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Home entertainment systems have lots of cables between the settop box,VCR, DVD,stereo audio system,speakers and TV.We hide them under carpets and molding and we still occasionally trip over them.
Your wireless phone needs a cable if you are to have hands-free operation.Automobiles and boats are full of cables connecting the climate control,braking,engine control,emission control,and other
systems. Nor is there any single kind of cable.There are PCMCIA cables,RS-232 cables,parallel cables,USB cables,and so on.As the information age expands,we can only expect to have other types of applications with even more cables. There is hope,however,that we
may soon be freed of many of these cables.A new technology is emerging that promises to eliminate them.Called Bluetooth,the technology
consists of a specification for the wireless communication of voice and data using a short range radio.
Bluetooth is an open,global standard,meaning that,unlike cables,
there will only be one kind of Bluetooth and any Bluetooth-certified device will be able to communicate with any other Bluetooth-certified device.
A person could buy any brand of PDA,cell phone or mouse that worked with the Bluetooth standard,take it home and begin using it with a Bluetooth equipped PC immediately,without any special effort Application software that is unique to a mobile phone,PDA or mouse could be automatically downloaded from the device to the PC,using the Bluetooth connection. Bluetooth can replace cables currently being used with laptops,PDAs,mobile phones, and digital cameras,to name a few. Bluetooth supports voice as well as data transmission,so headsets used within the office or home could also become wireless. Bluetooth might even be used to replace the control cables in automobiles,boats and
industrial control systems.Since Bluetooth is a global standard and uses universally available unlicensed radio frequency spectrum,any Bluetooth-certified devices would interact in the same way in any part of the world.
Since a Bluetooth mobile phone,Bluetooth PDA and Bluetooth PC can simultaneously send and receive signals,there must be some way to differentiate all the transmissions from each other.The computer needs to know if a transmission is from the PDA or the mobile phone and visa versa.V irtually all wireless communication accomplishes this feat by putting the data into packets.
Each packet contains a pre-determined amount of data.It also contains information about where it is coming from and where it is going. Thus,packets from the PDA have a unique identifier,while packets from the mobile phone have another unique identifier.
Packets also contain information on how the data was compressed,the order in which they were transmitted and information that is used to verify the correctness of the transmission.W hen the data is received it is checked for accuracy,un-packetized, reassembled,de-compressed and possibly filtered in some way.
The baseband processor handles all the tasks described above.It takes care of converting data from one form to another (e.g.voice to digital data),compressing it, putting it into packets,taking it out of packets, assigning identifiers and error correction information and then reversing the process for data that is received.In Bluetooth,the baseband function is called the Link Controller.
Application Software -The application software is the software embedded in the device that operates the Bluetooth application.This is the software that makes the PDA, mobile phone,or keyboard do its job.All Bluetooth devices are required to have compatible sections in the application software,so that any Bluetooth device will work with any other one.
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