Chapter 6 Wireless LAN

WLAN speeds typically range up to which of the following?

10 to 100 Mbps

Narrowband is below

200 kbps

Broadband is above

200kbps

WLAN Distances usually go

30 to 100 meters

inverse square law

A physical quantity varies inversely as another quantity squared.

Wi-Fi Alliance

An organization formed in 1999 that has set standards for wireless Internet access in public spaces

EMI

Electromagnetic Interference

Unlicensed Service bands

Hosts don't need to be licensed. 802.11 operates in unlicensed radio bands

Multipath Interference

Interference caused when a receiver receives two or more signals--a direct signal and one or more reflected signals. The multiple signals may interfere with one another

LAN connection

Is needed to give clients access to servers and internet access routers on the wired LAN

Narrowband means

Opposite

Absorptive Attenuation

Signal is absorbed by the air and water

802.11

The IEEE standard for wireless networking.

Service Bands

The frequency spectrum is divided into contiguous spectrum ranges.

Frequence

The number of waves per second (hertz)

The 2.4 GHz band

The range of radio frequencies from 2.4 to 2.4835 GHz. The 2.4 GHz band, which allows for 11 unlicensed channels, is used by WLANs that follow the popular 802.11b and 802.11g standards. However, it is also used for cordless telephone and other transmissions, making the 2.4 GHz band more susceptible to interference than the 5-GHz band.

Broadband means

Wide channel bandwidth and therefore high speed

WLAN (Wireless Local Area Network)

a LAN communication technology in which radio, microwave or infrared links take the place of physical cables

Frequency spectrum

a graph showing the different frequencies present in a sound

Shadow Zones

are Places the signal cannot penetrate because of obstacles in its path.

Wireless Access Point (WAP)

enables devices to connect to a wireless network to communicate with each other

Propogation

multiplying, reproducing, spreading

WLANs normally use ________.

unlicensed bands

Electromagnetic Interference

unwanted power at the same frequency from other devices

licensed service band

will interfere if on the same channel. Most service bands are licensed bands, in which hosts need a license to transmit (TV, AM radio)