Valve has enabled Bluetooth support on the Steam Controller via a Steam Client beta update. The update adds support for Bluetooth Low Energy (BLE) connectivity and Valve notes that the BLE feature is required for the Steam Link Mobile PC gaming streaming app, which will be released shortly. Players can switch between wireless modes when the update is applied, and Valve gives tips on when to use BLE.
When streaming games to iOS or Android devices through the Steam Link app, you must use BLE connectivity. You can also use BLE if you connect the Steam Controller to a tablet or laptop, which of course does not have a USB port. BLE works even if you have misplaced the Steam Controller Wireless Receiver.
In other situations, Valve recommends using the controller's original wireless connection as this is the fastest connection with the lowest latency. The original connectivity solution also supports up to four controllers per receiver and works with all major operating systems. BLE connectivity is "
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