Bluetooth is a wireless technology standard invented by Ericsson in 1994 for exchanging data over short distances using short-wavelength UHF radio waves (Range: 2.4 to 2.485 GHz) from fixed and mobile devices. This is in the globally unlicensed (but not unregulated) Industrial, Scientific and Medical (ISM) 2.4 GHz short-range radio frequency band.
The devices use a radio broadcast communications system, they do not have to be in visual line of sight of each other; however, a quasi optical wireless path must be viable.
Bluetooth Special Interest Group
Special Interest Group (SIG), which manages Bluetooth has more than 30,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. SIG oversees development of the specification, manages the qualification program and protects the trademarks.
Upon completion of the presentation you will be able to understand the following:
- What is Bluetooth?
- How it technology works?
- Transmission types and rates
- Error correction and security
- Connection protocol
- Usage Model
It uses frequency-hopping spread spectrum for transmission. The data is divided into packets, and transmits each packet on one of 79 designated channels. Each channel has a bandwidth of 1 MHz with 800 hops per second, with adaptive frequency-hopping (AFH). BLE uses 2 MHz spacing, accommodating 40 channels.
With the advent of BLE, developers are now able to create small sensors that run off tiny coin cell batteries, for months. Most applications are for indoor conditions, where attenuation of walls and signal fading due to signal reflections make the range far lower than specified line of sight ranges of the products.
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