| The networking standards of Bluetooth will | | | | Once the conversation has occured, the devices |
| transmit data via low power radio frequency. | | | | will form a network. Bluetooth devices will create |
| Bluetooth communicates on a 2.45 GHz | | | | a PAN (Personal Area Network) or piconet that |
| frequency. This very band of frequency has been | | | | may fill a room. Once the piconet has been |
| set aside by international agreement for the use | | | | established, the devices will randomly hop in |
| of industrial and medical devices. | | | | frequencies. |
| Many devices that you already known and use | | | | Bluetooth technology profiles will describe how the |
| take advantage of this frequency band. Garage | | | | technology is used. Profiles can be best described |
| door openers, baby monitors, and the next | | | | as vertical slices through the protocol stack. It will |
| generation of mobile phones all use this frequency | | | | define options in each protocol that are |
| within the ISM band. Ensuring that Bluetooth and | | | | mandatory for the profile. |
| the other devices do not interfere with each | | | | The profile will also define the parameter ranges |
| other is a crucial part of the design process. | | | | for each protocol. The concept of the profile is |
| One of the ways Bluetooth will avoid interfering | | | | used to decrease the risk of interoperability |
| with other electronic devices is by sending out | | | | problems between the different products. These |
| weak signals of around 1 mw. In comparison, | | | | profiles will not normally define any additions to |
| even the most powerful of cell phones can | | | | the Bluetooth specification, which is why you can |
| transmit a signal of 3 watts. | | | | add new profiles where you need them. The |
| The low power signals will limit the range of a | | | | Bluetooth underlying technology is the same, only |
| Bluetooth device to around 32 feet, which cut the | | | | the specific method that it's used is defined. |
| chances of interference between your computer | | | | Generally speaking, all profiles of Bluetooth are |
| and other electronic devices. Even though it has | | | | based on the GAP (Generic Access Profile). There |
| low power, Bluetooth does not require a line of | | | | are many profiles that fall in the GAP category.a) |
| sight between the communicating devices. The | | | | AVRCP, Audio/Video Remote Control Profileb) |
| walls in your home will not stop the signal, making | | | | ESDP, Extended Service Discovery Profilec) CIP, |
| it great for rooms throughout the house. | | | | Common ISDN Access Profiled) PAN, Public Area |
| Bluetooth can connect 8 devices at the same | | | | Network Profilee) HCRP, Hardcopy Cable |
| time. With each of those devices on the same | | | | Replacement Profilef) GAVDP, Generic Audio |
| radius, you may think they would interfere with | | | | Visual Distribution Profileg) A2DP, Advanced Audio |
| each other, although it is very unlikely. Bluetooth | | | | Distribution Profileh) VDP, Video Distribution |
| utilizes a technique known as low frequency | | | | Profilei) HID, Human Interface Device Profile |
| hopping, which makes it harder for more than one | | | | To put it another way, usage models will describe |
| device to transmit on the same frequency at the | | | | Bluetooth device applications and the associated |
| same time. | | | | profiles that are used. The usage model focuses |
| With this technique, a device will use 79 individual, | | | | mainly on three categories; voice/data access |
| randomly chosen frequencies within a designated | | | | points, peripheral interconnects, and PAN (Personal |
| range, which change from one anotheron a | | | | Area Networking). |
| regular basis. | | | | The voice and data access points involve |
| In the case of Bluetooth, the transmitters will | | | | connecting computing devices to communicating |
| change frequency 1,600 times or more every | | | | devices through a wireless link. This way, data can |
| second, meaning that more devices can make | | | | be transferred in a wireless manor, without the |
| fulluse of the radio spectrum. Since every | | | | need of cables or other types of connectivity. |
| transmitter of Bluetooth will use spread spectrum | | | | PAN is another very important usage model with |
| automatically, it is very unlikely that | | | | strong appeal to business customers. Bluetooth |
| twotransmitters will be on the same frequency at | | | | networks are easy to set up in virtually any type |
| the exact same time. | | | | of environment. An example would be meeting |
| When the Bluetooth devices come within close | | | | others at a trade show. |
| range of each other, an electronic conversation | | | | Instead of having contact information beamed via |
| will occur to determine whether or not they have | | | | infrared, business cards can quickly and easily be |
| data to share or whether one needs to take total | | | | transferred via Bluetooth wireless. The fact is that |
| control. The user does not have any buttons to | | | | many documents can be exchanged this very |
| press or commands to give, as the conversation | | | | same way, making the uses and possibilities |
| will occur automatically. | | | | virtually endless. |