Bluetooth Connections

Bluetooth connections are established through the following means:
1. Standby—Any device not connected through a PAN is initially in
standby mode. In this mode, devices monitor for messages every
1.28 seconds over 32 distinct hop frequencies.

2. Page/inquiry—When one of your devices needs to form a connection
with another device, it transmits a page message. If it knows
the address, then the inquiry is received along with a page message.
The master unit transmits 16 identical page messages throughout
16 hop frequencies to the slave unit. If there is no response, the master
unit retransmits on the other 16 hop frequencies. The inquiry
method needs an extra response from the slave unit, due to the fact
that the master unit does not know the specific MAC address.

3. Active—Data transmission takes place.

4. Hold—This occurs when either the master or slave must go into a
“hold mode,” when it doesn’t transmit any data in an effort to conserve
power. Normally, there is a constant data exchange so there
can be hold mode in the connection of several PANs.

5. Sniff—The sniff mode works only in slave units and is used mostly
for power conservation purposes. However, this mode is not as
restrictive as hold mode. When functioning in this mode, the slave
does not take an active role within the PAN. It does, however, listen
at a reduced level. Note that this is a programmable setting and can
be adjusted according to your needs.

6. Park—Park mode represents a significantly reduced level of activity
below that for hold mode. During this time the slave is synchronized
to the PAN, meaning it is neither required for full reactivation,
nor is it a division of the traffic. In park mode, these units do
not have MAC addresses; however they only listen to the traffic in
order to keep their synchronization with the master unit and to
check for broadcast messages.