IoT Protocols – A Complete Guide

In this article, we will see some of the most common IoT protocols. So let’s get started. 

IoT Protocols

The wireless hardwares used in IoT are the nodes and the base stations. Nodes or clients are the devices that connect to the base stations. Base stations are the routers or gateways. We will discuss the protocols used between these devices. 

Why are IoT protocols important?

The ability to interact with each other and resolve common problems is what separates Iot devices from traditional computers. These interactions are only possible if there is a medium or means of communication in the IoT ecosystem. The IoT protocols are thus a common “language” that allows devices to interact with other Iot devices. The IoT protocols lay  down standards that are adopted in every Iot ecosystem for proper functioning and to avoid security threats. 

There is no universal protocol that helps in communicating with all IoT devices yet. The OMA Lightweight protocol manages devices easily and offers adaptive solutions. 

Types of IoT Protocols

IoT protocols are briefly classified into two types:

1. IoT data protocols

a. Message Queuing Telemetry Transport(MQTT)

MQTT is one of the prime IoT protocols. MQTT protocol is a type of IoT communication protocol that is famous and is gaining popularity due to its transportation of messages through the publish/subscribe messaging. It is lightweight and easily transfers data between two or more machines.

Devices share information through a broker or server. Download the broker in your PC, MAC, Linux system or in Raspberry pie. The most common brokers available in the market these days are HIVEMQ and Mosquito. 

MQTT is different to the regular client-server model. It divides clients into two groups. MQTT brokers act as a mediator and pass on the messages from the clients(publishers in MQTT) to the consumers who receive data on the other end(MQTT subscriber). 

Base stations such as LPWAN receive messages from a sensor. The base station publishes the message on the MQTT broker. The broker passes on or forwards the message through the TCP/IP protocols. Only those devices that subscribe to the given topic receive the messages. 

b. Advanced Message Queuing Protocol

JPMorgan Chase& Co founded the AMQP protocol in 2003. This is an important protocol in IoT. It offers exchange of data within the network and it is open TCP/IP protocol. 

AMQP Protocol focuses mainly on banking systems and other businesses. It uses either the request-response messaging or the publisher-subscriber model. 

Publishers generate messages and consumers at the other end pick those messages to process them. Message brokers make sure that the right message goes to the right consumer. 

The brokers uses two components to achieve this as shown in the diagram:

• Exchange
• Queues 

A publisher posts a message and exchange forwards the message. Queues pick up the message and pass it to the correct consumer. This depends on the device configuration. 

AMQP is reliable, safe and guarantees message transfer to the destination. It also acknowledges the receiving of messages. AMQP protocol supports extensibility. 

c. Data Distribution Service

DDS is a widely used protocol in IoT due to its versatility and extensible nature. It does not depends on middlemen for communication and it directly connects sensor to other devices for open communication 

DDS finds large uses in IoT. Users can easily tackle large amounts of data coming from devices and process this data and then produce quick results. DDS gives rise to quick results, smart decisions, revenue and lesser costs. 

DDS mainly revolves around data and it knows how to transfer data from one messaging point to another. In message-centric middleware, programmers write code for sending messages whereas in data-centric middleware, programmers write code on how and where to share data values. DDS ensure secure message transfer and data sharing.

d. Constrained Application Protocol (CoAP)

CoAP is another promising protocol in the future of IoT. CoAP protocol transfers documents in a way similar to HTTP, however, CoAPs design fulfills the needs of constrained nodes. The packets in CoAP are much smaller in size when you compare it with HTTP TCP. CoAP operates through UDP. Clients and servers retrieve information through Connectionless datagrams.

CoAP permits UDP broadcast and multicast to address. 

CoAP also acts on the client/server model. Clients generate requests to servers and servers in return transfer responses. Clients can GET, POST, DELETE and PUT the resources.  

“Confirmable” and “non confirmable” are tags for request and response messages. Non-confirmable messages come under the label “fire and forget”. CoAP assures similar data security methods except that the data transfer takes place through UDP and not TLS.

e. Extensible Messaging and Presence Protocol(XMPP)

The XMPP protocol by the Jabber open source community is a protocol that extensively uses the XML language. It is a middleware and it is message-oriented. It offers exchange of data among two or more clients in the network. The XMPP modification known as XMPP-IoT finds its uses in the IoT technology. It is highly scalable and compatible since it is an open source community, it also fits consumer standards. 

Major disadvantages of XMPP- IoT include no Quality of service or encryption. 

2. IoT Network Protocols

a. Wireless Body Area Networks(WBAN)

This network has other names such as Body Area Network(BAN), Medical Body Area Network(MBAN) or Body Sensor Network(BSN). They form close connections and are usually within the 10 centimetre to 1 metre range.

The common ones include Bluetooth, NFC, Zigbee, RFID(Radio Frequency) and various other proprietary technologies. 

b. Wireless Personal Area Networks(WPAN)

These have an extended range when you compare them with the WBAN. These have a 1 metre to 10 metre range. 

These networks include Bluetooth, RFID and other similar proprietary software technologies. You can think of these devices as your personal devices that you want to connect with or make them connect with other personal devices. 

c. Wireless Local Area Network(WLAN)

You must have come across the word WLAN. Any local wireless network can be known as a Wireless Local Area Network. 

This includes WiFi/802.11 and Zigbee networks. WiFi is a standard and universal option whereas Zigbee handles protocols that require high level communication. Bluetooth can also come under WLAN. 

d. Wireless Metropolitan Area Networks(WMANs)

This network covers up a larger area such as a city or state. The network is capable of housing an entire city and various devices around the city can easily connect to this network. 

e. Wireless Wide Area Network(WWAN)

This is another common kind of network. This network provides connection at a much larger scale as compared to WMANs. It is capable of providing communication across the globe as well. 

f. Thread 

Thread is a network protocol based on IPv6 and it specializes in IoT device networking. Its design is suitable for low-power IoT devices in th WPAN. Thread does not depend on 802.15 mesh networking protocols such as Zigbee, Z-wave and bluetooth. 

Protocols used by our IoT devices

We can use cellular protocols such as LTE and 5G. LTE is Long-term evolution. It is used for communication in mobile phones and data ports. 

FDD and TDD use a wide range of bands as shown in the picture. 

1. LTE

When you communicate through an LTE, you require a gateway or a cellular device. Generally, all the wireless devices connect to this gateway and the gateway then talk to the 5G or 4G network. So you link all your IoT devices to a gateway that is an LTE subscriber. LoRa and Zigbee are commonly used. These gateways connect to LTE and provide your IoT devices with wide-area connectivity. 

2. 5G

5G Frequency range bands are most commonly in use these days. There are two frequency range bands known as the FR1 and FR2. 

FR1 are the traditional wavelengths and FR2 are the millimeter-wave technologies. The frequency bands keep changing over a period of time and new bands are added constantly. So you might want to stay up to date on these bands. 

Cellular Network

Cellular IoT is  a technology connecting IoT devices under the same cellular network. Smartphones use this technology to connect to mobile networks. This reduces the cost of developing a separate network for IoT devices. Most common cellular networks in Cellular Iot are 3G, 4G/LTE and 5G.

Service Provider Network

IoT service provider networks offer connectivity in the IoT ecosystem. They offer services such as bandwidth and sell permission to access network points. IoT devices can connect to the ISP and improve their functionality. 

Private Network 

LTE and private 5G networks are rapidly growing in both performance and usage.  

Bluetooth and BLE

It is the connection between a smartphone and any other Iot device that can also connect to the internet. Bluetooth SIG also known as the Bluetooth Special Interest Group controls Bluetooth. 

Bluetooth Low Energy or Bluetooth 4.0 is a recent discovery. It consumes less energy. Due to less power consumption, BLE makes it possible to connect devices with small battery lives. It exchanges small data packages.

LoRa(low range)/LoRaWAN

LoRaWAN is a type of low power wide area network. It’s specifications fit into the wireless batteries in operation of IoT applications. 

• It works for long ranges and less power consumption devices and sensors. 
• LoRa allows users to communicate long distances by consuming less power. 
• LoRa feeds to the potential of the internet of things.
• It is a non-cellular LPWA network

They contain different classes of devices: class A,B and C.

Class A contains battery powered sensors, class B contains both battery powered sensors and actuators and finally class C are main-powered actuators which are plugged into some form of power. The difference in operation is done on the basis of how these devices operate with and without power. 

WiFi

Wifi is a radio or frequency protocol and it transmits data in the frequency ranges of 2.4 Ghz or 5 Ghz. These frequencies are higher than other cellular networks frequencies we have seen above. Yet, WiFi has high power consumption and low range connectivity. Wifi works best for Iot devices that do not care about power drain or the devices that do not require higher ranges such as a smart home. 

Z-Wave 

Z-Wave is another wireless technology. Its main aim is to make smart homes more safer and secure. It makes IoT device communication easier. The Z-Wave starter kit is beginner friendly software for beginners. It was one device for end devices and their networking. 

ZigBee

Zigbee is a wireless technology whose protocols suit the global networking standards. It eliminates power and cost issues of the other Iot technologies. Zigbee standard works on the IEEE 802.15.4 physical radio. 

Zigbee protocol backs up mesh networking. Mesh networking connects constrained nodes with one another to allow multiple pathways for each node. 

6LoWPAN

6 LoWPAN is a wireless technology that is a combination of the Ipv6 and LoWPAN. 6LoWPAN connects small devices with less process abilities to send information wirelessly over an IoT protocol. It ensures that small devices can connect to the Iot framework as well.

 It is a request/response protocol, it takes in requests from clients and passes it to users who give back a response.

Lightweight M2M

This a simple, lightweight protocol and adapts industry standards. This protocol consumes less power and it’s design is specific to IoT applications. It is a success of the OMA DM standard. It uses less power and consumes less data comparatively. However, it has limited processing and storage capabilities. It is instantly deployable and is cross-platform. 

All of these features make Lightweight M2M one of the top IoT protocols in use. 

HyperText Transfer Protocol(HTTP)

The World Wide Web commonly communicates through the HTTP protocol.It supports web browsers and server functionality. HTTP/1.1 is the most supportive version currently in use around the globe. 

WebSocket 

WebSockets resolves a few issues involving HTTP. While using HTTP you can constantly request for updates whereas with WebSocket you get real time updates continuously. Client-server model communicates through the TCP connection. WebSocket fixes the latency issues in HTTPs request-response model as it keeps a single, continuous open connection. WebSockets reduces large data loads to the server. 

NFC

NFC or Near Field Communications builds communication for ranges as short as 4cm. You can share small amounts of data from an NFC tag and an android device  or between two android devices. Android devices with NFC can:

•  read and write NFC tags,
•  can exchange data with other NFC companions and
•  can behave as NFC cards.

Sigfox

Sigfox offers low power connectivity solutions for Iot technologies. It is an LPWA network and requires lower battery consumption. It offers the best customer user experience.

Sigfox uses 192kHz band for transferring messages. The transfers are narrow and data transfers happen at an accurate rate. Here is a list of the principles of Sigfox technology:

• It uses random access to achieve high quality of service.
• These networks use “spatial diversity” and time and frequency diversity to gain high quality service in the Sigfox network.
• Sigfox communication protocols transfer small messages to reduce costs.
• These messages are bidirectional.

Neul

Neul is an IoT protocol that connects everything at an economical cost. The methodology of Neul is practically similar to Sigfox as we have seen before. Neul works with small pieces of the TV white space spectrum to offer wider, scalable networking. 

Neul is weightless communication technology and matches IoT protocols such as GPRS, 3G, CDMA and LTE WAN. Power usage is less and hence their life is more. 

Conclusion:

In this article, we learned the highly common IoT protocols. We learned about the different kinds of data and networking protocols commonly used in the internet of things.