Get Latency of Bluetooth Headphoners UWP C++

Question

I want to make sure the latency between my app and the bluetooth headphones is accounted for, but I have absolutely no idea how I can get this value. The closest thing I found was: BluetoothLEPreferredConnectionParameters.ConnectionLatency which is only available on Windows 11... Otherwise there isn't much to go on.

Any help would be appreciated.

Thanks, Peter

Answer 1

It's very difficult to get the exact latency because it is affected by many parameters - but you're on the right track by guessing that the connection parameters are a factor of this equation. I don't have much knowledge on UWP, but I can give you the general parameters that affect the speed/latency, and then you can check their availability in the API or even contact Windows technical team to see if these are supported.

When you make a connection with a remote device, the following factors impact the speed/latency of the connection:-

• Connection Interval: this specifies the interval at which the packets are sent during a connection. The lower the value, the higher the speed. The minimum value as per the Bluetooth spec is 7.5ms.
• Slave Latency: this is the value you originally mentioned - it specifies the number of packets that can be missed before a connection is considered lost. A value of 0 means that you have the fastest most robust connection.
• Connection PHY: this is the modulation on which the packets are sent. If both devices support 2MPHY, then the connection should be quicker.
• Data Length/MTU Extension: these are two separate features but I am looping them together becuase the effect is the same - more bytes are sent per packet, which results in a higher throughput. The maximum value is 251 bytes per packet.

You can find more information about these parameters here:-

• A Practical Guide to BLE Throughput
• Maximizing BLE Throughput: Everything You Need to Know
• Bluetooth 5 Speed - How to Achieve Maximum Throughput

And below are some other links that might help you understand what is supported on UWP:-

• Bluetooth Developer FAQ
• BluetoothLEConnectionParameters.OptimizedProperty
• Bluetooth LE Preferred Connection Parameter Class
• Bluetooth LE Connection PHY class
• How to Change MTU Size and PHY on Windows UWP C++