site survey fundamentals

7/31/2019 Site Survey Fundamentals

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Si t e Survey Fundament alsSi t e Survey Fundament als

Chapt er 9Chapt er 9


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What is a Si t e Sur vey?What is a Si t e Sur vey?

z An RF site survey is a map to successfully

im plem ent ing a w ireless net w ork.

z

A site survey is the most important step inim plem ent ing any w ir eless net w ork.


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Prepar ing f or a Si t e SurveyPrepar ing f or a Si t e Survey

z Facil i t ies Analysis

z Purpose & Business Requi rem ent s

z Bandw id t h & Roam ing Requir ement s

z Available Resourcesz Exist ing Net w orks

z

Area Usage & Tow ers


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Facil i t y AnalysisFacil i t y Analysis

z What kind of faci l i t y is i t ?

z Consider the obvious differences that

would exist in conducting a site survey of asmall off ice with versus performing a si tesurvey of a large of f ice.


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Exist ing Net w orksExist ing Net w orks

z Is t here already a

network (wired orwireless) in place?


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Area Usage & Tow ersArea Usage & Tow ers

z Is t he wireless LAN

going t o be usedindoors, outdoors, orboth?


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Purpose & Business RequirementsPurpose & Business Requirements

z What is t he purpose of t he wireless LAN?

z What are the business requirements?


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Bandwidth & Roaming RequirementsBandwidth & Roaming Requirements

z What bandwidth and

roaming requirementsare there?


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5. 5 Mbps dat a rat e5. 5 Mbps dat a rat e


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Roam ing Requi rem ent sRoam ing Requi rem ent s

z How many users are t ypical ly in a given

area?z What t ype of appl icat ions wil l be used over

t he wireless LAN?

z Are t here any non-t ypical t imes in whichnet work needs may change for a part iculararea?

z What mobil i t y or roaming coverage isnecessary?


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Avai lable ResourcesAvai lable Resources

z What are t he available resources?

z Are facility blueprints available (electronicor print ed)?

z Are t here any previous sit e survey report s

available?z Is a facil i t ies escort or securit y badge

required?

z Is physical access t o wiring closets and t heroof available if needed?


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Security RequirementsSecurity Requirements

z What level of network security is

necessary?z What corporat e pol icies are in place

regarding wireless LAN securit yimplement at ion and management ?


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Preparation ChecklistPreparation Checklistz Bui lding blueprint s

z Previous w ir eless LAN sit e survey docum ent at ion

z Current net w ork diagram

z A meet ing wi th the network admin is t ra tor , the bu i ld ingmanager, t he secur i t y of f icer .

z

Access to al l areas of the faci l i ty to be affected by thew i rel ess LAN

z Access t o w ir ing closet s

z Access t o roof ( i f out door ant ennas are ant icipat ed)

z Future construction plans, i f avai lable.


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Site Survey EquipmentSite Survey Equipment

z Access Point

z PC Card and Ut i l i t iesz Lapt ops & PDAs

z Paper

z Outdoor Surveys

z Spect rum Analyzer

z Net w ork Analyzerz Si t e Survey Ki t Checkl ist


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Access PointAccess Point

z Used during a site survey should have

vari able out put power and ext ernal ant ennaconnectors.

z The var iable output power feature a l lowsfor easy sizing of coverage cells during the

si t e survey.


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PC Card and Ut i l i t iesPC Card and Ut i l i t ies

z Signal st rengt h (m easured i n dBm)

z Noise f loor (m easured in dBm)

z Signal- t o-noise rat io ( SNR ) (measured in

dB)z Link speed


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Laptops &Laptops & PDAsPDAs

z A laptop computer or PDA unit is used by

the site surveyor for checking for signalstrength and coverage while roamingaround t he f ac i l i t y.


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Out door SurveysOut door Surveys

z Outdoor si te surveys wi l l take more t ime,

ef for t , and equipment than wi l l indoorsurveys


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Spect rum AnalyzerSpect rum Analyzer


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Net w ork AnalyzerNet w ork Analyzer

z Pick up any

packet s beingt ransmi t t ed bywireless LANsand wi l l

providedetai ledinf ormat ion onchannel s inuse, di st ance,and signalstrength.


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Si t e Survey Ki t Checkl istSi t e Survey Ki t Checkl istz Lapt op and/ or PDA included sit e survey ut i l i t y soft w arez Wirel ess PC card wi t h dr i ver & ut i l i t y sof t ware

z Access poi nt s or br idges as neededz Bat t ery pack & DC-t o-AC convert erz Clipboard, pen, penci ls, notebook paper, gr id paper, & hi- l i t erz Bluepr int s & net w ork diagramsz Indoor & outdoor ant ennasz Cables & connect orsz Binoculars and t w o-way r adiosz Umbr el la and/ or rain sui tz Specialized software or hardware such as a spectrum analyzer or

snif ferz Tools, double-sided tape, and other i tems for temporary hardware

mount ingsz Secure & padded equipment case for housing computers, tools,

secure documents dur ing the survey and travel to and from the

survey sit e


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Conduct ing a Si t e SurveyConduct ing a Si t e Survey

z Indoor Surveys

z Outdoor Surveys


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RF Inf orm at ion Gat her ingRF Inf orm at ion Gat her ingz Range & coverage pat t erns

z

Dat a rat e boundar iesz Documentat ion

z Throughput t est s & capaci t y planning

z

In t er ference sourcesz Wired dat a connect ivi t y & AC pow erc requ irement s

z Out door ant enna p lacement

z

Spot checks


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Range and Coverage Pat t ernsRange and Coverage Pat t erns


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Marked up f l oor planMarked up f l oor plan


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Dat a Rat e Boundar iesDat a Rat e Boundar ies


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Int er f erence SourcesInt er f erence Sourcesz Are there any exist ing wireless LANs in use in or

near t he faci l i t y?z Are t here any plans for future wireless LAN

inst al lat ions other t han t he one in quest ion?

If t his is a mult i-tenant building, aret here any ot herorganizat ions wit hin

t he building t hathave wireless LANs orsources of RF? Are anyot her organizat ions

planning wireless LANimplementations?


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Int er f erence SourcesInt er f erence Sources

z Are there any ot her common sources of RF

int erference in t he 2.4 GHz band in use int he facil i t y?

z In case 802.11a net works are to be

inst al led, are t here any RF sources in the 5GHz range?


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ObstacleObstacle -- Induced Signal LossInduced Signal Loss


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Spot ChecksSpot Checks

z Coverage in per im et er areas

z Over lapping coverage f or seamless roaming

z Co-channel and adjacent channel

int erf erence in al l areas


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Si t e Survey Repor t ingSi t e Survey Repor t ingz Report Format

z

Purpose and Business Requirementsz Methodology

z RF Coverage Areas

z Throughputz Interference

z Problem Areas

z Drawings

z Hardware placement & configurationinformation

site survey fundamentals

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