An Introduction to BLUETOOTH TECHNOLOGY : An Introduction to BLUETOOTH TECHNOLOGY Presented by: nikhil ranjan CONTENT : 4 February, 2009 2 CONTENT Overview of Bluetooth History
The Bluetooth Specifications
Typical Bluetooth Scenario
Comparison with other technologies
Future of Bluetooth
Summary Example : The Networked Home : 4 February, 2009 3 Example : The Networked Home What is Bluetooth? : 4 February, 2009 4 What is Bluetooth? “Bluetooth wireless technology is an open specification for a low-cost, low-power, short-range radio technology for ad-hoc wireless communication of voice and data anywhere in the world.” One of the first modules (Ericsson) A recent module Ultimate Headset : 4 February, 2009 5 Ultimate Headset Cordless Computer : 4 February, 2009 6 Cordless Computer Bluetooth Goals & Vision : 4 February, 2009 7 Bluetooth Goals & Vision Originally conceived as a cable replacement technology
Short-Range Wireless Solutions
Voice and Data Capability
Other usage models began to develop:
Personal Area Network (PAN)
Data/voice access points
Wireless telematics Overview of Bluetooth History : 4 February, 2009 8 Overview of Bluetooth History What is Bluetooth?
Bluetooth is a short-range wireless communications technology.
Why this name?
It was taken from the 10th century Danish King Harald Blatand who unified Denmark and Norway.
When does it appear?
1994 – Ericsson study on a wireless technology to link mobile phones & accessories.
5 companies joined to form the Bluetooth Special Interest Group (SIG) in 1998.
First specification released in July 1999. Timeline : 4 February, 2009 9 Timeline 1994 : Ericsson study complete / vision
1995 : Engineering work begins
1997 : Intel agrees to collaborate
1998 : Bluetooth SIG formed: Ericsson, Intel, IBM, Nokia & Toshiba
1999 : Bluetooth Specification 1.0A
SIG promoter group expanded: 3Com, Lucent, Microsoft & Motorola
2000 : Bluetooth Specification 1.0B, 2000+ adopters
2001 : First retail products released, Specification 1.1
2003 : Bluetooth Specification 1.2
2005 : Bluetooth Specification 2.0 (?) Special Interest Group : 4 February, 2009 10 Special Interest Group Technical features : 4 February, 2009 11 Technical features Bluetooth FHSS : 4 February, 2009 12 Bluetooth FHSS Employs frequency hopping spread spectrum
Reduce interference with other devices
1600 hops/sec- time slot is defined as 625 microseconds
Packet 1-5 time slots long Time-Division Duplex Scheme : 4 February, 2009 13 Time-Division Duplex Scheme Channel is divided into consecutive slots (each 625 ?s)
One packet can be transmitted per slot
Subsequent slots are alternatively used for transmitting and receiving
Strict alternation of slots between the master and the slaves
Master can send packets to a slave only in EVEN slots
Slave can send packets to the master only in the ODD slots Classification : 4 February, 2009 14 Classification Classification of devices on the basis of Power dissipated & corresponding maximum Range. Typical Bluetooth Scenario : 4 February, 2009 15 Typical Bluetooth Scenario Bluetooth will support wireless point-to-point and point-to-multipoint (broadcast) between devices in a piconet.
Point to Point Link
Master - slave relationship
Bluetooth devices can function as masters or slaves
It is the network formed by a Master and one or more slaves (max 7)
Each piconet is defined by a different hopping channel to which users synchronize to
Each piconet has max capacity (1 Mbps) Piconet Structure : 4 February, 2009 16 Piconet Structure All devices in piconet hop together.
Master’s ID and master’s clock determines frequency hopping sequence & phase. Ad-hoc Network – the Scatternet : 4 February, 2009 17 Ad-hoc Network – the Scatternet Inter-piconet communication
Up to 10 piconets in a scatternet
Multiple piconets can operate within same physical space
This is an ad-hoc, peer to peer (P2P) network Bluetooth Protocol Stack : 4 February, 2009 18 Bluetooth Protocol Stack Baseband : 4 February, 2009 19 Baseband Baseband : 4 February, 2009 20 Baseband Addressing
Bluetooth device address (BD_ADDR)
48 bit IEEE MAC address
Active Member address (AM_ADDR)
3 bits active slave address
all zero broadcast address
Parked Member address (PM_ADDR)
8 bit parked slave address
This MAC address is split into three parts
The Non-significant Address Part (NAP)
Used for encryption seed
The Upper Address part (UAP)
Used for error correction seed initialization & FH sequence generation
The Lower Address Part (LAP)
Used for FH sequence generation Packet Structure : 4 February, 2009 21 Packet Structure Connection State Machine : 4 February, 2009 22 Connection State Machine Channel Establishment : 4 February, 2009 23 Channel Establishment There are two managed situations
A device knows the parameters of the other
It follows paging process
No knowledge about the other
Then it follows inquiring & paging process
Two main states and sub-states
Standby (no interaction)
Seven more sub-states for attaching slaves & connection establishment Connection State Machine Channel Establishment (contd.) : 4 February, 2009 24 Channel Establishment (contd.) Seven sub-states
Slave response Link Manager Protocol : 4 February, 2009 25 Link Manager Protocol Link Manager Protocol : 4 February, 2009 26 Link Manager Protocol The Link Manager carries out link setup, authentication & link configuration.
All the work related to the channel control is managed by the master
The master uses polling process for this
The master is the first device which starts the connection
This roles can change (master-slave role switch) L2CAP : 4 February, 2009 27 Service provided to the higher layer:
L2CAP provides connection-oriented and connectionless data services to upper layer protocols
Protocol multiplexing and demultiplexing capabilities
Segmentation & reassembly of large packets
L2CAP permits higher level protocols and applications to transmit and receive L2CAP data packets up to 64 kilobytes in length. L2CAP Middleware Protocol Group : 4 February, 2009 28 Middleware Protocol Group Additional transport protocols to allow existing and new applications to operate over Bluetooth.
Packet based telephony control signaling protocol also present.
Also includes Service Discovery Protocol. Middleware Protocol Group (contd.) : 4 February, 2009 29 Middleware Protocol Group (contd.) Service Discovery Protocol (SDP)
Means for applications to discover device info, services and its characteristics.
Network Protocols for packet data communication, routing.
Cable replacement protocol, emulation of serial ports over wireless network. IP Over Bluetooth : 4 February, 2009 30 IP Over Bluetooth IP over Bluetooth v 1.0 IP Over Bluetooth : 4 February, 2009 31 IP Over Bluetooth IP over Bluetooth v 1.1 File Transfer Profile : 4 February, 2009 32 File Transfer Profile Profile provides:
Enhanced client-server interactions:
- browse, create, transfer folders
- browse, pull, push, delete files Headset Profile : 4 February, 2009 33 Headset Profile Profile provides:
Both devices must provide capability to initiate connection & accept/terminate calls.
Volume can be controlled from either device.
Audio gateway can notify headset of an incoming call. Core Bluetooth Products : 4 February, 2009 34 Core Bluetooth Products Notebook PCs & Desktop computers
Other handheld devices
Cameras CD Player
Telephone Answering Devices
Cars Other Products… : 4 February, 2009 35 Other Products… 2004 Toyota Prius & Lexus LS 430
hands free calls
Digital Pulse Oximetry System
Toshiba Washer & Dryer
Nokia N-gage Security : 4 February, 2009 36 Security Security Measures
Link Level Encryption & Authentication.
Personal Identification Numbers (PIN) for device access.
Long encryption keys are used (128 bit keys).
These keys are not transmitted over wireless. Other parameters are transmitted over wireless which in combination with certain information known to the device, can generate the keys.
Further encryption can be done at the application layer. A Comparison : 4 February, 2009 37 A Comparison WLAN Bluetooth vs. IrD : 4 February, 2009 38 Bluetooth vs. IrD Bluetooth
Point to Multipoint
Data & Voice
Easier Synchronization due to omni-directional and no LOS requirement
Devices can be mobile
Range 10 m IrD
Point to point
Intended for Data Communication
Infrared, LOS communication
Can not penetrate solid objects
Both devices must be stationary, for synchronization
Range 1 m Bluetooth: Today & Tomorrow : 4 February, 2009 39 Bluetooth: Today & Tomorrow Will Bluetooth become a household name? : 4 February, 2009 40 Will Bluetooth become a household name? Future of Bluetooth : 4 February, 2009 41 Future of Bluetooth Success of Bluetooth depends on how well it is integrated into consumer products
Consumers are more interested in applications than the technology
Bluetooth must be successfully integrated into consumer products
Must provide benefits for consumer
Must not destroy current product benefits
Key Success Factors
Mass Production at Low Cost
Ease of Use
End User Experience Summary : 4 February, 2009 42 Summary A new global standard for data and voice
Low Power, Low range, Low Cost network devices
Master-Slave relationship can be adjusted dynamically for optimal resource allocation and utilization.
Adaptive, closed loop transmit power control can be implemented to further reduce unnecessary power usage. “Things that think… don’t make sense unless they link.” : 4 February, 2009 43 “Things that think… don’t make sense unless they link.” - Nicholas Negroponte, MIT Media Laboratory Thank You : 4 February, 2009 44 Thank You