BlueToothBy: Trevor Parker, Minh-Tri Le

What is Bluetooth?• Bluetooth is a wireless technology that is a low-

cost, low-power, short-range radio for ad-hoc wireless communication, were data or voice can be transmitted from a Master to slave module.

http://www.ni.com/white-paper/7104/en

History of Bluetooth

• Bluetooth is named after a 10th century Danish King Harald Blatand, who unified Denmark and Norway.

• In 1994 – Ericssons worked with the concept while studying wireless technology to link mobile phones

• In 1998 Bluetooth Special Interest Group (SIG) was formed• Ericsson, Intel, IBM, Nokia, Toshiba

• In 1999 the First Specifications were released• In 2001 the first retail products were sold

http://www.slideworld.com/slideshow.aspx/An-Introduction-to-BLUETOOTH-TECHNOLOGY-ppt-754898#

Classes and versions of Bluetooth

• 3 classes• Class 3 – range: 1-3m• Max power of 1mW

• Class 2 – range: 10-30m• Max power of 2.5mW

• Class 1 – range: 100-300m• Max power of 100mW

• Versions• Version 1- Data rate: 1Mbit/s• Newest version 4 – Data rate: +24Mbit/s• Includes Bluetooth low energy(BLE) and highspeed

Piconets/Scatternet

• Several Bluetooth devices joined are called a piconet, normally up to a maximum of 8 devices.

• The main device acts as the master and every other device turns into a slave to it.

• Though in turn any of those devise could be the master to another set of slaves. This is called a scatternet.

Net examples

Piconet Scatternet

http://www.slideworld.com/slideshow.aspx/An-Introduction-to-BLUETOOTH-TECHNOLOGY-ppt-754898#

http://www.developer.nokia.com/Community/Wiki/Bluetooth_Protocol

Security• Longer encryption keys (128 bit key)• Application encryptions• Link authentication• Personal Identification numbers• Frequency hopping

Packet Structure

Frequency Hopping

• Bluetooth uses Frequency Hopping, which reduces interference from things like microwaves and baby monitors

• The frequency hopping occurs 1600 times per sec

• http://www.slideworld.com/slideshow.aspx/An-Introduction-to-BLUETOOTH-TECHNOLOGY-ppt-754898#

Master-Slave Communication• Channel is divided into consecutive slots (each

625 us)• One packet can be transmitted per slot• Subsequent slots are alternatively used for

transmitting and receiving • Master can send packets to a slave only in EVEN slots• Slave can send packets to the master only in the ODD

slots

Software Protocols• LMP: control the radio link

between two devices• L2CAP: link the controller and

allows interoperability between Bluetooth devices

• SDP: allows automatic detection of Bluetooth devices without affecting the other service discovery protocols

• RFCOMM: serial data transfer• TCS: set up and control

speech and data calls between Bluetooth devices

Question?