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CompTIA A+ Certification All-in-One Exam Guide

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Bluetooth) is designed to create small wireless networks preconfigured to do

very specific jobs. Some great examples are wearable technology, audio

devices such as headsets or automotive entertainment systems that connect to

your smartphone, personal area networks (PANs) that link two computers for

a quick-and-dirty wireless network, and input devices such as keyboards and

mice. Bluetooth is not designed to be a full-function networking solution, nor

is it meant to compete with Wi-Fi.

Bluetooth, like any technology, has been upgraded over the years to make

it faster and more secure. The first generation (versions 1.1 and 1.2) supports

speeds around 1 Mbps. The second generation (2.0 and 2.1) is backward

compatible with its first-generation cousins and adds support for more speed

by introducing Enhanced Data Rate (EDR), which pushes top speeds to

around 3 Mbps. The third generation (3.0 + HS) tops out at 24 Mbps, but this

is accomplished over an 802.11 connection after Bluetooth negotiation. The

High Speed (+ HS) feature is optional. Instead of continuing to increase top

speed, the fourth generation (4.0, 4.1, and 4.2), also called Bluetooth Smart,

is largely focused on improving Bluetooth’s suitability for use in networked

“smart” devices/appliances by reducing cost and power consumption,

improving speed and security, and introducing IP connectivity. The fifth

generation (just Bluetooth 5) adds options to increase speed at the expense of

range or by changing packet size. Bluetooth 5 adds better support for the

Internet of Things (IoT) devices, like smart speakers, lights, and so on.

NOTE Chapter 21, “The Internet,” details the Internet of Things. We’ll get

there!

The IEEE organization has made first-generation Bluetooth the basis for

its 802.15 standard for wireless PANs. Bluetooth uses a broadcasting method

that switches between any of the 79 frequencies available in the 2.45-GHz

range. Bluetooth hops frequencies some 1600 times per second, making it

highly resistant to interference.

Generally, the faster and further a device sends data, the more power it

needs to do so, and the Bluetooth designers understood a long time ago that

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