Friendship - BLE Mesh

[erdemsimsek]

Hi,

I am trying to understand possibilities provıded by Bluetooth Mesh Technology.

In my topology, there are tywo types node.

The first type of node is connected to the electric grid and its position is fixed.

The second type of node is a battery-powered tag which can travel around rooms.

As much as I understand, a node in the BLE Mesh network can be relay, proxy, friend or low power node.

The node which is connected to the electric grid works as relay node.

The other node only requires to send data over BLE Mesh network. It does not need to receive any packet.

Is it necessary to configure the second type node as low power node ?
The position of battery powered node will change continously . How the friendship works for battery powered node ?

Thanks for your support

Best regarsd

[Joakim Jakobsen]

Hi.

As the position of your battery powered tag, a friend node might not be the best solution here.

Is it necessary to configure the second type node as low power node

 It isn't necessary to do this. You can use it as a normal mesh node just like all the other nodes. But the power consumption will be high, and the battery will most likely have to be charged or changed quite often. However, this might be acceptable for your usecase.

What I could suggest is configuring the battery powered tag as a beacon device. As you don't need the two-way comunication, this might be a good solution for you. Then it only needs to broadcast data when it needs to, but never stay in RX-mode listening for packets. We have a beaconing example in the nRF5 SDK for Mesh that you can take a look at.

Best regards,
Joakim Jakobsen

[erdemsimsek]

Hi Joakim,

Is the beacon device a part of BLE Mesh network?

If the answer is yes, how does updated network key transmitted to beacon device ?

Best regards

[erdemsimsek]

Hi Joakim,

Do you have any update about my question ?

Best regards.

[Joakim Jakobsen]

Hi. 

This is up to you and how you choose to solve this. You can have a beacon device that is provisioned into the network. You can also make your mesh network listen for BLE advertisement packets from the beacon. 

There are several alternatives to achieve low power besides the Low Power Node and Friendship solution.

- You can just put a normal node to sleep, it may miss packets send to it, but if it's simply a temperature sensor for example, you just need to receive data from it.

- Or you can make your device to advertise normal BLE advertising packet, and define a protocol in your normal mesh node to forward those packet into mesh, this is what we have in the Enocean energy harvesting light switch example.

- Another option is to configure your device as a GATT client proxy, to connect to a Proxy. This way you just need to maintain a normal BLE connection. 

Best regards, 
Joakim