2. 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
3. Bluetooth Goals & Vision
• Originally conceived as a cable replacement
technology
• Short-Range Wireless Solutions
• Open Specification
• Voice and Data Capability
• Worldwide Usability
4. Present wireless technology like Infra Red data
communication has two problems :
1)Line of Sight
2) One to One
BLUETOOTH OVERCOMES THESE PROBLEMS
5. 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
• Both devices must be stationary,
for synchronization
• Range 1 m
6. Logo
• A Scandinavian firm originally designed the logo at the time the SIG
(Special Interest Group) was formally introduced to the public
• The logo unites the Runic alphabetic characters "H", which looks
similar to an asterisk, and a "B", which are the initials for Herald
Bluetooth
7. Bluetooth History
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.
8. 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
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
10. Different Versions of Bluetooth
• Bluetooth 1.1:
Offers Only some Basic Features. The first Bluetooth core
specification version 1.1 was introduced in 1998
• Bluetooth 1.2:
New features to eliminate radio frequency interference
through frequency hopping and added greater security. It was
released in 2003.
• Bluetooth 2.0:
In 2004,Bluetooth version 2.0 + EDR(Enhanced data rate)
was introduced
11. Different Versions of Bluetooth
• Bluetooth 2.1:
The SIG then introduced version 2.1, which improved
pairing without the need for a PIN, requires even lower
power consumption, and offers more security.
• Bluetooth 3.0:
Created in 2009, Bluetooth 3.0 added the ability to use a
Wi-Fi connection to increase data transmission speeds
• Bluetooth 4.0:
Most recent is Bluetooth 4.0. Its major feature is Bluetooth
Low Energy, essentially strong power management skills.
12. The Basic Idea
• Bluetooth is a standard for a small , cheap radio chip to
be plugged into computers, printers, mobile phones, etc
• Bluetooth chip is designed to replace cables.
Information normally carried by the cable, is
transmitted at a special frequency to a receiver
Bluetooth chip.
• These devices can form a quick ad-hoc secure “piconet”
and start communication.
• Connections in the “piconets” can occur even when
mobile.
13. Requirements
• Low cost as cables – chip $5
• Secure as cables – must support authentication and
encryption
• Must support both data and voice.
• Must connect to a variety of devices.
• Must be able to function in a noisy environment.
• Data rates – 721kbps , using the 2.45Ghz radio
frequency band –I.S.M (Industrial, scientific and
medical)
• Must support many simultaneous and private
“piconets”.
• Must be low power, compact and global.
15. Bluetooth Classes
• If you wish to communicate over the 100m range, you
will need a class 3 Bluetooth device at both ends.
• If you wish to communicate over the 10m range, you can
have a class 2 device at both ends.
19. Piconet
• A piconet is an ad-hoc computer network linking a wireless
user group of devices using Bluetooth technology protocols.
A collection of devices connected via
Bluetooth technology in an ad hoc fashion
20. Piconet….cont.
• A piconet starts with two connected devices, and may grow
to eight connected devices.
• Master
• Slaves (up to 7)
One of the Bluetooth devices as a main controlling
unit or MASTER unit
Other devices that follow the master unit are SLAVE units.
21.
22. Piconet….cont.
• The master device acts as the hub, meaning the slave devices must
communicate through the master device in order to communicate with
each other. In most piconets, the computer serves as the master device.
• one master device interconnect with up to seven active slave devices using
a three-bit MAC address. In addition to this a further 255 slave devices can
be connected in an "inactive", or "parked" mode, which can be made
"active" at any time by the master device.
Each active device within a piconet is identifiable by a 3-bit
active device address.
23. • A master is the only one that may initiate a Bluetooth communication link.
However, once a link is established, the slave may request a master/slave
switch to become the master. Slaves are not allowed to talk to each other
directly. All communication occurs within the slave and the master.
• Where higher number of Bluetooth enabled devices need to communicate
for data exchange, the master Bluetooth-enabled device is capable of
swapping the active slaves for the parked slaves in a round robin sequence,
normally based of priority assigned.
24. How Piconet Works?
• Bluetooth piconets utilize frequency hopping.
• 79 frequencies are used and The frequency hopping is done
at a rate of 1600 times a second.
• Devices use an assigned frequency of 2.45 GHz, a frequency
set aside for this purpose by the ISM(Industrial Scientific and
Medical) frequency band.
25. Working…Cont.
• Each piconet has a unique master with it’s
>>Unique Bluetooth device address (BD_ADDR)
>>Clock
• Therefore, each piconet has its unique frequency hopping
sequence.
• When a connection is initiated by Bluetooth enabled devices,
the master device’s clock along with the device address
(BD_AAR) is transmitted to the slave devices in a packet known
as Frequency-Hop Synchronization Packet (FHS packet).
26. The device address of the master device is used to calculate the
sequence of frequency hops which all devices within a
piconet, follow. The clock of the master device assigns the
sequence of the frequency hops.
27. All devices within a piconet use the difference between their
own native clock and the master’s native clock to make use of
particular frequency in order to transmit or receive radio
signals on a particular moment.
• Using this method, the Bluetooth devices within a piconet are
able to avoid one another’s transmission by persistently
changing frequency channels.
28. Piconet…Features
• A piconet typically has a range of about 30 feet (or 10 meters).
Piconet range varies according to the class of the Bluetooth
device. Data transfer rates vary between about 200 and
2100 kilobits per second.
• Because the Bluetooth system hops over 79 channels, the probability of
interfering with another Bluetooth system is less than 1.5%. This allows
several Bluetooth Piconets to operate in the same area at the same time
with minimal interference.
29. After a Bluetooth device has been added to the temporary network (the
Piconet), each device is assigned a specific time period to transmit and
they do not collide or overlap with other units operating within the same
Piconet.
• Piconets can be setup to interact with other Piconets to form larger
networks called Scatternets. Scatternets allow the master in one Piconet to
operate as a slave in another Piconet. While this allows Bluetooth devices
in one Piconet to communicate with devices in another Piconet.
30. Piconet… Safety
• A Bluetooth piconet has encryption and verification built in to
the devises upon which it resides.
• There are error-correction schemas and a 4-digit PIN is used
on the master device to authenticate the user. However,
other devices may not be equipped with a PIN
authentication.
33. Usage Models
Set of protocols that implement a particular Bluetooth-based
application. Some of the highest priority usage models are:
• File transfer
• Internet bridge
• LAN access
• Synchronization
• Three-in-one phone
• Headset
35. File Transfer
• one of the most fundamental and useful applications
• simple point-to-point links to exchange files and other data
objects
• removes the need for cables
• much easier to form temporary links between devices to
quickly exchange data
• also includes the capability to browse folders on a remote
device.
37. Internet Bridge
• PC is wirelessly connected to a mobile phone or cordless
modem to provide dial-up networking and fax capabilities.
• AT-commands (Attention commands) are needed to control
the Mobile phone or modem.
39. LAN Access
• This usage model enables devices on a piconet to access a
LAN. Once connected, a device functions as if it were
directly connected (wired) to a LAN.
41. Synchronization
• It provides a device-to-device (phone, PDA, computer, etc.)
synchronization of the PIM (personal information
management) information such as phonebook, calendar,
message and note information.
• It requires task information to be transferred and processed
by devices utilizing a common protocol and format.
43. Three-in-one Phone
Telephone handsets may connect to three different service
providers and act as a:
• Walkie-talkie or handset extension
• Cellular phone
• Cordless phone connecting to a voice access point
45. The Ultimate Headset
• Headset is wirelessly connected to act as a remote device’s
audio input and output interface
• Increases user’s freedom of movement
• Headset must be able to send AT-commands (Attention
commands) and receive result codes
46. AT Commands
• AT is the abbreviation of Attention
• AT commands are instructions used to control and
communicate with a modem
• These commands modify modem's behavior or instruct
the modem to do something specific, such as dialing a
telephone number
48. Bluetooth Architecture
• The Bluetooth technology is divided
into two specifications:
the core and the profile specifications.
• The core specification discusses how
the technology works
• The profile specification focuses on
how to build interoperating devices
using the core technologies.
49. Bluetooth Architecture
• RF(radio frequency):
The Radio (layer) is the lowest defined
layer. It defines the requirements
of the Bluetooth transceiver device
operating in the 2.4GHz ISM band.
Transmits data to and from the Baseband
• Baseband:
Establishes and manages the physical
radio frequency (RF) link between
Bluetooth units that form a piconet.
50. Bluetooth Architecture
• LMP:
Link management protocol responsible
for control of radio links.
• L2CAP:
logical link control and adaptation
protocol provides multiplexing,
Segmentation.
• RFCOMM:
radio frequency communication,
serial port emulation.
• HID:
Human interface device for peripheral devices.
51. Types of links
• Synchronous Connection Oriented(SCO) link.
• Asynchronous Connectionless Link
52. Synchronous Connection Oriented(SCO) link
• SCO is a type of communication link that provides for the
continuous transfer of data in pre-assigned time periods.
• Point to point full duplex link.
• The SCO link reserves slots between the master and the
slave.
• Time slot is reserved at every fixed interval.
• Used for a circuit switching voice connection.
• Needs an asynchronous connectionless (ACL) type link to be
first established.
53. Asynchronous Connectionless Link
• ACL is a type of communication link that can send data in
bursts whenever data is ready to be sent.
• when the communication channel (radio channel) is
available (not transmitting another transmission).
• ACL connections can use various types of flow control such
as reliable or time bounded.
• This is a packet switched link between a master and slave.
• The Bluetooth system has two types of ACL links control
(ACL-C) and user data (ACL-U).
54. Bluetooth packets
• Bluetooth supports a wide variety of packet types
depending on the type of link, throughput and bit fault
tolerance.
• Data packets
SCO packet –for circuit switching
ACL packet –for packet switching
• On SCO links packets for low, medium and high quality
voice as well as combined data and voice are supported.
• For ACL links 1, 3 and 5 slot packets using medium and
high data rates are supported.
56. Access code
• The 72-bit access code is mainly used to identify
packets transmitted over a Bluetooth channel.
• All data packets sent on the channel share the same
access code.
• In addition the access code is used for device paging
(finding out if a specific device is in range) and
inquiries (used to discover new devices).
57. Header
• The 18-bit packet header contains the following
information
• A 3-bit target device address
• A 4-bit type code. Identifies the type of data or control
packet.
• A 1-bit fields for flow control, sequencing and packet
acknowledgement.
• An 8-bit header error check
• To protect the header from transmission errors each bit
is repeated three times in yielding a total length of 54 bits
60. Forward error correction(FEC)
• FEC is a technique for detecting and correcting errors by
adding a small number of extra bits.
• FEC allows optical transmission over longer distances by
correcting errors that can happen as the signal-to-noise
ratio decreases with distance.
• Within Bluetooth technology, there are 2 versions of this
1/3 FEC and 2/3 FEC.
• 1/3 FEC is a simple 3-times repetition of each info bit.
• 2/3 FEC is a shortened Hamming code.
61. Automatic Repeat Request scheme
• Also referred to as ”backward error correction”.
• This is an error control technique in this every block of data
received is checked using the error detection code used, and
if the check fails, retransmission of the data is requested
this may be done repeatedly, until the data can be verified.
Data and voice access points: Bluetooth facilitates real-time voice and data transmissions by providing effortless wireless connection of portable and stationary communication devices. Cable replacement: Bluetooth eliminates the need for numerous, often proprietary, cable attachments for connection of any kind of communication devices. Connections are instant and are maintained even when devices are not within line of sight. The range of each radio is approximately 10m but can be extended to 100m with an operational amplifier. Ad hoc networking: A device equipped with a Bluetooth radio can establish instant connection to another Bluetooth radio as soon as it comes into range.
File transfer: One of the most fundamental and useful applications for any type of data networking, including simple point-to-point links (like those of Bluetooth wireless communication), is to exchange files and other data objects. File transfer using floppy disks or cables is common; wireless communication removes the need for cables, making it much easier to form temporary links between devices to quickly exchange files and other data objects. This same sort of file and object transfer is possible with Bluetooth wireless communication. The file transfer usage model supports the transfer of directories, files, documents, images and streaming media formats. It also includes the capability to browse folders on a remote device. In an interactive conference room scenario, business cards and files could be exchanged among the participants of the meeting.
Three-in-one phone: Telephone handsets that implement this usage model may connect to three different service providers. First, telephones may act as cordless phones connecting to the public switched telephone network (PSTN) at home or the office and incurring a fixed line charge. This scenario includes making calls via a voice base station, making direct calls between two terminals via the base station and accessing supplementary services provided by an external network. Second, telephones can connect directly to other telephones for the purpose of acting as a walkie-talkie or handset extension. Referred to as the intercom scenario, the connection incurs no additional charge. Third, the telephone may act as a cellular phone connecting to the cellular infrastructure and incurring cellular charges.
Ultimate headset: The headset can be wirelessly connected for the purpose of acting as a remote device’s audio input and output interface. The headset increases the user’sfreedom of movement while maintaining call privacy. A common example is a scenario where a headset is used with a cellular handset, cordless handset, or personal computer for audio input and output. The headset must be able to send AT-commands (Attention commands) and receive result codes. This ability allows the headset to answer incoming calls and then terminate them without physically manipulating the telephone handset.
