For this demonstration, 1
I've got an end device registered in OTAA on the network server. On the left, 2
I always have my end device log and on the right one tab with my gateway logs and my application server. 3
Let's try it. 4
I power up my device and a few seconds later I can see that the join procedure have succeeded. 5
When we use OTAA, everything is simple because we don't have to worry about the frame counter. 6
Why ? 7
Because during the join procedure, the network server and the device reset their frame counters. 8
But one could said that we also did it in ABP. 9
We did it manually. 10
But was it very different from here ? 11
Actually, yes, there was a big difference. 12
The thing is that in OTAA, every time the join procedure restarts, a new set of session keys is shared 13
between the end device and the network server. 14
So they both have a new network session key and a new application session key. 15
So there is no problem to reset the frame counter because no frame counter values have already been used within 16
this session. 17
So of course, at the beginning, each time I send a packet, the frame counter increments and everything 18
is received on my application server. 19
And now what happened 20
if for some reason my end device reset. 21
That's what I will do now by pressing my reset button. 22
There we go. 23
There is a new join procedure, and new keys are exchanged. 24
And if I start a new packet, everything is received on my application, even if the frame counter is 25
back to one. 26
What I want to point out with this demonstration is that we've seen a first advantage of using OTAA instead 27
of ABP. 28
That's not the only one and we'll see many others. 29
So even if sometimes we can consider that a join procedure is a bit complicated, then we should keep 30
in mind that at the end of the day, we will find a lot of benefits to use OTAA.