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Bluetooth
Bluetooth is intended to get around the problems that came with infrared. The older Bluetooth 1.0 standard has a maximum transfer speed of 1 megabit per second (Mbps), while Bluetooth 2.0 can manage up to 3 Mbps. Bluetooth transmits data via radio waves, it communicates on a frequency of 2.402 gigahertz and 2.480 GHz. This frequency band has been set aside by international agreement for the use of industrial, scientific and medical devices. A number of other devices also use the same frequency like Baby monitors, garage-door openers and cordless phones. Bluetooth can connect up to eight devices at the same time, with all of those devices in the same 10 meter (32-foot) radius, you might think they'd interfere with one another, but it's unlikely. Bluetooth uses a technique called spread-spectrum frequency hopping that makes it rare for more than one device to be transmitting on the same frequency at the same time. When Bluetooth capable devices come within range of one another, an electronic conversation takes place to determine whether they have data to share or whether one needs to control the other. Once the conversation has occurred, the devices form a network. Bluetooth systems create a personal-area network (PAN), or piconet. |
Bluetooth
takes small area networking to the next level by removing the need for user
intervention and keeping transmission power extremely low to save battery
power. Each transmission signal to and from your cell phone consumes just 1
milliwatt of power, so your cell phone charge is virtually unaffected by all
of this activity.