TTN Node Channel set up

End Devices (Nodes)
1

Gentlemen,

We are trying some specific Lora channels with a couple of gateways, and need to setup a set of not continuous channels, so that those gateways can receive the transmissions.

One gateway is setup to receive first set of channels from 0 to 7, the other have channels 8, 10, 22, 31, 36, 40, 43 and 51.

This is done just to avoid interference from nearby transmitters.

Is there a way to set up channels at will with the TTN Node?, or at least change their original setup?

Does the Arduino TTN Node and TTN libraries allow to do this?

I used the pass through sketch to talk directly to the RN2903 module and set channels at will, but when reloading an sketch this configuration is lost.

I haven’t found any reference to commands on the libraries to perform the channel set up.

This is a capture of the port:

22:51:31.839 -> Sending: mac save
22:51:32.558 -> Sending: mac set ch status 0 off
22:51:32.558 -> Sending: mac set ch status 1 off
22:51:32.605 -> Sending: mac set ch status 2 off
22:51:32.605 -> Sending: mac set ch status 3 off
22:51:32.605 -> Sending: mac set ch status 4 off
22:51:32.605 -> Sending: mac set ch status 5 off
22:51:32.605 -> Sending: mac set ch status 6 off
22:51:32.605 -> Sending: mac set ch status 7 off
22:51:32.652 -> Sending: mac set ch status 8 on
22:51:32.652 -> Sending: mac set ch drrange 8 0 3
22:51:32.652 -> Sending: mac set ch status 9 on
22:51:32.652 -> Sending: mac set ch drrange 9 0 3
22:51:32.652 -> Sending: mac set ch status 10 on
22:51:32.652 -> Sending: mac set ch drrange 10 0 3
22:51:32.699 -> Sending: mac set ch status 11 on
22:51:32.699 -> Sending: mac set ch drrange 11 0 3
22:51:32.699 -> Sending: mac set ch status 12 on
22:51:32.699 -> Sending: mac set ch drrange 12 0 3
22:51:32.699 -> Sending: mac set ch status 13 on
22:51:32.699 -> Sending: mac set ch drrange 13 0 3
22:51:32.746 -> Sending: mac set ch status 14 on
22:51:32.746 -> Sending: mac set ch drrange 14 0 3
22:51:32.746 -> Sending: mac set ch status 15 on
22:51:32.746 -> Sending: mac set ch drrange 15 0 3
22:51:32.746 -> Sending: mac set ch status 16 off
.
.
.
22:51:33.127 -> Sending: mac set ch status 64 off
22:51:33.160 -> Sending: mac set ch status 65 on
22:51:33.160 -> Sending: mac set ch status 66 off
22:51:33.160 -> Sending: mac set ch status 67 off
22:51:33.160 -> Sending: mac set ch status 68 off
22:51:33.194 -> Sending: mac set ch status 69 off
22:51:33.194 -> Sending: mac set ch status 70 off
22:51:33.194 -> Sending: mac set ch status 71 off
22:51:33.194 -> Sending: mac set pwridx 5
22:51:33.194 -> Sending: mac set retx 7
22:51:33.228 -> Sending: mac set dr 3
22:51:33.228 -> Sending: mac join otaa
22:51:38.890 -> Join accepted. Status: 0001

So we can see that channels 8 to 15 and 65 are enabled, whereas all other disabled, this indicates that when starting the Node this configuration is applied eliminating any tother.

So one option will be to modify the library and/or setup, or configure after initial loading.

Any help will be greatly appreciated.

Thanks.

2

That can work, in theory, though it may not be compatible with TTN usage in your unspecified region.

That simply will not work. The SX1301/1302/1308 chips used in gateways are constrained to receiving two tightly grouped (effectively contiguous) clusters of 4 channels each.

Your random skipping pattern cannot be supported with ordinary or reasonably priced hardware.

It would also not be compatible with TTN, which imposes the frequency plan to be used per region, and it would thus not be on topic here.

3

Hi cslorabox,

Thanks for your reply.

Understand you answer so if I have to use channels packed by groups, is there a way to enable channels 0 to 7, or any other logical group, but different from the original 8 to 15?.

Again thanks for your reply.

Regards,

4

On a typical gateway channel setup is controlled by a file called global_conf.json You’ll have to state things in terms of the IFs of the two front end sx125x radio chips and then the offsets of the baseband channels detected by the SX130x from those two IF’s.

If you look at the existing file in comparison to the band plan it implements and spend a few minutes studying the numbers you should be able to see how each channel is expressed as an offset from one of the IFs. Change those, change the offsets within a limit of about +/- 200 KHz and you can have a different channel plan.

5

Hi again,

Ok, got it.

I will manage to talk directly to the Microchip’s modules and set up channels by group, as you suggested.

Will check configuration files as well and load the new configuration accordingly.

Thanks a lot for your time.

Regards.

6

Hi cslorabox,

Reading my posts from yesterday I noticed that my questions and explanations were not complete and might have caused confusion.

  1. We are working to integrate various Lora systems in Latin America which use the same US905 specs, as the USA, I didn’t mention that.

  2. We are not planning to modify the gateways, they are at fixed locations and already set to operate for a private IT firm, on fixed channels, however they do share some free bandwidth for experimental purposes.

  3. Those gateways have fixed channels as:
    3.1 Channels 0 to 7
    3.2 Channels 8 to 15
    3.3 Channels 20 to 27
    3.4 Channels 30 to 37
    3.5 Channels 40 to 47
    3.6 Channels 50 to 57

  4. there are a total of 25 gateways working with those channels, what we need to do is to be able to set the endpoints or motes, to work with them.

  5. We received some TTN Node motes as well as many other and just need to be able to configure them for these frequencies.
    The “Node TTN” is the only one left to set up as the Arduino sketch does not provide a function, class or method to configure channels, as you said, they are pre-configured according to zone.
    Working directly with the RN2903 directly we can setup channels but when running the sketches they got reconfigured.

I downloaded from Github the Library and will try to modify it but if someone has already been able to set channels independently, from the examples sketches, that will help a lot, and we don’t have to modify the libraries.

Thanks.

7

Those are some premium gateways if they actually have 6 concentrator cards in them. Typical TTN gateways only have one.

But are these premium gateways actually backended to TTN? This forum is really only about things that are. Using a node board designed for TTN on some other network isn’t really on topic here.

8

Dear cslorabox,

I guess that my english is so bad that you didn’t understand when I mentioned we are using TTN products, like the TTN Node.

I never mentioned Premium Gateways, those gateways mentioned are to my understanding in a great extent TTN GateWays.

And I also assume that the IT company is using TTN servers as well for some of its bandwidth.

Now if TTN’s politics in this forum dictates that only TTN products on TTN servers can be talked about, and does not accept cooperation between different suppliers, in my opinion is a very short vision of the market, which will have any amount of different suppliers and the whole idea of LoRa, as I understood it some years ago, when it appeared, was to integrate everybody not the opposite.

Anyway, I will not bother either you or any other person in this forum with my concerns, there are fortunately other places with more friendly people to talk to.

Thanks for your very kind attention and feel free to erase my posts.

Have a great day!

9

TTN is a network.

Nodes meant to work with TTN are not TTN, but merely an enabling technology. When used with something else, they aren’t TTN at all.

I never mentioned Premium Gateways, those gateways mentioned are to my understanding in a great extent TTN GateWays.

That seems unlikely, given the range of channels supported. TTN bandplans really assume only 8 channels

Or to put it another way, if your nodes were using TTN, you’d only be worried about the 8 channels in your region’s bandplan.

And I also assume that the IT company is using TTN servers as well for some of its bandwidth.

Again, unlikely - as (unfortunately) there isn’t really any viable scheme for connecting to multiple servers at present.

10

Wow, really impressed how a text is misinterpreted.

Never said that a single gateway supported more than 8 channels.

I explicitly said that there were around 25 gateways supporting different channels, as these IT providers selected to work at different frequencies, depending on interference, use, etc. at different places in the region.

The use of different servers are performed with different gateways, not one for all.

Again, I am really surprised from your replies, please read in detail what people write before replying with a no polite response, we all are here, at the LoRa community, to make this platform greater, better and open to everybody, the idea shall not be to exclude but to integrate.

Never again will use these forums, so you can be happy that your comments and forms are effective in causing people to exit.

Goodbye.

11

I explicitly said that there were around 25 gateways supporting different channels,

This would appear to be the first time you have specifically said that.

But anyway, if that is the case, then this has nothing to do with TTN (as TTN uses the same 8 channels on every gateway) and therefore does not belong here.

we all are here, at the LoRa community, to make this platform greater, better and open to everybody, the idea shall not be to exclude but to integrate.

No, this is not “the LoRa Community”. Or even “the LoRaWAN community”. This is the TTN forum, and what you are asking about is clearly not TTN.

You will need to seek support from whatever network these gateways actually do belong to.

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