Ieee 802.11 Technical Tutorial; Architecture Components; Figure 9-13. Fresnel Zone Clear Of Obstacles - Alvarion BreezeNET PRO.11 Series User Manual

When at least 80% of the first Fresnel Zone is clear of obstacles, propagation loss is
equivalent to that of free space.

9.5 IEEE 802.11 Technical Tutorial

The purpose of this chapter is to give technical readers a basic overview of the new
IEEE 802.11 Standard, enabling them to understand the basic concepts, principles
of operation, and the reasons behind some of the features and/or components of the
Standard.
The document does not cover the entire Standard and does not provide enough
information for the reader to implement an 802.11-compliant device (for this
purpose the reader should refer to the standard).

9.5.1 Architecture Components

An 802.11 LAN is based on a cellular architecture where the system is subdivided
into cells. Each cell (called Basic Service Set, or BSS, in the 802.11 nomenclature)
is controlled by a Base Station (called Access Point or, in short, AP).
Although a wireless LAN may be formed by a single cell, with a single Access
Point, (and as will be described later, it can also work without an Access Point),
most installations will be formed by several cells, where the Access Points are
BreezeNET PRO.11

Figure 9-13. Fresnel Zone Clear of Obstacles

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Appendix
User's
Guide