Guillermo Glaria

Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

8 years, 7 months ago.

Does libmDot control sequence number?

Hi,

I am working with mDot_AT_firmware connecting by a Multitech Conduit Gateway to Loriot cloud. The Loriot cloud sample application controls sequence number, but I don't know if the libmDot controls this and if it implements in LoRaWAN protocol.

Is there any source code of libmdot to study this?

Thanks and regards,

Gilen

Question relating to:

Last updated: 18 Nov 2016
Library for LoRa communication using MultiTech MDOT. Lora, mdot, multitech

Hi

posted by Guillermo Glaria 23 Sep 2015

3 Answers

Mike Fiore
8 years, 7 months ago.

Hi Gilen,

The mDot library source code isn't available for compliance reasons.

You can use the mDot::getUpLinkCouner() function to see the sequence number, but it is read-only.

Cheers,

Mike

Accepted Answer

Hi Mike,

My question is: Does libmDot build the LoraWAN frame incrementing the sequence number field from packet to next packet? My issue is that Loriot server is not accepting all my packets and I suspect the reason is related to the sequence number. Could it be?

Thank you, Gilen

posted by Guillermo Glaria 22 Sep 2015

Gilen,

Yes, the mDot library builds the frame and handles incrementing the sequence number. You can use the function I referred to in my answer to see if the sequence number lined up with what your gateway is expecting.

Cheers,

Mike

posted by Mike Fiore 22 Sep 2015
Jack Spades
8 years, 7 months ago.

Hi Gilen, if you don't see all frames arriving, the next thing I would check is the channel allocation. Is it in sync between the gateway and the mDot?

Cheers, Vit

Jason Reiss
8 years, 7 months ago.

Have you configured AT+FSB. By default mDot uses 64 frequencies. Conduit can only recieve on 8.

Hi all, Thank you for your suggestions. My implementation is in european market with 868 MHz band and it's not necessary any sub-band selecction. What about frequency plans? In LORIOT server can configure to the gateway some diferent frequency plans: EU868 Standard 6 Channel, EU868 Semtech 8 Channel, EU433 3 Minimal Channels, EU433 EU868 Dual Band and EU868 mDot compatible. This last one is:

Channel Frequency Modulation / BW

FSK 868.600 MHz FSK 250 kHz, 50 kbps

LoRa 868.300 MHz SF7 250 kHz

0 868.100 MHz MultiSF 125 kHz

1 868.300 MHz MultiSF 125 kHz

2 868.500 MHz MultiSF 125 kHz

3 869.100 MHz MultiSF 125 kHz

4 869.300 MHz MultiSF 125 kHz

5 869.500 MHz MultiSF 125 kHz

6 869.700 MHz MultiSF 125 kHz

7 869.900 MHz MultiSF 125 kHz

Is mDot programmed with this frequency plan in last versions? Thank you and regards, Gilen

posted by Guillermo Glaria 23 Sep 2015

Hi again,

I have investigated a little more, and when I send to the mdot the AT+TXCH command it list me those channels: AT+TXCH#CR#CR#LF0: 868100000 125k#CR#LF1: 868300000 125k#CR#LF2: 868500000 125k#CR#LF3: 0 125k#CR#LF4: 0 125k#CR#LF5: 0 125k#CR#LF6: 0 125k#CR#LF7: 0 125k#CR#LFD: 869525000 125k#CR#LF#CR#LFOK#CR#LF#CR#CR#LF

Is this correct? If there are only three channels configured, it's not matching with any frequency plan of Loriot or LoRaWAN standard...

Regards, Gilen

posted by Guillermo Glaria 23 Sep 2015

Channels 0-2 are configured by default in order to join the network. Channels 3-7 are expected to be sent with the OTAA join accept message.

posted by Jason Reiss 23 Sep 2015