We're developing a UWP app, which functions as our BLE central, and 'speaks' to many BLE peripheral units. When a connection is formed, the RSSI value for that central-peripheral connection is logged and reported.
We're seeing two flavors of the same problem, The problem is that some portion of the RSSI values we're reading make no sense.
first flavor- RSSI values we get are positive. Examples: 79, 80 etc.
second flavor- RSSI values we get are unreasonably low. Example: -127. This is well below the link budget and doesn't seem like a 'real' RSSI value.
These values are received from Windows.Devices.Bluetooth.Advertisement -> BluetoothLEAdvertisementReceivedEventArgs when receiving events from BluetoothLEAdvertisementWatcher. So they seem to be originating straight from the driver. No manipulation on our side.
Both of these problems are not constant. We'll get reasonable values for a while (-40, -48 etc) and then an anomaly will be recorded, and back to 'normal' values.
We suspect the fault lies with the windows driver, as when we try to switch dongles (different manufacturers with different chipsets), we still see the same strange values pop up every once in a while.
We use Windows.Devices.Bluetooth under UWP (universal windows platform) on Intel NUCs.
Updating windows to the latest version, and updating the BL drivers etc did not solve the problem.
Has anyone experienced these kind of issues before?