Table of Contents:
In this article, We will learn about LoRa & LoRaWAN Communication. First, we will see What is LoRa, who invented it??? How it works and why do we consider it as a boon for IoT Devices. Later we will develop a device for a real-time demonstration of LoRa Communication with RFM95 LoRa module and ESP32 Development kit. First, we will set up one machine as Transmitter and Another device as a receiver. Then we will try to transfer some data between them.
This RFM95 LoRa transceiver module does not breadboard friendly, meaning we cannot solder these 2.54mm male headers to it, or we can place it on neither breadboard nor Vero boards. So, I have designed a PCB to make it breadboard-friendly. I have created this PCB and ordered it on PCBWay.com; I choose PCBWay.com because it offers the best quality PCBs for just 5 dollars, that too with 24hrs build time. PCBWay.com is an Online PCB manufacturing Enterprise, which provides all services you need to make Hardware for your IoT or Embedded Devices. If you have a similar requirement, do check out their website for more details.
Video Tutorial: Lora & LoRaWAN Explained!
This tutorial is also available in video format, you can watch the below videos or continue reading this article.
INTERNET OF THINGS :
The Internet of Things, or IoT, is a network of physical devices connected to the Internet and can “talk” to each other.
There are many wireless technologies you can use to connect these devices to the Internet, such as:
– Short-range wireless communication – Bluetooth, WiFi,
– Cellular communication – 2G, 3G, 4G
– LPWAN communication – LoRa,
As you can see here, Bluetooth and WiFi offer good speed at lower Power Consumption, but the range is significantly less. On the other hand, Cellular Network offers good Network coverage and speed, but the power consumption is very high.
Imagine we have an IoT solution wherein the wireless sensor nodes spread over a few kilometers to transmit their sensor values via a network a few times every hour. Furthermore, these nodes operate on batteries that are supposed to run for a couple of years. Therefore, the data transmitted will be small and sporadic. Under such conditions, we need a wireless network that consumes low power and operates over large distances, and a low data rate is also acceptable.
Is such a network even possible?
Yes, it is possible—the LoRa.
What is LoRa?
LoRa is a wireless technology that offers long-range, low-power, and secure data transmission for M2M and IoT applications. LoRa is based on chirp spread spectrum modulation, which has low power characteristics like FSK modulation but can be used for long-range communications. We can use LoRa to connect sensors, actuators, monitoring devices wirelessly to the cloud.
It has been ten years since the invention of LoRa®; currently, more than 191 million devices connected to the cloud using LoRaWAN Technology.
Who invented LoRa?
The story of LoRa began in 2009 when two friends Nicolas Sornin and Olivier Seller from France, aimed at developing a long-range, low power modulation technology. In 2010 François Sforza joined the team, and together they started the company Cycleo.
Initially, the three founders targeted the metering industry and aimed at adding wireless communication capabilities for gas, water, and electricity meters. For this purpose, they used Chirp Spread Spectrum (CSS) modulation technology.
Later, they Convinced Semtech about the invention’s long-range and low power capabilities; Semtech acquired Cycleo in May 2012. Finally, Semtech collaborated with Nicolas, Olivier, and François to improve the technology and finalize the chips required for the end devices (SX1272 and SX1276) and the gateways (SX1301).
That’s how the LoRa was Invented.
At the same time, the creation of the proprietary MAC protocol called “LoRaMAC”, among other things, specified the message formats and security layers for a proper networking protocol. Finally, in February 2015, the LoRa Alliance® was founded by more than 500 member companies, and the networking protocol was renamed “LoRaWAN.” While LoRa has been invented by Cycleo. LoRaWan has been invented by Semtech IBM and Actility and Keeling made the first LoRaWAN outdoor gateway followed by Multitech with the conduit. The LoRa Alliance was an initiative from Semtech Kerlink IBM and Actility. The LoRa Alliance’s goals were, and still are, to “support and promote the global adoption of the LoRaWAN standard by ensuring the interoperability of all LoRaWAN products and technologies.”
I think you got confused with these two names, LoRa and LoRaWAN. Even I also got confused when I first read about LoRa. Let me clarify it.
LoRa is a proprietary radio modulation technology owned by Semtech and deals with only the stack’s physical layer. The LoRa technology uses a proprietary Chirp Spread Spectrum modulation technology that makes the low power long-range transmission possible over the unlicensed ISM band. Semtech has licensed its LoRa intellectual property (IP) to other chip manufacturers, such as HopeRF, Microchip, Dorji, etc.
In contrast, the LoRaWAN is the communication protocol and system architecture for the network. The LoRaWAN deals with the MAC layer and application layer of the LoRa protocol stack and is open source and is managed by the LoRa alliance.
The LoRa operates in the unlicensed ISM band in the sub-Giga Hertz frequency; This means that you do not need any license to transmit data via the LoRa technology.
The actual frequency of this sub-Giga Hertz ISM band for LoRa varies from country to country. You can find out the frequency band in which the LoRa network operates in your country by visiting this page. For example, I am from India, and In India, it is 865-867 MHz.
The range between LoRa sender and receiver depends on the environment of the equipment where it operates. Indoor coverage largely depends on the type of building material used.
In Urban areas, the range is 2-5 km, in rural areas 5-15km, and if there is Direct Line Of Sight between the Gateway and the LoRa end Nodes it is more than 15kms.
Some notable records in terms of range:
Sir Andreas Spiess, achieved ground to ground connection: 212 km (= 131.73 miles)
A group of people from the Netherlands achieved 702.62 km range by launching a LoRa Node to the sky using helium baloon.
How LoRa works?
In a LoRaWAN network, we have the LoRa nodes, LoRa gateways, Network Servers, and Application Servers.
LoRaWAN network architecture is deployed in a star topology & point to point communication topology.
LoRa nodes are devices with the radio modulation capability along with sensors and microcontroller to transmit sensors data to the Nearby gateways.
A LoRa end node consists of 2 parts: • A radio module with an antenna. A microprocessor to process the sensor data and Transmit it to the Gateway. End nodes are often battery-powered. Because the end nodes are configured to post data for a periodic cycle, An end node broadcasts its data to every Gateway in its vicinity. The nodes will wake up and transmit data and get back to deep sleep. They never turned on for 24×7.
LoRa gateways are supposed to capture data from the LoRa Nodes and channel the data to a network server.
A LoRa gateway consists of 3 parts: A radio module with an antenna for LoRa Communication, • A microprocessor to process the received sensor data, and an Internet connectivity medium such as WiFi, Ethernet, or Cellular Network to transfer the data to Network Server. Gateways are mains powered as it is supposed to turn on 24×7. The gateways can listen to multiple frequencies simultaneously, in every spreading factor at each frequency. Gateway doesn’t store any data, and they are just packet forwarders.
The communication between the end node and Gateway is bidirectional, which means the end node can send data to the Gateway, but it can also receive data from the Gateway.
Network server act as the LoRaWAN manager. It is responsible for scanning and rejecting duplicate data received by multiple gateways and serving the Application server. In addition, the network server performs network management functions like over-the-air activation, dynamic frame routing, adaptive rate control, traffic management, and administration.
Application Servers & Cloud IoT Services:
Applications interpret the data collected by end devices, applying machine learning and artificial intelligence to solve business problems for a Smarter Planet. Optionally the application server can send a response back to the end node.
When a response is sent, the network server receives the response and determines which Gateway to use to broadcast the answer back to the end node.
When an end node transmits data to the Gateway, it is called an uplink.
When the Gateway transmits data to the end node, it is called a downlink.
Key Features of LoRa:
Connects devices up to 30 miles apart in rural areas and penetrates dense urban or deep indoor environments
Requires minimal energy, with a prolonged battery lifetime of up to 10 years, minimizing battery replacement costs
Features end-to-end AES128 encryption, mutual authentication, integrity protection, and confidentiality
Offers device interoperability and global availability of LoRaWAN networks for speedy deployment of IoT applications anywhere
Enables GPS-free tracking applications, offering unique low power benefits untouched by other technologies
Maintains communication with devices in motion without strain on power consumption
Supports millions of messages per base station, meeting the needs of public network operators serving large markets
Reduces infrastructure investment, battery replacement expense, and ultimately operating expenses
What else do you need for an IoT Device? All these Key features made LoRa a boon for IoT Devices.
LoRa devices have revolutionized IoT by enabling data communication over a long range while using very little power. When connected to a non-cellular LoRaWAN network, LoRa devices accommodate a vast range of IoT applications by transmitting packets with important information. LoRaWAN networks fill the technology gap of Cellular and Wi-Fi/BLE based networks that require either high bandwidth or high power, or have a limited range or inability to penetrate deep indoor environments.
In effect, LoRa is flexible for rural or indoor use cases in smart cities, smart homes and buildings, smart agriculture, smart metering, and smart supply chain and logistics.
That’s all for the deep dive into the LoRa. I hope you have learned some thing ne from this episode. As promised earlier, we should make a LoRa Device now. But due to the long length of the article, we are not doing here. I will write a seperate article on that. You can find that article here.
Meet you on the LoRa realtime demonstration article… Untill then stay tuned to electronicsinnovation.com… Bubyeee