The Main Features of Bluetooth are given below:
• It operates in the 2.4GHz frequency band without having a license for wireless communication.
• Up to 10-100 meters data can be transfer in real time.
• Close proximity & accuracy is not required for Bluetooth as in case of infrared data (IrDA) communication device. Bluetooth does not suffer from interference from obstacles such as walls while infrared suffers due to obstacles.
• Bluetooth supports both point-to-point and point-to-multipoint wireless connections without cables between mobile phones and personal computers.
• Data transfer rate of blue tooth varies from version to version. Data rate of 1 Mbps for Version 1.2 Up to 3 Mbps for Version 2.0.
Then major parts of Bluetooth system are RF transceiver, base band, and protocol stack. Bluetooth is used for small-area networking without user intervention.
Due to extremely low transmission power in Bluetooth technique battery power is saved. It is a networking standard that works at two levels:
• Physical level.
• Protocol level
Due to these levels mobiles have to agree on these levels when bits are sent. It decides the amount of data to be sent at a time, and how the parties in a conversation can be sure that the message received is the same as the message sent.
Bluetooth networking transmits data through low-power radio waves. It can connect up to eight devices simultaneously. With in the range of about ten meters you must think that the devices will not interfere with each other.
Bluetooth solved the problem of devices interference while sending the data by using the technique of Spread-Spectrum Frequency Hopping due to which devices may transfer data at the same frequency at the same time.
The question rises here is how Bluetooth send the same data using same frequency band without devices interferences? In Bluetooth technique, transmitters change frequencies 1,600 times in every second. In this way devices can make full use of a limited band of the radio spectrum.
When Bluetooth devices came into the range of each other, conversations take place automatically. This conversation automatically determines whether they have the data to share or not.
In this way Bluetooth devices not only share the data but also control the data to be transferred. When the connection is established, the devices either they are part of a computer system or a network, Bluetooth systems create a personal-area network.
The technology used in Bluetooth also provides security in three ways:
• Pseudo-random frequency hopping,
Frequency hops make it difficult for anyone to eavesdrop. Authentication allows a user to limit connectivity to specified devices.
Encryption uses secret keys to make data intelligible only to authorized parties. Service-level security and device-level security work together to protect Bluetooth devices from unauthorized data transmission.