Coded PHY on a mesh of BLE devices to improve range

[Arif@Lynxemi]

I have an existing BLE project that works as a mesh but does not use nRF SDK for Mesh. Using sdk 17.0.2, s140 7.2.0 on nrf52840s and visualGDB.

It works well for most clients but the effective range is only 20-30 meters indoors in reinforced concrete buildings with noisy RF conditions. I have one place where devices in opposing hotel rooms have difficulty connecting to each other over a distance of less than 10 meters.

Currently a peripheral is set up using BLE_GAP_PHY_1MBPS and advertises using BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED to connect to a central and then starts scanning for more peripherals using the same PHY. I am thinking of switching to BLE_GAP_PHY_CODED to improve range however, I note that there is no GAP advertising type for being extended, connectable and scannable at the same time. I use the scannable feature to do DFU OTA using nrfConnect for Android as well as to check on-site whether a device is not connected to the mesh.

Is there an elegant solution for this use case to use coded PHY?

[Mttrinh]

Hi,

I have an existing BLE project that works as a mesh but does not use nRF SDK for Mesh

How is your mesh network implemented? What do you mean by "work" as a mesh? What is your use-case?

[Arif@Lynxemi]

Well it's more of a tree. It starts from a root node that connects to many peripherals who then become centrals. These peripherals can be powered lights who will stay connected. Messages are passed up or down. I think this part shouldn't be affected by the above.

We have a need to perform scan requests to low power devices like sensor nodes who aren't part of the mesh but communicate with it. 

Does this answer your question?