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)