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]

Thank you for elaborating. I've had some time to look into your questions and I have an answer for you

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

In nRF5 SDK for Mesh we had a custom RSSI model that we had written for RSSI monitoring purpose. This model is not available in NCS however, and it will not be ported to NCS. You can see the documentation for the nRF5 model here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.meshsdk.v5.0.0%2Fmd_models_vendor_rssi_monitor_README.html

If you want to create a similar model for nRF Connect SDK that does this, you will unfortunately have to write it yourself based on the link supplied, the Mesh specification as well as the documentation for creating a custom model developer.nordicsemi.com/.../ug_bt_mesh_vendor_model.html

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

We have no support for this. You can typically configure the TX power in your application yourself or it has been preset.

In normal BLE, you can advertise the TX power in the advertisement messages, see https://devzone.nordicsemi.com/f/nordic-q-a/91184/how-to-advertise-tx-power-of-a-peripheral, but this does not work in Bluetooth Mesh, as you're very limited with regards to accessing and changing the advertisement packs since they are controlled by the Mesh stack. 

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

 The same as 2. 

I hope this answer is of any help,

Kind regards,
Andreas

[Ubaid_M]

Hello AHaug,

Thanks, that helps.

AHaug said:

you will unfortunately have to write it yourself

I can write a custom model, but kindly help me with what APIs I can use for RSSI measurement and how do I go about invoking the APIs.

Thanks,

[AHaug]

Hi,

This is an update to let you know that I'm waiting for a reply from the Mesh team w.r.t. if we have an API for this or not. I will update you as soon as I can verify.

Kind regards,
Andreas

[Ubaid_M]

AHaug said:

I will update you as soon as I can verify.

Yes please

[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