A Bluetooth detection unit can be implemented to minimize the time required for executing the inquiry and paging scan procedures on a Bluetooth device associated with a collocated WLAN device. The Bluetooth detection unit can execute concurrent background spectral scanning to detect Bluetooth control packets while the WLAN device is receiving WLAN packets. The Bluetooth detection unit can analyze, for each Bluetooth control channel, the Bluetooth device can determine energy measurements associated with each Bluetooth control channel and can determine whether each Bluetooth control channel comprises a narrowband signal based, at least in part, on frequency domain samples associated with an RF signal received at the WLAN device. The Bluetooth detection unit can determine which of the Bluetooth control channels comprise a Bluetooth control packet.