Cisco Systems Linksys WAG54GX2 Guide Utilisateur page 86

Wireless-G ADSL Gateway with SRX200
What IEEE 802.11b and 802.11g features are supported?
The product supports the following IEEE 802.11b and IEEE 802.11g functions:
• CSMA/CA plus Acknowledge protocol
• Multi-Channel Roaming
• Automatic Rate Selection
• RTS/CTS feature
• Fragmentation
• Power Management
It also supports OFDM technology for 802.11g networking.
What is ad-hoc mode?
When a wireless network is set to ad-hoc mode, the wireless-equipped computers are configured to
communicate directly with each other, peer-to-peer without the use of an access point.
What is infrastructure mode?
When a wireless network is set to infrastructure mode, the wireless network is configured to communicate with
a network through a wireless access point.
What is roaming?
Roaming is the ability of a portable computer user to communicate continuously while moving freely throughout
an area greater than that covered by a single access point. Before using the roaming function, the computer must
make sure that it is the same channel number with the access point of dedicated coverage area.
To achieve true seamless connectivity, the wireless LAN must incorporate a number of different functions. Each
node and access point, for example, must always acknowledge receipt of each message. Each node must
maintain contact with the wireless network even when not actually transmitting data. Achieving these functions
simultaneously requires a dynamic RF networking technology that links access points and nodes. In such a
system, the user's end node undertakes a search for the best possible access to the system. First, it evaluates
such factors as signal strength and quality, as well as the message load currently being carried by each access
point and the distance of each access point to the wired backbone. Based on that information, the node next
selects the right access point and registers its address. Communications between end node and host computer
can then be transmitted up and down the backbone.
As the user moves on, the end node's RF transmitter regularly checks the system to determine whether it is in
touch with the original access point or whether it should seek a new one. When a node no longer receives
acknowledgment from its original access point, it undertakes a new search. Upon finding a new access point, it
then re-registers, and the communication process continues.
Appendix A: Troubleshooting
Frequently Asked Questions
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