Chapter 23. Bluetooth Wireless Technology


SOME OF THE MAIN TOPICS IN THIS CHAPTER ARE

The Bluetooth Special Interest Group ( SIG )

General Overview of Bluetooth

Piconets and Scatternets

Bluetooth Device Modes

SCO and ACL Links

What Are Bluetooth Profiles?

Bluetooth Is More Than a Wireless Communication Protocol

The preceding few chapters have covered IEEE 802.11b (Wi-Fi) and IEEE 802.11a, which are the two major contenders for the wireless networking market. Both of these technologies have trade organizations whose purpose is to advance their technology for the markets they target. The 802.11 wireless protocols aim for a market ranging from the home to the workplace to public spaces such as airports, malls, and just about anywhere you can use a cell phone today. The goal of the 802.11 protocols is to provide a worldwide standard that enables you to use a single wireless network adapter card in many different environments.

Bluetooth is another matter altogether. Bluetooth technology was originally designed to replace wires, and for only short distances. The original expectations for Bluetooth were that it would be used to connect such things as a keyboard, mouse, computer, and possibly mobile phone. It was not designed, from the start, to be a wireless networking solution that would span any great distance. Other technologies, such as Wi-Fi and 802.11a, were expected to cover that territory, giving mobile clients easy access to a network. In the home arena, this means that a single Internet connection can be shared by numerous wireless clients (computers, printers, gaming devices). In the work environment, Access Points can allow a mobile user to quickly connect to the corporate cabled network anywhere that a wireless Access Point has been placed. For the business and residential user , it's possible that one or the other of these standards will allow you to open your laptop in a coffee shop, an airport, or some other public space and instantly connect to an Internet provider.

Note

The name Bluetooth comes from the legacy of an ancient king named Harald Bl tand (940 “985 A.D.). The legend has it that he was able to unite the countries of Norway and Denmark. Yet, the word Bl tand can be translated to "Blue tooth." Some say that this name was given to him because he didn't have much time to visit a dentist, and he had blue teeth due to his fondness for blueberries. The adoption of this name is probably, however, based on the fact that he was able to unite the two countries. The Bluetooth technology does the same thing ”it enables different devices to work together, bringing together a wide range of manufacturers.

Bluetooth has been in development for several years . When the second edition of this book was written, it was expected to be the hottest new technology of the year. However, there were still parts of the specifications that needed to be refined, and very few manufacturers decided to create devices based on Bluetooth. Over the next few years the specifications were further defined, and short-distance networking became part of Bluetooth. Other profiles (which are discussed later in this chapter) were added so that Bluetooth became a practical solution for short-distance networking for many types of consumer and computer devices today. One might say that Bluetooth has finally arrived.

There are two good reasons to consider using Bluetooth to create a small wireless network although 802.11b and 802.11a are now readily available. First, as was the original intent, Bluetooth enabled devices, ranging from keyboards and mice to cellular telephones. But now you can also use this technology for networking computers (such as laptops) over short distances. This is the same capability that 802.11b (Wi-Fi) gives you.

Second, Bluetooth radio chips are inexpensive to manufacture, so you can expect to see them in many other devices in the next few years. And this includes not just computers and communications between computers and computer peripherals, but also many other consumer devices. At this time wireless networking based on the 802.11 specifications are pretty much limited to computers. You can't plug a PCI or CardBus network adapter into your cell phone yet. But you can do this with Bluetooth.

The Bluetooth wireless technology is

  • A short-range, lower-power wireless technology

  • A means to replace cables, such as those that connect your keyboard, mouse, printer, and other standard computer peripherals

  • A protocol that uses a very inexpensive radio transmitter compared to other wireless protocols

  • A method to allow data communications between diverse devices such as computers, mobile phones, network appliances, handheld devices, digital cameras , and other consumer devices

This chapter takes a quick look at Bluetooth because some major vendors still back this technology. For more than three years, promises have been made that this year will be the year of Bluetooth. That didn't happen last year, but now these kinds of devices are starting to make it into the consumer marketplace . Just check your local computer store and you are likely to find several different Bluetooth-enabled devices. The same could not be said a few years ago.

You might be wondering what the problem is. The actual radio devices are very inexpensive when used in more expensive peripherals, such as printers and laptop computers. Replacing a mouse or keyboard with a Bluetooth product is now feasible , because a simple mouse or keyboard can easily be had for less than $25, and usually much less ”but the addition of a Bluetooth transmitter adds little to the cost. If customers are satisfied with a $10 mouse, they probably won't pay the extra few dollars it costs to add a Bluetooth radio to a mouse. However, they might pay for other uses, such as a keyboard. Although IrDA (infrared) equipped devices can be used to place some distance between a keyboard and a computer, this technology is a line-of-sight technology. Bluetooth communicates via radio waves, so you don't have to try to get your keyboard pointed in just the right direction for it to work. Just think of what it would be like to put Bluetooth into your television's remote control. But for most of the market today, Bluetooth is an inexpensive chipset to add to more expensive devices, such as mobile phones, printers, and laptop computers, without significantly impacting the prices of these devices.



Upgrading and Repairing Networks
Upgrading and Repairing Networks (5th Edition)
ISBN: 078973530X
EAN: 2147483647
Year: 2003
Pages: 434

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