How to measure RSSI and TSSI for BLE Mesh

[Ubaid_M]

Hello,

I am using a nRF52840dk (nCS based app) with a nrf mesh android application,

 nRF52840dk has application running BLE-Mesh Server model. while I am using nrf mesh android app to trigger OPCODES to the server model.

Kindly help me with below queries:

1. How can I measure RSSI of BLE-Mesh for the server model running on nrf52840dk..?

2. How can i measure TSSI on the android mobile phone running the nrf mesh app..?

3.  How can I measure TSSI of BLE-Mesh on nrf52840dk, when my nrf52840dk extends the data further down the mesh..?

Thanks,

 

[AHaug]

Hi,

1. How can I measure RSSI of BLE-Mesh for the server model running on nrf52840dk..?

• You would only be able to measure the RSSI from the devices in the last jump of the message sequence. Is this what you're after?

2. How can i measure TSSI on the android mobile phone running the nrf mesh app..?

• Could you explain what you mean by TSSI? Do you mean as an indication of sender signal strength (TX)? 

3.  How can I measure TSSI of BLE-Mesh on nrf52840dk, when my nrf52840dk extends the data further down the mesh..?

• See #2
• Could you elaborate on this? Can you illustrate what this looks like when you say "extends the data further down the mesh"? 

Kind regards,
Andreas

[Ubaid_M]

Hello AHaug,

AHaug said:

You would only be able to measure the RSSI from the devices in the last jump of the message sequence. Is this what you're after?

Yes, how can I do it in code..?

AHaug said:

Could you explain what you mean by TSSI? Do you mean as an indication of sender signal strength (TX)? 

Yes sender signal strength

AHaug said:

Could you elaborate on this? Can you illustrate what this looks like when you say "extends the data further down the mesh"? 

I mean when my ble-mesh model sends data to other devices on mesh network, i need to measure sender signal strength

[AHaug]

Hi,

I will unfortunately have to retract my statement about writing your own custom model that monitors RSSI, as we do not have the API that will enable you to do so in nRF Connect SDK.

I will however add to a feature request list that this has been requested.

Kind regards,
Andreas

[Ubaid_M]

Hello AHaug,

AHaug said:

as we do not have the API that will enable you to do so in nRF Connect SDK

So you mean to say currently in nCS It is not possible to measure RSSI..?

Thanks,

[AHaug]

Hi,

That is correct. 

Kind regards,
Andreas

[Ubaid_M]

Thanks for the confirmation AHaug.

Please update me as to when this will be available in nCS

And also feature request URL

AHaug said:

I will however add to a feature request list that this has been requested.

[AHaug]

Glad to be of help, 

Feature requests are generally not something we have a horizon w.r.t. when they are finished, and we do not provide the feature request URL as they are on a internal list. However, if you want to know more about what is planned for Mesh in the future, I recommend that you contact your regional sales manager for more information. Let me know if you need the contact information for your regional sales manager, and I'll send it to you in a direct message.

Kind regards,
Andreas.

[AHaug]

Good news and apologies are in place from me,

Digging deeper in the documentation we found that there exists something that might help you create your custom model which does this. It is not as readily available as the API in nRF5 for Mesh, which is why I could not find it, but you can still use it to create a custom model.

• All messages delivered to the model handlers carries the RSSI information in bt_mesh_msg_ctx passed to the handler.
• developer.nordicsemi.com/.../msg.html

Using this information together with our guide for creating custom models you can write your own model similar to the RSSI model in nRF5 (or more tailored to your design.

Again, apologies for the early conclusion

Kind regards,
Andreas

[Ubaid_M]

Thank you AHaug,

I could see it in bt_mesh_msg_ctx,

1. Does something similar exists to check TSSI..?

2. Are there any nCS provided samples demonstrating RSSI measurement..?

[AHaug]

Hi,

Ubaid_M said:

1. Does something similar exists to check TSSI..?

No, unfortunately not

Ubaid_M said:

2. Are there any nCS provided samples demonstrating RSSI measurement..?

Not for Mesh in NCS. There exists a radio test sample, but this is used to test a radios performance, and not the to measure the strength of a received or transmitted signal

Kind regards
Andreas