Mesh like network base on BLE connection， BLE and long range conexist issue.

RE: Mesh like network base on BLE connection， BLE and long range conexist issue.

tesc — Thu, 16 Jul 2020 11:42:22 GMT

Hi,

The term "Low Power Node" (LPN) is for nodes that communicate using the normal ADV bearer for communication, but has a "Friend node" in the network that will store all messages addressed for the node. The LPN can then wake at certain intervals, and poll the Friend node for new messages.

If you use the GATT bearer, it will not be a "Low Power Node" in Bluetooth mesh terminology, but it will look similar to your illustration, yes. Except what you marked as "LPN" will be GATT client nodes, and what you marked as "Mesh relay" will be nodes with the GATT proxy feature enabled ("GATT proxy nodes").

GATT proxy nodes can connect to multiple GATT client nodes yes.

For getting familiar with the possibilities in Bluetooth mesh, I recommend having a look at the Bluetooth Mesh concepts section of our nRF5 SDK for Mesh documentation.

Regards,
Terje

RE: Mesh like network base on BLE connection， BLE and long range conexist issue.

jhc — Fri, 10 Jul 2020 08:31:49 GMT

Thanks, Torbjørn

As your mention: Another option in BT mesh is to set up a GATT proxy node, which is simply connecting to one of the mesh relay nodes over a normal Bluetooth connection (GATT connection). This can yield even lower average currents than the LPN

I draw the below illustration, the LPN node communicate with the Mesh relay node via GATT would be consume less power, Is it right?

By the way, is it possible to let the Mesh relay connect with multiple LPNs, like the left Mesh relay node in the illustration?

Thank you!

RE: Mesh like network base on BLE connection， BLE and long range conexist issue.

ovrebekk — Thu, 09 Jul 2020 13:00:14 GMT

The ble_aggregator example in the multi link example scans for both 1M and LR devices, and can be connected to different devices on different phy's at the same time, but be aware that this example is quite complex, and is not an official SDK example.

In other words it is provided "as is", and we can't guarantee that it works, or that we will support it in the future.

The power consumption of an LPN node in a mesh network depends on the usage scenario, friendship parameters and so forth, but typically you are looking at an average current consumption of 100uA or less.

Another option in BT mesh is to set up a GATT proxy node, which is simply connecting to one of the mesh relay nodes over a normal Bluetooth connection (GATT connection). This can yield even lower average currents than the LPN.

Best regards
Torbjørn

RE: Mesh like network base on BLE connection， BLE and long range conexist issue.

jhc — Wed, 08 Jul 2020 08:05:15 GMT

Hi again, Torbjørn

I have another additional question: how low could the power consumption of the SIG mesh LOW POWER NODE (LPN) reach?

Thank you!

RE: Mesh like network base on BLE connection， BLE and long range conexist issue.

jhc — Wed, 08 Jul 2020 05:14:57 GMT

Hi, Torbjørn

Thanks for reply.

I will study on the Wirepas mesh later, hope that would meeting our requirements.

As you mentioned: it is possible to have one connection running in 1M mode, and another connection running in long range mode, is there any example for this for reference.

RE: Mesh like network base on BLE connection， BLE and long range conexist issue.

ovrebekk — Mon, 06 Jul 2020 12:02:20 GMT

The S132 and S140 SoftDevices allow you to run up to 20 connections simultaneously, and you can use different PHY's on the different links if you want.

In other words it is possible to have one connection running in 1M mode, and another connection running in long range mode.

We don't have any examples showing how to do this type of connected Bluetooth mesh unfortunately.
We have an implementation following the Bluetooth mesh standard, but this is based on advertise packets and not Bluetooth connections. The advantage of this is that it is easy to support a large number of nodes in the network, but you get higher current consumption and lower data rate than you would with a connected mesh implementation.

If you want a connected mesh implementation without having to spend considerable development time to create one from scratch you might want to have a look at the Wirepas mesh implementation:
https://wirepas.com/what-is-wirepas-mesh/

Best regards
Torbjørn