Introduction
The IoT industry has approximately 25 billion devices all over the world. So, there should be infrastructure that can handle the traffic. Each IoT device communicates with the other or with the server through some technologies like WiFi, Bluetooth/BLE, Zigbee, Cellular network, and LoRa.
WiFi
Today WiFi is everywhere. WIFI is based on IEEE 802.11. Many IoT devices use WiFi technology for communication purposes to transmit lots of data and use a lot of energy. The range of this technology is 50 meters and 30 km with private antennas. The data rate is up to 54 MB per second. It is not the ideal solution when the desired criteria are low data transmission from nodes and low energy consumption of the node.
Bluetooth/BLE
When we consider version 4.0 and above of Bluetooth it provides a very limited range and consumes much power. The range of this technology is 30 to 50 meters, and the data rate is up to 1 MB per second. The devices connected are restricted to 8 in piconet whereas in BLE it is unlimited. A major disadvantage of Bluetooth is the security as it works on radio frequency so it can penetrate through walls, so this technology is not considered when security is the priority. Its bandwidth is lower than WiFi.
ZigBee
ZigBee is a technology used when the device communicates within a short range and is based on IEEE 802.15.4 protocol. It communicates through the wireless mesh network. This technology is simpler and low cost than other technologies. The range is up 10 to 100meters it can transfer the data over a longer distance through the mesh network and a low data rate of 20 to 250 KB per second. The number of devices connected in theory is 65000 but practically 240 devices can be connected.
Cellular Network
Cellular network protocol sends the wireless signal to connect to nearby cell towers thus it connects to the internet. It is a wireless communication protocol such as 2G,3G, 4G and 5G.
5G is 20 times faster than 4G. Its range is about 200 km, and it has security and reliability. But it has some disadvantages: it has a lower data rate. Wireless communication is affected by climatic conditions, obstacles and by other wireless devices.
LoRa
Developed from the Chirp Spread Spectrum (CSS) technology, LoRa is a wireless modulation technology that uses chirp pulses to encode radio waves, similar to how dolphins and bats use echolocation to transmit information. LoRa technology is capable of long-range communications: it can reach distances up to 5 kilometres (3 miles) in urban areas, and 15 kilometres (10 miles) in rural areas.
What is LoRa?
LoRa is a Long Range Wide Area wireless communication technology. It is a radio modulation which means that the information is encoded in the radio wave. It is the spread spectrum modulation technique derived from the chirp spread spectrum technology. This technology uses ultra-low power consumption with an effective long-range. Its range is from 13-15 km. A single LoRa gateway can provide a range that will cover the entire city.
LoRa Network Architecture consists of LoRa Gateway, servers and LoRa End Devices. The end devices are connected to the LoRa Gateway; one gateway can handle millions of nodes. The LoRa communication system is bidirectional i.e., the information collected by the sensors is sent to the network server through the gateway and the end device can actuate as per the information sent by the server.
Key Features of LoRa Protocol
- The range of this protocol is 2-5Km (urban) and 15Km (suburban).
- Its frequency is ISM 868/915MHz. It is based on standard IEEE 802.15.4g.
- It uses the spread spectrum modulation type based on frequency modulation pluses which vary.
- It has a long battery life as it transmits data over a long range by using little power.
- One LoRa gateway can be connected to thousands of nodes.
- The physical layer of LoRa consists of modulation and signalling between nodes and gateways, power and frequency.
LoRa Alliance
LoRa Alliance was founded in the year 2015. The number of member companies has risen drastically; no other technology alliance has grown this quickly. From 2019 to 2021, major companies have joined the alliance such as Arduino, Thingstream, Amazon, Intel etc.
Globally, there are 170 LoRaWAN Network Operators.
License-Free LoRa Frequency Bands in India
There are 8 channels for all frequency bands. The frequencies in Europe that are license-free are in the 863-870 MHz range, in America the range is between 902 MHz to 928 MHz and in China 779 MHz to 787 MHz. Similarly, 868 MHz also has 8 channels. The LoRa frequencies from 865 MHz to 867 MHz are license-free. Where the first channel starts with a frequency of 865.20 MHz and the last channel ends with 868 MHz. So mostly the channels out of the 8 channels are license-free in India. If we are specific then as shown in the figure below 7 channels are license-free in India.
Semtech has come up with various LoRa RF modules which operate between 860 to 1000 MHz and 137-960MHz frequency. Adafruit has come up with the breakouts and development boards for frequencies 433MHz, 868MHz and 960MHz for Semtech RFM69 and RFM95 modules.
Disadvantages of LoRa
- Spectrum interference: As LoRa develops and expands, LoRa equipment and network deployment will continue to increase, causing frequent spectrum interference.
- Need to build a new network: The user needs to build its network during the LoRa deployment process.
- Small payload: LoRa transmission data has a limited payload size and is relatively small.
Application Area of LoRa
The following sectors have greatly benefitted from the emergence and development of LoRa:
Smart Agriculture and Irrigation
Undoubtedly, this is one of the most common applications for LoRa, which is a long-distance technology that does its best work in open spaces.
Before LoRa’s release, agricultural and irrigation management projects could not be automated or smartly controlled. With wireless communications, it is now possible to cover distances up to 15 kilometres thanks to huge cost reductions in the installation of devices and control systems.
Different tech applications in the sector are covered by the term “Smart Agro”, such as
- Climate monitoring
- Soil monitoring via sensors (temperature, solar radiation, humidity, pH, electric conductivity)
- Automation and control of irrigation and ventilation
- Use of Big Data for crop forecasting, agricultural planning, etc.
Solar Power Generation
In line with agriculture and irrigation, solar panels can be installed as a smart application of LoRa technology that saves costs associated with installation, cabling, and maintenance. Combining LoRa with strings surveillance results in the most efficient communication system for photovoltaic plant monitoring.
One of LoRa’s main strengths is the low consumption required to collect and send data which makes it ideal for applications powered by batteries or 12/24 Vdc power supplies. Thanks to this characteristic, kilometres of solar panels can be wirelessly monitored using low-consumption devices via LoRa without manual interference.
Smart Buildings
In a smart building, different demands of energy efficiency, comfort, mechanics, maintenance, security, and operations are addressed in an automated, controlled, and non-intrusive manner. Signals are collected and transmitted via sensors, collectors, and detectors of the system, where they are processed for activating functions programmed in the system or to send information to an administrator for action.
LoRa can be applied in several Smart Building applications:
- Consumption monitoring by zones or uses
- Lighting control or Smart Lighting
- Temperatures remote control
- HVAC control systems, BMS and cold/warm air conditioning
Smart Energy and Submetering
Beyond the Smart Building, electrical consumption measurement is now essential for almost any application, sector or installation. When active and reactive energy monitoring is all that is needed, LoRa is the ideal wireless communication protocol.
LoRa connects energy meters without installing cables, allowing data to be collected over enormous areas when submetering is necessary. A few examples:
- Energy consumption of each plant on a building office
- Energy consumption metering and invoicing of each office in an office centre shared between different companies
- Energy consumption metering and invoicing of each warehouse in a logistics park that rents industrial plants
Smart Water and Gas Monitoring
Water and gas monitoring, a sector that already has low-consumption ultrasonic sensors, benefits greatly from technology such as LoRa as it minimizes costs and maximizes efficiency on automation solutions.
Water treatment, irrigation, wells, pumps, pipes, silos, and irrigation systems can be controlled with LoRa technology because of its extensive penetration and low cost.
LoRa technology can be used to monitor water and gas in the following ways:
- Consumption monitoring
- Flow adjustments
- Sensors remote configuration
- Leak detection
Conclusion
Despite not being fully developed, LoRa has already become a standard in most industries and is used in many countries around the world. An estimated $6.2 billion is predicted to be generated by LoRa and LoRaWAN devices by 2026, growing at a CAGR of 36.5% from 2021-2026. With major applications in IoT data transmission, the technology covers a wide field of applications. A variety of fixed and mobile IoT applications can benefit from its cost-effectiveness, simplicity, and ability to support bi-directional communications over a wide area. Robust and scalable physical layer options of the technology ensure power-efficient communications over significant distances. With its link and network layer protocols, end devices can select and adjust key parameters for scalable and efficient networks. In addition, it is freely available and maintained by the non-profit LoRa Alliance.