Presented by: Kedao Wang, Shaun Levin, Dave Chen A proprietary open wireless technology established by the: Bluetooth® Special Interest Group (SIG)

Presented by:Kedao Wang, Shaun Levin, Dave Chen

A proprietary open wireless technology established by the:

Bluetooth® Special Interest Group (SIG)

Overview• History3

• Applications4

• Specifications 5-8

• Components 9-12

• States13-15

• Connection Setup16-17

• Development Kits18-21

• Conclusion23

• References24

History & Creation

• Created by telecoms vendor

Ericsson in 1994

• Named after Scandinavian King

Bluetooth from 900's BCE

• A wireless alternative to RS-232

data cables

• Simple, secure, everywhere

• Robust, low power, low cost

• Simultaneously handle data and

voice transmissions

Applications

Audio - synchronization of separate stereo channels between devices

Mobile phone - Android and iPhone

Controls - Game Consoles, Mouse, Printer, Remote Controllers

Replacing RS-232 - GPS receivers in medical equipment, barcode scanners, and traffic control devices

Profiles: Overview

Provide standards which manufacturers follow to allow devices to use Bluetooth in the intended manner

Profiles describe:

• Dependencies on other profiles

• Suggested user interface formats

• Specific parts of the Bluetooth protocol stack used by the profile

Profiles: Common Uses

Audio/Video Remote Control Profile (AVRCP)

Provide standard interface for a single device to control several pieces of A/V equipment (TV, VCR, DVD, etc)

Human Interface Device Profile (HID)

Send mice, keyboards, joysticks, and game controllers presses. Low latency link with low power. Used for Playstation 3 and Wii controllers.

Advanced Audio Distribution Profile (A2DP)

High quality audio streamed from one device to another

Basic Imaging Profile (BIP)Designed for sending images between devices and includes the ability to resize and convert images

Serial Port Profile (SPP)Emulates a serial cable to provide a simple substitute for existing RS-232, including the familiar control signals

GATT ProfileGeneral development profile installed on Texas Instrument Development Kits

Version Improvements Power Advantages

1 (Basic Rate) GFSK modulation, 1 Mb/s

2 (Enhanced Data Rate)

π/4-QPSK modulation: 2 Mb/s8DPSK modulation: 3 Mb/s

Reduced Duty Cycle

3 (High Speed) Bluetooth establishes and negotiates a 802.11 (WiFi) link at 24 Mb/s

Enhanced Power Controls

4 (Low Energy) Low energy mode: 200 kbit/s over Bluetooth

Ultra-low power idle mode

Versions

π/4-QPSK GFSK

Range

Class Expected Range Power

1 42 meter 100 mW

2 16 meter 2.5 mW

3 10 meter 1 mW

Manufacturer can choose to create the device to match 1 of 3 class models

Networks: Piconets and Scatternets

http://www.freeopenbook.com/upgrading-repairing-networks/ch22lev1sec3.html

Piconet:One master => up to 7 slavesAll devices share the master's clockUp to 255 further slave devices can be inactive

Scatternet:Two or more piconets to form a scatternetOne device simultaneously is master in one piconet and slave in another

Networks: Frequency Hopping

• Versions use different modulations schemeso The modulation rate changes with Frequency-Hopping Spread

Spectrum (FHSS)

• 2.402 GHz to 2.480 GHz, 79 frequency bands of 1 MHz each

• To minimize interference between piconets, paired-up devices hop among 79 frequency bands together 1600 times/sec

• Data can be transferred between the master and one slave device at a time

• The master chooses the slave to address, and switches the slaves through a round-robin fashion

Synchronization and Transmission

• Time-division duplex (TDD) scheme = alternately transmit and receive data

• To transmit data, need:o Channel Hopping Sequence = derived from BD_ADDR of mastero Phase of Hopping Sequence = derived from clock of master

o Channel Access Code (CAC) = derived from BD_ADDR of master

• Piconet is synchronized by master's clocko Slaves adapt internal clock with a timing offset to match master

• Clockso Basic clock rate is 3.2 KHzo 2 clock ticks make up a sloto 1, 3, or 5 slots make up a packet

Packets

Access Code:

• 72 bits

• timing sync

• offset compensation

• paging

• inquiry

Header:

• 54 bits

• packet acknowledgement

• packet numbering

• flow control

• slave address

• error check for header

Payload:

• 0-2745 bits

• either voice field, data field, or both

• if it has a data field, payload also contains payload header

There are 13 special packets for synchronizing and making connections

Four Types of Device Addressing

BD_ADDR (Bluetooth Device Address)

48-bit device address used to identify each transceiver

AM_ADDR (Active Member Address)

3-bit MAC address of the active slave device

PM_ADDR (Parked Member Address)

8-bit MAC address of the parked slave device

AR_ADDR (Access Request Address)

Used by parked slavesDetermines when it can ask the master for messages

Connection States

Devices have two major states

Standby (disconnected)• Default state• Low power• Only native clock is running• No interaction with any device

Connection• Master and slaves can exchange

packets• Uses master's clock• Uses master access code

Connection ModesActive Mode Actively participates on the channel

Master schedules the transmissionsSlaves only respond if addressedHas AM_ADDR (unless it is the master)

Sniff Mode(low power-saving)(slave only)

Slave listens to piconet at programmable reduced rateIf addressed, switch to active modeHas AM_ADDR

Hold Mode(medium power-saving)(slave only)

Slave waits until an internal timer runs outMaster and/or slave can put the slave on HOLDData transfer restarts instantly once HOLD finishesHas AM_ADDR

Park Mode(high power-saving)(slave only)

Device is still synchronized to piconet, but does not participateHas given up MAC (AM_ADDR)Occasionally listens to master to re-synchronize and check on messagesHas PM_ADDR instead of AM_ADDR

Connection Setup: Step 1 (Discover)

• Source sends out inquiry packet and waits for an inquiry reply

• If a destination receives an inquiry packet, it:

o Enters the inquiry response state

o Sends the inquiry reply to the source

Connection Setup: Step 2 (Connect)

1. The source sends special ID packet (page) to the destination

2. The destination receives the page

3. The destination sends a reply to the source

4. The source sends an FHS (Frequency Hopping Synchronization) packet to the destination

a. FHS contains BD_ADDR and clock of the source in 144-bit data and 16-bit CRC

5. The destination sends its second reply to the source

6. The destination and source switch to modes where they can interact

http://www.palowireless.com/infotooth/tutorial.asp

Development Kits

GS-BT2416C1DB from ST Microelectronics

USB and RS 232

Serial Interface

$35 - cheapest

Older Bluetooth version (1.2)

Development Kits

DEV-PC-1309C-ND from CSR

$93.75

Flexible Communication Protocol

Serial and Ethernet

CSR also develops software for platforms with built in bluetooth (Android, iPhone) and has multiple development tools for multiple profiles

Development Kits

CC2540 Mini Development Kit from Texas Instruments

$99

Simple, flexible GATT Profile

Best documentation

Development KitsCC2540 Development Kit From Texas Instruments

$300

Complete hardware evaluation kit

Complete hardware performance test platform

GATT Profile

Conclusions

• Bluetooth is a wireless communication protocol with speeds between 1 Mbps and 24 Mbps

• < 40m range

• It avoids interfering with other devices by using FHSS

• Its version designs have been driven by power

• Its connection states are defined by power consumption

• 'Profiles' are provided for developing application specific uses

References

http://www.m2mgsm.com/download/BT/docs/general/Bluetooth_Overview.pdf

http://www.bluetooth.com/

http://grouper.ieee.org

http://www.palowireless.com/infotooth/tutorial.asp

Questions?