To start this chapter, we'll see the difference between the LoRa modulation and the LoRaWAN protocol. 1
These terms are sometimes mixed together and one is often used instead of the other. 2
So we'll try to have an overview of these two terms Lora and Lorawan. 3
Lora is the type of modulation. 4
It's the method that is used for two entities to understand each other. 5
We saw that the Lora modulaton uses chirp symbol and in addition to that we defined the Lora frame format, 6
which is mainly a preamble at the beginning to synchronize the receiver and then at the end a code 7
for error detection. 8
These are the only fields required with this kind of frame. 9
We can transmit from an end device to another end device, from an end device to a gateway. 10
And obviously the other way round works as well. 11
So from a gateway to an end device and finally we could imagine a Lora transmission between two gateways. 12
To content of the frame that we call payload does not matter. 13
You can put anything in it. 14
You can build your own application protocol depending on your use case. 15
Now, when you want to transmit information from an end device to a network server, you will probably 16
want to implement some security features. 17
You will also probably want to have a standardize protocol. So your end device could work with any network 18
server. 19
This is what we call interoperability. 20
So we have to define a protocol, a transmission method. 21
And this protocol is called LoRaWAN. 22
The Lorawan protocol involves a network server and an application server. We'll see later what their purposes. 23
But if we want that the network server and the application server can understand what the end device sends. 24
We must add more information inside a LoRa frame. 25
We will review this additional information in details later, but for now we can quote a few of them 26
like the device address for identification, the authentification, information, the frame counter and so 27
on. 28
When we work with Lorawan, we don't have the possibility to transmit from an end device to another end 29
device, but it's exclusively from an end device to a gateway. 30
And then it's the gateway itself that transfers the packet to the network server. 31
Actually between the end device and the gateway, 32
it's a LoRa packet transmission carrying a lorawan protocol message. 33
So eventually, what are you going to use, Lora modulation or Lorawan protocol? 34
First of all, if you use LoRaWAN, you necessarily use Lora. 35
On the other hand, if you want to use only Lora, it's possible. You would transmit Lora packet, for 36
example, between two end devices, and you will build your own application protocol. 37
There is no problem with that. 38
But when it comes to transfer information to the network server, you will have to use the LoRaWAN protocol. 39
And this is this protocol that we will explain in this chapter.