Windows does not answer BLE parameter update reque

Question

I have a custom embedded device with a Bluetooth low energy stack. The device is advertising itself until a connection is requested, I pair and connect to it via the Bluetooth menu in Windows 10, I can read/write to my custom GATT services using the following BLE GATT functions from the Win32 API.

For my application I need to receive high frequency data using notifications on a characteristic so I enable it using the same API as stated above and receive the correct data but too slow. The default connection parameters Windows is using is not enough and I want to update them so I can receive notification events at higher frequency, but Windows API does not provide such function. I had the same problem when connection to an Android phone, and I solved it by requesting connection parameters update from the device (the slave in the connection) and the Android phone accepted it and everything worked as expected.

The only problem is when I'm trying to ask for a connection parameter update from the device when connected to a Windows master, I don't receive any response (no accept nor reject), meanwhile I still receive notification events so I know the connection is still active. And the weird thing is that if I hold the device closer to the computer's Bluetooth antenna it does receive a response and update the connection parameters like intended.

Any idea what's going on? Is it a bug in Windows stack?

Answer 1

The fact that holding device closer to antenna helps should be verified. Try it multiple times in a different way.

You mentioned Android, does holding device further from Android also prevent connection parameters update?

If this proves true, I'd say the device is faulty. I would compare the behavior between different devices, better if they are from different manufacturers or at least models.