Datasheet

AP-5131 Introduction
1-15
• MAC Layer Bridging
• Content Filtering
• DHCP Support
• Media Types
• Direct-Sequence Spread Spectrum
• MU Association Process
• Operating Modes
• Management Access Options
1.2.1 Cellular Coverage
An AP-5131 establishes an average communication range with MUs called a Basic Service Set (BSS)
or cell. When in a particular cell, the MU associates and communicates with the AP-5131 supporting
the radio coverage area of that cell. Adding AP-5131’s to a single LAN establishes more cells to
extend the range of the network. Configuring the same ESSID (Extended Service Set Identifier) on all
AP-5131’s makes them part of the same Wireless LAN.
AP-5131’s with the same ESSID defines a coverage area. A valid ESSID is an alphanumeric, case-
sensitive identifier up to 32 characters. An MU searches for an AP-5131 with a matching ESSID and
synchronizes (associates) to establish communications. This device association allows MUs within
the coverage area to move about or roam. As the MU roams from cell to cell, it associates with a
different AP-5131. The roam occurs when the MU analyzes the reception quality at a location and
determines a different AP-5131 provides better signal strength and lower MU load distribution.
If the MU does not find an AP-5131 with a workable signal, it can perform a scan to find any AP. As
MUs switch APs, the AP updates its association statistics.
The user can configure the ESSID to correspond to up to 16 WLANs on each 802.11a or 802.11b/g
radio. A Wireless Local Area Network (WLAN) is a data-communications system that flexibly extends
the functionalities of a wired LAN. A WLAN does not require lining up devices for line-of-sight
transmission, and are thus, desirable. Within the WLAN, roaming users can be handed off from one
AP-5131 to another like a cellular phone system. WLANs can therefore be configured around the
needs of specific groups of users, even when they are not in physical proximity.