LevelOne N_One Wireless PCI Card, WNC-0600 About Wireless LANs

N_One Wireless PCI Card

Appendix B

About Wireless LANs

This Appendix provides some background information about using

Wireless LANs (WLANs).

Wireless LANs can work in either of two (2) modes:

• Ad-hoc

• Infrastructure

Ad-hoc mode does not require an Access Point or a wired (Ethernet) LAN.

Wireless Stations (e.g. notebook PCs with wireless cards) communicate directly

with each other.

In Infrastructure Mode, one or more Access Points are used to connect Wireless

Stations (e.g. Notebook PCs with wireless cards) to a wired (Ethernet) LAN. The

Wireless Stations can then access all LAN resources.

Access Points can only function in "Infrastructure" mode, and

can communicate only with Wireless Stations which are set to

"Infrastructure" mode.

A group of Wireless Stations and a single Access Point, all using the same ID (SSID),

form a Basic Service Set (BSS).

Using the same SSID is essential. Devices with different SSIDs are unable to

communicate with each other.

A group of Wireless Stations, and multiple Access Points, all using the same ID

(ESSID), form an Extended Service Set (ESS).

Different Access Points within an ESS can use different Channels. In fact, to reduce

interference, it is recommended that adjacent Access Points SHOULD use different

channels.

As Wireless Stations are physically moved through the area covered by an ESS, they

will automatically change to the Access Point which has the least interference or best

performance. This capability is called Roaming. (Access Points do not have or require

Roaming capabilities.)