Conduit AEP, How to get CFlist

[Alex Fernandes]

Hello,

I am a student and I’m working on a multitech gateway, the MultiConnect® Conduit – Application Execution Platform MTCDT-210A with the Firmware version 1.4.1.

I’m trying to create a LoRaWAN communication between this gateway and an end-device, a RFM95W without shield. I’m using a APB connection and I have a little problem, how can I get the CFlist field ? I need this field to know what is the channel list I need to use. How can I get this information without an OTAA connection ? Can I get it with a command in the terminal or with the web configuration application or something else ?

I have an another question, I won’t implement the full stack (on my end-device) and my boss won’t too, how can I found a good API to communicate with my RFM95W controlled by an Arduino UNO (or a Raspberry Pi 3) on the web ?

Thanks for all your answers.

A.F

[Mike Fiore]

Alex,

If you’re in the US915 frequency band (I’m assuming you are), you’ll end up configuring your conduit for a certain frequency sub band. This is because the MTAC-Lora card only has the bandwidth to receive on a portion of the available channels in the US915 frequency band.

You can get full information about the US915 band from the LoRaWan specification, which you can access from https://www.lora-alliance.org/For-Developers/LoRaWANDevelopers.

Here’s a quick rundown of how the US915 frequency band is set up:
* 64 total 125kHz uplink channels, numbered 0-63
* 8 total 500kHz uplink channels, numbered 64-71
* 8 total 500kHz downlink channels, numbered 0-7

FSB 0 is default operation where the device uses all channels – gatewawy must be able to listen on all channels. Our gateways can receive on a group of 8 125kHz channels.

Each of FSBs 1-8 consists of the following:
* 8 125kHz uplink channels
* 1 500kHz uplink channel
* 1 500kHz downlink channel
FSB 1 uses uplink channels 0-7 and 64 and downlink channel 0.
FSB 2 uses uplink channels 8-15 and 65 and downlink channel 1.
Etc, etc.

So the channel mask for your device will depend on what FSB you have your gateway configured for.

Hope this helps!
Cheers,
Mike

[Alex Fernandes]

Sorry I’m working in EU so 868MHz.

[Mike Fiore]

Alex,

In that case, the gateway is listening on the 3 default channels for the EU868 frequency band and sends down the center channel for the other 5 in the join accept. You can see the configured center channel in the AEP web UI on the LoRa configuration page.

Once you have the center frequency for the extra channels, you can determine the frequency for each of the 5 channels and configure your endpoint to use them as well as the default 3 channels.

Cheers,
Mike

[Alex Fernandes]

Thanks Mike,

I know about the 3 default channels, they are 868.1, 868.3, 868.5 MHz, but I can’t use this to communicate. I can only communicate with the 868.1 MHz channel and not all of time (the gateway don’t received all my message).

You talk about 5 channels, but on the web UI, I can configure only the field for “Additional Channels” (I set it on 869,5 MHz). I don’t know how I can determine the frequency for each of the 5 channels.

I’m using the TTN API, it is perhaps my problem, but the TTN community told me : “Our API works on all LoRa network”. So I didn’t know where is my problem.

A.F

[Mike Fiore]

Alex,

The 5 additional channels are derived as follows:

“additional channels” center frequency – 400kHz
“additional channels” center frequency – 200kHz
“additional channels” center frequency
“additional channels” center frequency + 200kHz
“additional channels” center frequency + 400kHz

So for an additional channels center frequency of 869.5 MHz, you’d get the following 5 channels:

869.1 MHz
869.3 MHz
869.5 MHz
869.7 MHz
869.9 MHz

Hope this helps!
Cheers,
Mike

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