nRF52840 Mesh Packet Dropout

[ramachandra]

Hi,

   We are developing the project based on nRF52840 chipset. We are configuring the chip for mesh application and using generic on/off model to send the data on the mesh. We are able to transmit and receive the data between multiple nRF52840 Device, But sometime the mesh packet dropout (ex out of 10 tries, couple of time its dropout) and will be received by the other device. Please let us know is there any way to resolve it so that the packet doesn't drop out and ensure it reaches to the other device without any loss.

How can we enable the reliable transmission in the mesh.

Regards,
Ram

[Didrik Rokhaug]

Hi, and sorry for the long wait.

At the moment, all our mesh experts are on vacation, but I'll do my best to help you until they are back.

Have you seen the documentation for reliable transmissions in the access layer?

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.meshsdk.v4.2.0/group__ACCESS__RELIABLE.html

However, looking through the implementation of the generic on/off model, it looks like that is already used.

I am also a bit confused about one thing you wrote in your ticket:

 

But sometime the mesh packet dropout (ex out of 10 tries, couple of time its dropout) and will be received by the other device.

 Did you mean that the packet will not be received by the other device?

Best regards,

Didrik

[ramachandra]

Hi Didrik,

  Thanks for the prompt reply.

  Ya you are right, it was my sentence mistake.

  sometime the mesh packet dropout (ex out of 10 tries, couple of time its dropout) and will not be received by the other device.

We will go through the Link shared by you and check it out how we can transfer the data with Reliable transmission Mechanism.

In current implementation we are using unreliable transmission method. 

In Mobile app while configuring the publish Address there is option for entering the retransmit count under the section PUBLISH RETRANSMISSION, Could you please let us know the purpose of setting this option, does it help out in transmitting the data multiple time .?

Please find the snippet below for the option in mobile APP.

Regards,

Ram

[Didrik Rokhaug]

ramachandra said:

In Mobile app while configuring the publish Address there is option for entering the retransmit count under the section PUBLISH RETRANSMISSION, Could you please let us know the purpose of setting this option, does it help out in transmitting the data multiple time .?

 Yes, it should help with reliability.

[ramachandra]

Hi Didrik,

   We tried configuring the the option Publish transmission in the module app but it didn't Help us out, Still we see lot of packet loss. 

Could you please suggest the latest proxy mesh sdk APP (Where we can configure both Generic On OFF Server and Generic On Off client in single provisioning APP like below screen shot) which we can use and try it out if there is any improvement.  

Regards,

Ram

[Didrik Rokhaug]

Hi Ram,

Could you tell me a bit about your network topology?

How many nodes are there, how spread out are they (how many hops are necessary for a message to reach its destination), are there a lot of noise in the environment, etc.?

If the message passes through any relay nodes, you must also edit the 'Retransmit Count' and 'Retransmit Interval' in the 'Relay' section in the app. Or, you can set it in the source code directly: https://devzone.nordicsemi.com/f/nordic-q-a/33319/are-relay-messages-transmitted-more-than-once

Best regards,

Didrik