Aerohive Networks HIVEAP340 802.11 a/b/g/n access point User Manual Aerohive Deployment Guide

Aerohive Networks, Inc. 802.11 a/b/g/n access point Aerohive Deployment Guide

Users Manaul 1

Aerohive Deployment Guide
1Aerohive Deployment GuideFor HiveAP and HiveManager DevicesAerohive Technical PublicationsCopyright NoticeCopyright © 2008 Aerohive Networks, Inc. All rights reserved.Aerohive Networks, the Aerohive Networks logo, HiveOS, HiveAP, and HiveManager are trademarks of Aerohive Networks, Inc. All other trademarks and registered trademarks are the property of their respective companies.Information in this document is subject to change without notice. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without receiving written permission from:Aerohive Networks, Inc.3150-C Coronado DriveSanta Clara, CA 95054P/N 330002-06, Rev. A
HiveAP Compliance Information2AerohiveHiveAP Compliance InformationFederal Communication Commission Interference StatementThis equipment has been tested and found to comply with the limits fora Class B digital device, pursuant to Part 15 of the FCC Rules. Theselimits are designed to provide reasonable protection against harmfulinterference in a residential installation. This equipment generates,uses and can radiate radio frequency energy and, if not installed andused in accordance with the instructions, may cause harmfulinterference to radio communications. However, there is no guaranteethat interference will not occur in a particular installation. If thisequipment does cause harmful interference to radio or televisionreception, which can be determined by turning the equipment off andon, the user is encouraged to try to correct the interference by one ofthe following measures:• Reorient or relocate the receiving antenna• Increase the separation between the equipment and receiver• Connect the equipment into an outlet on a circuit different fromthat to which the receiver is connected• Consult the dealer or an experienced radio/TV technician for helpFCC Caution: Any changes or modifications not expressly approved bythe party responsible for compliance could void the user's authority tooperate this equipment. This device complies with Part 15 of the FCCRules. Operation is subject to the following two conditions: (1) Thisdevice may not cause harmful interference, and (2) this device mustaccept any interference received, including interference that maycause undesired operation.Important: FCC Radiation Exposure StatementThis equipment complies with FCC radiation exposure limits set forthfor an uncontrolled environment. This equipment should be installedand operated with a minimum distance of 20 centimeters (8 inches)between the radiator and your body. This transmitter must not be co-located or operating in conjunction with any other antenna ortransmitter.Wireless 5 GHz Band StatementsHigh power radars are allocated as primary users (meaning they havepriority) of the 5250-5350 MHz and 5650-5850 MHz bands. These radarscould cause interference and/or damage to the HiveAP when used inCanada.The term "IC" before the radio certification number only signifies thatIndustry Canada technical specifications were met.Industry Canada - Class BThis digital apparatus does not exceed the Class B limits for radio noiseemissions from digital apparatus as set out in the interference-causingequipment standard entitled "Digital Apparatus," ICES-003 of IndustryCanada.Cet appareil numérique respecte les limites de bruits radioélectriquesapplicables aux appareils numériques de Classe B prescrites dans lanorme sur le matériel brouilleur: "Appareils Numériques," NMB-003édictée par l'Industrie.Wi-Fi CertificationThe Wi-Fi CERTIFIED™ Logo is a certification mark of the Wi-FiAlliance®. The Aerohive HiveAP 20 ag has been certified for WPA™,WPA2™, WMM® (Wi-Fi Multimedia™), WMM Power Save, and thefollowing types of EAP (Extensible Authentication Protocol):•EAP-TLS•EAP-TTLS/MSCHAPv2• PEAPv0/EAP-MSCHAPv2• PEAPv1/EAP-GTC•EAP-SIMEC Conformance DeclarationMarking by the above symbol indicates compliance with the EssentialRequirements of the R&TTE Directive of the European Union (1999/5/EC). This equipment meets the following conformance standards:• EN 60950-1 (IEC 60950-1) - Product Safety• EN 301 893 - Technical requirements for 5 GHz radio equipment• EN 300 328 - Technical requirements for 2.4 GHz radio equipment• EN 301 489-1 / EN 301 489-17 - EMC requirements for radioequipmentCountries of Operation and Conditions of Use in the European CommunityHiveAPs are intended to be operated in all countries of the EuropeanCommunity. Requirements for indoor vs. outdoor operation, licenserequirements and allowed channels of operation apply in somecountries as described below.• Before operating a HiveAP, the admin or installer must properlyenter the current country of operation in the command lineinterface as described in "Appendix A Country Codes" on page 177.Note to U.S. model owners: To comply with U.S. FCC regulations,the country selection function has been completely removed fromall U.S. models. The above function is for non-U.S. models only. • HiveAPs automatically limit the allowable channels determined bythe current country of operation. Incorrectly entering the countryof operation might result in illegal operation and cause harmfulinterference to other systems. The admin is obligated to ensureHiveAPs are operating according to the channel limitations,indoor/outdoor restrictions and license requirements for eachEuropean Community country as described in this section.• HiveAPs can be operated indoors or outdoors in all countries of theEuropean Community using the 2.4 GHz band: Channels 1 - 13,except where noted below.– In Italy, you must apply for a license from the nationalspectrum authority to operate a HiveAP outdoors.– In Belgium outdoor operation is only permitted using the 2.46 -2.4835 GHz band: Channel 13.– In France outdoor operation is only permitted using the 2.4 -2.454 GHz band: Channels 1 - 7.• HiveAPs are restricted to indoor use when operated in theEuropean Community using the 5.15 - 5.25 GHz band: Channels 36,40, 44, 48. Because the frequency ranges 5.25 – 5.35 and 5.47 –5.725 are affected by DFS (Dynamic Frequency Selection), HiveAPsblock channels 52, 56, 60, 64, and 100, 104, 108, 112, 116, 120,124, 128, 132, 136, 140.
Deployment Guide 3HIVEAP COMPLIANCE INFORMATIONThe availability of some specific channels and/or operationalfrequency bands are country dependent and are firmwareprogrammed at the factory to match the intended destination.The firmware setting is not accessible by the end user.• The 5 GHz Turbo Mode feature is not allowed for operation in anyEuropean Community country. You can find the current setting forthis feature in two places. In the HiveManager GUI, clickConfiguration > Network Objects>  Radio Profiles > profile >Advanced. In the HiveAP CLI, enter this command: show radioprofile profile. By default, Turbo Mode is disabled.Declaration of Conformity in Languages of the European CommunityHiveAP 20 ag Safety CompliancePower Cord SafetyPlease read the following safety information carefully before installinga HiveAP.Warning: Installation and removal of HiveAPs must be carried out byqualified personnel only.• HiveAPs must be connected to an earthed (grounded) outlet tocomply with international safety standards.• Do not connect HiveAPs to an A.C. outlet (power supply) withoutan earth (ground) connection.• The appliance coupler (the connector to the unit and not the wallplug) must have a configuration for mating with an EN 60320/IEC320 appliance inlet.• The socket outlet must be near the HiveAP and easily accessible.You can only remove power from a HiveAP by disconnecting thepower cord from the outlet.• HiveAPs operate under SELV (Safety Extra Low Voltage) conditionsaccording to IEC 60950. The conditions are only maintained if theequipment to which they are connected also operates under SELVconditions.• A HiveAP receiving power through its PoE (Power over Ethernet)interface must be in the same building as the equipment fromwhich it receives power.France and Peru only:HiveAPs cannot be powered from IT* supplies. If your supplies are of ITtype, then a HiveAP must be powered by 230 V (2P+T) via an isolationtransformer ratio 1:1, with the secondary connection point labelledNeutral, connected directly to earth (ground).* Impédance à la terreImportant! Before making connections, make sure you have the correctcord set. Check it (read the label on the cable) against the descriptionon the following page.Veuillez lire attentivement les informations de sécurité relatives àl'installation d'un point d'accès HiveAP.English Hereby, Edgecore, declares that this Radio LANdevice is in compliance with the essentialrequirements and other relevant provisions ofDirective 1999/5/EC.Finnish Valmistaja Edgecore vakuuttaa täten että Radio LANdevice tyyppinen laite on direktiivin 1999/5/EYoleellisten vaatimusten ja sitä koskevien direktiivinmuiden ehtojen mukainen.Dutch Hierbij verklaart Edgecore dat het toestel RadioLAN device in overeenstemming is met deessentiële eisen en de andere relevante bepalingenvan richtlijn 1999/5/EG.Bij deze Edgecore dat deze Radio LAN devicevoldoet aan de essentiële eisen en aan de overigerelevante bepalingen van Richtlijn 1999/5/EC.French Par la présente Edgecore déclare que cet appareilRadio LAN est conforme aux exigences essentielleset aux autres dispositions relatives à la directive1999/5/CE.Swedish Härmed intygar Edgecore att denna Radio LANdevice står I överensstämmelse med de väsentligaegenskapskrav och övriga relevanta bestämmelsersom framgår av direktiv 1999/5/EG.Danish Undertegnede Edgecore erklærer herved, atfølgende udstyr Radio LAN device overholder devæsentlige krav og øvrige relevante krav i direktiv1999/5/EF.German Hiermit erklärt Edgecore, dass sich dieser/diese/dieses Radio LAN device in Übereinstimmung mitden grundlegenden Anforderungen und den anderenrelevanten Vorschriften der Richtlinie 1999/5/EGbefindet". (BMWi)Hiermit erklärt Edgecore die Übereinstimmung desGerätes Radio LAN device mit den grundlegendenAnforderungen und den anderen relevantenFestlegungen der Richtlinie 1999/5/EG. (Wien)GreekItalian Con la presente Edgecore dichiara che questo RadioLAN device è conforme ai requisiti essenziali ed allealtre disposizioni pertinenti stabilite dalla direttiva1999/5/CE.Spanish Por medio de la presente Manufacturer declara queel Radio LAN device cumple con los requisitosesenciales y cualesquiera otras disposicionesaplicables o exigibles de la Directiva 1999/5/CE.Portuguese Manufacturer declara que este Radio LAN deviceestá conforme com os requisitos essenciais e outrasdisposições da Directiva 1999/5/CE.Power Cord SetU.S.A. and Canada The cord set must be UL-approved and CSA certified.Minimum specifications for the flexible cord:- No. 18 AWG not longer than 2 meters, or 16 AWG- Type SV or SJ- 3-conductorThe cord set must have a rated current capacity of at least 10 A.The attachment plug must be an earth-grounding type with NEMA 5-15P (15 A, 125 V) or NEMA 6-15 (15 A, 250 V) configuration.Denmark The supply plug must comply with Section 107-2-D1, Standard DK2-1a or DK2-5a.Switzerland The supply plug must comply with SEV/ASE 1011.U.K. The supply plug must comply with BS1363 (3-pin 13 A) and be fitted with a 5 A fuse that complies with BS1362.The mains cord must be <HAR> or <BASEC> marked and be of type HO3VVF3GO.75 (minimum).Europe The supply plug must comply with CEE7/7 ("SCHUKO").The mains cord must be <HAR> or <BASEC> marked and be of type HO3VVF3GO.75 (minimum).IEC-320 receptacle.
HiveAP Compliance Information4AerohiveAvertissement: L'installation et la dépose de points d'accès HiveAPdoivent être effectuées uniquement par un personnel qualifié.• Les points d'accès HiveAP doivent être connectés sur le secteurpar une prise électrique munie de terre (masse) afin de respecterles standards internationaux de sécurité.• Ne jamais connecter des points d'accès HiveAP à une alimentationélectrique non-pourvue de terre (masse).• Le boitier d'alimentation (connecté directement au point d'accès)doit être compatible avec une entrée électrique de type EN60320/IEC 320.• La prise secteur doit se trouver à proximité du point d'accèsHiveAP et facilement accessible. Vous ne pouvez mettre horstension un point d'accès HiveAP qu'en débranchant sonalimentation électrique au niveau de cette prise.• Pour des raisons de sécurité, le point d'accès HiveAP fonctionne àune tension extrêmement basse, conformément à la norme IEC60950. Les conditions de sécurité sont valables uniquement sil'équipement auquel le point d'accès HiveAP est raccordéfonctionne également selon cette norme.• Un point d'accès HiveAP alimenté par son interface réseauEthernet en mode POE (Power over Ethernet) doit êtrephysiquement dans le même bâtiment que l'équipement réseauqui lui fournit l'électricité.France et Pérou uniquement:Un point d'accès HiveAP ne peut pas être alimenté par un dispositif àimpédance à la terre. Si vos alimentations sont du type impédance à laterre, alors le point d'accès HiveAP doit être alimenté par une tensionde 230 V (2P+T) via un transformateur d'isolement à rapport 1:1, avecle neutre connecté directement à la terre (masse).Bitte unbedingt vor dem Einbauen des HiveAP die folgendenSicherheitsanweisungen durchlesen.Warnung: Die Installation und der Ausbau des Geräts darf nur durchFachpersonal erfolgen.• Das Gerät sollte nicht an eine ungeerdete Wechselstromsteckdoseangeschlossen werden.• Das Gerät muß an eine geerdete Steckdose angeschlossen werden,welche die internationalen Sicherheitsnormen erfüllt.• Der Gerätestecker (der Anschluß an das Gerät, nicht derWandsteckdosenstecker) muß einen gemäß EN 60320/IEC 320konfigurierten Geräteeingang haben.• Die Netzsteckdose muß in der Nähe des Geräts und leichtzugänglich sein. Die Stromversorgung des Geräts kann nur durchHerausziehen des Gerätenetzkabels aus der Netzsteckdoseunterbrochen werden.• Der Betrieb dieses Geräts erfolgt unter den SELV-Bedingungen(Sicherheitskleinstspannung) gemäß IEC 60950. Diese Bedingungensind nur gegeben, wenn auch die an das Gerät angeschlossenenGeräte unter SELV-Bedingungen betrieben werden.Liability DisclaimerInstallation of Aerohive equipment must comply with local and national electrical codes and with other regulations governing this type of installation.Aerohive Networks, its channel partners, resellers, and distributors assume no liability for personal injury, property damage, or violation ofgovernment regulations that may arise from failing to comply with the instructions in this guide and appropriate electrical codes.Cordon électrique - Il doit être agréé dans le pays d'utilisationEtats-Unis et Canada Le cordon doit avoir reçu l'homologation des UL et un certificat de la CSA.Les spécifications minimales pour un cable flexible- AWG No. 18, ou AWG No. 16 pour un cable delongueur inférieure à 2 mètres.- Type SV ou SJ- 3 conducteursLe cordon doit être en mesure d'acheminer un courant nominal d'au moins 10 A.La prise femelle de branchement doit être du type à mise à la terre (mise à la masse) et respecter la configuration NEMA 5-15P (15 A, 125 V) ou NEMA 6-15P (15 A, 250 V).Danemark La prise mâle d'alimentation doit respecter la section 107-2 D1 de la norme DK2 1a ou DK2 5a.Suisse La prise mâle d'alimentation doit respecter la norme SEV/ASE 1011.Europe La prise secteur doit être conforme aux normes CEE 7/7 ("SCHUKO").LE cordon secteur doit porter la mention <HAR> ou <BASEC> et doit être de type HO3VVF3GO.75 (minimum).Stromkabel. Dies muss von dem Land, in dem es benutzt wird geprüft werden:U.S.A. undKanadaDer Cord muß das UL gepruft und war das CSA beglaubigt.Das Minimum spezifikation fur der Cord sind:- Nu. 18 AWG - nicht mehr als 2 meter, oder 16 AWG.- Der typ SV oder SJ- 3-LeiterDer Cord muß haben eine strombelastbarkeit aus wenigstens 10 A.Dieser Stromstecker muß hat einer erdschluss mit der typ NEMA 5-15P (15A, 125V) oder NEMA 6-15P (15A, 250V) konfiguration.Danemark Dieser Stromstecker muß die ebene 107-2-D1, der standard DK2-1a oder DK2-5a Bestimmungen einhalten.Schweiz Dieser Stromstecker muß die SEV/ASE 1011Bestimmungen einhalten.Europe Europe Das Netzkabel muß vom Typ HO3VVF3GO.75 (Mindestanforderung) sein und die Aufschrift <HAR> oder <BASEC> tragen.Der Netzstecker muß die Norm CEE 7/7 erfüllen ("SCHUKO").
Deployment Guide 5ContentsChapter 1 Preparing for a WLAN Deployment ...............................................9Assessing Your Requirements .............................................................................10Planning ......................................................................................................10Upgrading from Existing Wi-Fi ...................................................................................10New WLAN Deployment...........................................................................................11Site Surveys.........................................................................................................12Budgeting Wi-Fi: The Chicken and Egg Problem ..............................................................13Planning Tools .................................................................................................13Associated Access Point Costs...............................................................................14Bandwidth Assumptions for Wi-Fi ...............................................................................14Overcoming Physical Impediments..............................................................................15Preparing the Wired Network for Wireless ....................................................................17Operational Considerations................................................................................18Tuning ...............................................................................................................18Troubleshooting....................................................................................................18Management........................................................................................................18Deploying with Confidence.......................................................................................18Basic Wi-Fi Concepts .......................................................................................19Chapter 2 The HiveAP 20 ag Platform.......................................................23HiveAP 20 Product Overview ..............................................................................24Ethernet and Console Ports ......................................................................................26Status LEDs .........................................................................................................27Antennas ............................................................................................................28Mounting the HiveAP 20....................................................................................29Ceiling Mount.......................................................................................................29Surface Mount......................................................................................................30Device, Power, and Environmental Specifications.....................................................31Chapter 3 The HiveAP 28 Outdoor Platform ............................................... 33HiveAP 28 Product Overview ..............................................................................34Ethernet Port.......................................................................................................35Power Connector ..................................................................................................36Antennas ............................................................................................................37
Contents6AerohiveMounting the HiveAP 28 and Attaching Antennas......................................................38Pole Mount..........................................................................................................39Strand Mount .......................................................................................................40Surface Mount......................................................................................................41Attaching Antennas................................................................................................42Connecting Antennas Directly to the HiveAP 28..........................................................42Mounting Antennas Separately ..............................................................................42Device, Power, and Environmental Specifications.....................................................44Chapter 4 The HiveAP 340 Platform.........................................................45HiveAP 340 Product Overview.............................................................................46Ethernet and Console Ports ......................................................................................48Smart PoE ......................................................................................................49Aggregate and Redundant Interfaces ......................................................................49Console Port ...................................................................................................51Status LEDs .........................................................................................................52Antennas ............................................................................................................52MIMO ............................................................................................................53Using MIMO with Legacy Clients.............................................................................55Mounting the HiveAP 340 ..................................................................................56Ceiling Mount.......................................................................................................56Locking the HiveAP 340 ......................................................................................57Surface Mount......................................................................................................58Device, Power, and Environmental Specifications.....................................................59Chapter 5 The HiveManager Platform....................................................... 61Product Overview ...........................................................................................62Ethernet and Console Ports ......................................................................................63Status LEDs .........................................................................................................64Rack Mounting the HiveManager..........................................................................65Device, Power, and Environmental Specifications.....................................................66Chapter 6 The High Capacity HiveManager Platform.....................................67Product Overview ...........................................................................................68Rack Mounting the High Capacity HiveManager ........................................................70Replacing Power Supplies..................................................................................73Replacing Hard Disk Drives ................................................................................74Device, Power, and Environmental Specifications.....................................................75
Deployment Guide 7Chapter 7 Using HiveManager.................................................................77Installing and Connecting to the HiveManager GUI ....................................................79Introduction to the HiveManager GUI....................................................................82Cloning Configurations............................................................................................83Multiselecting ......................................................................................................83Sorting Displayed Data............................................................................................84HiveManager Configuration Workflow ...................................................................85Updating Software on HiveManager......................................................................86Updating HiveOS Firmware ................................................................................87Updating HiveAPs in a Mesh Environment......................................................................88Chapter 8 HiveManager Configuration Examples..........................................89Example 1: Mapping Locations and Installing HiveAPs ................................................91Setting Up Topology Maps ........................................................................................91Preparing the HiveAPs ............................................................................................94Using SNMP .....................................................................................................94Using MAC Addresses..........................................................................................95Example 2: Defining Network Objects and MAC Filters ...............................................97Defining a MAC OUI................................................................................................97Mapping the MAC OUI and Services to Aerohive Classes ................................................98Defining VLANs ................................................................................................... 100Creating IP Addresses ........................................................................................... 101Creating a MAC Filter ........................................................................................... 103Example 3: Providing Guest Access .................................................................... 104Guest Access with Preshared Keys ............................................................................ 104Guest Access with Captive Web Portal....................................................................... 105Captive Web Portal with External DHCP and DNS Servers ............................................ 105Captive Web Portal with Internal DHCP and DNS Servers............................................. 107Customizing the Registration Page ....................................................................... 108Loading Customized Captive Web Portal Files.......................................................... 111Defining a Captive Web Portal ............................................................................ 112Example 4: Creating User Profiles...................................................................... 113Example 5: Setting SSIDs................................................................................. 117Example 6: Setting Management Service Parameters ............................................... 120Example 7: Defining AAA RADIUS Settings............................................................. 123Example 8: Creating Hives............................................................................... 125
Contents8AerohiveExample 9: Creating WLAN Policies .................................................................... 126WLANpolicy-hq1.................................................................................................. 126WLANpolicy-hq1 (Page 1) .................................................................................. 126WLANpolicy-hq1 (Page 2) .................................................................................. 128WLANpolicy-hq1 (Page 3) .................................................................................. 131WLANpolicy-hq2.................................................................................................. 134WLANpolicy-branch1 ............................................................................................ 134Example 10: Assigning Configurations to HiveAPs.................................................... 135Chapter 9 HiveOS.............................................................................. 141Common Default Settings and Commands............................................................. 142Configuration Overview .................................................................................. 143Device-Level Configurations ................................................................................... 143Policy-Level Configurations .................................................................................... 144HiveOS Configuration File Types........................................................................ 145Chapter 10 Deployment Examples (CLI) .................................................. 149Example 1: Deploying a Single HiveAP................................................................. 150Example 2: Deploying a Hive............................................................................ 153Example 3: Using IEEE 802.1X Authentication........................................................ 158Example 4: Applying QoS ................................................................................ 161Example 5: Loading a Bootstrap Configuration....................................................... 167CLI Commands for Examples ............................................................................ 170Commands for Example 1 ...................................................................................... 170Commands for Example 2 ...................................................................................... 170Commands for Example 3 ...................................................................................... 171Commands for Example 4 ...................................................................................... 172Commands for Example 5 ...................................................................................... 174Chapter 11 Traffic Types .................................................................... 175Appendix A Country Codes .................................................................. 177
Deployment Guide 9Chapter 1 Preparing for a WLAN DeploymentTo ensure a smooth WLAN deployment, you need to begin with a bit of planning. A straightforward review of your deployment plan before you begin will result in optimal results more quickly. The goals of this chapter are to assist you in assessing your readiness for WLAN implementation and to provide tips and tricks to resolve any issues that might arise in your environment. The chapter covers the following topics:•"Assessing Your Requirements" on page 10•"Planning" on page 10•"Upgrading from Existing Wi-Fi" on page 10•"New WLAN Deployment" on page 11•"Site Surveys" on page 12•"Budgeting Wi-Fi: The Chicken and Egg Problem" on page 13•"Bandwidth Assumptions for Wi-Fi" on page 14•"Overcoming Physical Impediments" on page 15•"Operational Considerations" on page 18•"Preparing the Wired Network for Wireless" on page 17•"Deploying with Confidence" on page 18Although this guide assumes an understanding of corporate data networking, previous experience with LAN configuration and deployment, and some basic Wi-Fi understanding, the chapter concludes with a section that provides additional support for the preceding sections: "Basic Wi-Fi Concepts" on page 19.Note: This guide assumes an understanding of corporate data networking and past experience with LAN configuration and deployment. It also assumes some basic Wi-Fi understanding.
Chapter 1 Preparing for a WLAN Deployment10 AerohiveASSESSING YOUR REQUIREMENTSTo get started with your Aerohive WLAN installation, examine the basic requirements of your implementation. First, consider who your stakeholders are and take the time to fully understand their access requirements. Talk to department managers within your organization and make sure everyone has documented the full complement of potential users of your network. Check if the applications are standard employee applications or if there are other requirements, such as access for guests or consultants.Next, make a complete list of the application types that your Aerohive network will need to support. Begin your list with mission-critical applications, paying special attention to those that generate high levels of traffic and those requiring deterministic behavior. Identify applications with heavy data requirements and expected service levels.Demanding applications such as voice and video will require a higher density of access points. Many enterprises are investigating the potential of VoWLAN (Voice over WLAN) in the hopes of integrating mobile phones and IP-PBX systems. Doing so requires an evaluation of other data transmission types that can disrupt the quality of voice conversations. Because voice traffic is sensitive to network jitter and latency, an inadequate number of access points can degrade quality. To the user, excessive jitter and delay can cause clipped conversations or dropped calls. Additional quality and reliability issues might arise when transmitting video, such as for training video or surveillance operations, because of the sheer size of the data stream.Other applications such as network backup and file transfers can also have an impact on the network. Therefore, take into account any bandwidth-intensive applications if you expect your mobile workforce to be accessing the WLAN while these applications or services are occurring.Considering the above issues will result in a more informed—and therefore more successful—deployment plan.PLANNINGThis section reviews the fundamental elements for planning your WLAN deployment. This includes conducting a site survey, both for an upgrade from an existing WLAN and for a completely fresh—or greenfield—deployment.Upgrading from Existing Wi-FiIf you are upgrading to Aerohive from an existing WLAN, you already have plenty of data about how your current network is performing. This information can lead to more informed decisions about your new implementation.To begin, perform a quick site survey with the existing access points in place. If they are less than three years old and support 802.11g, their coverage and capacity should be equivalent or slightly lower than the Aerohive 802.11g radio. If the coverage is correct and has the appropriate density for your deployment, then you simply need to replace one set of access points with a new set of HiveAPs. However, this scenario is rare because network upgrades are usually done to improve capacity and to augment the existing layout with a denser deployment of access points.Be sure to take note whether your existing network uses "fat" or "thin" APs (access points). A "fat" AP is an autonomous or standalone access point, which contains the intelligence and capability to connect to any Ethernet switch. With a "thin" AP, most of the intelligence has been removed and replaced in a centralized WAN controller. A fat upgrade to Aerohive HiveAPs is very natural. Generally, with fat APs you simply need to unplug the existing ones and plug in the new HiveAPs and provision them. With this approach, you can maintain or enhance all existing VLANs and security policies. This is a huge advantage over migrating from fat AP to controller-based solutions because you typically need to re-architect the network.
Deployment Guide 11 PLANNINGUpgrading from a thin AP solution is also easy. However, because a thin AP makes use of an overlay tunneled network, you sometimes have to add a local VLAN for access or use tunnels to replicate the overlay network. However, because using VLANs rather than tunnels provides significant performance and scalability advantages, that is clearly the recommended path.New WLAN DeploymentIn a new—or greenfield—WLAN deployment, you do not have the benefit of an existing network for testing and analysis, which makes your job a bit more difficult. In this case, the following key questions are critical to the proper design of your WLAN:• How many users will need wireless service and what applications will they use?Determining the scope of your WLAN deployment will have a major impact on capacity and coverage. Will only certain groups within the organization have WLAN access, or will it be rolled out across the enterprise? Will you provide guest access to visitors, consultants, and contractors? Most WLANs support just data applications, but many organizations are considering adding voice services. Voice support raises other design considerations that drive the need for denser deployments of access points and different QoS (Quality of Service) settings.• Are there any known major sources of interference?For example, is there a nearby cafeteria with microwave ovens? Commercial-grade microwaves are a particularly bad source of interference. Is there a wireless telephone or video surveillance system not using Wi-Fi? Is there a radar installation nearby? If you cannot find the answer to these questions easily, consider employing a spectrum analysis product, such as the AirMagnet Spectrum Analyzer.• Are building blueprints available?With blueprints, you can see the location of elevators, load-bearing walls, and other building characteristics that can impact signal quality. Different materials, such as concrete walls, brick walls, cubicle walls, glass, and elevator shafts impact signal quality differently. You can often load these blueprints into a planning or site survey tool to make the process easier.• What devices need to access the WLAN?Determine and document the full complement of devices that people will use to access the WLAN. The performance requirements of the WLAN will depend on both the applications and the capabilities of the client devices. For example, design engineers, architects, and doctors tend to work with bandwidth-hungry applications, so you might need to provide greater capacity. Conversely, if it is a warehouse with a low client density of mostly barcode scanners, a lower access point density might be suitable. Finally it is important to consider voice, or the future use of voice. If some or all people will use VoWLAN (Voice over WLAN) devices, that can affect how many users each access point can accommodate.Note: For some access point deployment guidelines, see "Bandwidth Assumptions for Wi-Fi" on page 14.
Chapter 1 Preparing for a WLAN Deployment12 AerohiveSite SurveysOne of the first questions IT managers ask when they are preparing for a WLAN deployment is whether or not a site survey should be performed. In a site survey, the administrator walks around the facility with a site survey tool to measure the RF (radio frequency) coverage of a test access point or the existing WLAN infrastructure.Whether or not you decide to do a site survey for your enterprise depends on the cost of the survey and the complexity of the environment. The three ways to deploy a wireless network—with and without a site survey—are explained below:• Predeployment SurveyThe safest approach is to perform a site survey before deployment to determine the best locations for the access points. Typically, site survey professionals temporarily place access points in different locations, take measurements, and adjust their settings and locations as necessary. After they complete the survey, they install the access points, and then perform another site survey to confirm that the goals have been achieved. This method is clearly the most reliable way to deploy a wireless network; however, it can be expensive, time consuming, and impractical if an enterprise has many sites.• Deploy and CheckIn this scenario, an initial site survey is not performed. Instead, wireless administrators make educated guesses on the best locations for the access points or they use a planning tool to determine the locations more reliably. After deploying the access points, the administrators do a quick site survey. If they need to provide greater coverage, they deploy additional access points. If there are areas where access points are interfering with each other, they then relocate one or more of them. With the Aerohive cooperative RF control, HiveAPs automatically adjust their channel and power to compensate for coverage gaps and areas of interference.The deploy-and-check approach is often much cheaper and faster than doing a predeployment site survey. The risk is that you might have to move some access points and CAT5 (Category 5) Ethernet cables if you do not plan properly. Aerohive provides a huge competitive advantage in the deploy-and-check approach, thanks to its flexible mesh networking capability. An administrator can deploy with mesh (before running wires) and check the performance in several layouts, determine the best layout, and then run the wires to their final location.• Deploy without SurveyWhile it is usually advisable to do a site survey, there are many situations in which it is not feasible or even necessary. If the location is sufficiently small—for example, a deployment of only three or fewer access points—site surveys have limited value because there is virtually no opportunity for interference. If there are numerous remote locations, a site survey might be impractical because of the cost of traveling to each site. In these locations, you can use a slightly denser deployment to ensure appropriate coverage and capacity. With Aerohive Cooperative RF control, HiveAPs automatically adjust their radio power levels to ensure that there is minimal overlap from interfering channels. Usually the cost of extra access points is offset by the cost saved by not doing a site survey in a remote location.
Deployment Guide 13 PLANNINGBudgeting Wi-Fi: The Chicken and Egg ProblemThe hardware cost of a Wi-Fi solution is generally driven by the number of access points needed, and an Aerohive network is no exception. Unfortunately, a traditional challenge of budgeting for Wi-Fi is that it is difficult to know how many access points to plan for until you have deployed and measured them. There are methods of doing site surveys before a deployment to answer these questions. While doing so is often worthwhile, you might just need a general idea of what you would need to budget. Fortunately there are some simple guidelines that you can use to figure out how many access points you need, including the number of access points per square foot, the number of clients per access point, and the distance between access points.• Access Points per Square FootThe simplest and most common way of budgeting access points is per square foot. You simply take the square footage of a building and divide it by some number. The most common metric used today is one access point for every 4,000 to 5,000 square feet for standard offices with cubicles. However, if you need to support voice applications, you need a higher concentration of access points. In this case, the recommended formula is one access point for every 3,000 square feet, or even as low as one access point for every 2,000 square feet. In the lightest weight convenience networks, it is possible to use fewer access points, and densities as low as one access point for every 10,000 to 15,000 square feet can be successful. Keep in mind that such a deployment often has dead spots and can only support very low client densities.• Number of Clients for Each Access PointAnother way to determine the number of access points needed is to consider the number of clients you want each access point to support. In a standard office environment, most enterprises plan to support an average of 5 to 15 clients per access point. While the specifications of most access points state that they can support up to about 120 clients, a significantly lower density is recommended to get an acceptable throughput for standard office applications. If you expect to support voice over Wi-Fi in the enterprise, account for those phones as well. With the addition of voice, the client density substantially increases, requiring you to plan for an average of 5 to 10 data clients and 5 to 10 voice clients for each access point. Remember that voice clients consume virtually zero bandwidth when they are not on a call. However, when they are on a call, it is imperative that the traffic goes through.• Distance Between Access PointsIn a standard office environment, it is a good idea to ensure that access points are between 30 and 100 feet from one another. A distance of 30 feet is needed in high-density environments and those with many walls separating access points. A distance of 100 feet is sufficient in low-density areas with plenty of open space.The three tips above can help determine how many access points to deploy in a given area. In general, the square footage estimate provides the best budgeting estimate, with client estimations and the distance between access points confirming the square footage calculations.As with all rules, there are exceptions. If certain locations in the network have a higher density of clients, such as conference rooms or lecture halls, a higher density of access points is required. Conversely if there are large open areas with few active clients, fewer access points are sufficient.Planning ToolsIf following general guidelines does not provide enough confidence or if the deployment environment is particularly challenging, you might consider using software planning tools like AirMagnet's Planner software. Such tools are useful in determining the placement of access points without performing a site survey.
Chapter 1 Preparing for a WLAN Deployment14 AerohiveAssociated Access Point CostsAfter you determine how many access points you need, it becomes simpler to determine the other costs involved with deploying Wi-Fi because most are driven by the quantity of access points. These costs include the following:• Installation and Wiring• CAT5 – CAT5 wiring is required for all HiveAPs acting as portals.1 One advantage of Aerohive Networks is that you can deploy HiveAPs in a mesh to avoid some of the wiring costs.• Power – Power lines are required for all HiveAPs acting as mesh points.2 Portals receive power through power lines or through Ethernet cables by using the Power-over-Ethernet (PoE) option.• Installation – HiveAPs can simply snap into standard dropped-ceiling environments. However, if the installation is in a warehouse or any environment without dropped ceilings, consider the installation costs.• Infrastructure: PoE SwitchesYou must cable every HiveAP acting as a portal to a switch port. For PoE, there are several considerations:• 802.3af – The current PoE specification provides enough power for all 802.11a/b/g access points.• 802.3at – The emerging PoE specification supports higher power devices like 802.11n access points. This standard is expected to be ratified at the end of 2008, so products are not yet available. • PoE injectors and midspans – These save money on switch upgrades by injecting power into standard Ethernet connections.• Site Survey and Debugging Software• For a sizable deployment, you probably will use site survey and debugging software. AirMagnet Laptop Analyzer and Survey are two products that pay for themselves very quickly. These products enable the validation of a deployment and allow you to troubleshoot client and access point issues. (For more information, see the section on "Operational Considerations" on page 18.)• Professional Services• When deploying wireless LANs, professional services are often required perform site surveys.•Client Software• Depending on the deployment, users can use built-in Microsoft Windows, Linux and/or Macintosh client software (supplicants).• For better services and troubleshooting, consider a third-party supplicant such as Juniper Networks Odyssey Client.Bandwidth Assumptions for Wi-FiPeople frequently talk about how much coverage an access point provides; however, it is capacity—not coverage—that typically constrains an access point in an enterprise environment. The challenge is not how far the RF signal can travel (coverage), but how to deliver enough bandwidth to meet the demands of business applications (capacity). In other words, you might be able to cover an office of 50 people with one access point, but if all 50 people choose to access it at the same time, it will certainly become overloaded. Indeed, if you use the formulas provided in this paper, you should find the saturation of access points on your campus to be more than sufficient. Enterprise users are accustomed to speedy switched networks and expect similar performance from their wireless LAN connections. This is why documenting the size and type of applications that will rely on your WLAN is so critical to your planning. In short, if you plan for optimal capacity, complete coverage will follow automatically.1. A portal is a hive member that links one or more mesh points to the wired LAN.2. Mesh points are hive members that use a wireless backhaul connection to link through a portal to the wired LAN.
Deployment Guide 15 PLANNINGIn general, the way to increase capacity is to add more access points (within reason) and tune down the radio power to avoid interference. One reason for deploying a high capacity network is to create a WLAN for voice and data applications. In such a WLAN, everyone has a VoIP handset running wirelessly all the time.In general, the following table shows the standard densities for office deployments.Overcoming Physical ImpedimentsNot every potential deployment is a standard business campus.The following scenarios are a few that merit special consideration.•Open SpaceOpen spaces, such as a large foyer or an outdoor area, are very easy to cover with Wi-Fi because there are few impediments to propagation and fewer opportunities for multipath interference. In such spaces, Wi-Fi signals can propagate many hundreds of feet. This is good if you want to provide coverage for just a few users.You will run into challenges if there are many users and high capacity service goals. In these situations, it is important to tune down the RF to a minimal level. If you are using Aerohive cooperative RF control, the HiveAPs do this on their own automatically. Another trick is to take advantage of obstacles that block Wi-Fi. Look for trees or walls and put neighboring access points on either side of them. Doing so limits the interference of the two access points and allows for the installation of more access points with less interference.•Warehouse and RetailWarehouse and retail environments present many challenges. One of the largest challenges is that RF characteristics often change because of varying inventory levels and, in the case of retail, seasonal displays (such as tinsel or a stack of soda cans on an end cap). Additionally, metal shelves and high ceilings can be challenges to propagation. To resolve with these issues, it is wise to put at least one access point per aisle to ensure coverage for that aisle. This usually requires a higher density of access points than would otherwise be required.•Configuring AntennasAs anyone who has administered a WLAN system in the past knows, proper configuration of the access point antennas at the outset can save you lots of trouble. HiveAPs come standard with fixed omnidirectional antennas. You typically orient these antennas vertically, positioning the antennas on all HiveAPs in the same direction. Omnidirectional antennas create a coverage area that looks like a doughnut, broadcasting to the sides much more effectively than up or down (see Figure 1 on page 16). In general, this is good for most office environments because you have large flat floors. However, it can be a problem in environments with high ceilings.Office Requirements Expected Data Rate Using 802.11g for Each Access Point Access Point DensityCoverage (low capacity) 12 Mbps to 24 Mbps 1 access point per 8000 square feetStandard office deployment 36 Mbps 1 access point per 5000 square feetStandard office deployment with voice 54 Mbps 1 access point per 2000 – 3000 square feetNote: Data rate is not the same as TCP throughput. Because of various headers, inter-frame gaps, and session creation, real TCP throughput usually does not exceed 22 Mbps at data rates of 54 Mbps.
Chapter 1 Preparing for a WLAN Deployment16 AerohiveFigure 1  Omnidirectional Antenna Radiation PatternThe HiveAP can accommodate external antennas via coaxial jacks on its chassis (see "Antennas" on page 28). The jack is a standard male RP-SMA connector. Various patch, directional, and omnidirectional antennas can be used to change the coverage pattern. The most common external antennas are patch antennas. These are directional antennas that provide coverage in a single direction. Most commonly they have a transmission pattern as shown in Figure 2. Based on the gain, the signal will be wide (like the low gain antenna shown on top) or narrow and long (like the high gain antenna shown on the bottom). Note that the coverage patterns are not perfect for these antennas and that they often broadcast slightly in other directions than the primary one. These extra "lobes" can be seen in both of the patterns shown below.Figure 2  Directional Antenna PatternsThe following are some quick hints for deploying access points:• Standard sheetrock walls and dropped ceilings are the best locations for mounting access points.• When deploying WLANs in retail stores, doing a site survey at each store is likely to be impractical. It is more common to run detailed site surveys at a few locations and use the results to set up deployment guidelines for the remaining sites.• Be aware of metal-lined firewalls, steel pillars, and other metallic surfaces. RF signals can reflect off metal surfaces, which can cause unexpected coverage patterns. Also watch out for objects that can block or reflect signals, such as mirrors, plants, walls, steel doors, elevator shafts, and bathroom stalls.Higher GainLower Gain(Bird’s Eye View)Patch AntennasHigher Gain
Deployment Guide 17 PLANNING• The quality and performance of a Wi-Fi network is a function of the signal-to-noise ratio. To avoid noise issues, check the area for common noise generators such as industrial microwave ovens, wireless video cameras, cordless phones and headsets, and Bluetooth devices. Such devices especially cause interference in the 2.4 GHz spectrum.• Plan appropriately for high ceilings. With an omnidirectional antenna, the downward coverage is not great. In normal office space, the ceilings rarely exceed 15 feet, so this issue does not come up very often. In environments such as warehouses, where ceilings can be up to 50 feet high, ceiling-mounted access points are not optimal. It is best to deploy them on non-metallic walls about 10 feet to 15 feet above the floor. If this is not feasible, using patch antennas can help direct the RF energy downward.• In high-density or high-capacity environments, placing access points on exterior walls allows for a greater number of cells inside the building and more capacity. In other deployments, it is recommended that the outer access points be no farther than 30 feet from the exterior walls to ensure coverage.Preparing the Wired Network for WirelessOne of the advantages of moving to an Aerohive WLAN is that you do not have to make changes to the underlying network, such as putting controllers into wiring closets. This can save you considerable time and effort during installation. However, some network changes might make sense for some deployments. For example, you might want to add additional VLANs or security settings. This section covers a few of the more common considerations that IT departments are handling.• 802.1Q VLANsHiveAPs can segment users into VLANs if an administrator wants. This decision can be made by a returned RADIUS attribute or it can be configured as part of a user profile or SSID. Enterprises often set up separate VLANs for wireless and guest access, so that this traffic is segmented from the rest of the network; however, it is possible to set up any number of other VLANs for further segmentation. (For an example, see "Example 9: Creating WLAN Policies" on page 126.)•FirewallsDepending on the environment, enterprises might use firewalls to segment wired and wireless data. This can be implemented as a discrete firewall enforcing traffic between VLANs or between ports, or you might use the stateful firewall that is integrated in HiveOS (the HiveAP operating system).• RADIUS AuthenticationIf RADIUS authentication is required, then a RADIUS server must be in place and be able to support the necessary protocols for wireless—often called 802.1X EAP types: PEAP, EAP-TLS, EAP-TTLS, WEP 8021.x (dynamic WEP), LEAP, EAP-FAST, and captive web portal authentication using CHAP.• DNS and DHCP ConfigurationIf you use the Aerohive HiveManager (see the section on "Operational Considerations" on page 18), it is possible to install HiveAPs without any extra configuration and they will be able to contact HiveManager for management. If the HiveAPs are linked to a different subnet than the one to which HiveManager is connected, then you can set either a DHCP option or DNS entry to give the location of HiveManager (see "How HiveAPs Connect to HiveManager" on page 95).
Chapter 1 Preparing for a WLAN Deployment18 AerohiveOPERATIONAL CONSIDERATIONSTo make your WLAN deployment process as smooth as possible, you should consider more than just the distribution and installation of access points. You should also consider how you will manage, optimize, and troubleshoot your WLAN after deployment.TuningApproach building an enterprise WLAN with the same life-cycle approach you would apply to a wired network. After you deploy the WLAN, revisit key network engineering processes to account for changes in the environment. Watch for access points that are overloaded or are under utilized, and check for potential dead spots. Furthermore, be aware that the likely points of failure can change as the environment changes. For example, a neighboring business might install access points that cause RF interference on your network. You should schedule and perform periodic walkthroughs to ensure that the design goals of the wireless network continue to be met. The Aerohive HiveManager provides quick views into how the network is behaving, which HiveAPs are the most heavily loaded, and which have the most clients.TroubleshootingSome of the most common issues that arise after deploying a new wireless network are RF interference, RADIUS issues, and desktop client issues. The first step in troubleshooting is to look at logs and use debug commands. Aerohive offers an extensive set of event monitoring and debug tools that you can use through HiveManager, the Aerohive network management system. For additional troubleshooting, particularly of clients or neighboring networks, Aerohive recommends two tools: Ethereal Warehouser (http://www.wireshark.org/) and AirMagnet Laptop Analyzer (http://www.airmagnet.com/products/laptop.htm).ManagementCurrent Wi-Fi networks typically span an entire company and have complex security policies. Fortunately, the HiveManager Network Management System makes it simple to manage large networks from a central location. It provides a single centralized management instance for the entire wireless network. While managed HiveAPs can operate without HiveManager, it simplifies the provisioning of global policy management and centralized configuration and monitoring. HiveManager lowers operating costs by speeding deployment, configuration, and monitoring of the wireless network.Managing faults and alarms is critical to maintaining uptime. You can view and manage events through HiveManager logging. Optionally, you can use a third-party tool such as HP OpenView.HiveManager makes it easy to monitor and troubleshoot HiveAPs within a WLAN infrastructure. HiveManager can import hierarchical map views that represent the physical location of the network, from the perspective of the entire world down to the floor level.Deploying with ConfidenceMoving a large enterprise—or even a small one—to a WLAN for the very first time need not be daunting. If you have moderate experience with LAN deployments of other types and you have taken time to get answers to the important questions that will affect the network data load, you have every prerequisite for success. The bottom line is to remember to take stock of your project before you begin to ward against unforeseen costs and performance bottlenecks. If you have considered the issues and guidelines presented here, you are not far away from a successful Aerohive WLAN deployment.
Deployment Guide 19 BASIC WI-FI CONCEPTSBASIC WI-FI CONCEPTSThe goal of this section is to provide some background on Wi-Fi propagation and how to lay out a wireless network. While RF (radio frequency) engineering is a rather complicated science, this section provides a simple overview on the basics of Wi-Fi propagation and channel layout that you need to be able to install an enterprise WLAN.The first thing to know is that Wi-Fi is forgiving. Wi-Fi tends to transmit a bit farther than you expect, and even in cases of interference, it tends to just work. This can be both a blessing and a curse. It is a blessing because people will likely have access to the network, and it is a curse because your overall performance might be suboptimal without obvious symptoms, like lack of connectivity. Understanding the basics presented in this section will help ensure a high performance layout.The first concept to understand is signal strength and how it relates to throughput. Radio power is measured in dBm (decibels relative to one milliwatt) where 0 dBm = 1 milliwatt, but decibels increase using a log10 math function. Rather than dusting off your old math books and pulling out your calculator, look at the dBm-to-milliwatt converter that appears below. Often in Wi-Fi, dBm and milliwatts (mW)—and microwatts (μW)—are used interchangeably. The following table converts between the two units of measurement.In RF, there is also a relative measurement that you can use to compare two numbers. This measurement is simply dB (without the "m"). To see how this concept is applied, consider how radio signal propagation changes over a distance and how it can be affected. Figure 3 on page 20 shows signal strength over distance as a curve that has the best signal strength closer to the access point. It also shows noise. In general, noise is considered to be low-level background RF signals that can interfere with a WLAN. This noise tends to be the garbled background RF that comes from everything from the sun and stars to man-made interfering devices like Bluetooth headsets. It is impossible to block out noise and it should not be attempted. This low level of background noise is called the "noise floor".dBm-to-milliwatt20 dBm = 100 mW 2 dBm = 1.6 mW15 dBm = 32 mW 1 dBm = 1.3 mW10 dBm = 10 mW 0 dBm = 1.0 mW 5 dBm = 3.2 mW -1 dBm = 794 µW4 dBm = 2.5 mW -5 dBm = 316 µW3 dBm = 2.0 mW -10 dBm = 100 µW
Chapter 1 Preparing for a WLAN Deployment20 AerohiveFigure 3  Path Loss in an Open SpaceWhen clients send a packet, the ratio of the signal-to-noise (SNR) level defines the quality of the link, which is directly related to the performance of the network. Based on the SNR, the client and AP negotiate a data rate in which to send the packet, so the higher the SNR the better. For good performance, the SNR should be greater than 20 dB, and for optimal performance it should be at least 25 dB.Signal strength not only diminishes over distance but it can also be affected by objects in the way (see Figure 4). This can be a wall, a tree, or even a person. There is a fairly predictable dB drop through most objects that also decreases the SNR, thus decreasing the data rate. While this appears to be a bad thing, clever Wi-Fi installers use it to their advantage. It allows them to place more access points in a tighter spot by using pre-existing walls and other impediments to Wi-Fi propagation to keep them from interfering with each other.Figure 4  Path Loss through a WallSignal-to-Noise RatioDistanceNoiseReceived SignalSignal-to-Noise RatioDistanceNoiseReceived SignalWall
Deployment Guide 21 BASIC WI-FI CONCEPTSMicrowave ovens, wireless video cameras, Bluetooth headsets, and cordless phones can all interfere with Wi-Fi signals (see Figure 5). Excess noise in an environment is often difficult to diagnose and can have a major negative impact on network performance. To discover noise sources, a spectrum analysis system is needed. AirMagnet provides an affordable spectrum analysis tool that operates in the 2.4 GHz and 5 GHz spectra.Figure 5  Path Loss with Noise (from Microwave)Now that you have a sense of how Wi-Fi performance changes over distance and with noise, look at some ways to perform channel assignment. If two access points are on the same channel right next to each other, they are forced to share the same spectrum. This means that they share the 54 Mbps available in 802.11a/g rather than each being capable of 54-Mbps speeds independently. This essentially halves the bandwidth for each access point. To manage this situation, make sure that neighboring APs are on different channels and that their power is adjusted so that it does not overlap that of other APs with the same channel.In the 2.4 GHz spectrum, there are 11 channels in the United States. However, a Wi-Fi signal consumes more than one channel. Consequently, there are only 3 non-overlapping channels: 1, 6, and 11. To achieve optimal performance, you need to design a channel layout pattern such as the one on the left in Figure 6.Figure 6  Channel Layout PatternsSignal-to-Noise RatioDistanceNoiseReceived Signal646052563644406460525636444064605256364440646052563644406460525636444064605256364440646052563644407-to-1 Layout Pattern11611161611161111116 11166111611111613-to-1 Layout Pattern1161

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