Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Wireless Home Networking For Dummies - Danny Briere.pdf
7.45 Mб


Part I: Wireless Networking Fundamentals

point. Phones that function as PDAs can update their address books and sync data from the PC. All your events, to-do lists, grocery lists, and birthday reminders can be kept current just by bringing your Bluetooth-enabled product in range. There are even Bluetooth headsets for your Bluetooth phones — getting rid of that wireless headset hassle.

Bluetooth technology is advancing into the arena of autos, too. The Bluetooth SIG formed the Car Profile Working Group in December 1999, in response to interest by the automotive industry. This working group has defined how Bluetooth wireless technology will enable hands-free use of mobile phones in automobiles. Microsoft is using Bluetooth-driven products in car dashboards to enable the car to access your cell phone service for downloading digital music and live traffic updates.

The Microsoft Pocket PC 2002 operating system supports both Bluetooth and IEEE 802.11b through add-on adapters. The initial release of Windows XP offered native driver support for IEEE 801.11b but not Bluetooth. Microsoft cited the lack of commercially available Bluetooth devices as the main reason for not including the necessary Host Controller Interface (HCI) device drivers out of the box. Subsequently, Microsoft has added Bluetooth support to Windows XP through a software update. Mac OS v. 10.2 (Jaguar) also has integrated support for Bluetooth.

Wirelessly synching your PDAs

Bluetooth is onboard inside PDAs, like the HP iPAQ Pocket PC H5450 (www. hp.com; $699) that has both 802.11b and Bluetooth inside. Now that’s really cool. (We won’t mention that the H5450 also has a thermal biometric fingerprint reader that authenticates the owner’s unique fingerprint, allowing access with a simple fingerprint swipe. That would probably be too cool for you to handle.)

If you have a PDA, you can get clip-on devices, like the BlueM from TDK Systems Europe (www.tdksys.com/products/intro.asp?id=2). Use the BlueM with your Palm handheld to communicate with other Bluetoothenabled devices, including PCs, notebooks, printers, and other handhelds that are within range. This one-ounce device has a thin, sled design and slides onto the back of the Palm m500, m505, and m125 handhelds, as well as IBM C500 devices, connecting via the docking port on the bottom of the PDA.

For example, if you have your Bluetooth-enabled PDA in your pocket and walk into the room where your Bluetooth-enabled PC is located, the two will automatically synchronize your calendar, your e-mail, and your to-do list — with no intervention on your part. Or, if your cell phone is Bluetooth enabled,

Chapter 3: Bluetooth, HPNA, and HomePlug


you can transfer your contact list wirelessly from your Bluetooth-enabled PC to the phone’s address list. (That’d cut down on those expensive directory assistance calls, wouldn’t it?)

Also now available are Bluetooth Compact Flash card adapters that can be used in Pocket PC-driven PDAs to add Bluetooth capability (see Figure 3-3).

Figure 3-3:

Use a Bluetooth CompactFlash card in some PDAs.

Toshiba and other manufacturers have released Bluetooth PC Cards that add the Bluetooth wireless technology to any PC with a PC Card slot. Other adapters are available that plug into a USB port, making it possible to easily add Bluetooth capability to any desktop or laptop PC (see Figure 3-4). Prices for these adapters range widely — from as low as about $50 to as much as $170.

Figure 3-4:

Use a USB adapter to add Bluetooth capability to a desktop or laptop PC.


Part I: Wireless Networking Fundamentals

Ultra-cool Ultra Wideband (UWB) is coming

With all the innovation happening in the Wi-Fi and Bluetooth area, more neat stuff is on the way. Ultra Wideband (UWB) is a revolutionary wireless technology for transmitting digital data over a wide spectrum of frequency bands with very low power. It can transmit data at very high rates (for wireless LAN applications in the home). Within the power limit allowed under current FCC regulations, Ultra Wideband also has the ability to carry signals through doors and other obstacles that tend to reflect signals at more limited bandwidths and a higher power. At higher power levels, UWB signals can travel to significantly greater ranges.

Ultra wideband radiobroadcasts digital pulses (instead of traditional sine waves) that are timed very precisely on a signal across a very wide spectrum at the same time. Transmitter and receiver are coordinated to send and receive pulses with an accuracy of trillionths of a second! Not only does UWB enable high data rates, but it also does so without suffering the effects of multipath interference. Multipath is

the propagation phenomenon that results in signals reaching the receiving antenna by two or more paths, usually because of reflections of the transmitted signal off walls or mirrors or the like. Because UWB has the ability to time-gate (that is, prescribe the precise time when it is supposed to receive the data), the receiver allows it to ignore signals arriving outside a prescribed time interval, such as signals caused by multipath reflections.

UWB is still in the early stages, but it is coming on strong. UWB is simpler, cheaper, less powerhungry, and 100 times faster than Bluetooth. What more could you want? UWB communication devices could be used to wirelessly distribute services such as phone, cable, and computer networking throughout a building or home. For now, it’s still on the drawing boards, so just know that more cool stuff is on the horizon.

You can find out more about UWB at the official UWB Working Group Web site: www.uwb.org.

Wireless printing and data transfer

Hewlett-Packard and other printer companies manufacture printers that have built-in Bluetooth wireless capability, enabling a computer that also has Bluetooth wireless capability to print sans printer cables. Other examples are a wireless keyboard and a wireless mouse from Microsoft that both use Bluetooth technology to replace their traditional cables.

Another great use of Bluetooth wireless technology is to wirelessly transfer your digital photographs from your Bluetooth-enabled digital camera to your Bluetooth-enabled PC or Bluetooth-enabled printer . . . or even directly to your Bluetooth-enabled PDA. The newest wave of PDAs from several manufacturers includes wireless-enhanced models that include both Bluetooth and Wi-Fi built in. Wouldn’t it be cool to carry your family photo album around on your Palm or iPAQ to show off at the office?