Bluetooth

Bluetooth is Wireless Communication

Bluetooth in Wireless Communication Fahad Aziz

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Index •Introduction •History •Requirements •Architecture •Network Topology •Baseband State Machine •Link Management •Host Controller Interface •Software Protocols •Logical Link Control & Adapter Protocol

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Introduction • Open Standard for short range wireless connectivity • Originally intended to replace the cable(s) connecting portable and/or fixed electronic devices • It is a radio frequency technology utilizing the unlicensed 2.5 Ghz industrial, scientific and medical band • Applications of Bluetooth are home networking and home appliances of future e.g. smart appliances, heating systems and entertainment devices Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

History • The technology was born in 1994. • The first version was released July 1999. • The Bluetooth name comes from the Danish Viking Harald Blåtand. • 1998 Intel, Ericsson, IBM, Nokia, and Toshiba formed the Bluetooth Special Interest Group. • December 1999 Add 3Com, Microsoft, Lucent and Motorola. • To date, 800 companies world wide are members of the Bluetooth SIG

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Why Bluetooth? – – – –

Cable replacement between devices. Supported by major companies. Open Specification Capable of handling both voice and data simultaneously – Low power consumption & slow transmission rate – Connection can be initiated without user interaction. – Devices can be connected to multiple devices at the same time.

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Architecture Bluetooth link control hardware One chip or Radio module

&

BaseBand module (that implements the RF, baseband and link manager)

– Handles radio transmission and reception – Accomodates digital signal processing for the basedband protocol. – Functions include establishing connection, support for asynchronous/synchronous links, error correction and authentication. Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Network Topologies • Bluetooth devices are organized into groups, called piconets, that consist of one master and up to seven active slave devices • A device can belong to more than one piconets either as a slave, or as a master • Multiple piconets with overlapping coverage areas form a scatternet

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Network Topologies M S

S

S

Slave

M

Master

M S

S S S

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Baseband State Machine • Piconets can be static or formed dynamically as devices movies in and out of range of one another • A devices leaves standby by – Initiating – receiving an inquiry – a page command

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Baseband State Machine STANDBY

Page Master Response

Page Scan

Inquiry Scan

Slave Response

Inquiry

Inquiry Response

CONNECTION

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Baseband State Machine Low-power States Sniff: A master can communicate with devices in sniff mode only during specific sniff-designated time slots Hold: A slave does not receive any asynchronous packets and listens only to determine if it should become active again Park: A device in park mode stops listening and also gives up its active member address

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Baseband Links • Responsible for channel coding/decoding, timing and managing a Bluetooth link. Master/slave – Devices in a connection are either master or slave. – Communication is only possible between a master and its slaves. – A master and the slaves are named piconets. – Scatternet; multiple piconets connected together.

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Link Manager Link Manager is responsible for controlling the baseband state machine • Handles Link setup • Manage security (authetication and security services) • Control (paging, changing slave modes and handling required changes in master/slave roles) • Also supervises link and control handling of multislot packet

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Host Controller Interface • Some link controller may include as HCI Layer above the link Manager. • Used to isolate the Bluetooth baseband and link manager from a transport protocol e.g. USB • Thus allowing standard interface to Bluetooth hardware. • Applications can use bluetooth hardware without any low level hardware knowledge

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Software Protocols Many Bluetooth protocols are implemented in software. • L2CAP: Provides the interface to the link controller and allows for interoperability between Bluetooth devices • SDP: provides service discovery specific to Bluetooth environment with out inhibiting the use of other service discovery protocols • RFCOMM: simple transport protocol providing serial data transfer. • TCS: Provided for voice and data call control, providing group management, connectionless TCS etc Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ

Bluetooth is Wireless Communication

Software Protocols • OBEX: It is only connection oriented protocol and offers three profiles. Can be used for synchronization of phone books, calendars, messaging etc • WAP: Specification outlines the interoperability requirements for implementing this capability.

Fahad Aziz – EE 586 – Wireless Networking & Protocols -

Stevens Institute of Technology Hoboken NJ