05-12-2012, 01:31 PM
Wi-Fi wireless -fidelity
Wi-Fi top.ppt (Size: 305 KB / Downloads: 75)
What is Wi-Fi?
The standard for wireless local area networks (WLANs). It’s like a common language that all the devices use to communicate to each other.
It’s actually IEEE 802.11, a family of standards.
WLAN Architecture—Ad Hoc Mode
Ad-Hoc mode:
Peer-to-peer setup where clients can connect to each other directly. Generally not used for business networks.
Ad Hoc StructureMobile stations communicate to each other directly.
It’s set up for a special purpose and for a short period of time. For example, the participants of a meeting in a conference room may create an ad hoc network at the beginning of the meeting and dissolve it when the meeting ends.
Roaming
In an extended service area, a mobile station (MS) can roam from one BSS (Basic Service Set) to another.
Roughly speaking, the MS keeps checking the beacon signal sent by each AP and select the strongest one and connect to that AP.
If the BSSs overlap, the connection will not be interrupted when an MS moves from one set to another. If not, the service will be interrupted.
Two BSSs coverage areas can largely overlap to increase the capacity for a particular area. If so, the two access points will use different channels, as we will explain later.
Wi-Fi network services
Distribution and integration
Association, re-association, and disassociation
Authentication and deauthentication
Providing privacy
Advantages
. flexible: With a wireless network you and your staff can have uninterrupted access to people, information and tools as you and they move through the workplace with your mobile PC.b. responsive: As you change your business operations your wireless network can change with you.c. customized: Your wireless network can be configured the way you want it.-even combined with your current wired network.