Cabletron Systems 9033073 manual Antenna Placement

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Installation Guidelines

Overview of the Outdoor Installation

Antenna Placement

To achieve maximum performance for your wireless outdoor connection, the RoamAbout Outdoor Antennas must have clear line-of-sight which is defined as:

No obstacles in the direct path between the two antennas.

No obstacles within a defined zone around the antenna beam.

The shape of a radio beam is not straight and narrow like a laser beam. The radio beam, also referred to as Fresnel Zone, is bulged in the middle, like a football or rugby ball. The exact shape and width of the Fresnel Zone is determined by the path length and frequency of the radio signal.

If any significant part of this zone is obstructed, a portion of the radio energy will be lost, resulting in reduced performance. Reduced performance may also occur when obstacles that are close to the antenna beam cause signal reflections or noise that interfere with the radio signal.

Figure 2-3 shows some typical examples of obstacles that you must avoid for a directional antenna to operate effectively:

A.Neighboring Buildings

B.Trees or other obstructions

C.Power lines

To allow optimal performance, ensure that the type and placement of the antennas allows sufficient clearance of the Fresnel Zone at the maximum width of the bulge, typically at the midpoint between the antennas. For more information, see Chapter 3 - Determining Range & Clearance.

Outdoor Antenna Installation Guide

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Contents RoamAbout 802.11 Outdoor Antenna Installation Guide Page RoamAbout 802.11 Outdoor Antenna Installation Guide Page Canada Regulatory InformationOutdoor Antenna Installation Guide Your email address Getting HelpPage Table of Contents Determining Range & Clearance RoamAbout 14-dBi Directional Antenna Page About This Guide IntroductionWho Should Use This Guide Introduction This Chapter Installation GuidelinesInstalling the Antenna Organization of this GuideAppendix D Calculating Range & Clearance Appendix C The Antenna Cabling SystemRoamAbout Outdoor Kit Introduction Finding Additional Information Installing a RoamAbout Access PointConfiguration and Management Hardware SpecificationsOther Sources of Information Additional files on your diskettesPage Site Prerequisites Installation GuidelinesOverview of the Indoor Installation Pre-Installation ChecklistSelecting the Right RoamAbout PC Card Indoor Installation OverviewRoamAbout PC Card Identification Installation Guidelines Placement of the RoamAbout Access Point Installation Guidelines Antenna Cable Route Placement of the Lightning ProtectorInstallation Guidelines Antenna Mast/Wall Bracket not included in kit Overview of the Outdoor InstallationAntenna Placement Potential Obstacles for a Directional Antenna Tripod Mount Antenna Mast/Wall BracketAntenna Mast Requirements Wall Side MountRoamAbout Antennas Grounding SystemAntenna Polarization Antenna Alignment AP Manager Point-to-Point Diagnostics ScreenAntenna Cable Routing Before Climbing the Roof Page Fresnel Zone Determining Range ClearanceDetermining Range & Clearance Other Considerations Page Planning the Antenna Installation Installing the AntennaElectrical Hazard Warnings Safety PrecautionsElectrical Hazard Warnings Installation Overview Mounting the Directional Antenna Mounting the AntennaMounting on a Mast Prevent damage to the plastic antenna mounting base Mounting on a Flat Surface Mounting the 14-dBi Antenna to a Wall Mounting the Omni-directional AntennaMounting the Omni-Directional Antenna to a Mast Connecting the Antenna Cable Installing the Antenna Sealing the Cable Connectors RoamAbout 14-dBi Directional Antenna Contents of the Antenna BoxGeneral Description RoamAbout 14-dBi Directional Antenna Table A-1 Specifications 14-dBi Directional AntennaRoamAbout 7-dBi Omni Directional Antenna RoamAbout 7-dBi Omni-Directional Antenna Antenna Cabling System Selecting the Correct Connector TypeOutdoor Cabling Components Antenna Cabling System Table C-1 Selecting the Correct N-Type ConnectorOutdoor Cabling Components Table C-2 Cable Assembly Specifications RoamAbout Cable AssemblyRoamAbout Lightning Protector Table C-3 Lightning Protector SpecificationsFigure C-1 Lightning Protector Installation InstallationRoutine Maintenance Low-Loss Antenna Cable Table C-4 Cable Specifications for the 6m 20 ft AntennaTable C-6 Cable Specifications for the 22m 75 ft Antenna Table C-5 Cable Specifications for the 15m 50 ft AntennaPage Introduction Calculating Range ClearanceDynamic Range Budget MBit/s Omni-Directional 7-dBi Table D-1 Dynamic Range FCCTable D-2 Dynamic Range ETSI. France & Japan Determine Line-of-Sight Clearance Link speed versus RangeDynamic Range Minimum Clearance Maximum Range Table D-3 Minimum Clearance for Maximum RangeCalculating Range & Clearance Determine Typical Range Table D-4 Actual Clearance and Typical Range Which Antenna do You Need