30-04-2011, 09:32 AM
ABHISHEK _BLUETOOTH.pptx (Size: 1.21 MB / Downloads: 43)
What Is Bluetooth?
• Designed to be used to connect both mobile devices and peripherals that currently require a wire
• Short range wireless radio technology
- operate range of 10 meters
• “USB without wires”
Advantages (+)
• Wireless (No Cables)
• No Setup Needed
• Low Power Consumption (1 Milliwat)
• Bluetooth Technology is Inexpensive
• Share Voice and Data both
Disadvantages (-)
• Short range (upto 10 meters)
• Small throughput rates Data Rate 780kb/s only
• Mostly for personal use (PANs)
• Security
How Does It Work?
• Bluetooth is a standard for tiny, radio frequency chips that can be plugged into your devices
• These chips were designed to take all of the information that your wires normally send, andtransmit it at a special frequency to something called a receiver bluetooth chip.
• They normally operate at 2.45GHZ in license free globally available ISM radio band.
• Advantage - worldwide availability and compatibility.
• Disadvantage - devices must share the band with other RF emitters including automobile security systems, noise sources such as microwaves
• The Piconet
• Bluetooth devices can interact with one or more other Bluetooth devices in several different ways. The simplest scheme is when only two devices are involved. This is referred to as point-to-point. One of the devices acts as the master and the other as a slave. This adhoc network is referred to as a Piconet.
• As a matter of fact, a Piconet is any such Bluetooth network with one master 2 and one or more slaves.
In, the case of multiple slaves, the communication topology is referred
to as point-to-multipoint.
• In this case, the channel (and bandwidth) is shared among all the devices in the Piconet. Once a Piconet has been established, master-slave roles can be exchanged.
Bluetooth Specifications
• Each channel is divided into time slots 625 microseconds long
• Packets can be up to five time slots wide
• Data in a packet can be up to 2,745 bits in length