Aruba AP-85 User manual

Aruba AP-85 Outdoor
Access Point Series
Installation Guide

www.arubanetworks.com
1344 Crossman Avenue
Sunnyvale, California 94089
Phone: [phone]
Fax [phone]
Aruba AP-85 Outdoor Access Point Series | Installation Guide 0510323-06 | October 2008
Copyright
© 2008 Aruba Networks, Inc. AirWave®, Aruba Networks®, Aruba Mobility Management System®, Bluescanner, For Wireless That
Works®, Mobile Edge Architecture®, People Move. Networks Must Follow®, RFprotect, The All Wireless Workplace Is Now Open For
Business, Green Island, and The Mobile Edge Company®are trademarks of Aruba Networks, Inc. All rights reserved. All other trademarks
are the property of their respective owners.
Open Source Code
Certain Aruba products include Open Source software code developed by third parties, including software code subject to the GNU
General Public License (GPL), GNU Lesser General Public License (LGPL), or other Open Source Licenses. The Open Source code used
can be found at this site:
http://www.arubanetworks.com/open_source
Legal Notice
The use of Aruba Networks, Inc. switching platforms and software, by all individuals or corporations, to terminate other vendors’ VPN
client devices constitutes complete acceptance of liability by that individual or corporation for this action and indemnifies, in full, Aruba
Networks, Inc. from any and all legal actions that might be taken against it with respect to infringement of copyright on behalf of those
vendors.
Warranty
This hardware product is protected by the standard Aruba warranty of one year parts/labor. For more information, refer to the
ARUBACARE SERVICE AND SUPPORT TERMS AND CONDITIONS.
Altering this device (such as painting it) voids the warranty.

Aruba AP-85 Outdoor Access Point Series | Installation Guide |3
Contents
Preface ................................................................................................................................... 5
Guide Overview .....................................................................................................5
Related Documents ...............................................................................................5
Contacting Aruba Networks ..................................................................................6
Chapter 1 AP-85 Series Hardware Overview .......................................................... 7
About the AP-85 Series .........................................................................................7
AP-85 Series Operation ..................................................................................7
Minimum Software Requirements .........................................................................8
Package Checklist.................................................................................................8
Hardware Model Overview ....................................................................................9
AP-85 Series Front View...........................................................................9
AP-85 Series Rear View............................................................................9
AP-85 Series Top View...........................................................................10
AP-85TX Bottom View............................................................................10
AP-85FX/LX Bottom View.......................................................................11
LED Status Indicators ...................................................................................13
Optional Accessories...........................................................................................14
Chapter 2 Outdoor Planning and Deployment Considerations........................... 15
Planning and Deployment Considerations ..........................................................15
Scale Requirements ......................................................................................15
Identifying Known RF Absorbers/Reflectors/Interferences Sources ............15
RF Absorbers..........................................................................................15
RF Reflectors ..........................................................................................15
RF Interference Sources.........................................................................16
Line of Sight (Radio Path Planning)...............................................................16
Antenna Height .............................................................................................17
Antenna Position and Orientation .................................................................18
Radio Interference.........................................................................................19
Weather Conditions ......................................................................................19
Ethernet Cabling ...........................................................................................19
Grounding .....................................................................................................19
Chapter 3 AP-85 Series Installation....................................................................... 21
Pre-Installation Network Setup............................................................................21
Pre-Installation Checklist ..............................................................................21
Access Point Setup .............................................................................................21
Verifying Pre-Installation Connectivity ..........................................................22
Provisioning the AP.......................................................................................22
Installing the AP-85.......................................................................................22
Mounting the AP-85 ...............................................................................23
Positioning the AP-85.............................................................................27
Connecting Required Cables..................................................................28
Lightning Arrestor Installation.................................................................31
Antenna Installation ................................................................................31
Verifying Post-Installation Connectivity ........................................................32

4|Aruba AP-85 Outdoor Access Point Series | Installation Guide
Configuring the AP-85...................................................................................32
Appendix A Understanding Antennas ...................................................................... 33
Aruba Antennas ...................................................................................................33
Understanding Wireless Antennas................................................................33
Omni-Directional vs. Directional Coverage ............................................33
Antenna Beamwidth, Pattern, and Gain Considerations........................34
Understanding Antenna Pattern Plots and Specifications .....................36
Detachable Antenna Selection......................................................................37
Detachable Outdoor Antenna Types ......................................................37
Detachable Antenna Selection Tips........................................................37
Appendix B Product Specifications.......................................................................... 43
Mechanical (AP-85TX, AP-85FX, and AP-85LX) ...........................................43
Electrical........................................................................................................43
AP-85TX .................................................................................................43
AP-85FX .................................................................................................44
AP-85LX..................................................................................................44
Maximum Power Draw ...........................................................................44
Wireless LAN.................................................................................................44
Safety and Regulatory Compliance.....................................................................45
Declaration of Conformity .............................................................................45
European Headquarters .........................................................................46
Instructions for Use in a Potentially Explosive Atmosphere................................46
Proper Disposal of Aruba Equipment ..................................................................47
Waste of Electrical and Electronic Equipment ..............................................47
European Union RoHS..................................................................................48
China RoHS ..................................................................................................48
Index..................................................................................................................................... 49

Aruba AP-85 Outdoor Access Point Series | Installation Guide Preface | 5
Preface
This preface includes the following information:
zAn overview of the contents of this manual
zA list of related documentation for further reading
zAruba Networks support and service information
Guide Overview
zChapter 1, “AP-85 Series Hardware Overview” on page 7 provides a detailed hardware overview of the three AP-85
models: the AP-85TX, the AP-85FX, and the AP-85LX.
zChapter 2, “Outdoor Planning and Deployment Considerations” on page 15 provides key questions to ask and items to
consider when deploying an outdoor wireless network.
zChapter 3, “AP-85 Series Installation” on page 21 describes the multi-step process for successful installation and
deployment of an AP-85.
zAppendix A, “Understanding Antennas” on page33 provides key tools that will help you understand Aruba antenna
specifications.
zAppendix B, “Product Specifications” on page43 includes product technical specifications and safety and regulatory
compliance information.
Related Documents
The following documents are referred to in this guide and are considered components of the complete documentation set
needed for successful AP deployment and management:
z ArubaOS Quick Start Guide
z ArubaOS User Guide
z Aruba Mobility Management System User Guide
zAruba Outdoor Antenna Specifications

6| Preface Aruba AP-85 Outdoor Access Point Series | Installation Guide
Contacting Aruba Networks
Web Site Support
Main Site http://www.arubanetworks.com
Support Site https://support.arubanetworks.com
Software Licensing Site https://licensing.arubanetworks.com/login.php
Wireless Security Incident
Response Team (WSIRT)
http://www.arubanetworks.com/support/wsirt.php
Support Emails
zAmericas and APAC [email protected]
zEMEA [email protected]
WSIRT Email
Please email details of any security
problem found in an Aruba product.
[email protected]
Telephone Support
Aruba Corporate [phone]
FAX [phone]
Support
zUnited States 800-WI-FI-LAN (800-943-4526)
zUniversal Free Phone Service Number
(UIFN): Australia, Canada, China,
France, Germany, Hong Kong, Ireland,
Israel, Japan, Korea, Singapore, South
Africa, Taiwan, and the UK.
+800-4WIFI-LAN ([phone])
zAll Other Countries [phone]

Aruba AP-85 Outdoor Access Point Series | Installation Guide AP-85 Series Hardware Overview | 7
Chapter 1
AP-85 Series Hardware
Overview
About the AP-85 Series
The AP-85 Series consists of resilient, environmentally hardened, outdoor rated, dual-band IEEE 802.11a/b/g devices, which
can be configured for deployment as a wireless access point, air monitor, mesh point, or mesh portal. This outdoor access
point series is part of Aruba’s comprehensive wireless network solution. The AP-85 Series works only in conjunction with an
Aruba Mobility Controller and each AP can be centrally managed, configured, and upgraded through the controller.
The AP-85 Series consists of the following models:
zAP-85TX (Ethernet)
zAP-85FX (Multi-mode Fiber)
zAP-85LX (Single-mode Fiber)
AP-85 Series Operation
zWireless access point (IEEE 802.11 a/b/g)
zWireless air monitor (IEEE 802.11 a/b/g)
zWireless access point with wireless backhaul support*
zEnterprise mesh point (MP; Mesh license required)*
zEnterprise mesh portal (MPP; Mesh license required)*
zProtocol-independent networking functionality
zIEEE 802.3af Power over Ethernet (PoE) compatible (AP-85TX only)
NOTE
Items noted with a asterisk (*) require a secure enterprise mesh license. Contact your Aruba sales
representative for a complete listing of available software licenses.
!
CAUTION
Aruba access points must be installed by trained service personnel. These installers are responsible
for ensuring that grounding is available and it meets applicable local and national electrical codes.
WARNING
Do not work on an AP and do not connect or disconnect cables during periods of lightning activity.

8| AP-85 Series Hardware Overview Aruba AP-85 Outdoor Access Point Series | Installation Guide
Minimum Software Requirements
The AP-85 Series requires ArubaOS 3.2.0 or later.
ArubaOS software builds prior to version 3.2.0 do not support the AP-85 Series. If your network currently runs on a software
build prior to 3.2.0, you must upgrade the software on your master and local controllers to 3.2.0 or later prior to installing an
AP-85 in your existing network.
Package Checklist
Included with all three AP-85 models:
zAruba AP-85 outdoor access point (TX, FX, or LX model)
zAP-85 wall/pole/mast mount kit (fixture with hardware)
z8-foot DC outdoor rated power cable
zWeatherproof connector shell for RJ-45 terminated CAT 5 cable
LTW P/N LTWRJS-00PFFA-SL8001
z Aruba AP-85 Outdoor Access Point Installation Guide
Included with the AP-85FX/LX models only:
z8-foot AC outdoor rated power cable (for FX/LX models only; US and EU options available)
zFiber Optic Termination Kit
AP-85FX: Tyco P/N 1828618-1
AP-85LX: Tyco P/N 1828618-2
NOTE
Inform your supplier if any parts are incorrect, missing, or damaged. If possible, retain the carton,
including the original packing materials. Use these materials to repack and return the unit to the
supplier if needed.
NOTE
Optional accessories are available for use with the AP-85 and are sold separately. Refer to "Optional
Accessories" on page14 for further details.

Aruba AP-85 Outdoor Access Point Series | Installation Guide AP-85 Series Hardware Overview | 9
Hardware Model Overview
AP-85 Series Front View
The front of the AP-85 Series has LED status indicators (see Figure 1). For descriptions of the LEDs and their behavior, refer
to "LED Status Indicators" on page13.
Figure 1 AP-85 Series Front View
AP-85 Series Rear View
The rear of the AP-85 Series has four mounting holes (see Figure 2). Refer to Chapter 3, “AP-85 Series Installation” on
page 21 for mounting and installation instructions.
Figure 2 AP-85 Series Rear View
arun_0100
LED
Status Indicators
Mounting Holes

10 | AP-85 Series Hardware Overview Aruba AP-85 Outdoor Access Point Series | Installation Guide
AP-85 Series Top View
The top of the AP-85 Series consists of four, female N-type antenna interfaces (see Figure 3).
Figure 3 AP-85 Series Top View
The AP-85 Series requires the use of detachable, outdoor rated antennas. Select the correct antenna type to support the
required frequency band (2.4 or 5 GHz) and the desired coverage pattern.
The four, female N-type antenna interfaces on the AP-85 models are grouped into diversity pairs, one pair is marked as
RADIO 0 and the other pair is marked as RADIO 1. RADIO 0 supports 2.4 GHz frequency band antennas and RADIO 1
supports 5 GHz frequency band antennas.
To select the correct antenna type for the deployment, download and read Aruba’s outdoor antenna specifications: http://
www.arubanetworks.com/products/access-points/antennas.php.
For further details, see Appendix A, “Understanding Antennas” on page33.
AP-85TX Bottom View
The bottom of the AP-85TX unit (see Figure 5) has the following ports and connections:
zDC PWR 12 VDC, 2 A: The AP is capable of accepting DC power in the range of 8 to 16 VDC. If the AP-85TX is not
connected to a PoE source, the AP must be powered via a DC power source. An outdoor rated, two-wire, 8-foot long DC
power cable (wiring harness) is supplied with the unit. For proper installation instructions, see "DC and AC Power
Cables" on page30.
zLAN/POE 48 VDC, 350 mA: Also known as a 10/100Base-T Fast Ethernet (RJ-45) port, which is IEEE 802.3 BaseT and
802.3u 100BaseTX compliant. This port supports IEEE 802.3af Power over Ethernet (PoE), accepting 48 VDC as a
standards-defined powered device (PD) from a power sourcing equipment (PSE), such as a PoE midspan injector. The
AP-85TX also supports SPoE (Serial Power over Ethernet).
!
CAUTION
An Aruba Lightning Arrestor, AP-LAR-1, must be installed on each antenna port for protection
against lightning induced surges. Failure to use an AP-LAR-1 can void the warranty of an Aruba
outdoor AP model and renders the AP susceptible to failure from lightning induced surges.
Four, Female N-Type
Antenna Interfaces.
RADIO 0 supports 2.4 Ghz;
RADIO 1 supports 5 GHz

Aruba AP-85 Outdoor Access Point Series | Installation Guide AP-85 Series Hardware Overview | 11
Figure 4 10/100Base-T Fast Ethernet (RJ-45) Port Pin-Out
zGrounding Point
Figure 5 AP-85TX Bottom View
AP-85FX/LX Bottom View
The bottom of the AP-85FX/LX unit (see Figure 5) has the following ports and connections:
zDC PWR 12 VDC, 2 A: The AP can accept DC power in the range of 8 to 16 VDC. If the AP-85FX/LX is not connected to an
AC power source, the AP must be powered by a DC power source. An outdoor rated, two-wire, 8-foot long DC power
cable (wiring harness) is supplied with the unit. For proper installation instructions, see "DC and AC Power Cables" on
page30.
zLAN - OPTICAL:
AP-85FX: This model has a 100BASE-FX data uplink port for multi-mode, dual-fiber network connectivity. A multi-
mode, fiber patch cable with a duplex LC connector is required for use. The cable is not included and must be
purchased separately.
AP-85LX: This model has a 100BASE-LX data uplink port for single-mode, dual-fiber network connectivity. A single-
mode, fiber patch cable with a duplex LC connector is required for use. The cable is not included and must be
purchased separately.
zCONSOLE: A serial console port is provided for connection to a terminal, allowing direct local management.
!
CAUTION
It is important that the AP-85TX be properly grounded and a grounding point is provided on the
bottom of the AP-85TX model. A professional installer should ensure that grounding is available and
meets applicable local and national electrical codes.
AP-85
10/100Base-T
Fast Ethernet (RJ-45)
RJ-45 Female
Pin-Out
*POE optional
**Serial optional
Serial RxD**
Serial RGND** (POE positive*)
Serial TxD**
Serial TGND** (POE negative*)
1
2
3
4
5
6
7
8
ETH Tx+ (POE negative*)
ETH Tx– (POE negative*)
ETH Rx+ (POE positive*)
ETH Rx– (POE positive*)
Direction
Input
Output
Grounding Point

12 | AP-85 Series Hardware Overview Aruba AP-85 Outdoor Access Point Series | Installation Guide
Figure 6 Serial Console Port Pin-Out
Communication settings for the serial console port are listed in Table 1.
zAC PWR 90-228 V~, 500 mA: The AP can accept AC power at the limits specified on the unit. If the AP-85FX/LX is not
connected to a DC power source, the AP must be powered by an AC power source. An outdoor rated, three-wire, 8-foot
long AC power cable (wiring harness) is supplied with the unit. Some installation locations are in the scope and under
the authority of the National Electric Code (NEC or NFPA 70), and some are not, as indicated in Article 90.2. The NEC
applies where:
The product must be grounded reliably using the external screw, as shown in this installation guide, and not solely
depend on the ground provided in the power supply cord.
The power cord should be less than 15" long.
The plug for the power cord should be installed in a dry location, such as with the use of an NRTL listed receptacle
box with cover that is weatherproof with the power plug inserted into the receptacle (such as the MultiMac model
from Taymac Corp).
The NEC does not apply when:
The installation must follow all regulations and established practices that are applicable for the particular installation
environment.
For international outdoor use:
The product must be grounded reliably using the external screw, as shown in this installation guide, and not solely
depend on the ground provided in the power supply cord. Considerations should include selection of weatherproofing
means (IP67 or better), proper strain relieving for the power cord, and adherence to all applicable regulations and
local practices.
The plug for the power cord should be installed in a dry location, such as with the use of a suitable certified
receptacle box with a cover, which is weatherproof (IP67 or better) with the power plug inserted into the receptacle.
zGrounding Point
.
Table 1 Console Terminal Settings
Baud Rate Data Bits Parity Stop Bits Flow Control
9600 8 None 1 None
!
CAUTION
It is important that the AP-85FX/LX be properly grounded; a grounding point is provided on the
bottom of the AP-85FX/LX model. The installer (trained service personnel) should ensure that
grounding is available and that the grounding meets applicable local and national electrical codes.
Serial
Console Port
1
2
3
4
5
6
7
8
TxD
GND
RxD
RJ-45 Female
Pin-Out
Direction
Input
Output
GND

Aruba AP-85 Outdoor Access Point Series | Installation Guide AP-85 Series Hardware Overview | 13
Figure 7 AP-85FX/LX Bottom View
LED Status Indicators
All AP-85 models include visual indicators for power, link, and radio status. Additionally, each radio has a seven-LED array
that indicates received signal strength (RSSI).
Table 2 lists the meanings of the LEDs on the AP-85 outdoor access points.
NOTE
The RSSI LED indicators represent varying degrees in the RSSI level. The absence of a signal is
indicated by no LED response, and full signal strength is indicated when all seven LEDs are active
and lit.
Table 2 AP-85 LED Status Indicators
LED Function Indicator Status
PWR AP Power/Ready
Status
Off No power to AP
Flashing Device booting, not ready
On Device ready
LINK/ACT
(applicable to the
AP-85TX only)
LAN/Network Link
Status
Off Ethernet link unavailable
On (Yellow) 10 Mbs Ethernet link negotiated
On (Green) 100 Mbs Ethernet link negotiated
Blinking Traffic on Ethernet link
LINK/ACT
(applicable to the
AP-85FX/LX models only)
LAN/Network Link
Status
Off Ethernet link unavailable
On (Green) 100 Mbs Ethernet link negotiated
Blinking Traffic on Ethernet link
RADIO 0 Radio 0 Status Off Radio 0 disabled
On (Green) Radio 0 enabled in WLAN mode
RADIO 1 Radio 1 Status Off Radio 1disabled
On (Green) Radio 1 enabled in WLAN mode
Grounding Point

14 | AP-85 Series Hardware Overview Aruba AP-85 Outdoor Access Point Series | Installation Guide
Optional Accessories
The following items are available for use with AP-85 outdoor access points and are sold separately. Contact your Aruba sales
representative for details and assistance.
zAruba 85 Field Replaceable Mount Kit: P/N AP-85-MNT-S
zAruba 85 Low-Profile Wall Mount Bracket: P/N AP-85-MNT-2
zAruba 85 Streetlight Power Tap Adapter (8 ft): P/N AP-85-PT-1
zAruba 85 AC Power Provisioning Cable (3 ft; indoor rated): P/N AP-85-CBL-1
zAruba 85 Antenna Mount Bracket: P/N AP-85-MNT-1
zAruba 85 AC Power Cable (8 ft): P/N AP-85-CBL-2-US-S or AP-85-CBL-2-EU-S
zAruba 85 AC Power Cable (40 ft): P/N AP-85-CBL-3-US-S or AP-85-CBL-3-EU-S
zAruba 85 DC Power Cable (8 ft): P/N AP-85-CBL-4-S
zAruba Lightning Arrester: P/N AP-LAR-1
RSSI (Radio 0) RSSI Level for
Radio 0
Off RSSI disabled/no signal
7 Step Progressive
Bars
3/6/9/12/15/21/27 dB
RSSI
Each bar represents a progressive
increase in signal strength, with 7
bars representing maximum signal
strength (100%).
Minimum data rate: Two lit LEDs
Maximum data rate: Six lit LEDs
RSSI (Radio 1) RSSI Level for
Radio 1
Off RSSI disabled/no signal
7 Step Progressive
Bars
3/6/9/12/15/21/27 dB
RSSI
Each bar represents a progressive
increase in signal strength, with 7
bars representing maximum signal
strength (100%).
Minimum data rate: Two lit LEDs
Maximum data rate: Six lit LEDs
NOTE
AC power cables are available for use with the AP-85FX/LX models only.
Table 2 AP-85 LED Status Indicators (Continued)
LED Function Indicator Status

Aruba AP-85 Outdoor Access Point Series | Installation Guide Outdoor Planning and Deployment Considerations | 15
Chapter 2
Outdoor Planning and
Deployment Considerations
Planning and Deployment Considerations
Prior to deploying an outdoor wireless network, the environment must be evaluated to plan for a successful Aruba WLAN
deployment. Successfully evaluating the environment enables the proper selection of Aruba APs and antennas and assists in
the determination of their placement for optimal RF coverage. This process is considered WLAN or RF planning and Aruba’s
system engineers can assist in the outdoor planning process.
Scale Requirements
The potentially immense scale of outdoor deployments requires consideration of factors that may not be as important in a
typical indoor deployment:
zRange (distance): Range or distance between APs must be taken into account during the planning phase. Available AP
mounting locations are often far less flexible in an outdoor environment. Regardless of these outdoor restrictions, the
desired goal is to achieve results similar to an indoor deployment: a “dense” RF deployment that supports advanced
Aruba features, such as ARM, efficient client roaming, and failover.
zElevation: Proper consideration and planning for elevation differences between APs (AP to AP) and AP to Client can be
critical to success. To plan for these differences in elevation, it is important to understand the 3D coverage pattern
provided by the antennas that will be deployed in the environment.
zNon-Fixed Considerations: The RF environment might change on a day to day basis. Keep non-fixed items, such as
shipping containers, vehicles, and future building construction, in mind when planning for an outdoor deployment.
Identifying Known RF Absorbers/Reflectors/Interferences Sources
Identifying known RF absorbers/reflectors/interference sources while out in the field during the installation phase is critical.
Even though outdoor environments consist of fewer RF absorbers/reflectors/interference sources compared to indoor
environments, ensure that these sources are identified and taken into consideration when installing and mounting an AP to
its fixed outdoor location.
RF Absorbers
zCement/Concrete
zNatural Items: Trees/vegetation
zBrick
RF Reflectors
zMetal Objects: Roof-installed air-conditioning equipment, chain link fences (depending on aperture size), other wire
fences, or water pipes

16 | Outdoor Planning and Deployment Considerations Aruba AP-85 Outdoor Access Point Series | Installation Guide
RF Interference Sources
zOther 802.11a/b/g or broadband access equipment operating nearby
zIndustrial RF welding equipment or other Industrial, Scientific and Medical (ISM) equipment that utilizes RF to heat or
alter the physical properties of materials
zMilitary, Commercial Aviation or Weather Radar Systems
Line of Sight (Radio Path Planning)
AP-85 Series access points are capable of performing as one of the following:
zEnterprise mesh point (MP)
zEnterprise mesh portal (MPP)
A wireless bridge or mesh link requires a “radio line of sight” between the two antennas for optimum performance. The
concept of radio line of sight involves the area along a link through which the bulk of the radio signal power travels. This
area is known as the first Fresnel Zone of the radio link. For a radio link, no object (including the ground) must intrude
within 60% of the first Fresnel Zone.
Figure 8 illustrates the concept of a good radio line of sight.
Figure 8 Line of Sight
If there are obstacles in the radio path, there may still be a radio link but the quality and strength of the signal will be
affected. Calculating the maximum clearance from objects on a path is important as it directly affects the decision on
antenna placement and height. It is especially critical for long-distance links, where the radio signal could easily be lost.
When planning the radio path for a wireless bridge or mesh link, consider these factors:
zAvoid any partial line of sight between the antennas
zBe cautious of trees or other foliage that may be near the path, or may grow and obstruct the path.
zBe sure there is enough clearance from buildings and that no building construction may eventually block the path.
zFor very long distance links, the curvature of the earth (20 cm per km) may need to be considered in the calculation of
relative heights.
NOTE
To configure the AP-85 as a mesh point or mesh portal, you must install a mesh software license on
a Mobility Controller as a software license key. Contact your sales account manager or authorized
reseller to obtain the software license. There are several mesh software licenses available that
support different maximum number of APs. The licenses are cumulative; each additional license
installed increases the number of APs (mesh nodes) supported by the Mobility Controller.
Radio Line of Sight
Visual Line of Sight

Aruba AP-85 Outdoor Access Point Series | Installation Guide Outdoor Planning and Deployment Considerations | 17
zCheck the topology of the land between the antennas using topographical maps, aerial photos, or even satellite image
data (software packages are available that may include this information for your area)
zAvoid a path that may incur temporary blockage due to the movement of cars, trains, or aircraft.
Antenna Height
A reliable wireless bridge or mesh link is usually best achieved by mounting the antennas at each end high enough for a clear
radio line of sight between them. The minimum height required depends on the distance of the link, obstacles that may be in
the path, topology of the terrain, and the curvature of the earth (for links over 3 miles).
For long-distance links, the AP may have to be mounted on masts or poles that are tall enough to attain the minimum
required clearance. Use the following table to estimate the required minimum clearance above the ground or path
obstruction (for 5 GHz bridge links).
Table 3 Antenna Minimum Height and Clearance Requirements
Total Link Distance
Max Clearance for
60% of First Fresnel
Zone at 5.8 GHz
Approximate Clearance
for Earth Curvature
Total Clearance
Required at
Mid-point of Link
0.25 mile (0.402 km) 4.6 ft (1.4 m) 0.007 ft (0.002 m) 4.6 ft (1.4 m)
0.5 mile (0.805 km) 6.2 ft (1.9 m) 0.03 ft (0.010 m) 6.2 ft (1.9 m)
1 mile (1.6 km) 8.9 ft (2.7 m) 0.13 ft (0.04 m) 8.9 ft (2.7 m)
2 miles (3.2 km) 12.5 ft (3.8 m) 0.5 ft (0.15 m) 13.1 ft (4.0 m)
3 miles (4.8 km) 15.4 ft (4.7 m) 1.0 ft (0.3 m) 16.4 ft (5.0 m)
4 miles (6.4 km) 17.7 ft (5.4 m) 2.0 ft (0.6 m) 19.7 ft (6.0 m)
5 miles (8 km) 20 ft (6.1 m) 3.0 ft (0.9 m) 23 ft (7.0 m)
7 miles (11.3 km) 23.6 ft (7.2 m) 6.2 ft (1.9 m) 30 ft (9.1 m)
9 miles (14.5 km) 27 ft (8.2 m) 10.2 ft (3.1 m) 37 ft (11.3 m)
12 miles (19.3 km) 30.8 ft (9.4 m) 18.0 ft (5.5 m) 49 ft (14.9 m)
15 miles (24.1 km) 34.4 ft (10.5 m) 28.0 ft (8.5 m) 62.7 ft (19.1 m)
NOTE
To avoid any obstruction along the path, the height of the object must be added to the minimum
clearance required for a clear radio line of sight. Consider the following simple example, illustrated in
Figure 9.

18 | Outdoor Planning and Deployment Considerations Aruba AP-85 Outdoor Access Point Series | Installation Guide
Figure 9 Antenna Height and Line of Sight
A wireless bridge or mesh link is deployed to connect building A to building B, which is located three miles (4.8 km) away.
Mid-way between the two buildings is a small tree-covered hill. From the above table it can be seen that for a three-mile link,
the object clearance required at the mid-point is 5.3 m (17.4 ft). The tree tops on the hill are at an elevation of 17 m (56 ft), so
the antennas at each end of the link need to be at least 22.3 m (73 ft) high. Building A is six stories high, or 20 m (66 ft), so a
2.3 m (7.5 ft) mast or pole must be constructed on its roof to achieve the required antenna height. Building B is only three
stories high, or 9 m (30 ft), but is located at an elevation that is 12 m (39 ft) higher than building A. To mount an antenna at
the required height on building B, a mast or pole of 1.3 m (4.3 ft) is needed.
Antenna Position and Orientation
Once the required antenna height has been determined, other factors affecting the precise position of the wireless bridge or
mesh link must be considered:
zBe sure there are no other radio antennas within 2 m (6 ft) of the wireless bridge or mesh link. These include other WiFi
radio antennas.
zPlace the wireless bridge or mesh link away from power and telephone lines.
zAvoid placing the wireless bridge or mesh link too close to any metallic reflective surfaces, such as roof-installed air-
conditioning equipment, tinted windows, wire fences, or water pipes. Ensure that there is at least 5 feet clearance from
such objects.
zThe wireless bridge or mesh link antennas at both ends of the link must be positioned with the same polarization
direction, either horizontal or vertical. Proper alignment helps to maximize throughput.
!
CAUTION
Never construct a radio mast, pole, or tower near overhead power lines.
NOTE
Local regulations may limit or prevent construction of a high radio mast or tower. If your wireless
bridge or mesh link requires a high radio mast or tower, consult a professional contractor for advice.
AB
3 miles (4.8 km)
5.4 m
17 m
20 m
2.4 m
12 m
9m
1.4 m
Radio Line of Sight
Visual Line of Sight

Aruba AP-85 Outdoor Access Point Series | Installation Guide Outdoor Planning and Deployment Considerations | 19
Radio Interference
The avoidance of radio interference is an important part of wireless link planning. Interference is caused by other radio
transmissions using the same or an adjacent channel frequency. You should first scan your proposed site using a spectrum
analyzer to determine if there are any strong radio signals using the 802.11a/b/g channel frequencies. Always use a channel
frequency that is furthest away from another signal.
If radio interference is still a problem with your wireless bridge or mesh link, changing the antenna direction may improve
the situation.
Weather Conditions
When planning wireless bridge or mesh links, you must take into account any extreme weather conditions that are known to
affect your location. Consider these factors:
zTemperature: The wireless bridge or mesh link is tested for normal operation in temperatures from
-. Operating in temperatures outside of this range may cause the unit to fail
zWind Velocity: The wireless bridge or mesh link can operate in winds up to. You must consider the known maximum
wind velocity and direction at the site and be sure that any supporting structure, such as a pole, mast, or tower, is built to
withstand this force.
zLightning: Rain: The wireless bridge or mesh link is weatherproofed against rain. However, it is recommended to apply
weatherproof sealing tape around the Ethernet port and antenna connectors for extra protection. If moisture enters a
connector, it may cause a degradation in performance or even a complete failure of the link.
zSnow and Ice: Falling snow, like rain, has no significant effect on the radio signal. However, a buildup of snow or ice on
antennas may cause the link to fail. In this case, the snow or ice has to be cleared from the antennas to restore operation
of the link.
Ethernet Cabling
When a suitable antenna location has been determined, you must plan a cable route from the wireless bridge or mesh link
outdoors to a suitable power and/or network source.
Consider these points:
zThe Ethernet cable length should never be longer than 90 m (295 ft).
zDetermine a building entry point for the cable (if applicable).
zDetermine if conduits, bracing, or other structures are required for safety or protection of the cable.
zFor lightning protection at the power injector end of the cable, consider using a lightning arrestor immediately before the
cable enters the building
Grounding
It is important that the wireless bridge or mesh link, cables, and any supporting structures are properly grounded. Each AP-
85 Series access point includes a grounding screw for attaching a ground wire. Be sure that grounding is available and that it
meets local and national electrical codes. Ground the access point first using the external ground stud on the unit before
making any other connection.
!
CAUTION
An Aruba Lightning Arrestor, AP-LAR-1, must be installed on each antenna port for protection
against lightning induced surges. Failure to use an AP-LAR-1 can void the warranty of an Aruba
outdoor AP model and renders the AP susceptible to failure from lightning induced surges.

20 | Outdoor Planning and Deployment Considerations Aruba AP-85 Outdoor Access Point Series | Installation Guide