ZyXEL Communications P-662HW-63, User Manual

Page: 483 / 561

Prestige 662HW Series User’s Guide
483 Appendix E Wireless LAN and IEEE 802.11
Ad-hoc Wireless LAN Configuration
The simplest WLAN configuration is an independent (Ad-hoc) WLAN that connects a set of
computers with wireless nodes or stations (STA), which is called a Basic Service Set (BSS). In
the most basic form, a wireless LAN connects a set of computers with wireless adapters. Any
time two or more wireless adapters are within range of each other, they can set up an
independent network, which is commonly referred to as an Ad-hoc network or Independent
Basic Service Set (IBSS). The following diagram shows an example of notebook computers
using wireless adapters to form an Ad-hoc wireless LAN.
Figure 306 Peer-to-Peer Communication in an Ad-hoc Network
Infrastructure Wireless LAN Configuration
For Infrastructure WLANs, multiple Access Points (APs) link the WLAN to the wired
network and allow users to efficiently share network resources. The Access Points not only
provide communication with the wired network but also mediate wireless network traffic in
the immediate neighborhood. Multiple Access Points can provide wireless coverage for an
entire building or campus. All communications between stations or between a station and a
wired network client go through the Access Point.
The Extended Service Set (ESS) shown in the next figure consists of a series of overlapping
BSSs (each containing an Access Point) connected together by means of a Distribution System
(DS). Although the DS could be any type of network, it is almost invariably an Ethernet LAN.
Mobile nodes can roam between Access Points and seamless campus-wide coverage is
possible.