ROK 101 007
12
Preliminary
Bluetooth Radio Interface
The Bluetooth module is a class 2
device with 4dBm maximum output
power with no power control needed.
Nominal range of the module with a
typical antenna is up to a range of 10
m (at 0 dBm). It is compliant with
FCC and ETSI regulations in the ISM
band.
Baseband
Bluetooth uses an ad-hoc net
structure with a maximum of eight
active units in a single piconet. By
default the first unit setting up a
connection is the master of the point
to point link. The master transmits in
the even timeslots and the slave
transmits in the odd timeslots.
For full duplex transmission, a Time-
Division Duplex (TDD) scheme is
used. Packets are sent over the air in
timeslots, with a nominal length of
625
µ
s. A packet can be extended to
a maximum of 5 timeslots (DM5 and
DH5 packets) and is then sent by
using the same RF channel for the
entire packet.
Two types of connections are
provided - Asynchronous
Connectionless Link (ACL) for data
and the Synchronous Connection
Oriented Link (SCO) for voice. Three
64 kb/s voice channels can be
supported simultaneously. Further-
more, there are also packages used
for link control purposes.
A variety of different packet types
with error correction schemes and
data rates can be used over the air
interface. Also asymmetric communi-
cation is available for high speed
communication in one direction.
The Baseband provides the link-
setup and control routines for the
layers above. Furthermore, the
Baseband also provides Bluetooth
security like encryption, authentica-
tion and key management.
Please refer to the Specification of
the Bluetooth System v1.0B part B
for in-depth information regarding the
Baseband.
Firmware (FW)
The module includes firmware for the
host controller interface, HCI, and the
link manager, LM.
The FW resides in the Flash and is
available in object code format.
Link Manager (LM)
The Link Manager in each Bluetooth
module can communicate with
another Link Manager by using the
Link Manager Protocol (LMP) which
is a peer to peer protocol.
The LMP messages have the highest
priority and are used for link-setup,
security, control and power saving
modes. The receiving Link Manager
User Payload
Symetric
Asymetric
Type
(bytes)
FEC
CRC
Max. rate
Max.rate
ID
na
na
na
na
na
NULL
na
na
na
na
na
POLL
na
na
na
na
na
FHS
18
2/3
yes
na
na
Link control packets
Asymetric
Payload
User
Symetric
Max rate (kb/s)
Header
Payload
Max. rate
Type
(bytes)
(bytes)
FEC
CRC
(kb/s)
Forward
Reverse
DM1
1
0-17
2/3
yes
108.8
108.8
108.8
DH1
1
0-27
no
yes
172.8
172.8
172.8
DM3
2
0-121
2/3
yes
258.1
387.2
54.4
DH3
2
0-183
no
yes
390.4
585.6
86.4
DM5
2
0-224
2/3
yes
286.7
477.8
36.3
DH5
2
0-339
no
yes
433.9
723.2
57.6
AUX1
1
0-29
no
no
185.6
185.6
185.6
ACL packets
Symetric
Payload header
User Payload
Max. rate
Type
(bytes)
(bytes)
FEC
CRC
(kb/s)
HV1
na
10
1/3
no
64.0
HV2
na
20
2/3
no
64.0
HV3
na
30
no
no
64.0
DV
1D
10+(0-9) D
2/3 D
Yes D
64.0+57.6 D
SCO packets
LM
LM
LC
RF
LC
RF
LMP
Physical layer
Table 1: Link Control Packets Table, ACL Packets Table, SCO packets
Figure 13. Link manager
filter-out the message and does not
need to acknowledge the message
to the transmitting LM due to the
reliable link provided by the
Baseband and radio.
LM to LM communication can take
place without actions taken by the
host. Discovery of features at other
Bluetooth enabled devices nearby
can be found and saved for later use
by the host.
Please refer to the Specification of
the Bluetooth System v1.0B part C
for in-depth information regarding
the LMP.