Chapter 6 Wireless LAN

6.3 What You Need To Know

BSS

A Basic Service Set (BSS) exists when all communications between wireless clients or between a wireless client and a wired network client go through one access point (AP). Intra-BSS traffic is traffic between wireless clients in the BSS.

ESS

An Extended Service Set (ESS) consists of a series of overlapping BSSs, each containing an access point, with each access point connected together by a wired network. This wired connection between APs is called a Distribution System (DS).

Operating Mode

The NWA1121-NI can run in four operating modes as follows:

•Root AP. The NWA1121-NI is a wireless access point that allows wireless communication to other devices in the network.

•Repeater. The NWA1121-NI acts as a wireless repeater and increase a root AP’s wireless coverage area.

•Client. The NWA1121-NI acts as a wireless client to access a wireless network.

•MBSSID. The Multiple Basic Service Set Identifier (MBSSID) mode allows you to use one access point to provide several BSSs simultaneously.

Refer to Chapter 1 on page 11 for illustrations of these wireless applications.

SSID

The SSID (Service Set IDentifier) is the name that identifies the Service Set with which a wireless station is associated. Wireless stations associating to the access point (AP) must have the same SSID. In other words, it is the name of the wireless network that clients use to connect to it.

Normally, the NWA1121-NI acts like a beacon and regularly broadcasts the SSID in the area. You can hide the SSID instead, in which case the NWA1121-NI does not broadcast the SSID. In addition, you should change the default SSID to something that is difficult to guess.

This type of security is fairly weak, however, because there are ways for unauthorized wireless devices to get the SSID. In addition, unauthorized wireless devices can still see the information that is sent in the wireless network.

Channel

A channel is the radio frequency(ies) used by wireless devices. Channels available depend on your geographical area. You may have a choice of channels (for your region) so you should use a different channel than an adjacent AP (access point) to reduce interference.

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NWA1121-NI User’s Guide