DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
The BluetoothTM wireless technology
A brief overview
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
Agenda for this presentation
The BluetoothTM wireless technology The obligatory question.. What is Bluetooth? What is Bluetooth good for?
Inside Bluetooth – How does it work? The protocol stack Bluetooth specific protocols
L2CAP, Link Manager & the Baseband Network creation:
Inquiry & Paging About Piconets and Scatternets
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
The obligatory Bluetooth question: Where does the name come from?
Ericsson, the principal inventor, borrowed the name from Harald Bluetooth (son of Gorm)
The King of Denmark circa 900AD United Denmark and Norway
Seemed like a good name for uniting many dissimilar devices from different manufacturers
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
What is Bluetooth?
A new wireless technology specifically for:
Short range Up to 10 meters typically
Modest performance (721Kbps) Dynamic configurability
i.e. ad hoc networking/roaming
Low power Well suited to handheld applications
Support for both voice and data
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
Locality sensitive services (i.e. roaming)Visibility and access to additional resources, but only when they are within range and useful to you
What is Bluetooth good for?
Personal Area Networking (PAN)Enabling a collection of YOUR personal devices to cooperatively work together
No wires!In the homeOn the move
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
Host Controller Interface
Inside Bluetooth – The protocol stack
RF (radio and antenna)
Aud
io
(SC
O)
Con
trol
Aud
io(S
CO
)
Con
trol
L2CAP
Baseband
Link Manager
Transport Interface
Application
RFCOMM SDP
Data (ACL)
Data (ACL)Host
Blue
toot
hM
odul
e
Transport Bus
Host Application
API and Legacy Support Modules
Bluetooth HCI Driver
Physical I/F
Physical I/F
HCI Firmware
Logical Link Control & Data Adaptation
Physical Link Control
Data Processing & Transmission Mgmt.
Transmission/Reception
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
L2CAP Logical Link Control and Adaptation Protocol
Manages the creation and termination of virtual connections called Channels with other devices
Negotiates and/or dictates parameters Including Security and Quality of Service (QoS) etc.
Manages data flow between the host and Link Manager
Multiplexing of multiple concurrent host I/O operations
Segmentation And Reassembly (SAR) of various data formats between the host and Bluetooth
L2CAP
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
Link Manager
Physically manages creation, configuration, and termination of device to device links
Also manages the data flow between the L2CAP and Baseband through established channel
Forwards data from the L2CAP to the Baseband with its associated link specific transmission parameters
Forwards data from the Baseband back to the L2CAP associated to its specific source channel
Link Manager
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
Baseband
Performs all digital data processing operations Speech coding Data whitening Optional encryption/decryption Packetization Header and payload error detection and
correction
Manages and controls the radio interfaceBaseband
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
How does Bluetooth work?
Master
Active Slave
Parked Slave*
Standby*
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IC
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Operational States
* Low power state
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
In the beginning.. Initially Bluetooth devices only know about
themselves Everyone passively monitors in Standby mode No devices are synchronizedD
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DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
InquiryDiscovering who’s out there
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Inquiry discovers what other devices are within range
10 meters
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Note that a device canbe “Undiscoverable”
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
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PagingCreating a Piconet
Paging creates a Master/Slave link called a Piconet
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BBAA
10 meters
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
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Expanding a Piconet (1) Successive Pages can attach up to 7 Active Slaves to a Piconet at
one time
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10 meters
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
BB
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Parking To save power and/or to connect to even more
devices Active Slaves can be Parked (up to 256 total!)
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10 meters
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
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Expanding a Piconet (2) Masters can then attach additional Active Slaves using
Active Member Addresses freed up through Parking
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10 meters
DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
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Advanced Scatternets
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Scatternets can evolve into extremely complex structures creating a rich fabric of many, many, devices
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DIUF, 20. 03. 2003 Seminar in Telecommunications, M. Hayoz
Conclusional part
Any questions..?