BLE Mesh connecting issue

[Prashanth_Raj]

Hello,

I'm Electronics designer, our Team faced some issue regarding BLE Mesh connectivity,

Q1. We have observed that It's taking so much of time(>3 min & upto 14 minutes) to join mesh(5 Devices), Most of the time some devices are not able to join the mesh, only 2-3 device are connected.

Q2. When kept device on ground level we are not able to establish connection(Devices are advertising and able to see in nRF Connect app) but not able to join mesh of distance above 8 meter, 

Here is the connection status.

All devices are in ground with distance of max 8 meter, failing to form mesh, but above 2 feet we are able to join upto 15 meter distance.

[AHaug]

Hi,

I have a couple of clarification questions and some information to give to you after discussing this case with my colleagues so it is split into two sections: Mesh and  Radio procedures 

Radio

Another point that got brought up was when talking about distance between the devices, it does not seem the issue is in Mesh procedures despite it looking like Mesh devices cannot `join` to each other. It seems to us like a lack of Tx power. Radio waves spreading is much worse if there are grounded environments (they mentioned ground level). We would recommend playing with controller Tx power first and only after this digging deep into mesh debugging.

The Mesh stack works with Tx power that has been configured in Bluetooth Controller. There are no algorithms for Tx power adaptation. If Tx power is not enough establish connection Mesh(as technology) cannot solve the issue, and if that is the case then try to answer the questions below and we might see if the issue is in the procedure part

Procedures:

It is not quite clear what you mean by "devices are not able to join" as there are no join procedure in the BLE Mesh specification.

1. Do you mean that this is happening in the provisioning procedure? If so: 
   1. Which provisioning bearer has been used?
   2. At which stage has the provisioning procedure gotten stuck?
2. Or is it happening on the configuration stage? If so:
   1. Which command of configuration model causes the issue?
3. Which part of provisioning procedure wasn't able to communicate? Was it the `provisioner` or `provisionee`?

Is it correct to assume that in the picture you attached, that it is a mobile phone that is the provisioner, not just the proxy)? If so, then it is not possible to perform multihop provisioning. Provisioning is p2p procedure in spec v1.0.1. 

Kind regards,
Andreas