Wireless & Mobile Lecture # 20Presentation Transcript
Bluetooth Techniques Chapter 15
Overview of Bluetooth
Initially developed by Swedish mobile phone maker in 1994 to let laptop computers make calls over a mobile phone. And then later on several thousands companies have signed to make it
Designed to provide universal short-range wireless capability
Industry observers expect Bluetooth to be installed in billions of devices by 2005
Uses 2.4-GHz band, available globally for unlicensed low power uses
Devices within 10 m can share up to 720 kbps of capacity
Supports open-ended list of applications
Data, audio, graphics, video
Audio devices can include headsets, cordless and standard phone, home stereos and digital MP3 players
Chapter No. 15
Bluetooth Application Areas Bluetooth provides support for three general application areas using short range wireless connectivity:
Data and voice access points
Real-time voice and data transmissions on portable and stationary communication devices
Eliminates need for numerous cable attachments for connection. Connections are instant and re maintained even when devices are not within line of sight. The range of each radio is approximately 10 m, but can be extended to 100 m with an optical amplifier
Ad hoc networking
Device with Bluetooth radio can establish connection with another when in range
Bluetooth Standards Documents
It describes the details of various layers of Bluetooth protocol architecture from the radio interface to link control
Are concerned with the use of Bluetooth technology to support various applications. The purpose of a profile specification is to define a standard of interoperability, so that products from different vendors that claim to support a given usage model will work together. For example when two devices come within range of one another, they can automatically query each other for a common profile. This might then cause the end users of the device to be alerted, or cause some automatic data exchange to take place
Bluetooth is a layered protocol architecture
Cable replacement and telephony control protocols
Specifies details of the air interface, including frequency, the use of frequency hopping, modulation scheme, and transmit power.
Concerned with connection establishment within a piconet, addressing, packet format, timing and power control.
Link manager protocol (LMP)
Responsible for link setup between Bluetooth devices and ongoing link management. This includes security aspects such as authentication and encryption, plus the control and negotiation of baseband packet sizes.
Logical link control and adaptation protocol (L2CAP)
Adapts upper layer protocols to the baseband layer, L2CAP provides both connectionless and connection-oriented services.
Service discovery protocol (SDP)
Device information, services and the characteristics of the service can be queried to enable the establishment of a connection between two or more Bluetooth devices.
Cable replacement protocol
Presents a virtual serial port that is designed to make replacement of cable technologies as transparent as possible. Hence RFCOMM enables the replacement of serial port cables with the minimum of modification of existing devices.
Telephony control protocol
Telephony control specification – binary (TCS BIN)
That defines the call control signaling for the establishment of speech and data calls between Bluetooth devices. In addition, it defines mobility management procedures for handling groups of Bluetooth TCS devices.
defined in specifications issued by other standards making organizations and incorporated in to the overall Bluetooth architecture. The Bluetooth strategy is to invent only necessary protocols and use existing standards whenever possible.
The point to point protocol is an internet standard protocol for transporting IP datagrams over a point to point link.
These are foundation protocols of the TCP/IP protocol suite.
OBEX provides functionality similar to that of HTTP, but in simpler fashion.
Bluetooth incorporates the wireless application environment and the wireless application protocol into its architecture.
Piconets and Scatternets
Basic unit of Bluetooth networking
Master and one to seven slave devices
Master determines channel and phase
Device in one piconet may exist as master or slave in another piconet