Mesh beaconing + flooding (or relaying)

[kmsmile2]

Hello, Team.

I always thank to you.

I tried to find some information, but it is a little bit hard to find, so I upload this Q&A.

Now I'm interested in Mesh protocol, so I tested some project.

1) Mesh beaconing

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.meshsdk.v4.2.0%2Fmd_examples_beaconing_README.html&cp=7_2_3_2

2) Light_switch_client, server (for relay data)

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.meshsdk.v4.2.0%2Fmd_examples_light_switch_README.html&cp=7_2_3_0

I'm not good at using mesh system, could you help me?

Q1. Does 'Mesh beaconing' offer relay or flood the data to other node? 

Q2. If yes, how could I use two functions together?

Q3. If not,  could you give me some tips which make it possible of Mesh beacon to relay or flood data?

I think that flooding is more suitable than relaying, because beaconing data include not specific destination's address (Just beacon's address, sensing data, etc...) 

I'll wait for reply.

Thank you so much.

Best,

Minsu Kim

[tesc]

Hi,

The "beaconing" of the mesh beaconing example is for sending and receiving normal BLE advertisements in a Mesh project, and this beaconing is not part of Bluetooth mesh. Packets sent this way are not mesh packets, and will not be relayed through the mesh network. It is rather an example of how to integrate a mesh node with existing BLE advertisement based communication.

The Light Switch examples show how to use Bluetooth mesh, and uses a mesh model for sending on/off state from an on/off client model (the switch) to an on/off server model (the light bulb). By default it has the relay feature enables, which means if you have three nodes A, B and C in your network, and A is in range of B, B is in range of C, but A is not in range of C, messages between A and C will be relayed by B so that A and C can communicate.

When you send mesh messages (that is, using mesh models,) messages will automatically get relayed by the relay nodes in the network. So that is what you want to use in the general case. As mentioned, the "beaconing" is just good old BLE beacon functionality. Use cases for mixing BLE beacons with your mesh network is for instance if you have sensors that uses beacon to communicate sensor readings, then you have a mesh node observing those beacons for reading and send the sensor data through the mesh network to e.g. a gateway.

Regards,
Terje

[kmsmile2]

Thank you for reply, tesc!

Your reply is so helpful to me.

Could I ask one more thing?

tesc said:

Use cases for mixing BLE beacons with your mesh network is for instance if you have sensors that uses beacon to communicate sensor readings, then you have a mesh node observing those beacons for reading and send the sensor data through the mesh network to e.g. a gateway.

When I tested 'Light Switch example', I needed to provision all of things which are units of mesh network. (Client, Server..)

When I read your reply, I think that the beacon data can be sent by node to node if they are provisioned. (one node do work as gateway)

If so, I'm curious that it is possible to send data which is from beacon sensor without provisioning all nodes.

Is it possible to relay without provisioning?

I'm sorry to bother you.

Best,

Minsu Kim.

[kmsmile2]

I mean, is it possible for relay node to relay data without provisioning?

[tesc]

Hi,

For a Bluetooth mesh network, any node involved in the network must be provisioned. (Provisioning is the procedure for including a device into the network. The device then becomes a "node" in the network.

I assume your use case is BLE beacons and a Bluetooth mesh network for relaying the sensor readings to a gateway. All of the nodes which are part of the mesh network (including the gateway and the observers) will then have to be provisioned. You also need to configure gateway and observers, so that observers publishes to an address and the gateway subscribes to the same address.

The sensor nodes, who only advertise sensor readings using normal BLE, they will not be part of the Bluetooth mesh network, and so are not provisioned into the network. They can be normal BLE devices based off of nRF5 SDK.

Regards,
Terje