1. Bluetooth Protocol
A Customer support preview
Ehud Mantzuri

2. Bluetooth - Main properties
 Simple to use
 Short-range communications technology
 Operates in the unlicensed industrial, scientific and medical
(ISM) band at 2.4 to 2.485 GHz, using a spread spectrum,
frequency hopping, full-duplex signal at a nominal rate of 1600
hops/sec.
 Provides developers both link layer and application layer
definitions, which support data and voice applications
 Robustness, low power, and low cost.
 Enhanced Data Rate (EDR) up to 2.1 Mbps
 PCM digital audio/voice interface
Bluetooth Protocol 2

3. Main properties
 Power Saving Modes (Sniff, Hold and Park) – synchronized
clocks
 Page and inquiry scans
 Standard UART interface w/ Rates of up to 4Mbps
 Standard Host Controlled Interface (HCI)
 Communication error correction schemes
 Maintain high levels of security
 Ad-hoc networks known as piconets established dynamically
 Each device in a piconet can also simultaneously communicate
with up to seven other devices within that single piconet and
each device can also belong to several piconets simultaneously
Bluetooth Protocol 3

4. Usage
 Cable Replacement
 File transfer
 MODEM control
 Wireless Sensors
 Flood Alarm
 Heating Control
 Medical Devices
 Heart Rate Monitor
 Blood Pressure Sensor
 Blood Glucose Meter
 Thermometer
Bluetooth Protocol 4

5. Usage
 Computer Peripherals
 Mouse
 Printers, Scanners
 Consumer Devices
 Phones, PDAs
 Earphones
 fitness sensors
 Watches
 Toys
 Entertainment Devices
 Personal Navigation Devices
 Automotive Applications
Bluetooth Protocol 5

6. Profiles
 SDAP – Service Discovery Application Profile
 FTP – File Transfer Profile
 SPP – Serial (virtual COM) Port Profile
 DUN – DialUp Networking - may be accessed using a simple AT command set.
 HDP – Health Device Profile
 HSP – HeadSet Profile
 HFP - Handsfree Profile
 A2DP - Advanced Audio Distribution Profile
 AVRCP - A/V Remote Control Profile
 HID – Human Interface Device
 OBEX – Object Exchange
 OPP – Object Push Profile
 CTP - Coredless Telephony
 BPP – Basic Printer Profile
 BIP – Basic Imaging Profile
 And many more …
Bluetooth Protocol 6

7. Core Block Diagram
Bluetooth Protocol 7

8. Core Architecture Blocks
Bluetooth Protocol 8

9. Core Architecture Blocks
Bluetooth Protocol 9

10. HCI Transport Layer
 Allows control over the BT Device
 Full Uart HW flow control
 Transports
 Commands
 Events
 ACL
 synchronous data
 Vendor specific
 SCO, eSCO
between the Bluetooth device and its host using HCI data packets (Not
between devices)
Bluetooth Protocol 10

11. Pairing
 Provides Trust, Authorization, and Authentication
 Each side can declare own security level and request
compliance from the other side
 Upon completing the pairing process, the device may
wish to enable the user to "Trust" the device and
services.
 the device is added to the user's Trusted Devices list
and the said device will be allowed to reconnect
 the device may be visible or non-visible and also
connectable or not-connectable
Bluetooth Protocol 11

12. Application - SPP
SPP defines how to set up virtual serial ports and connect
two Bluetooth enabled devices
Bluetooth Protocol 12

13. Application - OBEX
OBEX uses a client-server model and is independent of the transport
mechanism and transport API
Bluetooth Protocol 13

14. Profile Dependencies
Bluetooth Protocol 14

15. Protocol Layers
 L2CAP - Logical Link Control and Adaptation
Protocol
 SDP - Service Discovery Protocol
 RFCOMM
Bluetooth Protocol 15

16. L2CAP
 Provides
 higher level protocol multiplexing,
 packet segmentation and reassembly, and
 the conveying of quality of service (QoS)
information.
 Connected to the HCI
Bluetooth Protocol 16

17. RFCOMM
 Emulates the serial cable line (9-Pin) settings
and status of an RS-232 serial port and is used
for providing serial data transfer.
 Connects to the lower layers of
the Bluetooth protocol stack through the
L2CAP layer
 supports up to 60 simultaneous connections
between two BT devices
Bluetooth Protocol 17

18. SDP
 Provides a means for applications to
discover which services are available on the
remote side and to determine the
characteristics of those available services.
Bluetooth Protocol 18

19. STACK Layers
Bluetooth Protocol 19

20. STACK Layers
 Physical link
 A baseband connection between Bluetooth enabled devices.
 A physical link is always associated with exactly one physical
channel
 Stateless/connectionless - has no direct representation
within the structure of a transmitted packet. The access code
packet field, together with the clock and address of the
master Bluetooth device, are used to identify a physical
channel.
 may be active (a default ACL logical transport exists) or
parked (synchronized in the piconet but has no default ACL).
Bluetooth Protocol 20

21. Logical Links
 Logical Links and Logical Transports
 A variety of logical links are available to support different
application data transport
 Each logical link is associated with a logical transport -
flow control, acknowledgement/repeat mechanisms,
sequence numbering and scheduling behavior.
Has 3 categories:
 Casting
 Scheduling and Acknowledgement Scheme
 Class of Data
Bluetooth Protocol 21

22.  Casting
 Unicast
 connection-oriented - connection procedure takes place
before the link may be used.
 Traffic may be sent in either direction
 Broadcast
 Connectionless - no procedure to create these links, and
data may be sent over them at any time
 exist between one source device and zero or more
receiver devices
 Traffic is unidirectional
Bluetooth Protocol 22

23. Logical Links
 Scheduling and Acknowledgement Scheme
 Synchronous
 associating the Bluetoothpiconet clock with the transported data.
 transporting data that has no time-based characteristics.
 The data is normally expected to be retransmitted until successfully
received
 Isochronous
 transporting data that has time-based characteristics.
 retransmitted until received or expired
 Asynchronous
 transporting data that has no time-based characteristics.
 The data is retransmitted until successfully received
 The data rate on the link need not be constant
Bluetooth Protocol 23

24. Logical Links
 Class of Data
 Control links
 transporting LMP messages between two link managers
 invisible above the baseband layer, and cannot be directly instantiated,
configured or released by applications,
 always takes priority over the L2CAP link traffic.
 L2CAP links
 Transport L2CAP PDUs, which may carry the L2CAP signaling channel or
framed user data
 May be fragmented
 Stream links
 Transport user data that has no inherent framing that should be preserved
when delivering the data.
 Lost data may be replaced by padding at the receiver
Bluetooth Protocol 24

25. Logical Transport
 ACL - Asynchronous Connection-Oriented
 Reliable or time-bounded, bi- directional, point-to-point.
 SCO - Synchronous Connection-Oriented
 Bi-directional, symmetric, point-to-point, AV channels. Used for 64Kb/s
constant rate data.
 eSCO - Extended Synchronous Connection-Oriented
 Bi-directional, symmetric or asymmetric, point-to-point, general regular data,
limited retransmission. Used for constant rate data synchronized to the
master Bluetooth clock.
 ASB - Active slave broadcast
 Unreliable, uni-directional broadcast to any devices synchronized with the
physical channel. Used for broadcast L2CAP groups.
 PSB – Parked slave broadcast
 Unreliable, uni-directional broadcast to all piconet devices. Used for LMP and
L2CAP traffic to parked devices, and for access requests from parked devices.
Bluetooth Protocol 25

26. LMP
The Link Manager Protocol contains PDUs (Protocol Data Units)
 Implemented as firmware in BT device
Enabling the following messages between two devices:
 Connection Control
 Connection Establishment
 Detach
 Power control
 Adaptive frequency hopping
 Channel quality driven data rate change
 Quality of service (QoS)
 Paging scheme parameters
 Control of multi-slot packets
 Enhanced Data Rate
 Encapsulated LMP PDUs
Bluetooth Protocol 26

27. LMP
 Security  Role Switch
 Authentication  Slot Offset
 Pairing  Role Switch
 Change Link Key  Modes of Operation
 Change Current Link Key Type  Hold Mode
 Encryption  Park Stats
 Request Supported Encryption  Sniff Mode
Key Size  Logical Transports
 Secure Simple Pairing  SCO Logical Transport
 Informational Requests  eSCO Logical Transport
 Timing Accuracy  Test Mode
 Clock Offset  Activation and Deactivation of Test
 LMP Version  Control of Test Mode
 Supported Features
 Name Request
Bluetooth Protocol 27

28. Sniffer
Bluetooth Protocol 28

29. Network
 Bluetooth nodes can work together to
establish a multi-hop network
 Each Bluetooth device is allocated a unique
48-bit Bluetooth device address (BD_ADDR)
obtained from the IEEE Registration
Authority
Bluetooth Protocol 29

30. Network
Piconets with a single slave operation (a), a multi-slave operation
(b) and a scatternet operation (c).
Bluetooth Protocol 30

31. scatternet
 A group of piconets in which connections
consists between different piconets
Bluetooth Protocol 31

32. Bluetooth SIG - Special Interest
Group
 The Bluetooth Qualification Program
 The purpose of the Bluetooth Qualification Program is to
 promote interoperability,
 verify conformance to the Bluetooth specifications,
 enforce compliance,
 grant IP license,
 recognize members who meet a high standard of testing.
 Requires certain testing standards for all designs and
products which use the Bluetooth.
Bluetooth Protocol 32

33. Create a Test Plan
 STEP 1: Create/Select a Project
 STEP 2: Declaration Summary
allows you to choose which layers you will be supporting.
 STEP 3: Edit Core PICS
The Core PICS consist of (RF), (BB), (LMP), (L2CAP), (SDP), and (GAP).
mandatory requirements of these layers must be supported.
 STEP 4: Edit Profile PICS
Any profiles that your product contains can be edited here.
 STEP 5: Consistency Check
a static consistency check needs to be performed to ensure that the
proper features are supported. Many features have prerequistes,
dependencies, or groupings that are required if they are supported.
 STEP 6: Generate the Test Plan
Bluetooth Protocol 33

34. PICS
Bluetooth Protocol 34

35. PICS
Bluetooth Protocol 35

36. Bluetooth Profile Tuning Suite
(PTS)
 The OTS is a PC-based test tool created by the Bluetooth
SIG for its members.
 The PTS automates protocol and profile testing
producing more accurate, higher quality test results and
improved interoperability for allproducts.
 The PTS uses Executable Test Suite (ETS) files to exercise
an IUT. There is one ETS file per profile/protocol and
each file contains a series of test cases
 The PTS tool contains an easy-to-use XML based test
report generator
Bluetooth Protocol 36

37. PTS
Bluetooth Protocol 37

38. HID Dongle – SW Example
 The initialization of the application occurs in two
phases:
 first, the hidappInit function is called that when ends
sets an HIDAPP_EVT_START event
 This triggers the second phase of the initialization,
which can be found within the main event processing
function hidappProcessEvent function.
 The HIDDongle application contains two callback
functions: hidappKeyCback and centralEventCB.
Bluetooth Protocol 38

39. Sources
 Bluetooth SIG - www.bluetooth.org
 Texas Instruments - www.ti.com
 Wireless Connectivity > Bluetooth technology
 www.palowireless.com/bluetooth
Bluetooth Protocol 39