What is Bluetooth ?

As most of you do when you want to know anything you'd never heard of... try wikipedia.

It (http://en.wikipedia.org/wiki/Bluetooth) says as follow.

Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the ISM band from 24002480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Created by telecoms vendor Ericsson in 1994,[1] it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization.

To understand any kind of communication technology, you should be able to answer to several basic questions about it. In other words, if you can answer the following questions, I would say you already have some general understanding on it.

• Is it wired communication ? or Wireless communication ?
• If it is wireless communication, what kind of wave length (frequency) range it uses ?
• What is the typical range of communication ? (How far it can go) ?
• What is the typical data rate you can transmit and receive ?
• What is the typical connection topology ? (Is it one-to-one connection ? or one-to-many connection ? etc)

Can you find the answers to these questions from the wikipedia definition that I quoted above ?

Let's tackle each of the questions one by one.

• Is it wired communication ? or Wireless communication ? ==> It is 'wireless Communication'.
• If it is wireless communication, what kind of wave length (frequency) range it uses ? ==> It is 2400~2800 Mhz frequency Range called ISM (Industrial Science Medical) band.
• What is the typical range of communication ? (How far it can go) ? ==> It is usually a couple meter range (The wikipedia definition does not explictely say about the range though)
• What is the typical data rate you can transmit and receive ? ==> At the beginning, it started with the max data rate of 1 Mbp and now mostly 2,3 Mbps (EDR). Recent specification defines the technology for even higher data rate.
• What is the typical connection topology ? (Is it one-to-one connection ? or one-to-many connection ? etc) ==> It support both one-to-one and one-to-many connection.