Cabletron Systems 802.11 User Manual

RoamAbout 802.11

Outdoor Antenna

Site Preparation Guide

9033153

Notice

Cabletron Systems reserves the right to make changes in specifications and other information contained in this document without prior notice. The reader should in all cases consult Cabletron Systems to determine whether any such changes have been made.

The hardware, firmware, or software described in this manual is subject to change without notice.

IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE FOR ANY INCIDENTAL, INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING BUT NOT LIMITED TO LOST PROFITS) ARISING OUT OF OR RELATED TO THIS MANUAL OR THE INFORMATION CONT AINED IN IT, EVEN IF CABLETRON SYSTEMS HAS BEEN ADVISED OF, KNOWN, OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES.

Order Number: 9033153

Cabletron Systems and RoamAbout are registered trademarks of Cabletron Systems, Inc.

All other trademarks and registered trademarks are the property of their respective holders.

Web Site: http://www.cabletron.com/wireless

iii

Tab le of Contents

Overview ..............................................................................................................1

Requirements.......................................................................................................2

Lightning protection.......................................................................................2

Grounding system..........................................................................................2

Line of sight...................................................................................................2

Factors that can reduce antenna range...........................................................5

Required Data for Antenna Installation Company..........................................6

The Fresnel Zone ...........................................................................................6

Other Considerations......................................................................................8

Antenna Options..................................................................................................9

RoamAbout 14-dBi Directional Antenna ......................................................9

RoamAbout 7-dBi Omni-Directional Antenna............................................13

Verify Component Connector Polarity.........................................................15

Reviewing the Site Preparation Checklist.......................................................16

Contents

For Additional Assistance.................................................................................17

Table of Contents v

Site Preparation Guide

Overview

This guide describes the site requirements that are needed for the successful installation of RoamAbout Outdoor Antennas. It is intended for sales engineers or site evaluators.

The outdoor antenna uses RF antenna technology, which lets you extend your LAN from building to building. Use the R oam About outdoor antenna as a solution when connecting buildings across distances as an alternative to costly T1 leased lines.

Before you start the installation process, ensure that all the requirements described here are met.

If after reviewing this document you require additional technical

NOTE

information or support prior to ordering product, see the RoamAbout web site listed on page iii or contact your authorized Cabletron Sales Representative.

Site Preparation Guide

Requirements

Lightning protection

A lightning rod must be placed close to the antenna mast or wall bracket. This is required to protect the antenna from direct lightning strikes.

Grounding system

Direct earth grounding of the antenna and the lightning arrestor is necessary to protect the installation from lightning and the build-up of static electricity. The wireless device and the lightning arrestor must be connected to the same ground. The antenna and the mounting structure require a separate earth ground connection.

Check with a certified antenna installer to make sure the antenna is properly grounded.

Line of sight

Spread spectrum systems for LANs are complete point-to-po int systems and req uire a clear line of sight from location to location. Zone widths of the beam depend on the distance between the antennas. The defined radius is an area that is widest at its center. The table below shows the zone radius required at 2.4 GHz.

Building A

Figure 1: Clear Line of Sight

No Obstruction Area

Direct RF Path

100_05

Building B

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