O'Reilly logo

Windows Vista Security: Praxisorientierte Sicherheit für Profis by Marcus Nasarek

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Wireless Networking
|
617
Try again
The wizard attempts to make the dial-up connection again, using the same set-
tings as your previous attempts.
Try a different connection
The wizard takes you back to the “Select a network to connect to” page, allow-
ing you to choose a different connection.
Wireless Networking
If you travel frequently, chances are you are quite familiar with the existence of wire-
less networks. Most hotels, coffee shops, airports, and libraries offer WiFi or 802.11
networks. Many cities are beginning to offer WiFi connections also, offering low-cost
Internet access to residents. Eventually wireless networks may become so prevalent
that we’ll be able to connect to the Internet from just about anywhere. With this in
mind, Windows Vista makes creating and connecting to wireless networks very easy.
With Windows Vista, Microsoft has taken the time to revamp the wireless network-
ing interface, making it considerably easy to create and connect to wireless networks.
The beauty of wireless networking correlates directly to the word wireless. Wireless
networks allow you the freedom to move about, whether in your home or on the
road, which can make your life considerably easier when you need to connect to a
network. With wireless networking, you gain the complete functionality of a stan-
dard network without the need for any cables to connect the computers or devices.
This eases the requirements and restrictions of regular networks, but it adds some
complexity and additional pitfalls to the networking process.
Wireless Network Technologies
The most common wireless network technologies fall under the Institute of Electrical
and Electronics Engineers (IEEE) 802.11 specification. Although other wireless tech-
nologies exist, they are not as prevalent as 802.11 (WiFi) networks. WiFi networks
transmit radio waves between devices to allow network communications. WiFi uses
the 2.4 GHz and 5 GHz spectrums. There are three major standards within the WiFi
designation. See Table 17-4 for a listing of the major standards and their specifications.
Table 17-4. Common wireless networking technologies
Version Transmission frequency Transmission rate
802.11a 5 GHz Up to 54 Mbps
802.11b 2.4 GHz Up to 11 Mbps
802.11g 2.4 GHz Up to 54 Mbps
618
|
Chapter 17: Mastering Dial-Up, Broadband, and On-the-Go Networking
The 802.11b specification was the first WiFi technology introduced to the market. It
uses the 2.4 GHz spectrum to transmit data at 11 Mbps. The 802.11b specification
uses Complimentary Code Keying (CCK) coding to transmit data. While 802.11b
has enjoyed the most widespread use, the lowering costs of faster technologies are
rapidly replacing it with newer technologies.
The 802.11a specification transmits in the 5 GHz spectrum at a transmission rate of
54 Mbps. This specification uses Orthogonal Frequency-Division Multiplexing
(OFDM) to transmit data, which is considerably better than the CCK coding stan-
dard. This gives 802.11a a considerably faster transmission rate.
The 802.11g specification transmits in the 2.4 GHz spectrum at a transmission rate
of 54 Mbps. This specification also uses OFDM to transmit data, and it enjoys the
most widespread use of the newer technologies.
These technologies fall under the WiFi designation, since they transmit in the 2.4
GHz and 5 GHz spectrums. Windows Vista supports each of these wireless technolo-
gies and the devices used to make connections to these types of networks.
New networking standards are also in the marketplace today. It bears noting that
early adoption of new technologies does not always favor the consumer, because
some products in the market may support early adoption of a standard that is not yet
finalized. Therefore, if you purchase products too early you may have to purchase
additional hardware to support the additional features defined in the final version of
the standard. While this is not always true, be wary of purchasing the latest and
greatest wireless products. Take some time to research the technology before buying
equipment on impulse.
Newer 802.11 transmission specifications include 802.11n, which offers up to 540
Mbps while using Multiple-Input-Multiple-Output (MIMO) technology. Essentially
this means that the client computer and the wireless access point will use multiple
receivers and multiple transmitters to achieve improved performance.
Not all 802.11 specifications are about transmission speed and rate, however. The
802.11i specification offers enhanced security. The 802.11h specification offers fre-
quency and power control management. The 802.11e specification offers quality of
service enhancements. The 802.11x specification provides a framework for authenti-
cating users and controlling their access to a protected network.
Another emerging wireless technology is Worldwide Interoperability for Microwave
Access (WiMax). WiMax is not really a technology, but a stamp of approval for use
with the 802.16 specification in broadband wireless deployments in metropolitan
areas. WiMax-certified equipment usually uses the 2.5 GHz spectrum, but the 3.5
GHz, 2.3 GHz, and 5 GHz spectrums are available in other countries. Currently, a
movement exists to use the 700 MHz spectrum for future WiMax deployments.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required