0 1 00:00:00,900 --> 00:00:04,220 So now let's make a demonstration about this lorawan device classes. 1 2 00:00:04,230 --> 00:00:10,770 We will start with a class A end device, and then after we'll switch to class C. 2 3 00:00:11,670 --> 00:00:18,000 So first let me explain the application we're going to use. Again we will consider a one byte transmission 3 4 00:00:18,000 --> 00:00:19,650 representing a temperature sensor. 4 5 00:00:20,460 --> 00:00:27,420 This temperature is sent on the application server each time we press the button. So we have a total 5 6 00:00:27,420 --> 00:00:33,110 control of when the end device would transmit. Then we'll focus on the downlink capabilities. 6 7 00:00:33,120 --> 00:00:37,320 So basically we'll program the downlink on the application server. 7 8 00:00:38,400 --> 00:00:41,280 It will be scheduled on the network server. 8 9 00:00:42,240 --> 00:00:46,770 and here comes the big question. When will the downlink frame be sent? 9 10 00:00:47,730 --> 00:00:53,100 Obviously, the behavior will be different when we use a class A or class C end device. 10 11 00:00:53,910 --> 00:00:59,880 You get to the class A end device will be able to receive only on the RX1 or RX2 slot. 11 12 00:01:00,330 --> 00:01:02,160 So just after transmission. 12 13 00:01:02,700 --> 00:01:07,140 And on the other hand, the Class C end device will be able to receive whenever it wants. 13 14 00:01:07,410 --> 00:01:11,250 That is, there is no specific time slot for the reception of downlink packet. 14 15 00:01:12,030 --> 00:01:12,420 What ever 15 16 00:01:12,420 --> 00:01:14,130 a device on the network server. 16 17 00:01:14,460 --> 00:01:20,850 If you want to set up a Class A Lorawan transmission, we have to first register a class A end device 17 18 00:01:20,850 --> 00:01:22,020 on the network server. 18 19 00:01:22,980 --> 00:01:27,060 Secondly, configure the end device as a class A on the device itself. 19 20 00:01:29,520 --> 00:01:35,760 To prepare this demonstration, we have enregister the class A end device called device one OTAA on the Lorawan server. 20 21 00:01:35,760 --> 00:01:42,240 On this part of Lorawan server call TTN class A is the default class. 21 22 00:01:42,600 --> 00:01:47,820 So there is no need to explicitly specify. On the device side, 22 23 00:01:47,940 --> 00:01:50,880 I configured it as a class A end device. 23 24 00:01:51,510 --> 00:01:54,750 Again, the configuration method depends on your end device. 24 25 00:01:54,960 --> 00:01:57,420 In my case is just a text. 25 26 00:01:57,420 --> 00:01:57,860 file. 26 27 00:01:57,870 --> 00:02:02,220 So I just have to define the macro class A in the corresponding field. 27 28 00:02:03,540 --> 00:02:09,360 and you can see that I've also written all the Lorawan information, but for that part, we'll explain 28 29 00:02:09,360 --> 00:02:09,900 it later. 29 30 00:02:10,320 --> 00:02:12,690 So right now we just need to concentrate on the class. 30 31 00:02:13,290 --> 00:02:17,520 We are now ready. For demonstration, 31 32 00:02:17,520 --> 00:02:21,090 I have the following Windows organization. On the left, 32 33 00:02:21,450 --> 00:02:24,060 I have my device log for my cellular link. 33 34 00:02:24,780 --> 00:02:31,710 Thanks to that, i will know exactly when it sends uplink data. And as soon as there will be a reception 34 35 00:02:32,520 --> 00:02:33,900 that will also be ready 35 36 00:02:33,940 --> 00:02:40,290 on a log. When it would be the case, it will tell me exactly when and what was received. 36 37 00:02:40,710 --> 00:02:41,670 Now ont the right, 37 38 00:02:41,880 --> 00:02:43,590 I have a window with two tops. 38 39 00:02:43,980 --> 00:02:49,770 The first tops represents the getway traffic and the second tops is represent the traffic on my registered end 39 40 00:02:49,770 --> 00:02:51,120 device on the server. 40 41 00:02:52,410 --> 00:02:53,250 So let's go, 41 42 00:02:53,670 --> 00:02:55,260 I pull up my end device. 42 43 00:02:56,550 --> 00:02:58,860 When it starts up, there is a joint procedure. 43 44 00:02:58,860 --> 00:02:59,970 We'll see that later. 44 45 00:03:00,900 --> 00:03:02,850 Then it falls in my application. 45 46 00:03:03,570 --> 00:03:05,250 It's a very simple application. 46 47 00:03:05,250 --> 00:03:10,580 It's just wait for me to press the push button each time I press it, then a temperature data is sent. 47 48 00:03:10,590 --> 00:03:17,760 This frame is transmitted from my device here, it goes all the way through my gateway. 48 49 00:03:18,210 --> 00:03:24,780 I can see it in my gateway log here, my network server and finally my application server here. 49 50 00:03:26,310 --> 00:03:29,160 On this version of TTN, I see two frames. 50 51 00:03:29,370 --> 00:03:31,590 It's a little bit confusing, but don't worry. 51 52 00:03:31,770 --> 00:03:32,840 They have the sames, 52 53 00:03:33,000 --> 00:03:34,290 There is only one to consider. 53 54 00:03:35,930 --> 00:03:43,790 Each time a frame is sent, a counter increments, we can see the different value here one, two, three 54 55 00:03:43,800 --> 00:03:44,600 and so on. 55 56 00:03:45,290 --> 00:03:51,040 And on the end device, we have exactly the same counter one, two, three. 56 57 00:03:51,050 --> 00:03:54,230 and so. There is no downlink for the moment. 57 58 00:03:54,290 --> 00:03:57,260 Since I haven't transmitted anything from my application server. 58 59 00:03:57,710 --> 00:03:58,970 But that's what I'm going to do now. 59 60 00:03:59,420 --> 00:04:06,530 For that, all of Lorawan server offer a downlink messaging to. We need to go to the messaging tab and 60 61 00:04:06,920 --> 00:04:08,060 downlink tab. 61 62 00:04:08,930 --> 00:04:13,210 With this tool, you can choose the application port number called export. 62 63 00:04:13,820 --> 00:04:20,720 And there is another field with the value you want to send called payload. For the port number and the 63 64 00:04:20,720 --> 00:04:21,290 payload. 64 65 00:04:21,290 --> 00:04:23,300 We can choose any value right now. 65 66 00:04:23,780 --> 00:04:31,820 So let's choose, for example, Fport is equal to 20, this is a decimal value and a payload of AA. 66 67 00:04:31,970 --> 00:04:33,620 This is a negative symbol value. 67 68 00:04:34,100 --> 00:04:35,630 Then it discard all downlink. 68 69 00:04:35,630 --> 00:04:35,870 bytes. 69 70 00:04:39,090 --> 00:04:40,070 On the end device, 70 71 00:04:40,110 --> 00:04:42,750 do we see any data coming from the network server? 71 72 00:04:43,380 --> 00:04:48,330 Of course not, because we know that we have to send if we want to receive data. 72 73 00:04:49,020 --> 00:04:54,750 Moreover, on the server we can see that a new downlink has been scheduled ready to be sounds. 73 74 00:04:55,830 --> 00:04:59,580 So I just hit the end device push button to launch a new uplink. 74 75 00:05:01,010 --> 00:05:07,910 And right after I get my downlink, I can check the right value and the right port. 75 76 00:05:08,360 --> 00:05:12,710 I can also see that this downlink has been received on the RX1 window. 76 77 00:05:13,340 --> 00:05:19,700 It could have been either RX1 or RX2, but it's up to the network server to choose and there is nothing 77 78 00:05:19,700 --> 00:05:20,600 I can do about it. 78 79 00:05:21,440 --> 00:05:21,800 Okay. 79 80 00:05:22,190 --> 00:05:26,750 Now I'm wondering how the downlink message can find its way through the network. 80 81 00:05:27,260 --> 00:05:32,900 In other words, how the network server knew that my device was under these gateway coverage. 81 82 00:05:33,860 --> 00:05:39,500 Because you can imagine that this downlink message hasn't been broadcasted on all gateway on earth 82 83 00:05:39,500 --> 00:05:46,460 fortunately. The answer is that the network server simply choose the gateway used during the uplink, 83 84 00:05:47,060 --> 00:05:53,600 and if there were several then the network server would choose the one with the best RSSI during the 84 85 00:05:53,600 --> 00:05:57,620 uplink reception. That will increase the chance of receiving. 85 86 00:05:59,210 --> 00:06:01,130 Let's try another downlink frame. 86 87 00:06:01,520 --> 00:06:05,810 I hit the end device push button and here we go. 87 88 00:06:06,230 --> 00:06:06,800 It's here. 88 89 00:06:07,400 --> 00:06:09,620 I can check the gateway used for my uplink. 89 90 00:06:10,310 --> 00:06:11,120 That's this one. 90 91 00:06:11,810 --> 00:06:13,790 And I can take the gateway during the downlink. 91 92 00:06:14,360 --> 00:06:15,680 It's indeed the same one. 92 93 00:06:16,850 --> 00:06:22,790 So we are done with this demonstration with Class A end device, and in the next video we'll see what 93 94 00:06:22,790 --> 00:06:24,110 happens for the Class C.