One of the essential factors of the IoT are communication protocols. One of the key aspects of the IoT is the communication between devices and it will be provided with communication protocols.
The following paragraphs will provide a brief overview about each of the Internet of Things communication techniques.
6LoWPAN that is a IP based communication protocol is an acronym of IPv6 over Low Power Wireless Personal Area Network. 6LoWPAN, therefore, allows for the smallest devices with limited processing ability to transmit information wirelessly using an internet protocol. The most important detail of 6LoWPAN is IPv6. IPv6 (Internet Protocol version 6) is a 128-bit internet protocol developed due to inability of 32-bit IPv4 in addressing. While IPv6 developed, rapid increase of the number of connected devices has been considered.
MQTT (Message Queue Telemetry Transport)
It was created about 15 years back for monitoring remote sensor nodes and is designed to conserve both power and memory. It is based on the ‘Publish Subscribe’ communication model. Using MQTT, a connected device can subscribe to any number of topics hosted by an MQTT broker. It is overall a lightweight protocol that runs on embedded devices and mobile platforms. The good performance and reliability of MQTT is demonstrated by Facebook Messenger, Amazon IoT (AWS-IoT), IBM Node-Red, etc.—organizations that are using it to serve millions of people daily.
CoAP (Constrained Application Protocol)
Constrained Application Protocol (CoAP) is an Internet application protocol for constrained devices (defined in RFC 7228). It enables constrained devices to communicate with the wider Internet using similar protocols. CoAP is designed for use between devices on the same constrained network, between devices and general nodes on the Internet, and between devices on different constrained networks joined by the Internet. CoAP is a client/server protocol and provides a one-to-one “request/report” interaction model with accommodations for multicast. CoAP is designed to interoperate with HTTP and the RESTful web through simple proxies, making it natively compatible with the Internet.
The two messaging protocols MQTT and CoAP are emerging as leading lightweight messaging protocols for the booming IoT market.
Bluetooth and Bluetooth Low Energy
While MQTT and CoAP are infrastructure-independent, which means that it doesn’t matter whether you’re connected to a wired or a wireless network, Bluetooth provides only wireless communication over radio frequency. Bluetooth, generally, is divided into three categories.
Bluetooth Classic: This is meant for high data rate applications like streaming audio wirelessly.
Bluetooth Smart or Low Energy/BLE: This is meant for low powered battery-operated devices that stream low packets of data.
Bluetooth SmartReady: These are essentially the ‘hub’ devices such as computers, smartphones, etc. They support both the ‘classic’ and ‘smart’ devices.
Bluetooth technology is being used in the beacon technology that expected to revolutionize real-time marketing in the coming years. The new features of Bluetooth 5.0 version that is introduced as Bluetooth 5 have been developed completely for the Internet of Things. Generally, Bluetooth’s range is 10 meters, but its range is up to 100 meters. Its data rate is 1 mbps.
The mobile network or in other words the cellular network, means wireless communication protocols such as 2G, 3G and 4G. It’s easy to send and receive data in high quantity through especially 4G. High cost and high-power requirement are the disadvantages of this technology, but having a high range of 200 km will be helpful for mobile applications in the IoT area. If it is based on LTE Advanced which is a 4G technology, the maximum data rate of this communication protocol is 1 gbps.
Wi-Fi is highly suited for IoT applications where high-volume data transfer is made, however, it requires high power consumption. Generally, Wi-Fi technology’s range is 10 meters, but Wi-Fi connectivity can be provided for up to 30 kilometers by using private antennas.
Z-Wave is a wireless communication protocol developed specifically for home automation and has a low power requirement. Because it operates at 900 MHz, it is not affected by Wi-Fi and other wireless communication protocols running at 2.4 GHz, such as Bluetooth and Zigbee. Z-Wave is a simpler protocol than other communication protocols. This makes it possible to develop faster and simpler. Generally, Z-Wave’s range is 30 meters, but this range can be up to 100 meters. Its maximum data rate is only 100 kbps.
Zigbee is a short-range wireless communication protocol based on the IEEE 802.15.4 protocol, which is widely used in home automation and the industry. It is preferred in applications where low power is required and data exchange is infrequent at low data rates. Low power consumption, high scalability, security, and durability makes Zigbee suitable for M2M and IoT applications. Generally, Zigbee’s range is 10 meters, but this range can be up to 100 meters in certain situations. Its maximum data rate is 250 kbps.
Radio frequency identification (RFID) is the wireless use of electromagnetic fields to identify objects. Short-range RFID is about 10cm, but long-range can go up to 200m. This protocol was designed specifically so devices without batteries could send a signal. In most systems, one side of an RFID system is powered, creating a magnetic field, which induces an electric current in the chip. This creates a system with enough power to send data wirelessly over and over again. Because of this, RFID tags are used for shipping and tracking purposes.
SigFox is a global IoT network operator. It uses differential binary phase-shift keying (DBPSK) in one direction and Gaussian frequency shift keying (GFSK) in the other direction. SigFox and their partners set up antennas on towers (like a cell phone company) and receive data transmissions from devices such as parking sensors or water meters.
There are many different protocols and industry standards that are specially designed for IoT or can be used for it, such as the few mentioned above and others like Wi-Fi WebSockets, Zigbee, LoRA, Simple RF, XMPP, RFID, NFC, etc. Yet, one’s choice should be based on the project requirements and the constraints of the application you are thinking of developing. The possibilities in the IoT space are endless.