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Bluetooth Wireless Technology

Bluetooth Basics

Bluetooth is, at its central part, an approach to eliminate the need for physical wires in a massive

amount of situations. The specification eliminates this need through the utilization of low-cost,

low power radio communication. Most radio communications are done over a specific spectrum.

The Federal Communications Commission assigns frequencies for designated uses. For example,

151.625 mhz is a communications band given over to the use of itinerate workers and events,

like sports teams and trade shows. Bluetooth removes the need for having a specific band

assigned to it by using every frequency band at extremely low power. The original spec, in fact,

calls for Bluetooth communications to reach only as far as 10 meters. More recent specs allow

for broadcasts of up to 100 meters under certain circumstances

This low-power, frequency independent radio communication system was intended to be as

flexible as possible. Removing wires from so many different situations meant that Bluetooth

technology would be put to use in a multitude of ways. Additionally, this sort of technology

would open the door for many completely new technologies. The ways in which the Bluetooth

SIG ensured the technology's flexibility are threefold: The Master-Slave Relationship, Energy

Use Decisions, and Fluid Topology.

The Master Slave Relationship is the term used to depict the two distinctive functions that

Bluetooth nodes can play. Any Bluetooth node can be either a Master or a Slave. Functionality

for both should be built into each node, according to the spec. The "Master" status simply means

that, within a currently active Bluetooth network, the node decides which frequency the nodes of

the currently active network will broadcast on. Master status is usually conferred to whichever

node starts communication with the other Bluetooth nodes in the area. The broadcast frequency

changes every few seconds (as discussed above), according to the Master node's internal clock,

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Airlogic ABM-400 Manual de usuario Pagina 41