Now The Internet of Things (IoT) is more than a buzzword. Actually, what IoT is, how it works and how it simplifies our daily lives we will discuss in this article. Let’s start with the definition of IoT.
The Internet of Things (IoT) refers to a system of interrelated, internet-connected objects that are able to collect and transfer data over a wire or wireless network without human intervention.
The personal or business possibilities are endless. A ‘thing’ can refer to a connected medical device, a biochip transponder (think livestock), a solar panel, a connected automobile with sensors that alert the driver to a myriad of possible issues (fuel, tire pressure, needed maintenance and more) or any object outfitted with sensors, that has the ability to gather and transfer data over a network.
Today, businesses are motivated by IoT and the prospects are of increasing revenue, reducing operating costs and improving efficiencies. Businesses also are driven by a need for regulatory compliance. Regardless of the reasons, IoT device deployments provide the data and insights necessary to streamline workflows, visualize usage patterns, automate processes, meet compliance requirements and compete more effectively in a changing business environment.
What are IoT Protocols?
Now the interesting question comes here, how these devices can communicate with each other in IoT? And how IoT works? Well, how we humans communicate with each other, similarly these devices can communicate with other through protocols which are known as IoT protocols.
IoT communication protocols are modes of communication that protect and ensure optimum security to the data being exchanged between connected devices. The IoT devices are typically connected to the Internet via an IP (Internet Protocol) network. However, devices such as Bluetooth and RFID allow IoT devices to connect locally. In these cases, there’s a difference in power, range, and memory used.
Connection through IP networks are comparatively complex, requires increased memory and power from the IoT devices while the range is not a problem. On the other hand, non-IP networks demand comparatively less power and memory but have a range limitation.
As far as the IoT communication protocols or technologies are concerned, a mix of both IP and non-IP networks can be considered depending on usage.
Types of IoT Protocols:
IoT protocols and standards can be broadly classified into two separate categories.
1. IoT Data Protocols
IoT data protocols are used to connect low power IoT devices. These protocols provide point-to-point communication with the hardware at the user side without any internet connection. Connectivity in IoT data protocols is through a wired or a cellular network. Some of the IoT data protocols are:
• Message Queue Telemetry Transport (MQTT)
Probably the most widely adopted standard in the Industrial Internet of Things to date, Message Queuing Telemetry Transport is a lightweight publication/subscription type (pub/sub) messaging protocol. Designed for battery-powered devices, MQTT’s architecture is simple and lightweight providing low power consumption for devices. Working on top of TCP/IP protocol, it has been specially designed for unreliable communication networks in order to respond to the problem of the growing number of small-sized cheap low-power objects that have made their appearance in the network in the recent years.
MQTT is based on subscriber, publisher and broker model. Within the model, the publisher’s task is to collect the data and send information to subscribers via the mediation layer which is the broker. The role of the broker, on the other hand, is to ensure security by cross-checking the authorization of publishers and subscribers. MQTT offers three modes of achieving this (Quality of Service), thanks to which the publisher has the possibility to define the quality of its message:
Having found wide application in such IoT devices as electric meters, vehicles, detectors and industrial or sanitary equipment, MQTT responds well to the following needs:
- Minimum bandwidth use
- Operation over wireless networks
- Low energy consumption
- Good reliability if necessary
- Little processing and memory resources
• Constrained Application Protocol (CoAP)
While the existing Internet infrastructure is freely available and usable for any IoT device, it often proves too heavy and power-consuming for most IoT use cases. Created by the IETF Constrained RESTful Environments working group and launched in 2013, Constrained Application Protocol (CoAP) was designed to translate the HTTP model so that it could be used in restrictive device and network environments.
Designed to address the needs of HTTP-based IoT systems, CoAP relies on the User Datagram Protocol (UDP) for establishing secure communication between endpoints. By allowing for broadcasting and multicasting, UDP is able to transmit data to multiple hosts while retaining communication speed and low bandwidth usage, which makes it a good match for wireless networks typically employed in resource-constrained M2M environments. Another thing that CoAP shares with HTTP is the RESTful architecture which supports a request/response interaction model between application endpoints. What is more, CoAP adopts the basic HTTP get, post, put and delete methods, thanks to which ambiguity can be avoided at the time of interaction with clients.
CoAP features Quality of Service which is used to control the messages sent and mark them as ‘confirmable’ or ‘non-confirmable’ accordingly which indicates whether the recipient should return an ‘ack’ or not. Other interesting features of CoAP are that it supports content negotiation and resource discovery mechanism. Apart from transferring IoT data, CoAP leverages Datagram Transport Layer Security (DTLS) for the secure exchange of messages in the transport layer. CoAP fully addresses the needs of an extremely light protocol in order to meet the demands of battery-operated or low-energy devices. All in all, CoAP is a good match when it comes to existing web service-based IoT systems.
• Advanced Message Queuing Protocol (AMQP)
AMQP is a software layer protocol for message-oriented middleware environment that provides routing and queuing. It is used for reliable point-to-point connection and supports the seamless and secure exchange of data between the connected devices and the cloud. AMQP consists of three separate components namely Exchange, Message Queue and Binding.
All these three components ensure a secure and successful exchange and storage of messages. It also helps in establishing the relationship of one message with the other.
AMQP protocol is mainly used in the banking industry. Whenever a message is sent by a server, the protocol tracks the message until each message is delivered to the intended users/destinations without failure.
• Machine-to-Machine (M2M) Communication Protocol
It is an open industry protocol built to provide remote application management of IoT devices. M2M communication protocols are cost-effective and use public networks. It creates an environment where two machines communicate and exchange data. This protocol supports the self-monitoring of machines and allows the systems to adapt according to the changing environment.
M2M communication protocols are used for smart homes, automated vehicle authentication, vending machines, and ATM machines.
• Extensible Messaging and Presence Protocol (XMPP)
The XMPP is uniquely designed. It uses a push mechanism to exchange messages in real-time. XMPP is flexible and can integrate with the changes seamlessly. Developed using open XML (Extensible Markup Language), XMPP works as a presence indicator and shows the availability status of the servers or devices transmitting or receiving messages.
Other than the instant messaging apps such as Google Talk and WhatsApp, XMPP is also used in online gaming, news websites, and Voice over Internet Protocol (VoIP).
2. IoT Network Protocols
IoT network protocols are used to connect devices over the network. These are the set of communication protocols typically used over the Internet. Using IoT network protocols, end-to-end data communication within the scope of the network is allowed. Following are the various IoT Network protocols:
Cellular (3G, 4G, and 5G)
Cellular networks, as the name suggests, are well-established in the mobile consumer market. 2G is an “old school” cellular network that, along with 3G, is being phased out in most parts of the world. But, the world is quickly embracing new high-speed cellular networks like 4G and 5G. Cellular networks provide high bandwidth and reliable broadband communication for voice calls or video streaming but with high operational costs and power consumption. Cellular networks cannot be used with most IoT devices due to their frequency, range and security challenges. However, cellular networks can be viable options in some specific IoT devices like connected cars. Connected cars can use cellular networks for traffic routing with the help of GPS systems. GPS systems and cellular networks can help track road traffic in real-time as cellular networks can transfer high quantities of data over the network.
Creating a Wi-Fi network requires devices that can send wireless signals which means devices such as telephones, computers or routers, to name a few. At home, a router is used to transfer the internet connection from a public network to a private home or office network. WiFi provides an Internet connection to nearby devices that are within a certain range. Another way to use WiFi is to create a WiFi hotspot, i.e. telephones or computers may share a wireless or wired internet connection with other devices by broadcasting a signal. WiFi uses radio waves that broadcast information on specific frequencies, such as 2.4 GHz or 5 GHz channels. Both frequency ranges have a number of channels through which different wireless devices can work, which helps to distribute the load so that the individual connections of the devices are not interrupted. This largely prevents overflowing of wireless networks.
A range of 100 meters is the typical range of a standard WiFi connection. The most common range, however, is limited to 10-35 meters. Effective network coverage is greatly affected by antenna strength or transmission frequency. The range and speed of a WiFi Internet connection depend on the environment and whether it provides internal or external coverage. Thus, the speed of various devices using the WiFi internet connection increases as the computer approaches the main source, while the speed decreases as the computer moves away from the source.
LoRaWan (Long Range Wide Area Network)
LPWANs (Low Power Wide Area Networks) are new sets of protocols developed for IoT solutions but can also be used by other devices to communicate over a wide area. Even cellular networks can provide a wide-area communication network, but the cost of communication over cellular networks is high because of its high power consumption. LPWANs enable communications over a wide area with the help of small and inexpensive batteries that last for the long-term making it a cost-saving option in comparison to cellular networks.
There are different types of licensed (NB-IoT, LTE-M) and unlicensed (MIOTY, LoRa) LPWANs that are built differently for different purposes. While power consumption is one of the biggest challenges for licensed LPWANs, Quality of Service (QoS) and scalability are some challenges faced by unlicensed LPWANs.
NFC (Near Field Communication)
It is a technology that enables simple and safe two-way interactions between electronic devices and especially applicable for smartphones, allowing consumers to perform contactless payment transactions, access digital content and connect electronic devices. Essentially it extends the capability of contactless card technology and enables devices to share information at a distance that is less than 4cm.
Bluetooth and BLE
Bluetooth is a 2.4GHz network for personal wireless network communication. 2.4GHz network is preferred for providing personal networks by network providers as it is cheaper and has a much better range than other networks. Bluetooth low energy (BLE) is the new and optimized version of Bluetooth for connections between IoT applications. BLE consumes lesser power than standard Bluetooth for communication. BLE-enabled devices are commonly used with electronic devices that can act as a hub for data transfer from IoT devices to the cloud. This makes BLE a perfect match for IoT wearables.
BLE is widely integrated into health and fitness trackers, as well as some smart home devices like door locks. Data from BLE-enabled IoT wearables can be easily communicated to smartphones. In the retail context, BLE can be used with beacon technology to provide customer service like in-store navigation. Beacons are essentially small transmitters that use BLE to transmit signals to nearby IoT devices. By transmitting signals to nearby IoT devices, beacons can make location-based searching and navigation much easier and accurate.
ZigBee is an IoT protocol that allows smart objects to work together. It is commonly used in home automation. More famous for industrial settings, ZigBee is used with apps that support low-rate data transfer between short distances. Street lighting and electric meters in urban areas, which provide low power consumption, use the ZigBee communication protocol. It is also used with security systems and in smart homes.
RFID (Radio-frequency identification) uses radio waves to transfer small data packets over the network within small areas. It is easy to embed an RFID chip in IoT devices. RFID readers can then read the tags and give information about the product that is attached to tags. One of the common applications of RFID is inventory management. By attaching RFID tags to all products and connecting it to IoT devices, businesses can keep track of the number of products available in stock. Thus RFID can help in better stock planning leading to an optimized supply chain management. RFID tags can also help smart home IoT devices. For instance, a smart washing machine that can read RFID tags can be controlled.
An alternative wide-range technology is Sigfox, which in terms of the range comes between WiFi and cellular. It uses the ISM bands which are free to use without the need to acquire licenses, to transmit data over a very narrow spectrum to and from connected objects. The idea for Sigfox is that for many M2M applications that run on a small battery and only require low levels of data transfer, WiFi’s range is too short while cellular is too expensive and also consumes too much power. Sigfox uses a technology called Ultra Narrow Band (UNB) and is only designed to handle low data-transfer speeds of 10 to 1,000 bits per second. It consumes only 50 microwatts compared to 5000 microwatts for cellular communication or can deliver a typical standby time of 20 years with a 2.5Ah battery while it is only 0.2 years for cellular.
Already deployed in tens of thousands of connected objects, the network is currently being rolled out in major cities across Europe, including ten cities in the UK for example. The network offers a robust, power-efficient and scalable network that can communicate with millions of battery-operated devices across areas of several square kilometers, making it suitable for various M2M applications that are expected to include smart meters, patient monitors, security devices, street lighting and environmental sensors.