Wi-Fi Blog Let8217s prøver å gjenskape all awesomeness fra dag 2 av Wireless LAN Pros Conference. Så mange flotte presentasjoner, av mange talentfulle presentatører, som dekker noe svært relevant Wi-Fi-innhold. Da ble dagen sterk med en annen fantastisk maker-sesjon. Noen høydepunkter fra Dag 2: Samle krav før du designer Lee Badman (kabletnot) gjorde en fantastisk å levere en like underholdende og viktig melding om viktigheten av å samle krav før du designer. Eksempel: Krav 1 8211 Systemet kan8217t suge Les mer rsaquo Hei, It8217 har vært en fin første dag her på den fullbookede Wireless LAN Pros Conference (WLPC) 2017 i Phoenix, med tonnevis av flotte høyttalere og boatloads av Wi-Fi kunnskap deling. Par av høydepunktene på den første dagen under. Vi vil også prøve å følge opp med sammendrag av dagene 2 amp 3, så hold deg oppdatert. Les mer rsaquo Besøk Aruba Atmosfære i Nashville 26. februar 8211 3. mars Kom og gi oss en klem, vi står på stand 5. Jussi gir også en presentasjon på konferansen. Don8217t savner det Emne: 822010 Essentials Hver ingeniør må vite8221 Dato for forstørrelse: onsdag 1. mars, 1:45 8211 15:00 Sted: Gaylord Opryland Resort. Les mer rsaquo AP Navn sending er en valgfri funksjon implementert av noen av Wi-Fi-leverandørene som aktiverer et tilgangspunkt for å annonsere enhetens vertsnavn, vanligvis innenfor beaconrammer. Når denne funksjonen er aktivert, tillater Ekahau Site Survey å identifisere tilgangspunktnavnene under en undersøkelse. Denne muligheten til å identifisere og fylle AP-navnet. Les mer rsaquo Q: Du er en WLAN-konsulent med oppgave å designe et WLAN med CAD-planer. Etter å ha importert. dwg-filen og tilordnet veggtyper ved hjelp av veiviseren for veiviser, forbereder du deg for å legge til simulerte AP-er i prosjektet. Du oppdager at AP, Antenne eller AP-Antenna-kombinasjonen du ønsker å designe med, ikke er. Les mer rsaquo Gå til BICSI Vinterkonferanse i Tampa denne måneden Møt oss på messe 509 for å si hei og se en demonstrasjon Åh, og vi har noen utstillingsgulvpasker for deg, så ta kontakt hvis du vil få en. ) Don8217t savner også Jussi8217s presentasjon på konferansen. Emne: 8220Walking er bra. Les mer rsaquo Vår nettinarieplan for 2017 fyller seg pent og vi har en flott serie med gjesteforelesere for dette året. Sjekk ut listen nedenfor, og vær sikker på å registrere deg for e-postvarsler for blogg for å motta påminnelser for de kommende webinarene. 7 måter å mislykkes som en trådløs ekspert med Steven Heinsius av Cisco. Les mer rsaquo 2016 var et flott år for oss på Ekahau. Mange nye ting, mange endringer. Heres bare noen få: 1) Produkt: Utgitt versjoner 8.5 og 8.6 med spektrumanalysatorintegrasjon, helt ny Real-Time Frequency Monitor-funksjon, og et par hundre andre ting. Mac-versjonen ble publisert som beta. 2) Markedsføring: Vi gjorde mange show: Cisco Live. Les mer rsaquo Gjestens høyttaler på vårt neste webinar er Steven Heinsius fra Cisco selv. Steven er en av Cisco8217s høyest karakteriserte høyttalere. Når Steven snakker, møter konferanserommet, uansett hvilken størrelse, opp 8211 og tankene blåses til venstre og høyre. Webinaret er dedikert til de beste metodene for å utføre en trådløs nettverksinstallasjon. Don8217t. Les mer rsaquo En stor takk til alle våre 2016 webinar guest presenters Hvis du savnet noen av våre tidligere webinarer, sjekk ut opptakene nedenfor eller se hele listen over webinaropptak på vår YouTube-kanal. Slideshare bruker informasjonskapsler for å forbedre funksjonalitet og ytelse , og å gi deg relevant reklame. Hvis du fortsetter å surfe på nettstedet, godtar du bruken av informasjonskapsler på denne nettsiden. Se vår brukeravtale og personvernregler. Slideshare bruker informasjonskapsler for å forbedre funksjonalitet og ytelse, og for å gi deg relevant annonsering. Hvis du fortsetter å surfe på nettstedet, godtar du bruken av informasjonskapsler på denne nettsiden. Se vår personvernerklæring og brukeravtale for detaljer. Utforsk alle favorittemner i SlideShare-appen Få SlideShare-appen til å lagre for senere, selv frakoblet Fortsett til mobilnettstedet Opplast innloggingsoppføring Dobbeltklikk for å zoome ut Del denne SlideShare LinkedIn Corporation kopien 2017Cisco CleanAir - Cisco Unified Wireless Network Design Guide Spectrum intelligence (Spectrum intelligence SI) er en kjerne-teknologi designet for å proaktivt håndtere utfordringene i et delt trådløst spektrum. I hovedsak bringer SI avanserte interferensidentifikasjonsalgoritmer som de som brukes i militæret til den kommersielle trådløse nettverksverdenen. SI gir synlighet til alle brukere av det felles spekteret, både Wi-Fi-enheter og utenlandske interferere. For hver enhet som opererer i det ulisensierte bandet, forteller SI deg: Hva er det Hvor er det Hvordan påvirker det Wi-Fi-nettverket Cisco har tatt det dristige skrittet for å integrere SI direkte i Wi-Fi-silisium - og infrastrukturløsningen. Den integrerte løsningen, referert til som Cisco CleanAir, betyr at WLAN IT-leder for første gang kan identifisere og lokalisere ikke-802.11-interferenskilder, som øker linjen på enkel styring og sikkerhet for trådløse nettverk. Viktigst, et integrert SI setter scenen for en ny rase av Radio Resource Management (RRM). I motsetning til tidligere RRM-løsninger som bare kan forstå og tilpasse seg andre Wi-Fi-enheter, åpner SI banen for en andre generasjons RRM-løsning som er fullt klar over alle brukerne av det trådløse spekteret, og kan optimalisere ytelsen i ansiktet av disse varierte enhetene. Det første viktige punktet som må gjøres er det fra et designperspektiv. CleanAir-aktiverte tilgangspunkter (APs) er bare at AP og ytelsen er nesten identisk med de 1140 AP-ene. Utforming for Wi-Fi-dekning er det samme med begge. CleanAir eller interferensidentifikasjonsprosesser er en passiv prosess. CleanAir er basert på mottakeren, og for at klassifisering skal fungere, må kilden være høy nok til å bli mottatt ved 10 dB over støynivået. Hvis nettverket ditt distribueres på en slik måte at kundene dine og AP-ene kan høre hverandre, kan CleanAir høre godt nok til å varsle deg om forstyrrende forstyrrelser i nettverket ditt. Dekningskravene til CleanAir er beskrevet i dette dokumentet. Det er noen spesielle tilfeller avhengig av CleanAir-implementeringsrutinen du velger. Teknologien er designet for å komplimentere dagens beste praksis i Wi-Fi-distribusjon. Dette inkluderer distribusjonsmodeller av andre brukte teknologier som Adaptive WIPS, Voice, og plassering. Cisco anbefaler at du har kunnskap om CAPWAP og Cisco Unified Wireless Network (CUWN). Informasjonen i dette dokumentet er basert på disse programvarene og maskinvareversjonene: CleanAir-kompatible AP-er er Aironet 3502e, 3501e, 3502i og 3501i Cisco WLAN Controller (WLC) som kjører versjon 7.0.98.0 Cisco Wireless Control System (WCS) som kjører versjon 7.0.164.0 Cisco Mobility Services Engine (MSE) kjører versjon 7.0 Se Cisco Technical Tips-konvensjoner for mer informasjon om dokumentkonvensjoner. CleanAir er et system, ikke en funksjon. CleanAir-programvare og maskinvarekomponenter gir muligheten til å måle Wi-Fi-kanalens kvalitet nøyaktig og identifisere ikke-Wi-Fi-kilder for kanalinterferens. Dette kan ikke gjøres med et standard Wi-Fi-brikkesett. For å forstå designmål og krav til vellykket implementering er det nødvendig å forstå hvordan CleanAir jobber på høyt nivå. For de som allerede er kjent med Cisco Spectrum Expert teknologi, er CleanAir et naturlig evolusjonært skritt. Men det er en helt ny teknologi ved at dette er en bedriftsbasert distribuert spektrumanalyseteknologi. Som sådan er det ligner på Cisco Spectrum Expert på noen punkter, men veldig forskjellig i andre. Komponentene, funksjonene og funksjonene diskuteres i dette dokumentet. De nye CleanAir-kompatible AP-ene er Aironet 3502e, 3501e, 3502i og 3501i. E angir ekstern antenne, jeg betegner intern antenne. Begge er fullt funksjonelle neste generasjon 802.11n AP og kjører på standard 802.3af strøm. Figur 1: C3502E og C3502I CleanAir Capable APs Spectrum Analysis-maskinvaren er integrert direkte i radioens brikkesett. Dette tillegget tilsatte over 500 K logiske porter til radiosilikonet, og har gitt en utrolig nær kopling av funksjonene. Det er mange andre tradisjonelle funksjoner som har blitt lagt til eller forbedret med disse radioene. Men det er utenfor rammen av dette dokumentet, og disse er ikke dekket her. Tilstrekkelig er det å si at det på egenhånd uten CleanAir pakker 3500-serien APs mange funksjoner og ytelse inn i en attraktiv og robust enterprise AP. Den grunnleggende Cisco CleanAir-arkitekturen består av Cisco CleanAir-aktiverte AP og en Cisco WLAN-kontroller (WLC). Cisco Wireless Control System (WCS) og Mobility Services Engine (MSE) er valgfrie systemkomponenter. For å få full verdi fra informasjonen som CleanAir-systemet leverer, er WCS og MSE sammen nøkkelen til å utnytte en bredere effektivitet av CleanAir. Dette gir brukergrensesnitt for avanserte spektrumfunksjoner som historiske diagrammer, sporingsinterferens enheter, plasseringstjenester og konsekvensanalyse. En AP utstyrt med Cisco CleanAir-teknologi samler inn informasjon om ikke-Wi-Fi-interferenskilder, behandler den og videresender til WLC. WLC er en integrert kjerne del av CleanAir-systemet. WLC kontrollerer og konfigurerer CleanAir-kompatible AP, samler og behandler spektrumdata og gir den til WCS og / eller MSE. WLC gir lokale brukergrensesnitt (GUI og CLI) for å konfigurere grunnleggende CleanAir-funksjoner og - tjenester og vise dagens spektruminformasjon. Cisco WCS gir avanserte brukergrensesnitt for CleanAir som inkluderer funksjonstillatelse og konfigurasjon, konsolidert visningsinformasjon, historiske luftkvalitetsregistre og rapporteringsmotorer. Figur 2: Logisk systemflyt Cisco MSE er nødvendig for lokalisering og historisk sporing av interferensenheter, og sørger for koordinering og konsolidering av interferensrapporter på tvers av flere WLCs. Merk: En enkelt WLC kan kun konsolidere interferensvarsler for AP-er som er direkte koblet til den. Koordinering av rapporter som kommer fra AP-er tilknyttet forskjellige kontroller krever MSE som har et bredt syn på alle CleanAir AP og WLCs. Hjertet i CleanAir-systemet er Spectrum Analysis Engine (SAgE) ASIC, spektrumanalysatoren på en brikke. Det er imidlertid mye mer enn bare en spektrumanalysator. Kjernen er en kraftig 256-punkts FFT-motor som gir en fantastisk 78 KHz RBW (Oppløsning Båndbredde, minimumsoppløsningen som kan vises) Formålet med puls - og statistikkinnsamlingsmotorer, samt DSP Accelerated Vector Engine (DAvE). SAgE-maskinvaren går parallelt med Wi-Fi-brikkesettet og behandler nær linjeprisinformasjon. Alt dette gir ekstrem nøyaktighet og vekt for stort antall like interferenskilder, uten straff i gjennomstrømming av brukertrafikk. Wi-Fi-brikkesettet er alltid på linje. SAgE-skanninger utføres en gang per sekund. Hvis en Wi-Fi-preambel oppdages, blir den sendt direkte til brikkesettet og påvirkes ikke av den parallelle SAgE-maskinvaren. Ingen pakker går tapt under SAgE-skanning, SAgE er deaktivert mens en Wi-Fi-pakke behandles gjennom mottakeren. SAgE er veldig rask og nøyaktig. Selv i et travelt miljø er det mer enn nok skanningstid for å vurdere miljøet nøyaktig. Hvorfor betyr RBW Hvis du må telle og måle forskjellen mellom flere Bluetooth-radioer som hopper med smale signaler på 1600 humle per sekund, må du skille forskjellige humlehoppere i prøven din hvis du vil vite hvor mange er det. Dette tar oppløsning. Ellers vil det alle se ut som en puls. SAgE gjør dette, og det gjør det bra. På grunn av DAvE og å være tilknyttet ombord, er muligheten til å behandle flere samspillere parallelt, der. Dette øker hastigheten, som gjør det mulig å behandle datastrømmen i nær sanntid. Nær sanntid betyr det en viss forsinkelse, men det er så minimalt at det tar en datamaskin å måle den. Cisco CleanAir APs produserer to grunnleggende typer informasjon for CleanAir-systemet. En IDR (Interference Device Report) genereres for hver klassifisert interferenskilde. AQIs (Air Quality Index) rapporter genereres hvert 15. sekund og sendes til Cisco IOS reg for gjennomsnittlig og eventuell overføring til kontrolleren basert på det konfigurerte intervallet. CleanAir meldinger håndteres på kontrollplanet i to nye CAPWAP-meldingstyper: Spectrum Configuration og Spectrum Data. Formater for disse meldingene er listet her: Spektrumdata AP WLC Interferensrapporten (IDR) er en detaljert rapport som inneholder informasjon om en klassifisert interferensanordning. Denne rapporten er svært lik den informasjonen som vises i Cisco Spectrum Expert Active Devices, eller Devices View. Aktive IDRer kan ses på WLC GUI og CLI for alle CleanAir-radioer på den WLC. IDRer sendes bare til MSE. Dette er formatet for en IDR-rapport: Tabell 1 - Interferensapportapport Merk: Interferenskilder merket som Security Interferers er brukerens betegnelse og kan konfigureres via Wireless gt 802.11abgn gt interferens for sikkerhetsavbrudd for sikkerhetsalarm. Enhver interferenskilde som er klassifisert, kan velges for en sikkerhetsfellevarsel. Dette sender en sikkerhetsfelle til WCS eller en annen konfigurert felle mottaker basert på hvilken type interferer som er valgt. Denne fellen inneholder ikke den samme informasjonen som en IDR. Det er bare en måte å utløse en alarm på tilstedeværelsen av interfereren. Når en interferer er utpekt som en sikkerhetsproblem, er den merket som sådan ved AP og er alltid inkludert i de ti enhetene som rapporteres fra AP, uavhengig av alvorlighetsgraden. IDR-meldinger sendes i sanntid. Ved påvisning er IDR merket som en enhet opp. Hvis det stopper en enhet, sendes meldingen. En oppdateringsmelding sendes hvert 90 sekund fra AP for alle enheter som nå spores. Dette gjør det mulig for statusoppdateringer av sporede interferenskilder og en revisjonsspor i tilfelle en opp - eller nedmelding ble tapt i transitt. Luftkvalitet (AQ) rapportering er tilgjengelig fra ethvert spektrum i stand til AP. Luftkvalitet er et nytt konsept med CleanAir og representerer et godhetsmål for det tilgjengelige spekteret og indikerer kvaliteten på båndbredden tilgjengelig for Wi-Fi-kanalen. Luftkvalitet er et rullende gjennomsnitt som evaluerer virkningen av alle klassifiserte interferensanordninger mot et teoretisk perfekt spektrum. Skalaen er 0-100 med 100 som god. AQ-rapporter sendes uavhengig for hver radio. Den nyeste AQ-rapporten er synlig på WLC GUI og CLI. AQ rapporter lagres på WLC og pollet av WCS regelmessig intervall. Standard er 15 minutter (minimum) og kan forlenges til 60 minutter på WCS. For tiden evaluerer de fleste standard Wi-Fi-brikker spekteret ved å spore all pakkenergi som kan demoduleres på mottak, og alle pakkenergiene som den overfører. Enhver energi som forblir i spekteret som ikke kan demoduleres eller regnes for av RXTX-aktivitet, klumpes i en kategori som kalles støy. I virkeligheten er mye støy faktisk rester fra kollisjoner, eller Wi-Fi-pakker som faller under mottakstærskelen for pålitelig demodulering. Med CleanAir tas en annen tilnærming. All energi innenfor spekteret som absolutt ikke er Wi-Fi, er klassifisert og regnskapsført. Vi kan også se og forstå energi som er 802.11 modulert og klassifisere energi som kommer fra samkanal og tilstøtende kanalkilder. For hver klassifisert enhet beregnes en alvorlighetsindeks (se avsnittet alvorlighetsgrad), et positivt heltall mellom 0 og 100 hvor 100 er den mest alvorlige. Forstyrrelsesgraden blir deretter trukket fra AQ-skalaen (starter ved 100 gode) for å generere den faktiske AQ for en kanalradio, AP, etasje, bygning eller campus. AQ er så en måling av virkningen av alle klassifiserte enheter på miljøet. Det er definert to AQ rapporteringsmoduser: normal og rask oppdatering. Normal modus er standard AQ rapporteringsmodus. Hverken WCS eller WLC henter rapporter ved normal oppdateringshastighet (standard er 15 minutter). WCS informerer Controller om standard polling perioden, og WLC instruerer AP å endre AQ gjennomsnitt og rapporteringsperiode tilsvarende. Når brukeren driller seg til Monitor gt Access Points og velger et radiogrensesnitt fra WCS eller WLC, blir den valgte radioen plassert i rask oppdateringsrapporteringsmodus. Når en forespørsel er mottatt, instruerer Controlleren AP om å endre standard AQ-rapporteringsperioden midlertidig til en fast rask oppdateringshastighet (30 sek.), Noe som gjør det mulig å nærme sanntid i AQ-endringer på radionivå. Standard rapporteringsstatus er PÅ. Tabell 3: Luftkvalitetsrapport Merk: I forbindelse med spektrumrapportering representerer luftkvalitet interferens fra ikke-Wi-Fi-kilder og Wi-Fi-kilder som ikke kan oppdages av en Wi-Fi AP under normal drift (for eksempel gammel 802.11-frekvensbeholder enheter, endrede 802.11 enheter, tilstøtende overlappende kanalinterferens, etc). Informasjon om Wi-Fi-basert interferens samles inn og rapporteres av AP ved hjelp av Wi-Fi-brikken. En lokalmodus-AP samler inn AQ-informasjon for gjeldende serverkanal (e). En Monitor Mode AP samler inn informasjon for alle kanaler som er konfigurert under skannealternativer. Standard CUWN-innstillingene for land, DCA og alle kanaler støttes. Når en AQ-rapport er mottatt, utfører kontrolløren nødvendig behandling og lagrer den i AQ-databasen. Som tidligere nevnt, er CleanAir integrering av Cisco Spectrum Expert-teknologi innenfor en Cisco AP. Mens likheter kan eksistere, er dette en ny bruk av teknologien, og mange nye konsepter presenteres i denne delen. Cisco Spectrum Expert introduserte teknologi som kunne identifisere ikke-Wi-Fi-kilder til radioenergi positivt. Dette tillot operatøren å fokusere på informasjon som driftssyklus og driftskanaler, og ta en informert beslutning om enheten og dens innvirkning på Wi-Fi-nettverket. Spectrum Expert tillater operatøren å låse det valgte signalet i søkeren til søkeren og fysisk lokalisere enheten ved å gå rundt med instrumentet. Designmålet med CleanAir er å gå flere skritt videre, ved å i hovedsak fjerne operatøren videre fra ligningen og automatisere flere av oppgavene innen systemadministrasjon. Fordi du kan vite hva enheten er og hva den påvirker, kan bedre beslutninger gjøres på et systemnivå om hva du skal gjøre med informasjonen. Flere nye algoritmer er utviklet for å legge til intelligens i arbeidet som ble startet med Cisco Spectrum Expert. Det er alltid tilfeller som krever fysisk deaktivering av en forstyrrelsesenhet, eller avgjørelse om en enhet og innvirkning som involverer mennesker. Det overordnede systemet skal helbrede det som kan helbredes og unngå det som kan unngås, slik at innsatsen for å gjenvinne påvirket spektrum kan være en proaktiv øvelse i stedet for en reaktiv. Lokal modus AP (anbefalt) (LMAP) En Cisco CleanAir AP-operasjon i LMAP-modus serverer klienter på den tildelte kanalen. Det overvåker også Spektret på den kanalen og den kanalen BARE. Tett silisiumintegrasjon med Wi-Fi-radioen gjør at CleanAir-maskinvaren kan lytte mellom trafikk på kanalen som for øyeblikket blir servert, med absolutt ingen straff til gjennomstrømming av vedlagte klienter. Det er line rate deteksjon uten å forstyrre klient trafikk. Det er ingen CleanAir dwells behandlet under normal avgangskanaler. Ved normal drift utfører en CUWN Local Mode AP en passiv avskanning fra de alternative tilgjengelige kanalene i 2,4 GHz og 5 GHz. Avkanalscanninger brukes til systemvedlikehold, for eksempel RRM-metriske og falsk deteksjon. Frekvensen av disse skanningene er ikke tilstrekkelig til å samle tilbakebetalinger som kreves for positiv enhetsklassifisering, slik at informasjonen som oppsamles under denne skanningen, blir undertrykt av systemet. Øk frekvensen av avgangskanaler er også ikke ønskelig, da det tar bort fra tiden som radiotjenesten trafikk. Hva betyr alt dette En CleanAir AP i LMAP-modus skanner bare en kanal for hvert bånd kontinuerlig. I normale virksomhetsdensiteter bør det være mange AP-er på samme kanal, og minst én på hver kanal som antar at RRM håndterer kanalvalg. En interferenskilde som bruker smalbåndsmodulasjon (opererer på eller rundt en enkelt frekvens) blir bare oppdaget av AP som deler frekvensområdet. Hvis interferensen er en frekvens hoppetype (bruker flere frekvenser som vanligvis dekker hele båndet), oppdages det av alle AP som kan høre det som opererer i bandet. Figur 4: Eksempel på LMAP AP-deteksjon I 2,4 GHz har LMAPs tilstrekkelig tetthet til generelt å sikre minst tre punkter for klassifisering. Det kreves minst tre deteksjonspunkter for plasseringsoppløsning. I 5 GHz er det 22 kanaler som opererer i USA, og dermed er det ikke sannsynlig at deteksjonstettheten og tilstrekkelig stedstetthet er mindre. Men hvis interferens opererer på en kanal som er opptatt av en CleanAir AP, oppdager den den og varsler eller tar skritt for å redusere om disse funksjonene er aktivert. Mest sett interferens er begrenset til 5,8 GHz-delen av bandet. Dette er hvor forbrukerinnretninger bor og dermed hvor det mest sannsynlig vil oppstå. Du kan begrense kanalplanen din for å tvinge flere AP-er til dette rommet hvis du ønsker det. Men det er egentlig ikke berettiget. Husk at forstyrrelser er bare et problem hvis det bruker spektrum du trenger. Hvis AP-en din ikke er på den kanalen, er det sannsynlig at du fortsatt har mye spekter igjen for å flytte inn. Hva om behovet for å overvåke alle 5 GHz er drevet av sikkerhetspolitikk Se AP-definisjonen Monitor Mode nedenfor. Skjermmodus AP (valgfritt) (MMAP) En CleanAir Monitor-modus AP er dedikert og serverer ikke klienttrafikk. Det gir full tid skanning av alle kanaler ved hjelp av 40 MHz dwells. CleanAir støttes i skjermmodus sammen med alle andre nåværende skjermmodusprogrammer, inkludert Adaptive WIPS og lokaliseringsutvidelse. I en dobbel radiokonfigurasjon sikrer dette at alle bandkanaler rutinemessig skannes. CleanAir-aktiverte MMAP-er kan distribueres som en del av en omfattende distribusjon av CleanAir-aktiverte LMAPs for å gi ytterligere dekning i 2,4 og 5 GHz, eller som en frittstående overleggsløsning for CleanAir-funksjonalitet i en eksisterende ikke-CleanAir AP-distribusjon. I et scenario som nevnt ovenfor hvor sikkerhet er en primær driver, er det sannsynlig at Adaptive WIPS også vil være et krav. Dette støttes samtidig med CleanAir på samme MMAP. Det er noen forskjellige forskjeller i hvordan noen av funksjonene støttes når de brukes som en overleggsløsning. Dette er dekket i diskusjonen om distribusjonsmodeller i dette dokumentet. Spectrum Expert Connect Mode SE Connect (valgfritt) En SE Connect AP er konfigurert som en dedikert spektrumsensor som tillater tilkobling av Cisco Spectrum Expert-programmet som kjører på en lokal vert for å bruke CleanAir AP som en ekstern spektrumsensor for den lokale applikasjonen. Forbindelsen mellom Spectrum Expert og den eksterne AP omgår kontrolleren på dataplanet. AP er fortsatt i kontakt med kontrolleren på kontrollplanet. Denne modusen tillater visning av råspektrumdataene, for eksempel FFT-plott og detaljerte målinger. All CleanAir-systemfunksjonalitet er suspendert mens AP er i denne modusen, og ingen klienter blir servert. Denne modusen er kun ment for fjerning av feilsøking. Spectrum Expert-applikasjonen er et MS Windows-program som kobles til AP via en TCP-sesjon. Den kan støttes i VMWare. I CleanAir ble begrepet Air Quality introdusert. Luftkvalitet er en måling av prosentsatsen som spektret ved en bestemt observert beholder (radio, AP, Band, Floor, Building) er tilgjengelig for Wi-Fi-trafikk. AQ er en funksjon av alvorlighetsindeksen, som beregnes for hver klassifisert interferenskilde. Alvorlighetsindeksen evaluerer hver ikke-Wi-Fi-enhet over luftegenskapene og beregner hvilken prosentvis tid spekteret ikke er tilgjengelig for Wi-Fi med denne enheten til stede. Luftkvalitet er et produkt av alvorlighetsindeksene for alle klassifiserte interferenskilder. Dette blir deretter rapportert som den samlede luftkvaliteten av radiokanalen, båndet eller RF-forplantningsdomenet (gulv, bygning) og representerer den totale kostnaden mot tilgjengelig lufttid for alle ikke-Wi-Fi-kilder. Alt som er igjen er teoretisk tilgjengelig for Wi-Fi-nettverket for trafikk. Dette er teoretisk fordi det er en hel vitenskap bak å måle effektiviteten til Wi-Fi-trafikk, og dette er utenfor rammen av dette dokumentet. Men å vite at forstyrrelser er eller ikke påvirker at vitenskapen er et nøkkelmål hvis planen din er vellykket i å identifisere og redusere smertepunkter. Hva gjør en forstyrrelseskilde alvorlig Hva bestemmer om det er ikke et problem Hvordan bruker jeg denne informasjonen til å administrere nettverket Disse spørsmålene er omtalt i dette dokumentet. I de enkleste termer kommer ikke-Wi-Fi-bruk ned til hvor ofte en annen radio bruker nettverksspekteret (Driftssyklus) og hvor høyt er det i forhold til mine radioer (RSSIlocation). Energi i kanalen som ses av et 802.11-grensesnitt som prøver å få tilgang til kanalen, oppfattes som en opptatt kanal hvis den er over en viss energitærskel. Dette bestemmes av klar kanal vurdering (CCA). Wi-Fi bruker en lytte før tilgang til tilgangskanalen for tilgang til gratis PHY-tilgang. Dette er per CSMA-CA (-Kollisjonssvikt). RSSI av interfereren bestemmer om det kan høres over CCA-terskelen. Driftssyklusen er på tidspunktet for en sender. Dette bestemmer hvor vedvarende en energi er i kanalen. Jo høyere arbeids syklus, desto mer er kanalen blokkert. Enkel alvorlighetsgrad kan demonstreres på denne måten, og deretter bruker du strengt RSSI og Driftssyklusen. For illustrasjonsformål antas en enhet med 100 pluss syklus. Figur 5: Når interferenssignalet minker - AQI øker I diagrammet i denne figuren kan du se at da signalstyrken til interferensen minker, øker den resulterende AQI. Teknisk sett, så snart signalet faller under -65 dBm, er AP ikke lenger blokkert. Du trenger å tenke over virkningen dette har på klienter i cellen. 100 duty cycle (DC) sikrer konstant forstyrrelse av klientsignaler med utilstrekkelig SNR i nærvær av støyen. AQ øker raskt når signalet strømmer under -78 dBm. Så langt er det to av de tre største konsekvensene av interferens som er definert i den alvorlighetsbaserte Air Quality metriske: Interferens er rettferdig når man ser på 100 DC. Dette er typen signal som oftest brukes i demonstrasjoner av påvirkning av interferens. Det er lett å se i et spektrogram, og det har en svært dramatisk innvirkning på Wi-Fi-kanalen. Dette skjer også i den virkelige verden, for eksempel i analoge videokameraer, bevegelsesdetektorer, telemetriutstyr, TDM-signaler og eldre trådløse telefoner. Det er mange signaler som ikke er 100 DC. Faktisk er mye av forstyrrelsen som oppstår, forstyrrelser av denne typen: variabel til minimal. Her blir det litt tøffere å ringe alvorlighetsgraden. Eksempler på interferens av denne typen er Bluetooth, trådløse telefoner, trådløse høyttalere, telemetri enheter, eldre 802.11fh utstyr osv. For eksempel gjør et enkelt Bluetooth-headsett ikke mye skade i et Wi-Fi-miljø. Imidlertid kan tre av disse med overlappende forplantning koble fra en Wi-Fi-telefon hvis den har gått gjennom. I tillegg til CCA er det bestemmelser i 802.11-spesifikasjonene som for eksempel vinduet, som trengs for å imøtekomme tidstro av forskjellige basisprotokoller. Deretter legger du til disse ulike QOS-mekanismene. Alle disse mediereservasjonene brukes av forskjellige applikasjoner for å maksimere effektiviteten i luften og minimere kollisjoner. Dette kan være forvirrende. Men fordi alle grensesnittene på luften deltar og er enige om samme gruppe standarder, fungerer det veldig bra. Hva skjer med dette bestilte kaoset når du introduserer en meget spesifikk energi som ikke forstår påstandsmekanismene eller for den saks skyld ikke engang deltar i CSMA-CA Vel, mayhem faktisk, i større eller mindre grad. Det avhenger av hvor opptatt mediet er når forstyrrelsen oppleves. Figur 6: Lignende, men forskjellige kanaler Driftssykluser Du kan ha to identiske signaler i forhold til Driftssyklusen målt i kanalen og amplituden, men har to helt forskjellige nivåer av interferens opplevd på et Wi-Fi-nettverk. En rask gjentatt kort puls kan være mer ødeleggende for Wi-Fi enn en relativt langsom gjentatt fett. Se på en RF-jammer, som effektivt slår ned en Wi-Fi-kanal og registrerer svært liten pluss syklus. For å gjøre en riktig jobbevaluering trenger du en bedre forståelse av minimumsinterferensintervallet som er innført. Minimum interferensintervallet står for at in-channel-pulsene avbryter Wi-Fi-aktiviteten i en periode som er lengre enn deres faktiske varighet, på grunn av tre effekter: Hvis det allerede teller ned, må Wi-Fi-enheter vente en ekstra DIFS-periode etter forstyrrelsen puls. Denne saken er typisk for tungt lastede nettverk, hvor forstyrrelsen starter før Wi-Fis-back-off-telleren har talt ned til null. Hvis en ny pakke kommer til å overføres midtforstyrrelser, må Wi-Fi-enheten dessuten slå seg av igjen ved å bruke en tilfeldig verdi mellom null og CWmin. Denne saken er typisk for lettlastede nettverk, hvor forstyrrelsen starter før Wi-Fi-pakken kommer til MAC for overføring. Hvis Wi-Fi-enheten allerede sender en pakke når forstyrrelsesbruken kommer, må hele pakken sendes videre med den neste høyere verdien av CW, opp til CWmax. Denne saken er typisk hvis forstyrrelsen starter andre, delvis gjennom en eksisterende Wi-Fi-pakke. Hvis backtidspunktet utløper uten en vellykket retransmisjon, er neste tilbaketrekking dobbelt det forrige. Dette fortsetter med mislykket sending frem til CWmax er nådd, eller TTL overskrides for rammen. Figur 7 - For 802.11bg CWmin 31, for 802.11a CWmin er 15, begge har CWmax på 1023 I et ekte Wi-Fi-nettverk er det vanskelig å estimere den gjennomsnittlige varigheten av disse tre effektene fordi de er funksjoner av antall enheter i BSS, overlappende BSSs, enhetsaktivitet, pakkelengder, protokoller for støttet hastighet, QoS og nåværende aktivitet. Derfor er det nest beste å lage en beregning som forblir konstant som referansepunkt. Dette er hva Alvorlighet gjør. Den måler effekten av en enkelt interferer mot et teoretisk nettverk, og opprettholder en konstant rapport av alvorlighetsgrad uavhengig av underliggende utnyttelse av nettverket. Dette gir oss et relativt poeng å se på på tvers av nettverksinfrastrukturer. Svaret på spørsmålet hvor mye ikke-Wi-Fi-interferens er dårlig er subjektiv. I lettlastede nettverk er det ganske mulig å ha nivåer av ikke-Wi-Fi-forstyrrelser som går ubemerket av brukerne og administratorer. Dette er det som fører til problemer i slutten. Naturen til trådløse nettverk er å bli busier over tid. Success leads to faster organizational adoption, and to new applications being committed. If there is interference present from day one, it is quite likely that the network have a problem with this when it becomes busy enough. When this happens it is difficult for people to believe that something that has been fine seemingly all along is the culprit. How do we use CleanAirs Air Quality and Severity metrics AQ is used to develop and monitor a baseline spectrum measurement and alert on changes indicating a performance impact. You can also use it for long term trend assessment through reporting. Severity is used to evaluate interference impact potential and prioritize individual devices for mitigation. Non Wi-Fi transmitters are less than friendly when it comes to unique characteristics that can be used to identify them. That is essentially what made the Cisco Spectrum Expert solution so revolutionary. Now with CleanAir there are multiple APs that potentially all hears the same interference at the same time. Correlating these reports to isolate unique instances is a challenge that had to be solved to provide advanced features, such as location of interference devices, as well as an accurate count. Enter the Pseudo MAC or PMAC. Because an analog video device does not have a MAC address or, in several cases, any other identifying digital tag an algorithm had to be created to identify unique devices being reported from multiple sources. A PMAC is calculated as part of the device classification and included in the interference device record (IDR). Each AP generates the PMAC independently, and while it is not identical for each report (at a minimum the measured RSSI of the device is likely different at each AP), it is similar. The function of comparing and evaluating PMACs is called merging. The PMAC is not exposed on customer interfaces. Only the results of merging are available in the form of a cluster ID. This merging is discussed next. Figure 8: Raw Detection of Interference In this graphic you can see several APs all reporting DECT, such as Phone energy. However, the APs in this graphic are actually reporting on the presence of two distinct DECT, such as Phone sources. Before the assignment of a PMAC and subsequent merging, there is only the device classification, which can be misleading. PMAC gives us a way to identify individual interference sources, even if they do not have any logical information that can be used such as an address. There are several APs all reporting a similar device. For each reporting AP, the PMAC is assigned to the classified signal. The next step is to combine the PMACs that are likely the same source device to a single report for the system. This is what merging does, consolidating multiple reports to a single event. Merging uses spatial proximity of the reporting APs. If there are six similar IDRs with five from APs on the same floor, and another one from a building a mile away, it is unlikely this is the same interferer. Once a proximity is established, a probability calculation is run to further match the distinct IDRs that belong and the result is assigned to a cluster. A cluster represents the record of that interference device and captures the individual APs that are reporting on it. Subsequent IDR reports or updates on the same device follow the same process and instead of creating a new cluster are matched to an existing one. In a cluster report, one AP is designated as the Cluster Center. This is the AP that hears the interference the loudest. Figure 9: After the PMAC Merge - APs hearing the same physical device are identified The merging algorithm runs on every CleanAir enabled WLC. A WLC performs the merge function for all IDRs from APs that are physically associated to it. All IDRs and resulting merged clusters are forwarded to an MSE, if it exists in the system. Systems with more than one WLC require an MSE to provide merging services. The MSE performs a more advanced merging function that seeks to merge clusters reported from different WLCs and extract location information to be reported to the WCS. Why do we need an MSE to merge IDRs across multiple WLCs Because a single WLC only knows the neighbors for the APs physically associated to it. RF Proximity cannot be determined for IDRs coming from APs located on different controllers unless you have a full system view. The MSE has this view. How physical proximity is determined differs, depending on how you implement CleanAir as well. For LMAP pervasive implementations, the APs all participate in Neighbor Discovery, so it is an easy matter to consult the RF neighbor list and determine spatial relationships for IDRs. In an MMAP overlay model you do not have this information. MMAPs are passive devices and do not transmit neighbor messages. Therefore, establishing the spatial relationship of one MMAP to another MMAP has to be done using X and Y coordinates from a system map. In order to do this, you also need the MSE that knows about the system map and can provide merging functions. More detail on the different modes of operation as well as practical deployment advice is covered in the deployment models section. Deploying APs in mixed mode LMAP CleanAir APs with an overlay of MMAP CleanAir APs is the best approach to high accuracy and total coverage. You can use the neighbor list created by the received neighbor messages for the MMAP as part of the merging information. In other words, if you have a PMAC from a LMAP AP and a PMAC from a MMAP, and the MMAP shows the LMAP AP as a neighbor, then the two can be merged with a high degree of confidence. This is not possible with CleanAir MMAPs deployed within legacy standard APs because those APs do not produce IDRs to compare with the merge process. The MSE and the X and Y references are still needed. Determining the location of a radio transmitter in theory is a fairly straightforward process. You sample the received signal from multiple locations and you triangulate based on the received signal strength. On a Wi-Fi network clients are located and Wi-Fi RFID tags with good results as long as there is a sufficient density of receivers and adequate signal to noise ratio. Wi-Fi clients and tags send probes on all supported channels regularly. This ensures that all APs within range hear the client or TAG regardless of the channel it is serving. This provides a lot of information to work with. We also know that the device (tag or client) subscribes to a specification that governs how it operates. Therefore, you can be certain that the device is using an omni-directional antenna and has a predictable initial transmit power. Wi-Fi devices also contain logical information that identifies it as a unique signal source (MAC address). Note: There is no guarantee of accuracy for location of non - Wi-Fi devices. Accuracy can be quite good and useful. However, there are a lot of variables in the world of consumer electronics and unintentional electrical interference. Any expectation of accuracy that is derived from current Client or Tag location accuracy models does not apply to non - Wi-Fi location and CleanAir features. Non Wi-Fi interference sources pose a special opportunity to get creative. For instance, what if the signal you are trying to locate is a narrow video signal (1 MHz) that is only affecting one channel In 2.4 GHz this probably works fine because most organizations have sufficient density to ensure that at least three APs on the same channel will hear it. However, in 5 GHz this is more difficult since most non-Wi-Fi devices only operate in the 5.8 GHz band. If RRM has DCA enabled with country channels, the number of APs actually assigned in 5.8 GHz declines because its goal is to spread out channel re-use and make use of open spectrum. This sounds bad, but remember if you are not detecting it, then it is not interfering with anything. Therefore, is really not a problem from a standpoint of interference. This is however an issue if your deployment concerns extend to security. In order to gain proper coverage you require some MMAP APs in addition to the LMAP APs to ensure full spectral coverage within the band. If your only concern is securing the operating space you are using, then you can also limit the channels available in DCA and force increased density in the channel ranges you wish to cover. The RF parameters of non - Wi-Fi devices can and do vary widely. An estimate has to be made based on the type of device that is being detected. The starting RSSI of the signal source needs to be known for good accuracy. You can estimate this based on experience, but if the device has a directional antenna the calculations will be off. If the device runs on battery power and experiences voltage sags or peaks as it operates, this will change how the system sees it. A different manufacturers implementation of a known product might not meet the expectations of the system. This will affect the calculations. Fortunately, Cisco has some experience in this area, and non-Wi-Fi device location actually works quite well. The point that needs to be made is that the accuracy of a non - Wi-Fi device location has a lot of variables to consider, accuracy increases with power, duty cycle, and number of channels hearing the device. This is good news because higher power, higher duty cycle, devices that impact multiple channels is generally what is considered to be severe as far as interference to the network goes. Cisco CleanAir APs, first and foremost, are access points. What this means is that there is nothing inherently different about deploying these APs over deploying any other currently shipping AP. What has changed is the introduction of CleanAir. This is a passive technology that does not impact the operation of the Wi-Fi network in any way, other than the noted mitigation strategies of ED-RRM and PDA. These are only available in a Greenfield installation and configured off by default. This section will deal with the sensitivity, density and the coverage requirements for good CleanAir functionality. These are not all that different from other established technology models such as a Voice, Video, or Location deployment. Valid deployment models for CleanAir products and feature functionality. Table 5: CleanAir Deployment Models vs Features CleanAir is a passive technology. All it does is hear things. Because an AP hears a lot farther than it can effectively talk this makes it a simple task to do a correct design in a Greenfield environment. Understanding how well CleanAir hears, and how classification and detection works, will give you the answers you need for any configuration of CleanAir. CleanAir depends on detection. The detection sensitivity is more generous than Wi-Fi throughput requirements with a requirement of 10 dB SNR for all classifiers, and many operable down to 5 dB. In most conceivable deployments where coverage is pervasive, there should not be any issues in hearing and detecting interference within the network infrastructure. How this breaks down is simple. In a network where the average AP power is at or between 5-11 dBm (power levels 3-5) then a class 3 (1 mW0 dBm) Bluetooth device should be detected down to -85 dBm. Raising the noise floor above this level creates a slight degradation in detection dB for dB. For design purposes it is worth adding a buffer zone by setting the minimum design goal to say -80. This will provide sufficient overlap in most conceivable situations. Note: Bluetooth is a good classifier to design for because it represents the bottom end power wise in devices you would be looking for. Anything lower generally does not even register on a Wi-Fi network. It is also handy (and readily available) to test with because it is a frequency hopper and will be seen by every AP, regardless of mode or channel in 2.4 GHz. It is important to understand your interference source. For instance Bluetooth. Here are multiple flavors of this in the market presently and the radios and specification have continued to evolve as most technologies do over time. A Bluetooth headset that you would use for your cell phone is most likely a class3 or class2 device. This operates on low power and makes ample use of adaptive power profiles, which extends battery life and reduces interference. A Bluetooth headset will transmit frequently on paging (Discovery mode) until associated. Then it will go dormant until needed in order to conserve power. CleanAir will only detect an active BT transmission. No RF, then nothing to detect. Therefore, if you are going to test with something, make sure it is transmitting. Play some music across it, but force it to transmit. Spectrum Expert Connect is a handy way to verify if something is, or is not transmitting and will end a lot of potential confusion. CleanAir was designed to compliment what is largely considered a normal density implementation. This definition of Normal continues to evolve. For instance, just five years ago 300 APs on the same system was considered a large implementation. In a lot of the world it still is. Numbers of 3,000-5,000 APs with many hundreds of them sharing direct knowledge through RF propagation are routinely seen. What is important to understand is: CleanAir LMAP supports the assigned channel only . Band Coverage is implemented by ensuring that channels are covered. The CleanAir AP can hear very well, and the active cell boundary is not the limit. For Location solutions, the RSSI cutoff value is -75 dBm. A minimum of three quality measurements is required for Location Resolution. In most deployments it is hard to image a coverage area that will not have at least three APs within ear shot on the same channel in 2.4 GHz. If there are not, then location resolution suffers. Add a Monitor Mode AP and use the guidelines. Remember that the location cutoff is -75 dBm corrects this because an MMAP listens to all channels. In locations where there is minimal density location resolution is likely not supported. But, you are protecting the active user channel extremely well. Also in such an area, you are generally not talking about a lot of space so locating an interference source does not pose the same problem as a multifloor dwelling. Deployment considerations come down to planning the network for desired capacity, and ensuring that you have the correct components and network paths in place to support CleanAir functions. RF proximity and the importance of RF Neighbor Relations cannot be understated. Make sure to understand PMAC and the merging process well. If a network does not have a good RF design, the neighbor relations is generally affected. This affects CleanAir performance. If you plan to install CleanAir MMAPs as an overlay to an existing network there are some limitations you need to keep in mind. CleanAir 7.0 software is supported on all of Ciscos shipping controllers. Each model controller supports the maximum rated AP capacity with CleanAir LMAPs. There are limits in the number of MMAPs that can be supported. The maximum number of MMAPs is a function of memory. The controller must store AQ details for each monitored channel. An LMAP requires two channels storage of AQ information. However, an MMAP is passively scanning and the channel data can be 25 channels per AP. Use the table below for design guidance. Always refer to the current release documentation for current information by release. Table 6: MMAP limits on WLCs Note: The numbers quoted for clusters (merged interference reports) and device records (individual IDR Reports before merging) are generous and highly unlikely to be exceeded in even the worst environments. Suppose you simply want to deploy CleanAir as a sensor network to monitor and be alerted about non - Wi-Fi interference. How many Monitor Mode APs (MMAPs) do you need The answer is generally 1-5 MMAP to LMAP radios. This of course depends on your coverage model. How much coverage do you get with an MMAP AP Quite a bit actually since you are strictly listening. The coverage area is far greater than if you also had to communicate and transmit. How about you visualize this on a map (you can use any planning tool available following a similar procedure as described below) If you have WCS and already have the system maps built, then this is an easy exercise. Use the planning mode in theWCS maps. Select Monitor gt Maps. Select the map you want to work with. In the right hand corner of the WCS screen use the radio button to select Planning Mode, then click go. Figure 10: WCS Planning mode Select the AP type. Use the default antennas for internal or change to match your deployment: 1 AP TX Power for both 5 GHz and 2.4 GHz is 1 dBm Class3 BT 1 mW Select ADD AP at the bottom. Figure 11: Add AP in WCS planner Move the AP to place on your map and select apply. The heat map populates. Choose -80 dBm for the RSSI cutoff at the top of the map, the map re-draws if this is a change. Here is what your CleanAir MMAP covers for 1 dBm out to -80 dBm. These results show a cell with a radius of 70 feet or 15,000 ft2 of coverage. Figure 12: Example Coverage of CleanAir MMAP using 1 dBm power and -80 dBm cutoff for coverage Note: Keep in mind that this is a predictive analysis. The accuracy of this analysis depends directly on the accuracy of the maps used to create it. It is beyond the scope of this document to provide a step by step instruction on how to edit maps within a WCS. A good question you want to ask is are these MMAPs going to be deployed strictly for CleanAir Or, are you going to take advantage of the many benefits that can be derived from the inclusion of monitoring APs in your network All of these applications work with CleanAir enabled APs. For Adaptive wIPS, refer to the Cisco Adaptive wIPS Deployment Guide as the coverage recommendation of Adaptive wIPS are similar, but dependent on your goals and customers needs. For location services ensure that you review and understand the deployment requirements for your technology. All of these solutions are complimentary with CleanAir design goals. Why should I not mix CleanAir LMAP and Legacy LMAP APs in the same physical area This question pertains to this use case: I currently have non CleanAir APs deployed (1130,1240, 1250, 1140) in local mode. I want to add just a few CleanAir APs to increase my coveragedensity. Why cant I just add some APs and get all the CleanAir features This is not recommended because CleanAir LMAPs only monitor the serving channel and all CleanAir features rely on measurement density for quality. This installation would result in indiscriminate coverage of the band. You could well end up with a channel (or several) that has no CleanAir coverage at all. However with the base installation, you would be using all of the channels available. Assuming RRM is in control (recommended) it is entirely possible that all of the CleanAir APs could be assigned to the same channel in a normal installation. You spread them out to try to get the best spatial coverage possible, and that actually increases the odds of this. You certainly can deploy a few CleanAir APs in with an existing installation. It is an AP and would function fine from a client and coverage standpoint. CleanAir functionality would be compromised and there is no way to really guarantee what the system would or would not tell you regarding your spectrum. There are far too many options in density and coverage which can be introduced to predict. What would work AQ would be valid for the reporting radio only. This means it is only relevant for the channel that it is serving, and this could change at any time. Interference alerts and zone of impact would be valid. However, any location derived would be suspect. Best to leave that out all together and assume closest AP resolution. Mitigation strategies would be ill-advised to operate because most of the APs in the deployment would not operate the same way. You would be able to use the AP to look at spectrum from Spectrum Connect. You would also have the option to temporarily switch to monitor mode at any time in order to perform a full scan of the environment. While there are some benefits, it is important to understand the pitfalls and adjust expectations accordingly. It is not recommended, and issues arising from this type of deployment are not supportable based on this deployment model. A better option if your budget does not support adding APs that do not serve client traffic (MMAP) is to collect enough CleanAir APs to deploy together in a single area. Any area that can be enclosed on a map area can contain a Greenfield CleanAir deployment with full feature support. The only caveat on this would be location. You still need enough density for location. While it is not advisable to mix legacy APs and CleanAir APs operating in local mode in the same deployment area, what about running both on the same WLC This is perfectly fine. Configurations for CleanAir are only applicable to APs that support CleanAir. For instance, in the RRM configuration parameters for both 802.11an and 802.11bgn you see both ED-RRM and PDA configurations for RRM. One might consider that these would be bad if applied to an AP that was not a CleanAir capable AP. However, even though these features do interact with RRM, they can only be triggered by a CleanAir event and are tracked to the AP that triggers them. There is no chance that a non - CleanAir AP has these configurations applied to them, even though the configuration applies to the whole RF group. This raises another important point. While CleanAir configurations on a 7.0 or later controller are effective for any CleanAir AP that attaches to that controller, ED-RRM and PDA are still RRM configurations. Implementation of CleanAir draws on many of the architecture elements present within the CUWN. It has been designed to fortify and add functionality to every system component, and draws on information that is already present top enhance usability and tightly integrate the features. This is the overall breakdown classified into license tiers. Notice that it is not necessary to have a WCS and or the MSE in the system to get good functionality from the system. The MIBs are available on the controller and are open to those who wish to integrate these features into an existing management system. For a basic CleanAir system, the requirements are a CleanAir AP and a WLC that runs version 7.0 or later code. This provides both a CLI and the WLC GUI for customer interface and all CURRENT data is displayed, including interference sources reported by band and the SE connect feature. Security Alerts (Interference sources designated as a security concern) are merged before triggering the SNMP trap. As previously stated though, WLC merging is limited to the view of just the APs associated to that controller. There is no historical support of trend analysis supported directly from the WLC interfaces. Adding a BASIC WCS and managing the controller adds trending support for AQ and alarms. You receive historical AQ reporting, threshold alerts through SNMP, RRM Dashboard support, Security alert support, and many other benefits including the client troubleshooting tool. What you do not get is Interference history and location. This is stored in the MSE. Note: Adding an MSE to the WCS for location requires both a WCS plus license and Context Aware feature licenses for the MSE. Adding an MSE and location solution to the network supports the historical IDR reporting as well as location based functions. In order to add this to an existing CUWN solution, you require a plus license on the WCS, and CAS or Context Aware licenses for the location targets. 1 Interferer 1 CAS license Interferers are managed through context aware and an interference that is tracked in the system is the same as a client for purposes of licensing. There are many options on how to manage these licenses and what they are used for. On the WLC configuration you can limit which interference sources are tracked for location and reporting in the maps by selecting them from the controller gt Wireless gt 802.11ba gt CleanAir menu. Interference devices selected there are reported, and choosing to ignore them keeps them out of the location system and MSE. This is completely separate from what is actually happening at the AP. All classifiers are always detected at the AP level. This determines what isdone with an IDR report. If you use this to limit reporting, then it is reasonably safe because all energy is still seen at the AP and is captured in AQ reports. AQ reports break out the contributing interference sources by category. If you eliminate a category here to conserve licensing, it is still reported as a contributing factor in AQ and you are alerted if you exceed a threshold. Figure 13: WLC CleanAir configuration - reporting For instance, suppose the network you are installing is in a retail environment, and the map is cluttered with Bluetooth targets coming from headsets. You could eliminate this by de-selecting the Bluetooth Link. If at some time later Bluetooth became a problem, you would see this category rise in your AQ reporting and could re-enable at will. There is no interface reset required. You also have the element manager under the MSE configurations: WCS gt Mobility Services gt Your MSE gt Context Aware Service gt administration gt tracking Parameters. Figure 14: MSE Context Aware element manager This gives the user complete control to assess and manage what licenses are used for and how they are divided among target categories. Table 7: CleanAir Features matrix by CUWN Component The minimum required configuration for Cisco CleanAir is the Cisco CleanAir AP, and a WLC which runs version 7.0. With these two components you can view all of the information provided by CleanAir APs. You also get the mitigation features available with the addition of CleanAir APs and the extensions provided through RRM. This information is viewable via the CLI or the GUI. The focus is on the GUI in this section for brevity. WLC Air Quality and Interference Reports On the WLC you can view current AQ and Interference reports from the GUI menu. In order to view interference reports, there must be interference active as the report is for current conditions only Interference Device Report Select Monitor gt Cisco CleanAir gt 802.11a802.11b gt Interference Devices. All active interference devices being reported by CleanAir Radios are listed by RadioAP reporting. Details include AP Name, Radio Slot ID, Interference Type, Affected Channels, Detected Time, Severity, Duty Cycle, RSSI, Device ID and Cluster ID. Figure 15: Accessing WLC Interference Device Report Air Quality Report Air Quality is reported by Radiochannel. In the example below, AP0022.bd18.87c0 is in monitor mode and displays AQ for channels 1-11. Selecting the radio button at the end of any line allows the option of showing this information in the radio detail screen, which includes all information gathered by the CleanAir interface. Figure 16: WLC Interference Device Report CleanAir Configuration AQ and Device Traps control CleanAir allows you to determine both the threshold and types of traps that you receive. Configuration is by band: Wireless gt 802.11ba gt CleanAir. Figure 17: WLC CleanAir configuration You can enable and disable CleanAir for the entire controller, suppress the reporting of all interferers, and determine which interferers to report or ignore. Selecting specific interference devices to ignore is a useful feature. For instance you might not want to track all Bluetooth headsets because they are relatively low impact and you have a lot of them. Choosing to ignore these devices simply prevents it from being reported. The RF that comes from the devices is still calculated into the total AQ for the spectrum. EnableDisable (on by default) the AirQuality trap. AQI Alarm Threshold (1 to 100). When you set the AirQuality threshold for traps, this tells the WLC at what level you want to see a trap for AirQuality. The default threshold is 35, which is extremely high. For testing purposes setting this value to 85 or 90 proves more practical. In practice, the threshold is variable so you can tune it for your specific environment. Enable Interference for Security Alarm. When you add the WLC to a WCS system, you can select this check box to treat interference device traps as security Alarm traps. This allows you to select the types of devices that appear in the WCS alarm summary panel as a security trap. Dodo not trap device selection allows control over the types of devices that generates interferencesecurity trap messages. Lastly, the status of ED-RRM (Event Driven RRM) is displayed. Configuration for this feature is covered under the Event Driven RRM - EDRRM section later in this document. Rapid Update Mode - CleanAir Detail Selecting Wireless gt Access Points gt Radios gt 802.11ab shows all of the 802.11b or 802.11a radios attached to the WLC. Selecting the radio button at the end of the line allows you to see either the radio detail (traditional non CleanAir metrics of utilization, noise and the like) or CleanAir detail. Figure 18: Accessing CleanAir Detail Selecting CleanAir produces a graphic (default) display of all CleanAir information pertaining to that radio. The information displayed is now in Rapid Update Mode by default. This means it is being refreshed every 30 seconds from the AP instead of the 15 minute averaging period displayed in system level messaging. From top to bottom, all interferers being detected by that radio along with the interference parameters of Type, Affected Channels, Detection Time, Severity, Duty Cycle, RSSI, Device ID, and Cluster ID. Figure 19: CleanAir Radio Detail Page From this figure, the displayed charts include: Air Quality by Channel Non - Wi-Fi Channel Utilization Air Quality by Channel displays the Air Quality for the channel that is being monitored. Non Wi-Fi channel utilization shows the utilization that is directly attributable to the interference device being displayed. In other words, if you get rid of that device you regain that much spectrum for Wi-Fi applications to use. There are two categories that are introduced here under Air Quality details: Adjacent Off Channel Interference (AOCI)This is interference from a Wi-Fi device that is not on the reporting operating channel, but is overlapping the channel space. For channel 6, the report would identify interference attributable to an AP on channels 4, 5, 7, and 8. UnclassifiedThis is energy that is not attributable definitively to Wi-Fi or non - Wi-Fi sources. Fragments, collisions, things of this nature frames that are mangled beyond recognition. In CleanAir guesses must not be made. Interference power displays the receive power of the interferer at that AP. The CleanAir Detail page displays information for all monitored channels. The examples above are from a Monitor Mode (MMAP) AP. A local Mode AP would show the same detail, but only for the current served channel. CleanAir Enabled RRM There are two key Mitigation Features that are present with CleanAir. Both rely directly on information that can only be gathered by CleanAir. Event Driven RRM Event Driven RRM (ED-RRM) is a feature that allows an AP in distress to bypass normal RRM intervals and immediately change channels. A CleanAir AP is always monitoring AQ, and reports on this in 15 second intervals. AirQuality is a better metric than relying on normal Wi-Fi chip noise measurements because AirQuality only reports on Classified Interference devices. This makes AirQuality a reliable metric because it is known what is reported is not because of Wi-Fi energy (and hence not a transient normal spike). For ED-RRM a channel change only occurs if the Air Quality is sufficiently impacted. Because Air Quality can only be affected by a classified known to CleanAir non - Wi-Fi source of interference (or an adjacent overlapping Wi-Fi channel), the impact is understood: Not a Wi-Fi anomaly A crisis condition at this AP Crisis means that CCA is blocked. No clients or the AP can use the current channel. Under these conditions RRM would change the channel on the next DCA pass. However, that could be a few minutes away (up to ten minutes depending on when the last run was performed), or the user could have changed the default interval and it could be longer (selected an anchor time and interval for longer DCA operation). ED-RRM reacts very quickly (30 seconds) so the users that change with the AP are likely unaware of the crisis that was close. 30 -50 seconds is not long enough to call a help desk. The users that do not are in no worse shape than they would have been in the first place. In all cases the interference source was identified and the AP change reason logs that source, and the users that have poor roaming receives an answer as to why this change was made. The channel change is not random. It is picked based on device contention, thus it is an intelligent alternate choice. Once the channel is changed there is protection against triggering ED-RRM again in a hold down timer (60 seconds). The event channel is also marked in RRM DCA for the affected AP to prevent a return to the event channel (3 hours) in the event the interferer is an intermittent event and DCA does not see it immediately. In all cases the impact of the channel change is isolated to the affected AP. Suppose a hacker or someone of ill intent fires up a 2.4 GHz jammer and all channels are blocked. First off, all the users within the radius are out of business anyway. However, suppose ED-RRM triggers on the all APs that can see it. All APs change channels once, then hold for 60 seconds. The condition would be met again, so another change would fire with the condition still being met after 60 seconds. There would be no channels left to change to and ED-RRM activity would stop. A security alert would fire off on the jammer (default action) and you would need to provide a location (if with MSE) or nearest detecting AP. ED-RRM would log a major AQ event for all affected channels. The reason would be RF jammer. The event would be contained within the effected RF domain and well alerted. Now the next question that is generally asked, quotwhat if the hacker walks around with the jammer, would that not that cause all the APs to trigger ED-RRMquot. Sure you are going to trigger ED-RRM channel changes on all the APs that have ED-RRM enabled. However, as the jammer moves so does its effect and usability is restored as soon as it moves. It really does not matter because you have a hacker walking around with a jammer in their hand disconnecting users everywhere they go. This is a problem in itself. ED-RRM does not compound that issue. CleanAir on the other hand is also busy alerting, locating, and providing the location history of where they went and where they are. These are good things to know in such a case. Configuration is accessed under Wireless gt 802.11a802.11b gt RRM gt DCA gt Event Driven RRM . Figure 20: Event Driven RRM Configuration Note: Once ED-RRM is triggered on an APChannel the AP is prevented from returning to that channel for three hours. This is to prevent thrashing if the signal source is intermittent in nature. Persistent Device Avoidance Persistent Device Avoidance is another mitigation feature that is only possible with CleanAir APs. A device that operates periodically, such as a microwave oven, can introduce destructive levels of interference while it is operating. However, once it is no longer in use the air goes quiet again. Devices such as video cameras, outdoor bridge equipment, and microwave ovens are all examples of a type of device called persistent. These devices can operate continuously or periodically, but what they all have in common is that they do not move frequently. RRM of course sees levels of RF noise on a given channel. If the device is operating long enough RRM even moves an active AP off the channel that has interference. However, once the device goes quiet, it is likely that the original channel presents as the better choice once again. Because each CleanAir AP is a spectrum sensor the center of the interference source can be evaluated and located. Also, you can understand which APs are affected by a device that you know is there, and potentially operates and disrupts the network when it does. Persistent Device Avoidance allows us to log the existence of such interference and remember that it is there so you do not place an AP back on the same channel. Once a Persistent Device has been identified it is remembered for seven days. If it is not seen again then it is cleared from the system. Each time you see it, the clock starts over. Note: Persistent Device Avoidance information is remembered at the AP and Controller. Rebooting either re-sets the value. Configuration for Persistent Device Avoidance is located at Wireless gt 802.11a802.11b gt RRM gt DCA gt Avoid Devices . In order to see if a radio has logged a Persistent Device you can view the status at Wireless gt Access Points gt Radios gt 802.11ab gt . Select a radio. At the end of the line click the radio button and select CleanAir RRM. Figure 21: CleanAir Persistent Device Avoidance status Spectrum Expert Connect CleanAir APs can all support the Spectrum Expert connect mode. This mode places the APs radios into a dedicated scanning mode that can drive the Cisco Spectrum Expert application across a network. The Spectrum Expert console functions as if it had a local Spectrum Expert card installed. Note: A routable network path must exist between the Spectrum Expert host and the target AP. Ports 37540 and 37550 must be open to connect. The Protocol is TCP, and the AP is listening. Spectrum Expert connect mode is an enhanced monitor mode, and as such the AP does not serve clients while this mode is enabled. When you initiate the mode the AP reboots. When it re-joins the controller it is in Spectrum Connect mode and have generated a session key for use to connect the application. All that is required is Cisco Spectrum Expert 4.0 or later, and a routable network path between the application host and the target AP. In order to initiate the connection, start by changing the mode on from Wireless gt Access Points gt All APs . Figure 22: AP Mode Configuration Go to AP Mode, and select SE-Connect. Save the configuration. You receive two warning screens: one advising that SE-connect mode is not a client-serving mode, the second warning that the AP is rebooted. Once you have changed the mode and saved the configuration navigate to the Monitor gt Access Points screen. Monitor the AP status and reload. Once the AP rejoins and reloads navigate back to the AP configuration screen, you need the NSI Key for the session that is displayed there. You can copy and paste the NSI key for the inclusion in launching Spectrum Expert. Figure 23: NSI Key generated You need Cisco Spectrum Expert 4.0. Once installed, launch Spectrum Expert. On the initial splash screen you see a new option, Remote Sensor. Select Remote Sensor and paste in the NSI Key, and tell Spectrum Expert the IP address of the AP. Select which radio you wish to connect to and click OK. Figure 24: Cisco Spectrum Expert Sensor connect screen When you add a WCS to the feature mix you get more display options for CleanAir information. The WLC can display current information, but with WCS the ability to track, monitor, alert, and report historical AirQuality levels for all CleanAir APs is added. Also, the ability to correlate CleanAir information to other award winning dashboards within WCS allows the user to fully understand their spectrum like never before. WCS CleanAir Dashboard The home page has several elements added and is customizable by the user. Any of the elements displayed on the home page can be re-arranged to user preferences. That is beyond the scope of this discussion, but keep it in mind as you use the system. What is being presented here is simply the default view. Selecting the CleanAir tab takes you to the CleanAir information available on the system. Figure 25: WCS Home Page Note: The default settings for the page include a top 10 interferers report by band in the right hand corner. If you do not have an MSE, this report does not populate. You can edit this page and add or delete components to customize it to your liking. Figure 26: WCS CleanAir Dashboard Charts displayed on this page display the running historical averages and minimums for CleanAir spectrum events. The average AQ number is for the entire system as displayed here. The minimum AQ chart for example tracks, by band, the minimum reported AQ received from any specific radio on the system in any 15 minute reporting period. You can use the charts to quickly identify historical minimums. Figure 27: Minimum Air Quality history chart Selecting the Enlarge Chart button on the bottom right in any chart object produces a pop-up window with an enlarged view of the chart in question. A mouse hover in any chart produces a time and date stamp, and AQ level seen for the reporting period. Figure 28: Enlarged Minimum Air Quality Chart Knowledge of the date and time gives you the information that you need to search for the particular event, and gather additional details such as APs that registered the event and device types operating at that time. AQ threshold alarms are reported to the WCS as performance alarms. You can also view them through the Alarm Summary panel at the top of the home page. Figure 29: Alarm Summary panel Either Advanced Search or simply selecting performance category from the alarm summary panel (provided you have a performance alarm) yields a list of performance alarms that contain details about a particular AQ event that is below the configured threshold. Figure 30: Air Quality Threshold Alarms Selecting a particular event displays the detail related to that event including the date, time, and most importantly the reporting AP. Figure 31: Performance Alarm Detail Configurations for Air Quality Thresholds is located under Configure gt Controller, either from the WCS GUI or the Controller GUI. This can be used for all CleanAir Configurations. The best practice is to use the WCS once you have assigned a controller to it. In order to generate performance alarms, you can set the AQ threshold for a low threshold such as 90 or even 95 (remember that AQ is good at 100 and bad at 0). You need some interference to trigger it such as a microwave oven. Remember to put a cup of water in it first and run it for 3-5 minutes. Air Quality History Tracking Reports AirQuality is tracked on each CleanAir AP at the radio level. The WCS enables historical reports for monitoring and trending AQ in your infrastructure. Reports can be accessed by navigating to the report launchpad. Select Reports gt Report Launchpad. CleanAir reports are at the top of the list. You can choose to look at Air Quality vs Time or Worst Air Quality APs. Both reports should be useful in tracking how Air Quality changes over time and identifying areas that require some attention. Figure 32: Report Launchpad CleanAir Maps Monitor gt Maps Selecting Monitor gt Maps displays the maps configured for the system. Average and minimum AQ numbers are presented in hierarchical fashion corresponding to the container levels of campus, building, and floor. For instance, at the building level the AverageMinimum AQ is the average of all CleanAir APs contained in the building. The minimum is the lowest AQ reported by any single CleanAir AP. Looking at a floor level, the average AQ represents the average of all APs located on that floor and the minimum AQ is that of the single worst AQ from an AP on that floor. Figure 33: Maps main page - showing Air Quality Hierarchy Selecting a map for a given floor provides detail relevant to the selected floor. There are a lot of ways that you can view the information on the map. For instance, you can change the AP tags to display CleanAir information such as CleanAir Status (shows which APs are capable), minimum or average AQ values, or Average and Minimum values. The values are relevant to the band selected. Figure 34: AP Tags show lots of CleanAir information You can see the interferers that are being reported by each AP in several ways. Hover over the AP, select a radio, and select the show interferers hotlink. This produces a list of all Interference detected on that interface. Figure 35: Viewing Interference Devices detected on an AP Another interesting way to visualize the impact of interference on the map is to select the interference tag. Without the MSE, you cannot locate interference on the map. However, you can select show interference labels, which are labels with the interferers currently being detected is applied to all CleanAir radios. You can customize this to limit the number of interferers displayed. Selecting the hotlink in the tab allows you to zoom in to the individual interferer details, and all interferers are displayed. Note: CleanAir APs can track unlimited numbers of interferers. They only report on the top 10 ordered by severity, with preference being given to a security threat. Figure 36: Interference Tag being displayed on all CleanAir APs A useful way to visualize non - Wi-Fi interference and its effect is to view AQ as a heatmap on the map display. Do this by selecting heatmaps and selecting Air Quality. You can display the average or the minimum AQ. The map is rendered using the coverage patterns for each AP. Notice that the upper right corner of the map is white. No AQ is rendered there because the AP is in monitor mode and passive. Figure 37: Air Quality Heat Map CleanAir Enabled RRM Dashboard CleanAir allows you to see what is in our spectrum that is non - Wi-Fi. In other words, all those things that were considered just noise can now be broken down to understand if and how it is impacting your data network. RRM can and does mitigate noise by selecting a better channel. When this occurs the solution is generally better than it was, but you are still letting something that is not your data network occupy your spectrum. This reduces the overall spectrum available to your data and voice applications. Wired and Wireless networks differ in that on a wired network if you need more bandwidth you can install more switches, or ports, or Internet connections. The signals are all contained within the wire and do not interfere with one another. In a wireless network, however, there is a finite amount of spectrum available. Once used, you cannot simply add more. The CleanAir RRM Dashboard on the WCS allows you to understand what is going on in your spectrum by tracking non - Wi-Fi interference as well as Signal from our network, Interference from foreign networks and balancing all within the spectrum that is available. The solutions that RRM provides do not always seem optimal. However, there is often something that you cannot see which causes two APs to operate on the same channel. The RRM Dashboard is what we use to track events that affect the balance of spectrum and provide answers as to why something is the way it is. CleanAir information being integrated to this dashboard is a big step forward to total control of the spectrum. Figure 38: CleanAir RRM Channel Change reasons from RRM Dashboard Channel Change reasons now include several new categories which refine the old Noise category (anything that is not Wi-Fi is recognized as noise by Cisco and all other competitors): Noise (CleanAir) represents non - Wi-Fi energy in the spectrum as being a cause or a major contributor to a channel change. Persistent Non-WiFi interference indicates that a persistent interferer has been detected and logged on an AP, and the AP changed channels to avoid this interference. Major Air Quality Event is the reason for a channel change invoked by the Event Driven RRM feature. Other there is always energy present in the spectrum that is not demodulated as Wi-Fi, and cannot be classified as a known interference source. The reasons for this are many: the signals are too corrupted to separate, left over remnants from collisions is one possibility. Knowing that non-WiFi interference is affecting your network is a big advantage. Having your network know and act on this information is a big plus. Some interference you are able to mitigate and remove, some you do not (in the case of a neighbors emissions). Typically most organizations have interference at one level or another, and a lot of this interference is low level enough to not pose any real problems. However, the busier your network gets the more it needs an unaffected spectrum. CleanAir Enabled Security Dashboard Non-Wi-Fi devices can offer quite a challenge to wireless security. Having the ability to examine signals at the physical layer allows for much more granular security. Normal every day consumer wireless devices can and do bypass normal Wi-Fi security. Because all existing WIDsWIPs applications rely on Wi-Fi chipsets for detection, there has been no way to accurately identify these threats until now. For instance, it is possible to invert the data in a wireless signal so that it is 180 degrees out of phase from a normal Wi-Fi signal. Or, you could change the center frequency of the channel by a few kHz and as long as you had a client set to the same center frequency you would have a private channel that no other Wi-Fi chip could see or understand. All that is required is access to the HAL layer (many are available under GPL) for the chip and a little bit of skill. CleanAir is able to detect and understand what these signals are. In addition, CleanAir can detect and locate a PhyDOS attack such as RF Jamming. You can configure CleanAir to report any device that is classified as a security threat. This allows the user to determine what should and should not be transmitting within their facility. There are three ways to view these events. The most convenient is through the Alarm Summary panel located at the top of the WCS home page. A more detailed analysis can be gained by using the Security Dashboard tab on the main page. This is where all security related information on the system is displayed. CleanAir now has its own section within this dashboard allowing you to gain a full understanding of the security of your network from all wireless sources. Figure 39: Security Dashboard with CleanAr integration No matter where you view this information from, you have the detecting AP, the time and date of the event, and the current status to work with. With an MSE added you can run periodic reports on just CleanAir security events. Or, you can look at the location on the map and see the history of the event, even if it was moving. CleanAir enabled Client Troubleshooting Dashboard The client dashboard on the WCS home page is the one stop for all things for clients. Because interference often affects a client before it affects the AP (lower power, poorer antennas) a key thing to know when troubleshooting client performance issues is if non - Wi-Fi interference is a factor. CleanAir has been integrated to the Client Troubleshooting tool on the WCS for that reason. Access the client information in any way you choose from the dashboard, either by searching on a MAC address or user. Once you have the client displayed, select the Client Troubleshooting tool Icon to launch the Client Troubleshooting Dashboard. Figure 40: Client Troubleshooting Dashboard - with CleanAir The client tools provide a wealth of information about the clients status on the network. Select the CleanAir tab on the Monitor Client screen. If the AP that the client is currently associated to is reporting any interference, it is displayed here. Figure 41: CleanAir tab from Client Troubleshooting tool In this case, the interference being detected is a DECT like phone, and because the severity is only 1 (very low) it would be unlikely to cause a lot of trouble. However, a couple of Severity 1 devices can cause issues for a client. The Client Dashboard allows you to quickly rule out, as well as prove, issues in a logical fashion. The MSE adds a significant amount of information to CleanAir features. The MSE is responsible for all location calculations, which are much more intensive for non-Wi-Fi interference than for a Wi-Fi target. The reason for this is the range of conditions that location has to work with. There are a lot of non-Wi-Fi interferers in the world, and they all operate differently. Even among similar devices there can be great differences in signal strength or radiation patterns. The MSE is also who manages merging of devices that span multiple controllers. If you recall, a WLC can merge devices that APs reports, which it is managing. But, interference can be detected that is present on APs that are not all on the same controller. All of the features that MSE enhances are located only in the WCS. Once you have located an interference device on a map, there are several things that can be calculated and presented about how that interference interacts with your network. WCS CleanAir Dashboard with MSE Previously in this document, the CleanAir Dashboard and how the top 10 interferers per band would not be displayed without the MSE was discussed. With the MSE, these are now active because you have the interference device and location information from the MSEs contribution. Figure 42: MSE enabled CleanAir dashboard The upper right hand tables are now populated with the 10 most severe interference sources detected for each band: 802.11an and 802.11bgn. Figure 43: Worst Interference for 802.11an The information displayed is similar to that of the interference report from a specific AP. Interference ID this is the database record for the interference on the MSE Type the type of interferer being detected Status currently only displays Active interferers Severity the severity calculated for the device Affected Channels the channels that the device is being seen affecting Discovered last updated time stamps Floor the map location of the interference If you choose the floor location, it hotlinks you to the map display of the interference source directly where much more information is possible. Note: There is one other difference beyond having a location between information displayed about interferers over what you can see on the AP radio level directly. You might have noticed that there is no RSSI value for the interference. This is because the record as seen here is merged. It is the result of multiple APs reporting the device. The RSSI information is no longer relevant, nor would it be correct to display it because each AP sees the device at different signal strength. WCS Maps with CleanAir device location Choose the link at the end of the record in order to navigate directly to the map location of the interference device from the CleanAir dashboard. Figure 44: Interference located on the map Now locating the interference source on the map allows us to understand its relationship to everything else on the map. In order to product specific information about the device itself (see figure 36), pass a mouse over the interference Icon. Notice the detecting APs, this is the list of APs that currently hears this device. The cluster Center is the AP that is closest to the device. The last line shows the Zone of Impact. This is the radius that the interference device would be suspected of being disruptive. Figure 45: Interference Detail from Mouse Hover The Zone of Impact is only half the story though. It is important to remember that a device might have a long reach or large zone of impact. However, if the severity is low it might or might not matter at all. Zone of impact can be viewed on the map by selecting Interferers gt Zone of Impact from the map display menu. Now you can see the Zone of Impact (ZOI) on the map. ZOI is rendered as a circle around the detected device, and its opacity darkens with higher severity. This aids visualizing the impact of interference devices greatly. A small dark circle is much more of a concern than a large translucent circle. You can combine this information with any other map display or element that you choose. Double-clicking on any interference icon takes you to the detail record for that interference. Figure 46: MSE Interference Record Interferer details include a lot of information about the type of interferer that is being detected. In the upper right hand corner is the help field which tells about what this device is and how this particular type of device affects your network. Figure 47: Detailed Help Other workflow links within the detail record include: Show Interferers of this Type links to a filter to show other instances of this type of device Show Interferers affecting this band links to a filtered display of all same band interferers Floor links back to the map location for this device MSE links to the reporting MSE configuration Clustered by links to the controllers that performed the initial merge Detecting APs hot links to the reporting APs for use in viewing the interference directly from the AP details Interference Location History From the command window in the upper right corner of the record display you can select to view the location history of this interference device. Location History shows the position and all relevant data such as timedate and detecting APs of an interference device. This can be extremely useful in understanding where the interference has been detected and how it has behaved or impacted your network. This information is part of the permanent record of the interference in the MSE database. WCS Monitor Interference The contents of the MSE interferer database can be viewed directly from the WCS by selecting Monitor gt Interference. Figure 48: Monitor Interferers display The list is sorted by status by default. However, it can be sorted by any of the columns contained. You might notice that RSSI information on the interferer is missing. This is because these are merged records. Multiple APs hear a particular interference source. All of them hear it differently, so severity replaces RSSI. You can select any interference IDs in this list to display the same detailed record as was discussed above. Selecting the device type produces the help information that is contained within the record. Selecting the floor location takes you to the map location of the interference. You can select Advanced Search and query the Interferers database directly, then filter the results by multiple criteria. Figure 49: Advance Interference Search You can choose all interferers by ID, by Type (includes all classifiers), severity (range), Duty Cycle (range) or location (floor). You can select the time period, the status (ActiveInactive), select a specific band or even a channel. Save the search for future use if you like. There are two basic types of information generated by the CleanAir components within the system: Interference Device Reports and AirQuality. The controller maintains the AQ database for all attached radios and is responsible for generating threshold traps based on the users configurable thresholds. The MSE manages Interference Device Reports and merges multiple reports arriving from controllers and APs that span controllers into a single event, and locates within the infrastructure. The WCS displays information collected and processed by different components within the CUWN CleanAir system. Individual information elements can be viewed from the individual components as raw data, and the WCS is used to consolidate and display a system wide view and provide automation and work flow. CleanAir installation is a straightforward process. Here are some tips on how to validate the functionality for an initial installation. If you upgrade a current system or install a new system, the best order of operations to follow is Controller code, WCS code, then add MSE code to the mix. Validation at each stage is recommended. In order to enable CleanAir functionality in the system, you first need to enable this on the controller through Wireless gt 802.11ab gt CleanAir . Ensure CleanAir is enabled. This is disabled by default. Once enabled it takes 15 minutes for normal system propagation of Air Quality information because the default reporting interval is 15 minutes. However, you can see the results instantly at the CleanAir detail level on the radio. Monitor gt Access Points gt 802.11an or 802.11bn This displays all radios for a given band. CleanAir status is displayed in the CleanAir Admin Status and CleanAir Oper Status columns. Admin Status relates to the radio status for CleanAir should be enabled by default Oper Status relates to the state of CleanAir for the system this is what the enable command on the controller menu mentioned above controls The operational status cannot be up if the admin status for the radio is disabled. Assuming that you have an Enable for Admin Status, and Up for Operational Status, you can select to view the CleanAir details for a given radio using the radio button located at the end of the row. The selection of CleanAir for details places the radio into Rapid Update mode and provides instant (30 second) updates to Air Quality. If you get Air Quality then CleanAir works. You might or might not see interferers at this point. This depends if you have any active. As previously mentioned, you do not have Air Quality reports for up to 15 minutes displaying in the WCS gt CleanAir tab after initially enabling CleanAir. However, Air Quality reporting should be enabled by default and can be used to validate the installation at this point. In the CleanAir tab you do not have interferers reported in the worst 802.11ab categories without an MSE. You can test an individually interference trap by designating an interference source that you can easily demonstrate as a security threat in the CleanAir configuration dialogue: Configure gt controllers gt 802.11ab gt CleanAir. Figure 50: CleanAir configuration - Security Alarm Adding an interference source for a Security Alarm causes the controller to send a trap message on discovery. This is reflected in the CleanAir tab under the Recent Security-risk Interferers heading. Without the MSE present you do not have any functionality for Monitor gt Interference. This is driven purely by the MSE. There is nothing particularly special about adding an MSE to the CUWN for CleanAir support. Once added, there are some specific configurations you need to make. Ensure that you have synchronized both the system maps and controller before you enable CleanAir tracking parameters. On the WCS console, choose Services gt Mobility Services gt select your MSE gt Context Aware Service gt Administration gt Tracking Parameters . Choose Interferers to enable MSE interference tracking and reporting. Remember to save. Figure 51: MSE Context Aware interference configuration While in the Context Aware Services Administration menu, also visit History Parameters and enable Interferers here as well. Save your selection. Figure 52: Context Aware History Tracking Parameters Enabling these configurations signals the synchronized controller to start the flow of CleanAir IDR information to the MSE and initiates the MSE tracking and convergence processes. It is possible to get the MSE and a controller out of synchronization from a CleanAir perspective. This can happen during an upgrade of controller code when interference sources from multiple controllers might get bounced (deactivated, and re-activated). Simply disabling these configurations and re-enabling with a save forces the MSE to re-register with all synchronized WLCs. Then, the WLCs send fresh data to the MSE, effectively re-starting the processes of merging and tracking of interference sources. When you first add an MSE, you must synchronize the MSE with the network designs and WLCs that you wish for it to provide services for. Synchronization is heavily dependent on Time. You can validate synchronization and NMSP protocol functionality by going to Services gt Synchronization services gt Controllers. Figure 53: Controller - MSE Synchronization Status You see the sync status for each WLC you are synchronized with. A particularly useful tool is located under the MSE column heading NMSP Status. Selecting this tool provides a wealth of information about the state of the NMSP protocol, and can give you information on why a particular synchronization is not occurring. Figure 54: NMSP Protocol Status One of the more common issues experienced is that the time on the MSE and WLC are not the same. If this is the condition, it is displayed in this status screen. There are two cases: WLC Time is after the MSE timeThis synchronizes. But, there are potential errors when merging multiple WLCs information. WLC time is before the MSE timeThis does not allow synchronization because the events have not occurred yet according to the MSEs clock. A good practice is to use NTP services for all controllers and the MSE. Once you have the MSE synchronized and CleanAir enabled, you should be able to see Interference sources in the CleanAir tab under Worst 802.11ab interferers. You can also view them under Monitor gt Interference, which is a direct display of the MSE interference database. One last potential gotcha exists on the Monitor Interferers display. The initial page is filtered to only display interferers that have a severity greater than 5. Figure 55: WCS - Monitor Interferers display This is stated on the initial screen, but often goes overlooked when initializing and validating a new system. You can edit this to display all interference sources by simply making the severity value 0. There are many terms used in this document that are not familiar to a lot of users. Several of these terms come from Spectrum Analysis, some are not. Resolution Band Width (RBW), the minimum RBWThe minimum band width that can be accurately displayed. SAgE2 cards (including the 3500) all have 156 KHz minimum RBW on a 20 MHz dwell, and 78 KHz on a 40 MHz dwell. DwellA dwell is the amount of time the receiver spends listening to a particular frequency. All lightweight access points (LAPs) do off channel dwells in support of rogue detection and metrics gathering for RRM. Spectrum Analyzers do a series of dwells to cover a whole band with a receiver that only covers a portion of the band. DSPDigital Signal Processing SAgESpectrum Analysis Engine Duty CycleDuty Cycle is the active on time of a transmitter. If a transmitter is actively using a particular frequency, the only way another transmitter can use that frequency is to be louder than the first, and significantly louder at that. A SNR margin is needed to understand it. Fast Fourier Transform (FFT)For those interested in the math, google this. Essentially, FFT is used to quantify an analog signal and convert the output from the Time domain to the Frequency domain.
No comments:
Post a Comment