Presentation on Bluetooth (Wireless Technology)

Presentation on:

Bluetooth (Wireless Technology)

Logical Link, Control Adaptation Protocol Layer (L2CAP)

Asynchronous Connection-less (ACL)

• used for packet switched data that is available at irregular intervals
• delivers traffic on a best effort basis. Frames can be lost & may have to be retransmitted
• slave can have only one ACL link to its master
• used where correct delivery is preferred over fast delivery
• can achieve a maximum data rate of 721 kbps by using one, three or more slots

• Equivalent to logical link control sublayer of LAN
• The ACL link uses L2CAP for data exchange but SCO channel does not use it
• The various function of L2CAP is:

1. Segmentation and reassembly

2. Multiplexing

3. Quality of Service (QOS)

Other Upper Layers

Bluetooth defines several protocols for the upper layers that use the services of L2CAP. These protocols are specific for each purpose.

Group 5B

Baseband Layer

• equivalent to the MAC sublayer in LANs
• uses a form of TDMA called TDD-TDMA
• Master and slave stations communicate with each other using time slots.
• The master in each piconet defines the time slot of 625µ sec
• two types of links can be created between a master and slave

Group Members:

Topic Covered

• Naznin Sultana (201414094)
• Juthika Bhattacharjee (201414101)
• Adnan Sharif (201414114)
• Afsana Abida Khushbu (201414115)
• Lameya Afroz (201414116)
• Ashratuz Zavin (201314020)

Conclusion

Radio Layer

Synchronous Connection Oriented (SCO)

• About Bluetooth Technology
• Bluetooth Architecture
• Bluetooth Layers
• Radio Layer
• Baseband Layer
• Logical Link, Control Adaptation Protocol Layer (L2CAP)
• Other Upper Layers

• used for real time data such as sound. It is used where fast delivery is preferred over accurate delivery
• a physical link is created between the master and slave by reserving specific slots at regular intervals
• Damaged packet; are not retransmitted over sco links
• A slave can have three sco links with the master and can send data at 64 Kbps

This presentation was intended as a brief introduction to the many challenges that the Bluetooth technology faces if it is to succeed as a technology for building adhoc networks and also gives the small description of related work that had been done in this area. We hope that the paper will also encourage others in exploring what we feel is a promising and rich research area.

• Roughly equivalent to the physical layer of the Internet model
• Lower power and a range of 10m
• Deals with ratio transmission and modulation
• Moves data from master to slave or vice versa
• A low power system that uses 2.4 GHz ISM band in a range of 10 meters
• To change bits into a signal, it uses a version of FSK called GFSK
• Band is divided into 79 channels of 1MHz each
• Bluetooth hops 1600 times per second

Bluetooth Layers

Bluetooth

• Bluetooth is a wireless LAN technology which is an ad-hoc network, which means that the network is formed spontaneously
• A Bluetooth LAN can even be connected to the Internet if one of the gadgets has this capability
• Peripheral devices such as a wireless mouse or keyboard can communicate with the computer through this technology

Bluetooth Layers

• Radio Layer

• Baseband/Link Controller

• Link Manager

• Host Controller

• Logical Link Control

• RFCOMM

• SDP

Piconets

• A Bluetooth network is called a piconet, or a small net.
• A piconet can have up to eight stations, one of which is called the primary; the rest are called secondaries.
• All the secondary stations synchronize their clocks and hopping sequence with the primary.
• A piconet can have only one primary station. The communication between the primary and the secondary can be one-to-one or one-to-many.

Piconet

Figure: Piconet

Scatternet

• Piconets can be combined to form what is called a scatternet.
• A secondary station in one piconet can be the primary in another piconet. This station can receive messages from the primary in the first piconet (as a secondary) and, acting as a primary, deliver them to secondaries in the second piconet. A station can be a member of two piconets.

Architecture

• Piconet
• Scatternet

Scatternet

Figure: Scatternet