Bluetooth is low-cost, low-power, short-range wireless technology.
It was designed as a replacement for cables and other short-range
technologies like IrDA. Bluetooth operates in personal area range
that typically extends up to 10 meters. More information about
Bluetooth can be found at <http://www.bluetooth.com/>.

Linux Bluetooth subsystem consist of several layers:
Bluetooth Core (HCI device and connection manager, scheduler)
HCI Device drivers (Interface to the hardware)
SCO Module (SCO audio links)
L2CAP Module (Logical Link Control and Adaptation Protocol)
RFCOMM Module (RFCOMM Protocol)
BNEP Module (Bluetooth Network Encapsulation Protocol)
CMTP Module (CAPI Message Transport Protocol)
HIDP Module (Human Interface Device Protocol)
SMP Module (Security Manager Protocol)

Say Y here to compile Bluetooth support into the kernel or say M to
compile it as module (bluetooth).

To use Linux Bluetooth subsystem, you will need several user-space
utilities like hciconfig and bluetoothd. These utilities and updates
to Bluetooth kernel modules are provided in the BlueZ packages. For
more information, see <http://www.bluez.org/>.

source code:

net/bluetooth/