Following are Bluetooth states:
A) Connected States
STANDBY mode: Before any connection in a piconet is created, all devices are in STANDBY mode.
Inquiry mode: A connection is made by a PAGE message if the address is already known, or by an INQUIRY message followed by a subsequent PAGE message if the address is unknown.
Page mode: In this the master unit sends a train of page messages on different hop frequencies defined for the device to be paged (slave unit). If no response is received, the master transmits a train on the remaining hop frequencies in the wake-up sequence.
B) Active States
Connected state : It shows maser Connected with slave.
Transmit Data state: It shows Transmitted Data from maser to slave.
C) Low Power States
HOLD mode: The HOLD is used when connecting several piconets or managing a low-power device such as a temperature sensor.
SNIFF mode: In this a slave device listens to the piconet at a reduced rate, thus reducing its duty cycle. The SNIFF interval is programmable and depends on the application.
PARK mode: In this a device is still synchronized to the piconet but does not participate in the traffic. Parked devices have given up their MAC address and occasionally listen to the traffic of the master to resynchronize and check on broadcast messages.