Hello and welcome to another episode of “Learn Technology in 5-minutes from MAKERDEMY
and I am Venkatesh, the founder of MAKERDEMY
In this video, we will learn about LoRa, the low power wide area network technology for the Internet of Things
You are familiar with Wide Area Network technology like the cellular 4G and 5G which allow data transmission over long distances
However, cellular WAN consumes a lot of power. How often do you charge your mobile phone? I charge my phone every day
Cellular WAN allows us to transmit large amounts of data at high speeds over long distances
The trade-off here is high power consumption
Now let us think of an IoT solution wherein we have 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 at least for a couple of years
These nodes can’t be mains charged like your mobile phone
The data transmitted will be small and sporadic
Under such conditions, we need a wireless network that consumes very low power
but also operates over distances larger than those of say, WiFi
Is such a network even possible?
Enter LoRa. LoRa is an abbreviation of LongRange
Let’s first get some confusion related to terminology out of our way
There is LoRa and there is LoRaWAN
LoRa is a proprietary radio modulation technology owned by Semtech and deals with only the Physical layer of the stack
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 the LoRa technology to several vendors who produce  LoRa devices
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, a non profit association of over 500 companies that
is responsible for the development and promotion of the LoRAWAN open standard
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 what the frequency band in which LoRa network operates in your country by clicking on this link
For example, in India, it is 865-867 MHz
To get some perspective, let us take a look at this chart, which compares several wireless technologies on
2 dimensions - transmission range and the bit rate. As you can see, the LoRa bit rate is quite low...it is in the order of tens of kilobits per second
But this comes with a much larger transmission range and much lower transmission power
In a LoRaWAN network, we have the LoRa nodes and the LoRa gateways
LoRa nodes are devices with the LoRa radio modulation capability along with sensors and microcontrollers
The LoRa nodes typically run on batteries that are expected to run for several years
Several LoRa nodes connect to LoRa gateways, which channel the data from the
nodes to a network server and from then on the data is moved to a variety of application servers
In LoRaWan, The LoRa nodes to gateway connection are in the form of a star network and the nodes cannot talk to each other directly
Also, the communication between the gateway and the nodes is bidirectional, so that
we can also get the nodes to perform some actuations like turning on some status lights and so on
Each node can transmit to multiple gateways and the network server removes the
duplicates and forwards the appropriate data from the node to the correct application server
That is all from me in this video folks
