any cycles, like spanning trees. Each node in this tree aspires to reach a single destination. Packet loss is a possibility with this protocol.

Any node can send a multicast message called a Dodag Information Object (DIO). It notifies other nodes of the status.
A node sends a Dodag Information Solicitation message if it wants to join the Dodge.

DODAG advertisement object (DAO) requests are sent from the child node to the parent node, while DODAG-ACK responses are sent from the parent node to the child node.

g. CORPL Protocol

This is the cognitive RPL protocol, which is an expansion of the RPL protocol. It follows the same DODAG structure as the previous example. Its design is appropriate for cognitive networks. Packets were forwarded by nodes via opportunistic forwarding. The distinction is that in this protocol, instead of only the parent, each node has access to the information. Every node updates each other using DIO messages, and the forwarding set is built on this foundation.

h. CARP

The Channel Aware Routing Protocol, often known as CARP, uses lightweight packets. This protocol is mostly used in underwater communication and IoT technology. It does not support security or forwarding technologies. It chooses the forwarding nodes based on the link quality from the transmission data history.

Initialization and data forwarding are the two processes of CORP routing. It broadcasts from the sink to the rest of the nodes during network startup. E-CARp is a step up from CARP.

i. 6LoWPAN

IPv6 is connected to 802.11 and IoT devices via this protocol. Thread is a great example of how 6LoWPAN may be used.

j. Radio transmission methods

The most common radio protocols for low-power and private area networks are Zigbee, Z-Wave, and thread. They utilize less energy yet produce faster results. They are inexpensive, but they raise the bar for small local device networks.

ZigBee (ZigBee)

Zigbee is a widely used Internet of Things protocol. It uses the 2.4 GHz frequency, which is widely utilized around the world. High-level communication protocols are well-suited to Zigbee. It works with Zigbee Green Power devices, which are energy harvesting devices.

Energy harvesting is a technique for extracting energy from the environment using vibration, light, wind, or water. These sources are converted into energy that is used to power a vast number of gadgets. Sunlight, for example, is utilized to power solar panels that generate electricity.

LoRaWAN/LoRa(low range)

In the industrial sector, this is a widely used protocol. It is primarily used in industrial IoT. LoRa is a standardized protocol for IoT devices that are utilized in devices and boards.

The wireless link is called LoRa, and the communication link on the other side is called LoRaWAN. It connects to an IoT Network, such as a server or an application. It addresses issues at the physical layer, whereas LoRaWAN addresses issues at the higher layer.

They contain gadgets from three separate classes: A, B, and C.

Class A includes battery-powered sensors, class B includes both battery-powered sensors and actuators, and class C includes main-powered actuators that are connected to a power source. The difference in functioning is based on how these gadgets work when they have electricity and when they don’t.

Z-wave

Another communication protocol is Z-wave, which is commonly used in smart home networks. It enables smart home gadgets to communicate with one another. It’s a low-cost, wireless communication system. This enables two-way communication and message response between devices via a mesh network. It consumes less power than WiFi and has a larger range than Bluetooth.

BLE (Bluetooth Low Energy)

It reduces the cost, power consumption, and maintenance costs by a significant amount, and as a result, it is widely used. Bluetooth is managed by the Bluetooth special interest group or Bluetooth SIG.

Bluetooth Low Energy, which was recently introduced, consumes very little power. The job of locating is done by beacons. Direction-finding and Mesh were introduced with Bluetooth 5.0, and they are now widely utilized.

Bluetooth is continually improving its game as a result of a slew of high-tech advancements. It’s gaining traction, and it could soon become a widely used IoT standard. It has a great deal of potential in the future.

Wireless Internet

Wifi is a frequency or radio protocol that allows devices to communicate wirelessly. It is a wireless alternative to ethernet, which needs the use of wires. Wifi uses frequencies of 2.4 GHz and 5 GHz to deliver data. It is compatible with both broadband and narrowband applications. It works with the Internet of Things (IoT) applications that require a lot of bandwidth and latency.

Telecommunications Network

The cellular network is the most robust and reliable connectivity technology available. LTE-A is a step further in LTE technology. It greatly improves coverage while also lowering latency. It has a lot of uses in IoT, such as vehicles and UAVs.

Network of Service Providers

This is a frequent IoT technology choice. It also gives normal mobile phone access, as well as access to laptops and tablets, as well as backup internet connections via LTE/5G routers and mobile vehicular access, and fleet tracking.

A personal network

These days, private LTE and private 5G of the private network are getting a lot of attention.

RFID and NFC

Near Field Communication, or NFC is a technology that allows powerless devices to communicate with each other. Using embedded NFC in underpowered gadgets, you may add intelligence to any situation. NFC is simple to use and allows users to connect quickly. You may quickly join the network and begin sharing information. NFC also provides security for both the device and the network.
Radiofrequency identification, or RFID, employs a two-way radio to identify and track things with tags.

Thread

Thread is a low-power wireless communication protocol that uses mesh networking to communicate. It can connect hundreds of devices while also providing security and safety. In the event of a threat, it can also reconfigure and self-heal. Thread makes connections simple, provides a flexible platform, and integrates effortlessly with big networks.

NB-IoT

Narrow Band IoT is a 5G technology that is designed for networks with minimal bandwidth requirements or dense connections. The system’s coverage is expandable, providing minimal latency and real-time security and protection.

NB-IoT is commonly used in rural and deep indoor settings. It can connect to a huge number of devices in single disposal due to its ultra-low device complexity. It has a long battery life, is easily disposable, and is dependable.

Protocols for network communication

Data is sent and shared via network protocols securely and simply. ISO’s Open Systems Interface is the most widely used method of establishing communication between two open systems.

a. OSI model (Open Systems Interconnection)

The OSI model simply directs and describes each layer’s input and output data. These definitions are then used by network architects.

The OSI model is divided into seven layers: physical, network, datalink, transport, session, presentation, and application. OSI is implemented by the TCP-IP paradigm. TCP-IP reduces the seven levels of the internet protocol to four.

1. Physical Layer: This layer contains physical equipment such as cable and modem, as the name implies. It carries data that is both raw and unfiltered. It is a device that sends and receives data.
2. Data Link Layer: This layer is made up of limited nodes that exchange data and information with other nodes. Flow control and multiplexing are provided by Media Access Control (MAC). Flow and medium control, as well as well-known line protocols, are provided by Logical Link Control (LLC).
3. Network Layer: This layer takes information from the data link layers and passes it on according to the instructions and addresses written in them.
4. Transport Layer: This layer transmits data and checks for eros. One example of this layer is TCP.
5. Session Layer: This layer establishes and maintains a machine-to-machine connection. This layer also connects and authenticates.
6. Presentation Layer: Based on the syntax and semantics that the application layer accepts, this layer interprets data for the application layer.
7. Application layer: This layer communicates with the software and the end user. End-user services, such as office360, are provided by it.

b. TCP/IP

The TCP/IP layer is made up of four levels that incorporate some of the OSI model layers.

1. Physical and Network Access Layer: This layer combines the first and second OSI levels into one. This layer establishes connections and sets an IP address to each device for easy identification.
2. Internet Layer: This layer describes how routers send data packets based on IP addresses from a host to a destination.
3. Transport Layer: This layer assures that packets are sent along the same path they came from.
4. Application Layer: This layer ensures messaging at the application level. HTML and FTP are two examples.

c. File Transfer Protocol

FTP (File Transfer Protocol) is a protocol that allows you to transfer files from one computer to another

IoT continually sends files from one location to another. FTP, or File Transfer Protocol, is a protocol that manages file transfer requests within a network. The following are some of FTP’s features:

Files can be transferred between any two networks.
Even if the connection stops, file transfers continue, but the protocol setup must be right.
A geographically separated team can collaborate.

d. Point-to-Point Protocol (PPP)

PPP stands for point-to-point protocol, and it is used to transport basic transfer units. It is made up of three primary parts:

The transfer units are encapsulated in this procedure.
LCP stands for Link Control Protocol, and it is used to set up, configure, and test data-link connections.
NCP stands for National Control Protocols, which are used to set up and configure network-layer protocols.

Conclusion

In this article, we looked at the most prevalent IoT communication protocols, including the Link layer, network layer, transport layer, and application layer.