Difference Friend node and Relay nodes

[SamTheMan]

Hello everyone,

 

I have a Bluetooth Mesh network of Friend nodes that communicate with eachother and allow message to pash through them.

Currently only a few need to have Low Power Nodes attached to them and the rest is needed to extend my network.

But maybe far into the future this will change.

 

So I'm wondering; Would it be beneficial to disable the friend feature on some of the nodes?

Are there any negatives to just making all backbone nodes be friend nodes (for possible future changes / flexibility)?

What is the major difference between Friend nodes and relay nodes?

[Amanda Hsieh]

Hi, 

The Friend feature and the Low Power feature combines to provide low power message reception for the Low Power Node. (TX from the Low Power Node uses the standard protocol of sending normal ADV bearer packets.)

The relay feature makes the node retransmit messages over the advertising bearer. (Mostly affects the network / bearer layers.)

For the short story about layers and concepts, see Bluetooth mesh concepts.

For the full specification, see the Mesh Profile Specification from bluetooth.com, where the features are specified.

I suggest you go through these documentations:

Bluetooth Mesh Network: Friendship

Low Power node feature

Integrating Low Power node feature

Low Power node example

You will get a better understanding of Relay, LPNs and Friendship nodes and how things work between them.

Regards,
Amanda

[Senchoi]

can LPN nodes send messages to other nodes beyond and through the friend node? Those materials talks about LPN nodes receiving msgs from friend nodes but not the other way around.