ZyXEL Communications Prestige 653HWI series, User Manual

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Prestige 653HWI Series User’s Guide
C-2 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). See the following diagram of an example of an
Ad-hoc wireless LAN.
Diagram C-1 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.