Large scale Bluetooth mesh network (hundreds of nodes)

[Max]

Hello,

In my quest to monitor the activity of hundreds of nodes (directly addressable), I am facing quite an obstacle.

The small memory of the nrf52 (nice piece of hardware btw) in a light-switch like configuration only allows for 50 nodes with persistent storage and 150 without it.

Would it be possible to offload the configuration and "client" role to a PC in order to allow for a bigger network (several hundreds of nodes) ?

I have been looking at the serial example, but I can hardly imagine the difficulty and time to port all the configuration and other model complexity on a PC/python program.

Thank you,

Max

[Susheel Nuguru]

Hi Maximo,

If I understand the question correctly, you are asking if we can shift all the configuration and state data to the Gateway!!?

Well, technically, you could do that, but you need to change our mesh stack a lot. You would also increase the network traffic quite significantly for all the data polls from clients to the the gate for every smallest transaction. Also this will a huge task and will deviate a lot from our solution. The latencies of data transaction between nodes will change and probably be out of spec (in terms of latencies). 

 

[Max]

Thanks a lot for the answer.

I figured out the hard way ahah.. What I will do is the following:

Since my goal is to have a +200 nodes/sensors and only one client (the node connected to my computer), I will try to create a protocol on the top of the beacon one. that way each beaconing node will beacon their sensor info every 20  seconds (or so).  The data will be eventually caught by my PC node. I'll be able to recognize each of them with their address. and in order to address each of these node with my PC node, I may have 2 options:

The easy one: send a beacon from my PC node with the address of the node in it, that way the destination node will recognize that the message is for her. ("node" is a female word in French :) )

The harder one: add remote provisioning, and provision one remote node at the time to have a dual way connection, send my message, and remove the connection (since I cannot keep more that 60 nodes provision info in the RAM).

 Could you please let me know what do you think about this solution ?

Thanks again.

[Susheel Nuguru]

Hi Maximo,

Both your approach will accomplish what you are trying to do, but the easy way will get more complicated for the client if you intend to increase the number of nodes in your system. Since the client is connected to PC, one good thing is that we do not have to think about its power consumption.

If I were you, I would have chosen the harder one, to make the solution future proof. I see no disadvantages of this mention.

[Max]

Thanks again Aryan !

I follow your advices. 

Although for the beginning, I will go the easy way to develop a quick proof of concept for our client and later on, move to the provisioning/unprovisioning system !

[Susheel Nuguru]

sounds good. I will mark your answer as verified.