Cabletron Systems RoamAbout 802.11 Supplementary Manual

RoamAbout 802.11

Outdoor Antenna

Site Preparation Guide

9033153

Notice

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 ADVIS ED OF, KNOWN, OR SHOULD HAVE KNOWN, THE POSS IBILIT Y OF
SUCH DAMAGES.

 Copyright 1999 by Cabletron Systems, Inc., 35 Industrial Way, Rochester, NH 03867

All Rights Reserved. Printed in the United States of America.

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

Table 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

Contents

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

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 RoamAbout outdoor antenna as a so lution 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
Cabletro n Sales Representative.

1

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 antenn a and the lightning ar restor 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

Building A

Spread spectrum systems for LANs are complete p oint-to-point systems and require 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 ar ea that is widest at its center.
The table below shows the zone radius required at 2.4 GHz.

Figure 1: Clear Line of Sight

No Obstruction Area

Direct RF Path

100_05

Building B

2