The e-book treats this honestly: Channel Sounding commoditizes centimeter-level ranging by riding Bluetooth's ecosystem of nearly 5 billion units shipped annually and its existing regulatory framework, while UWB retains advantages where absolute peak precision and performance are required. In high-stakes automotive access, the most compelling model is hybrid, with BLE CS for discovery, coarse ranging, and wake-up, and UWB for the final secure authorization. The e-book details that architecture.