Packet loss in mesh network

[Cooper]

I use the nRF OpenMesh from the GitHub. (https://github.com/NordicSemiconductor/nRF51-ble-bcast-mesh)

My mesh network just has two mesh node, node A and B. I made A node as a broadcaster, B node as a receiver. "MESH_INTERVAL_MIN_MS" setting to 20. And I send a mesh packet every 200ms from A node. But in this low broadcast speed, it still has packet loss issue. About 10~20s loss one mesh packet. What is the problem?

Is it possible that the scan interval and scan window size doesn't match the advertising interval? If so. How to modify the scan interval and scan window size?

And what is the default value on scan interval and scan window size?

[Cooper]

Hi Hung, thanks for your answer. But I still have some question.

The mesh node stays in scanning mode all the time except broadcast packet, right? If so, the node still has chance can't receive the packet when it prepares and starts to broadcast packet.

I use sniffer can see all broadcasting packet, so I can confirm there is no loss in broadcasting at the time. So, the problem is on the node B(receiver).

I have tried to add more node nearby(increase 5 nodes and they just like a repeater) want to improve packet loss issue. But doesn't see any improve.