Bluetooth


 * Topic:**

What is Bluetooth? How does Bluetooth work? How is it applied in everyday settings?

=**Description:**= A wireless technology that pairs devices from different industries to each other. An example would be the pairing of a cellular phone and a car. Through the use of this type of wireless technology, the user can utilize features such as a "hands-free" phone system while driving.

=History:= The term "Bluetooth" was actually coined from a Viking king in Denmark. Harald I Bluetooth, son of King Grom The Old and husband to Thyre Danebold, ruled Denmark from 940 to 985 AD. As with many Vikings, Harald considered it honorable to fight for treasure in foreign lands. Harald's sister Gunhild came to him, seeking help in securing control of Norway after her husband was killed by the Norwegian king Erik Blood Axe. Harald was successful in his conquest, and by 960 he ruled over both Denmark and Norway. He then created a monument that read: "King Harald raised this monument to the memory of Grom his father and Thyre his mother. Harald conquered all of Denmark and Norway and made the Danes Christian". He died in battle in 985 after having completed his father's campaign to unite the country, convert the Dane's to Christian, and conquer Norway. Bluetooth was created as a way to unite the worlds of computers and telecom in the same way Harald Bluetooth united Denmark and Norway.

=**How Bluetooth Creates a Connection**:= Bluetooth is a networking standard that works on two levels of agreement. They are physical level and protocol level. The physical level is a radio-frequency standard. The protocol level allows the products to agree on how many bits will be sent at a time and the recieved and sent messages are the same. Bluetooth creates and recieve low-power signals in which it connects to transfer data. Bluetooth communicates on a frequency of 2.45 gigahertz. When Bluetooth devices are in range with each other, a conversation occurs to determine if data will be shared or both devices need to connect. The conversation automatically occurs with out any physical notification. One of the most popular ways to create a large ad-hoc network is through a scatternet, which works through connecting multiple piconets.



=**Common applications of Bluetooth technology****:**=


 * The ability to connect various office peripherals without the use of cables. For example, you can connect your PC or laptop to printers, scanners, or fax machines. You can also connect your mouse and/or keyboard to your PC cable-free.


 * If you own a digital camera with Bluetooth technology enabled, you can transfer pictures and videos to your PC or notebook without the use of cables.


 * With Bluetooth-enabled PDA's, you can transfer selected documents and even electronic business cards to other Bluetooth-enabled devices.


 * If your cellular phone is Bluetooth-enabled, you can send pictures, video clips, ringtones, and other files to any other Bluetooth-enabled phone that is within range.


 * Replaces wired connections in test equipment, GPS receivers, medical equipment, barcode scanners, and traffic control devices.


 * Next-generation video game consoles use Bluetooth for connection between wireless controllers and the console.

=Bluetooth vs. Wifi= While both Wifi and Bluetooth are forms of wireless interfaces, they do have their differences. Many might wonder why there are two different forms of wireless technology. The answer is simple; it is mainly due to how these different technologies are applied as well as the difference in aesthetics.


 * Applications**: For the most part Wifi (Wireless Fidelity) is used as an internet interface. It's a standard for establishing wireless connectivity amongst users as well as to the internet itself, in which a typical network would be for the size of a small campus or city. Bluetooth is mainly used for hooking up short distance peripheral devices, more or less within a users home or office. In principle they both eliminate the need for hard-line connections and make it easier for users to be mobile.


 * Speed/Properties**: Typically Wifi and Bluetooth operate at different frequencies based on their intended distance of use. In order for Wifi to reach users, the wireless network spans across an 802.11 frequency and can generally operate between 10-15 mbps. Bluetooth is only about 600-800 kbps, which isn't good for downloading heavy information processes but it makes interconnectivity of devices for a user much easier due to the low use of bandwidth.


 * Usability**: Generally Bluetooth devices are known for two things, one of which is their low power demand which makes for efficient use of various devices. The other is the "awareness" ability in which multiple Bluetooth devices can connect and work between each other. Wifi has much more of a power demand because of the network that has to be generated. Access to a Wifi network is generally from a central broadcast point and cannot be connect via other laptops and PC's. Also it's just as "manage oriented" as a hard-line network, to make sure the right users are on the right networks. Typically Bluetooth devices aren't as much of a security risk as a Wifi connection based on what a person can obtain by hacking into a Bluetooth network.

In the end, Bluetooth is the best interface for connecting wireless devices without having to partition USB's or other connections on your PC or notebook computer. However since it operates on a much lower frequency than Wifi, it’s not the best sort of connection for transferring media that requires a higher bandwidth.

=**Web Resources:**= __Official Sites__:


 * [|http://www.bluetooth.com/bluetooth]
 * [|Bluetooth.org — The Official Bluetooth Membership Site]

__Other Sites:__
 * http://electronics.howstuffworks.com/bluetooth1.htm
 * http://electronics.howstuffworks.com/bluetooth2.htm
 * http://www.mobileinfo.com/Bluetooth/applic.htm

=**Terminology:**=
 * **[|Hands-free]** - an adjective describing equipment that can be used without the use of hands (for example via voice commands) or, in a wider sense, equipment which needs only limited use of hands, or for which the controls are positioned so that the hands are able to occupy themselves with another task (such as driving) without needing to hunt far afield for the controls.
 * Source: Wikipedia [|http://en.wikipedia.org/wiki/Handsfree]
 * **Interoperability -** an interoperable Bluetooth device is able to establish a link and communicate with another Bluetooth unit regardless of vendor or implementation. An Ericsson mobile should thus be just as happy talking to a Toyota sat-nav system or Sony camcorder as it should to another Ericsson mobile. Only devices which have been comprehensively tested for interoperability may carry the Bluetooth logo.
 * Source: http://ntrg.cs.tcd.ie/undergrad/4ba2.01/group3/terminology.html
 * **Bluetooth Connection Protocol** - describes the set of rules by which all Bluetooth devices must abide in order to establish a link a communicate with one another. Although the Bluetooth protocol has its foundations in the [|IEEE 802.11] standard it incorporates many significant changes. The essence of Bluetooth is based upon dynamically configured units. Hopping very quickly between frequencies, the protocol specifically caters for many different modes to allow for minimal power consumption.
 * Source: [|http://ntrg.cs.tcd.ie/undergrad/4ba2.01/group3/protocol.html]
 * **Scatternet** - A scatternet is comprised of two or more independent piconets which communicate with one another. The scatternet is created by either a master or slave in one piconet electing to become a slave in a neighbouring piconet. The device connected to both piconets may then relay communications. This setup enables communication between many and possibly remote piconets. Bandwidth is reduced proportionally if more than 10 piconets are operating in the same 10m radius.
 * Source: http://ntrg.cs.tcd.ie/undergrad/4ba2.01/group3/terminology.html
 * **Piconet** - A collection of devices connected via Bluetooth technology in an ad hoc fashion. A piconet is initialised with two Bluetooth enabled devices, such as a PDA and mobile phone. A 3-bit address space limits the number of devices in any piconet to eight. All devices in a piconet are peer units and have identical implementations. When establishing a piconet, however, one device must act as a master for synchronisation purposes - the master is dynamically elected when a link is created. The other piconet units will act as slaves for the duration of the network.
 * Source: http://ntrg.cs.tcd.ie/undergrad/4ba2.01/group3/terminology.html

=**Graphics:**=