Asus PCI-N10 User Manual download pdf (Page 29)

PCI-N10 WLAN Card User Manual

ASUS WLAN Card

ICS

ICS is used to share one computer’s Internet connection with the rest of the

computers on your network. When this computer is connected to the Internet, all

the communications to and from the Internet on your network are sent through this

computer which is called the host computer. The rest of the computers can send

and receive e-mail messages and access the web as if it were connected directly

to the Internet.

IEEE

The Institute of Electrical and Electronics Engineers. The IEEE sets standards

for networking, including Ethernet LANs. IEEE standards ensure interoperability

between systems of the same type.

IEEE 802.11

IEEE 802.xx is a set of specications for LANs from the Institute of Electrical

and Electronic Engineers (IEEE). Most wired networks conform to 802.3, the

specication for CSMA/CD based Ethernet networks or 802.5, the specication for

token ring networks. 802.11 denes the standard for wireless LANs encompassing

three incompatible (non-interoperable) technologies: Frequency Hopping Spread

Spectrum (FHSS), Direct Sequence Spread Spectrum (DSSS), and Infrared. 802.11

species a carrier sense media access control and physical layer specications for

1 and 2 Mbps wireless LANs.

IEEE 802.11a (54Mbits/sec)

Compared with 802.11b: The 802.11b standard was designed to operate in the

2.4GHz ISM (Industrial, Scientic and Medical) band using direct-sequence

spreadspectrum technology. The 802.11a standard, on the other hand, was

designed to operate in the more recently allocated 5-GHz UNII (Unlicensed

National Information Infrastructure) band. And unlike 802.11b, the 802.11a standard

departs from the traditional spread-spectrum technology, instead using a frequency

division multiplexing scheme that’s intended to be friendlier to ofce environments.

The 802.11a standard, which supports data rates of up to 54 Mbps, is the Fast

Ethernet analog to 802.11b, which supports data rates of up to 11 Mbps. Like

Ethernet and Fast Ethernet, 802.11b and 802.11a use an identical MAC (Media

Access Control). However, while Fast Ethernet uses the same physical-layer

encoding scheme as Ethernet (only faster), 802.11a uses an entirely different

encoding scheme, called OFDM (orthogonal frequency division multiplexing).

The 802.11b spectrum is plagued by saturation from wireless phones, microwave

ovens and other emerging wireless technologies, such as Bluetooth. In contrast,

802.11a spectrum is relatively free of interference.

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Asus PCI-N10 User Manual Page 29