bluetooth

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 examplesPiconet 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?