According to Gartner’s statistics, nearly 20.4 billion IoT devices are connected to the internet by 2020. These devices communicate with the internet through various channels. It always depends on the application and based on that the solution is provided. In the given image below, the left blocks indicate the TCP/IP protocol and the right-side blocks indicate the communication protocols for IoT.
Mostly the Internet of Things follows device-to-device communication. It is about connecting various sensors/actuators or devices to the internet. These are called sensor nodes or motes (used in America). They communicate over many types of networks, including IP networks or the Internet, but most often use protocols like WiFi, Bluetooth, Z-Wave, and ZigBee.
An IoT solution engineer decides the best communication protocol is used for the suitable application. There are many communication protocols available for the IoT and we will discuss the best protocols one by one.
Bluetooth Low Energy (BLE)
Bluetooth provides wireless communication through a radio frequency (2.45 GHz). It is low cost, highly reliable and low power usage. Bluetooth Low Energy (BLE) is a modified version of Bluetooth that decreases power usage and data rates by allowing incoming connections to control when the device uses power.
Data Rate is up to 0.27 MB per second and the range is medium up to 100 meters. The IoT product developers chose BLE for its efficiency and small chip size.
Physical range: Typically less than 10 m (33 ft), up to 100 m (330 ft); Bluetooth 5.0: 40–400 m (100–1,000 ft).
Applications
- Audio Signal Transmission (Bluetooth Earphone, Bluetooth speaker),
- Industrial ( Replacing the cable The original thought of Bluetooth, SPP (Serial Port Profile), Multi UART Port, Makes it easy to transfer data wirelessly to smartphones / PC, Makes it possible to upgrade parameter/program wirelessly),
- Smart Home ( Remote Control for A.C, TV, … Door Bell /Lock, Illumination, Music /Audio, Security, Valve for Water/Gas, Windows/Curtain, Power Socket )
- Wearable Devices (Smartwatch, Smartpen, Smart shoes, etc)
- BLE Broadcast
- Short Range Real-time communications
Wi-Fi
Wi-Fi is based on the IEEE 802.11 family of standards originally released in 1997 to replace the ethernet. It uses wireless transmitters and radio signals to transmit broadband Internet to devices. Wi-Fi is known for its high bandwidth, ease of device operability and moderate cost.
Wi-Fi is more suitable for IoT applications, where more number of data transfer is made. The data rate is high up to 54 MB per second and the range of Wi-Fi technology is up to 50 meters but can be provided up to 30 kilometres by private antennas.
The security standard, Wi-Fi Protected Setup, allows embedded devices with a limited graphical user interface to connect to the Internet with ease. Wi-Fi Protected Setup has 2 configurations: The Push Button configuration and the PIN configuration. These embedded devices are also called The Internet of Things and are low-power, battery-operated embedded systems. A number of Wi-Fi manufacturers design chips and modules for embedded Wi-Fi, such as GainSpan.
Applications:
- Office IoT
- Smart Home IoT
- Smart city (Public Wi-fi)
Zigbee
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 as a low-power, low-cost, low-bandwidth protocol.
Zigbee uses mesh networking–connections to other connected devices–to connect its devices to each other and the Internet. 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. It is necessary only for small amounts of data transfer in a short-range area.
Applications:
- Home automation
- Monitoring Sensor data
- Industrial device sensing and controlling
Cellular (Mobile Network)
The cellular network or the mobile network connects to the internet by sending a wireless signal to the nearby cell towers. The cellular network is wireless communications protocols such as 2G, 3G, 4G, and 5G. The fifth-generation will be deployed in the year 2020 and will be a turning point for all the IoT devices which is 20 times faster than the 4G (only 1 Gbps). The cellular network uses significant amounts of power and however the IoT devices should be within the network range. Hence the need for high power is a disadvantage of this tech. The cellular network is known for its security, reliability, and range of about 200 kilometres. The cost to set up with the network is very complicated and should maintain relationships with the network providers, and the cost alone subjects to more than $10000 excluding the monthly payments.
LoRa
LoRa (Long Range) network is a low power communication technology patented and owned by a company called Semtech. It was first introduced in the year 2008 and doesn’t have much documentation on this protocol. The advantage of this protocol is that it is highly reliable, medium cost, and has low power usage with long-range. But it has a low data rate up to 50Kbps.
Application
- Smart City
- Energy Management
- Supply Chain Management
Z Wave
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 and makes it possible to develop faster and simpler. Z-Wave’s range is up to 30 meters, but this range can be up to 100 meters. Its maximum data rate is only 100 kbps.
RFID
Radio-frequency identification uses electromagnetic fields to automatically identify and track tags attached to objects. The tags contain electronically stored information. Passive tags collect energy from a nearby RFID reader’s interrogating radio waves. Short-range RFID is about 10cm, but long-range can go up to 200m.
RFID is specially designed for the devices to send a wireless signal without batteries. One side of the RFID is powered creating a magnetic field that induces an electric current in the chip to send a wireless signal over and over again. It is used for shipping and tracking purposes.
SIGFOX
SIGFOX is a French company and was founded in the year 2009. It is known for its global IoT network operation. SIGFOX has deployed tens of thousands of connected objects in more than 60 countries with the aim of connecting billions of IoT devices with low power. It uses DBPSK- Differential Binary Phase Shift Keying in direction and GFSK- Gaussian Frequency Shift Keying in another direction. SIGFOX had set up antennas like a cell tower and receives data transmissions from the IoT devices. The data rate is very low up to 1 kbps but provides a large range. It is highly reliable and has very low power usage.
Conclusion
If you want to choose an IoT communication protocol, study the application thoroughly. There are many protocols available that differs based on the range, usage of power, reliability and cost. The protocol should be chosen based on the project requirements and the application.
