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O ex-major leaguer Manny Ramirez assina com a liga independente do Japão 9 de janeiro de 2017 O ex-meio-campeão da liga principal, Manny Ramirez, concordou em termos com o Pilar Core começa a remodelar o processo para o Pagode do Nara Periodo 10 de janeiro de 2017 NARA - A 4. Pilar central de 3 toneladas Foi reinstalado na base de pedra de um Lisas Eye em Tóquio: FUCHU - Como despejar corretamente uma cerveja e ter um parto seguro 10 de janeiro de 2017 Coloque um copo seco na palma da mão esquerda e levante a mão direita, o amigo dos parques se recusa a testemunhar No julgamento de impeachment em Seul 10 de janeiro de 2017 SEOUL - Presidente desastrado da Coréia do Sul Park Geun-hyes amigo de longa dataCisco CleanAir - Guia de Design de Rede Sem Fio Cisco Unified A Inteligência do Espectro (SI) é uma tecnologia básica projetada para gerenciar proativamente os desafios de um espectro sem fio compartilhado . Essencialmente, o SI traz algoritmos avançados de identificação de interferência semelhantes aos utilizados nos militares para o mundo comercial de redes sem fio. O SI fornece visibilidade a todos os usuários do espectro compartilhado, tanto dispositivos Wi-Fi quanto interferentes estrangeiros. Para cada dispositivo que opera na banda sem licença, a SI diz-lhe: O que é Onde está? Como isso afeta a rede Wi-Fi A Cisco tomou o passo ousado para integrar SI diretamente na solução de silício e infra-estrutura Wi-Fi. A solução integrada, conhecida como Cisco CleanAir, significa que, pela primeira vez, o gerenciador de TI da WLAN é capaz de identificar e localizar fontes de interferência não-802.11, o que aumenta a facilidade de gerenciamento e segurança das redes sem fio. Mais importante ainda, uma SI integrada prepara o cenário para uma nova geração de gerenciamento de recursos de rádio (RRM). Ao contrário das soluções RRM anteriores que só podem entender e se adaptar a outros dispositivos Wi-Fi, o SI abre o caminho para uma solução de RRM de segunda geração plenamente consciente de todos os usuários do espectro sem fio e é capaz de otimizar o desempenho no rosto Desses dispositivos variados. O primeiro ponto importante que precisa ser feito é a partir de uma perspectiva de design. Os pontos de acesso habilitados para o CleanAir (APs) são apenas os APs e o desempenho é praticamente idêntico aos 1140 APs. O design para cobertura Wi-Fi é o mesmo com ambos. CleanAir ou processos de identificação de interferência são um processo passivo. O CleanAir baseia-se no receptor e para a classificação funcionar, a fonte precisa ser suficientemente alta para ser recebida a 10 dB acima do nível de ruído. Se a sua rede for implantada de tal forma que seus clientes e APs possam ouvir um ao outro, o CleanAir pode ouvir o suficiente para alertá-lo para interferências preocupantes na sua rede. Os requisitos de cobertura para o CleanAir estão detalhados neste documento. Existem alguns casos especiais, dependendo da rota de implementação do CleanAir que você finalmente escolhe. A tecnologia foi projetada para complementar as melhores práticas atuais na implantação do Wi-Fi. Isso inclui os modelos de implantação de outras tecnologias amplamente utilizadas, tais como implantações de WIPS, Voz e localização adaptáveis. A Cisco recomenda que tenha conhecimento da CAPWAP e Cisco Unified Wireless Network (CUWN). As informações contidas neste documento baseiam-se nestas versões de software e hardware: os APs compatíveis com CleanAir são Aironet 3502e, 3501e, 3502i e 3501i Cisco WLAN Controller (WLC) executando a versão 7.0.98.0 Cisco Wireless Control System (WCS) executando a versão 7.0.164.0 Mecanismo de Serviços de Mobilidade da Cisco (MSE) executando a versão 7.0 Consulte as Convenções de Dicas Técnicas da Cisco para obter mais informações sobre as convenções do documento. CleanAir é um sistema, não um recurso. Os componentes de software e hardware da CleanAir oferecem a capacidade de medir com precisão a qualidade do canal Wi-Fi e identificar fontes não-Wi-Fi de interferência de canal. Isso não pode ser feito com um chipset Wi-Fi padrão. Para entender os objetivos de projeto e os requisitos para uma implementação bem sucedida, é necessário entender como o CleanAir funciona em um nível alto. Para aqueles que já estão familiarizados com a tecnologia Ciscos Spectrum Expert, o CleanAir é um passo evolutivo natural. Mas, é uma tecnologia completamente nova na medida em que esta é uma tecnologia de análise de espectro distribuída baseada em empresas. Como tal, é semelhante ao Cisco Spectrum Expert em alguns aspectos, mas muito diferente em outros. Os componentes, funções e recursos são discutidos neste documento. Os novos APs compatíveis com CleanAir são Aironet 3502e, 3501e, 3502i e 3501i. O e designa Antena Externa, eu designo a antena interna. Ambos são APL. 802.11n de próxima geração totalmente funcionais e funcionam com energia padrão 802.3af. Figura 1: APs C3502E e C3502I CleanAir Capables O hardware da Análise do Espectro é integrado diretamente no chipset do rádio. Esta adição adicionou mais de 500 K logs lógicos ao rádio silício e forneceu um acoplamento excepcionalmente próximo dos recursos. Existem muitas outras características tradicionais, que foram adicionadas ou melhoradas com esses rádios. Mas, está além do escopo deste documento e estes não são abordados aqui. Basta dizer que, por conta própria, sem o CleanAir, os APs da série 3500 oferecem muitos recursos e desempenho em um AP empresarial atraente e robusto. A arquitetura básica do Cisco CleanAir consiste em APs habilitados para Cisco CleanAir e um controlador Cisco WLAN (WLC). O Cisco Wireless Control System (WCS) eo Mobility Services Engine (MSE) são componentes opcionais do sistema. Para obter o valor total da informação que o sistema CleanAir fornece, o WCS e o MSE juntos são fundamentais para alavancar uma eficácia mais ampla do CleanAir. Isso fornece interfaces de usuário para recursos de espectro avançados, como gráficos históricos, dispositivos de interferência de rastreamento, serviços de localização e análise de impacto. Um AP equipado com a tecnologia Cisco CleanAir coleta informações sobre fontes de interferência não-Wi-Fi, processe-as e encaminhe-as para o WLC. O WLC é uma parte essencial do sistema CleanAir. O WLC controla e configura os APs compatíveis com CleanAir, coleta e processa dados de espectro e fornece-o para o WCS e ou MSE. O WLC fornece interfaces de usuário locais (GUI e CLI) para configurar os recursos e serviços básicos do CleanAir e exibir a informação atual do espectro. O Cisco WCS fornece interfaces de usuário avançadas para o CleanAir que incluem ativação e configuração de recursos, informações de exibição consolidada, registros históricos da Qualidade do Ar e mecanismos de relatórios. Figura 2: Fluxo do sistema lógico O Cisco MSE é necessário para localização e rastreamento histórico de dispositivos de interferência e fornece coordenação e consolidação de relatórios de interferência em vários WLCs. Nota: Um único WLC só pode consolidar alertas de interferência para APs diretamente conectados a ele. A coordenação de relatórios provenientes de APs anexados a diferentes controladores requer o MSE que possui uma visão abrangente do sistema de todos os APs e WLC CleanAir. O coração do sistema CleanAir é o Spectrum Analysis Engine (SAgE) ASIC, o analisador de espectro em um chip. No entanto, é muito mais do que apenas um analisador de espectro. No núcleo é um poderoso motor FFT de 256 pontos que fornece uma incrível 78 KHz RBW (Resolução de Largura da Banda, a resolução mínima que pode ser exibida), impulsos construídos, mecanismos de coleta de estatísticas, bem como o DSP Accelerated Vector Engine (DAvE). O hardware SAgE é executado em paralelo com o chipset Wi-Fi e processa informações de taxa de linha próxima. Tudo isso permite extrema precisão e escalas para um grande número de fontes de interferência semelhantes, sem penalidade no fluxo de tráfego do usuário. O chipset Wi-Fi está sempre na linha. As varreduras de SAgE são realizadas uma vez por segundo. Se um preâmbulo do Wi-Fi for detectado, ele é passado para o chipset diretamente e não é afetado pelo hardware paralelo do SAgE. Nenhum pacote é perdido durante a varredura SAgE, o SAgE é desativado enquanto um pacote Wi-Fi é processado pelo receptor. O SAgE é muito rápido e preciso. Mesmo em um ambiente ocupado, há tempo de verificação suficiente para avaliar com precisão o meio ambiente. Por que o RBW importa Se você precisa contar e medir a diferença entre vários rádios Bluetooth pulando com sinais estreitos em 1600 lúpulos por segundo, você precisa separar diferentes lúpulos de transmissores em sua amostra se quiser saber quantos existem. Isso leva a resolução. Caso contrário, tudo pareceria um pulso. A SAgE faz isso, e isso funciona bem. Por causa do DAvE e estar associado na memória da placa, existe a capacidade de processar vários interferentes de amostras em paralelo. Isso aumenta a velocidade, que permite que você processe o fluxo de dados em tempo quase real. Perto de tempo real significa que há algum atraso, mas é tão mínimo que leva um computador para medi-lo. Os APs Cisco CleanAir produzem dois tipos básicos de informações para o sistema CleanAir. Um IDR (Interference Device Report) é gerado para cada fonte de interferência classificada. Os relatórios AQIs (Air Quality Index) são gerados a cada 15 segundos e passados ​​para o Cisco IOS reg para a média e eventual transmissão para o controlador com base no intervalo configurado. A mensagem CleanAir é tratada no plano de controle em dois novos tipos de mensagem CAPWAP: Configuração do espectro e dados do espectro. Os formatos para estas mensagens estão listados aqui: Dados do espectro AP WLC O Relatório de Dispositivo de Interferência (IDR) é um relatório detalhado que contém informações sobre um dispositivo de interferência classificado. Esse relatório é muito semelhante à informação que é vista nos Dispositivos ativos do Cisco Spectrum Expert ou na Exibição de dispositivos. IDRs ativos podem ser visualizados na GUI e CLI do WLC para todos os rádios do CleanAir naquela WLC. Os IDRs são encaminhados apenas para o MSE. Este é o formato de um relatório de IDR: Tabela 1 - Relatório de dispositivo de interferência Nota: As fontes de interferência marcadas como Interferers de segurança são designadas pelo usuário e podem ser configuradas através de Gt 802.11abgn gt cleanair gt para interferência de segurança para alarme de segurança. Qualquer fonte de interferência classificada pode ser escolhida para um alerta de trap de segurança. Isso envia uma armadilha de segurança para o WCS ou outro receptor de armadilha configurado com base no tipo de interferência selecionado. Esta armadilha não contém a mesma informação que um IDR. É simplesmente uma maneira de disparar um alarme sobre a presença do interferente. Quando um interferente é designado como uma preocupação de segurança, ele é marcado como tal no AP e está sempre incluído nos dez dispositivos que são relatados a partir do AP, independentemente da gravidade. As mensagens IDR são enviadas em tempo real. Na detecção, o IDR é marcado como dispositivo para cima. Se parar um dispositivo, a mensagem é enviada. Uma mensagem de atualização é enviada a cada 90 segundos do AP para todos os dispositivos que estão sendo rastreados. Isso permite atualizações de status de fontes de interferência rastreadas e uma trilha de auditoria no caso de uma mensagem para cima ou para baixo ter sido perdida em trânsito. O relatório de qualidade do ar (AQ) está disponível a partir de qualquer AP compatível com espectro. A qualidade do ar é um conceito novo com o CleanAir e representa uma métrica de qualidade do espectro disponível e indica a qualidade da largura de banda disponível para o canal Wi-Fi. A qualidade do ar é uma média móvel que avalia o impacto de todos os dispositivos de interferência classificados contra um espectro teórico perfeito. A escala é 0-100 com 100 representando o Bom. Os relatórios AQ são enviados de forma independente para cada rádio. O relatório AQ mais recente é visível na WCL GUI e CLI. Os relatórios AQ são armazenados no WLC e são consultados pelo intervalo regular WCS. O padrão é 15 minutos (mínimo) e pode ser estendido para 60 minutos no WCS. Atualmente, a maioria dos chips Wi-Fi padrão avaliam o espectro rastreando toda a economia de pacotes que pode ser desmodulada no recebimento e toda a economia de pacotes que está transmitindo. Qualquer energia que permanece no espectro que não pode ser desmodulada ou contabilizada pela atividade RXTX é agrupada em uma categoria chamada ruído. Na realidade, muito do ruído é realmente restos de colisões, ou pacotes Wi-Fi que se situam abaixo do limite de recebimento para demodulação confiável. Com o CleanAir, uma abordagem diferente é tomada. Toda a energia dentro do espectro que definitivamente NÃO é Wi-Fi é classificada e contabilizada. Nós também podemos ver e entender a energia que é modulada 802.11 e classificar a energia que vem das fontes do canal Co-channel e Adjacent. Para cada dispositivo classificado é calculado um índice de gravidade (veja a seção Gravidade), um número inteiro positivo entre 0 e 100, sendo 100 o mais severo. A gravidade da interferência é então subtraída da escala AQ (começando em 100 bom) para gerar o AQ real para um canalradio, AP, Piso, Edifício ou campus. AQ então é uma medida do impacto de todos os dispositivos classificados no ambiente. Existem dois modos de relatório AQ definidos: atualização normal e rápida. O modo normal é o modo de relatório AQ padrão. O WCS ou o WLC recuperam relatórios na taxa de atualização normal (o padrão é 15 minutos). O WCS informa o controlador sobre o período de polling padrão e a WLC instrui o AP a alterar a média de AQ e o período de relatório de acordo. Quando o usuário verifica os pontos de acesso do Monitor gt e escolhe uma interface de rádio do WCS ou do WLC, o rádio selecionado é colocado no modo de relatório de atualização rápida. Quando um pedido é recebido, o Controlador instrui o AP a alterar o período de relatório AQ padrão temporariamente para uma taxa de atualização rápida fixa (30 seg), o que permite uma visibilidade quase em tempo real das mudanças AQ no nível de rádio. O estado de relatório padrão é ON. Tabela 3: Relatório de qualidade do ar Nota: No contexto do relatório do espectro, a qualidade do ar representa interferência de fontes não-Wi-Fi e fontes de Wi-Fi não detectáveis ​​por um AP Wi-Fi durante a operação normal (por exemplo, funil de freqüência 802.11 antigo Dispositivos, dispositivos 802.11 alterados, interferência de canal sobreposta adjacente, etc.). Informações sobre interferência baseada em Wi-Fi são coletadas e relatadas pelo AP usando o chip Wi-Fi. Um modo local AP coleta informações AQ para o (s) canal (es) de serviço atual (s). Um Modo Monitor AP coleta informações para todos os canais configurados nas opções de digitalização. São suportadas as configurações CUWN padrão de Country, DCA e Todos os canais. Quando um relatório AQ é recebido, o Controlador executa o processamento necessário e armazená-lo no banco de dados AQ. Como mencionado anteriormente, a CleanAir é a integração da tecnologia Cisco Spectrum Expert dentro de um Cisco AP. Embora existam semelhanças, este é um novo uso da tecnologia e muitos novos conceitos são apresentados nesta seção. O Cisco Spectrum Expert introduziu uma tecnologia capaz de identificar positivamente fontes de energia de rádio que não sejam Wi-Fi. Isso permitiu ao operador se concentrar em informações como o ciclo de trabalho e os canais operacionais, e tomar uma decisão informada sobre o dispositivo e seu impacto em sua rede Wi-Fi. Spectrum Expert permitiu que o operador bloqueie o sinal escolhido no aplicativo do localizador de dispositivos e localize fisicamente o dispositivo caminhando com o instrumento. O objetivo de design do CleanAir é avançar ainda mais, removendo essencialmente o operador da equação e automatizando várias tarefas no gerenciamento do sistema. Como você pode saber o que o dispositivo e o que está afetando, melhores decisões podem ser feitas no nível do sistema sobre o que fazer com a informação. Vários novos algoritmos foram desenvolvidos para adicionar inteligência ao trabalho que foi iniciado com o Cisco Spectrum Expert. Há sempre casos que exigem a desativação física de um dispositivo de interferência, ou tomar uma decisão sobre um dispositivo e o impacto que envolve seres humanos. O sistema geral deve curar o que pode ser curado e evitar o que pode ser evitado para que o esforço para recuperar o espectro afetado possa ser um exercício proativo em vez de um reativo. Modo Local AP (recomendado) (LMAP) Um Cisco CleanAir AP que opera no modo LMAP está atendendo clientes no canal atribuído. Também está monitorando o Spectrum nesse canal e esse canal SOMENTE. A integração de silício apertado com o rádio Wi-Fi permite que o hardware da CleanAir ouça entre o tráfego no canal que atualmente está sendo servido com absolutamente nenhuma penalidade para o débito de clientes anexados. Essa é a detecção da taxa de linha sem interromper o tráfego do cliente. Não há demoras CleanAir processadas durante as verificações normais do canal. Em operação normal, um modo CUWN Local Mode AP executa uma varredura passiva de canal off dos canais disponíveis alternativos em 2,4 GHz e 5 GHz. As varreduras de canal fora são usadas para manutenção do sistema, como métricas RRM e detecção desonesta. A frequência destas varredura não é suficiente para coletar backs back-back necessárias para a classificação positiva do dispositivo, de modo que informações recolhidas durante esta verificação são suprimidas pelo sistema. Aumentar a frequência de varreduras fora do canal também não é desejável, pois tira do tempo que o tráfego dos serviços de rádio. O que tudo isso significa que o CleanAir AP no modo LMAP varre apenas um canal de cada banda de forma contínua. Nas densidades de empresas normais, deve haver muitos APs no mesmo canal, e pelo menos um em cada canal assumindo que o RRM está gerenciando a seleção do canal. Uma fonte de interferência que usa modulação de banda estreita (opera em ou ao redor de uma única freqüência) é detectada somente por APs que compartilham esse espaço de freqüência. Se a interferência é um tipo de salto de frequência (usa freqüências múltiplas geralmente cobrindo toda a banda), é detectado por cada AP que pode ouvi-lo operar na banda. Figura 4: exemplo de detecção de LMAP AP Em 2,4 GHz, os LMAPs têm densidade suficiente para geralmente garantir pelo menos três pontos de classificação. Um mínimo de três pontos de detecção é necessário para a resolução da localização. Em 5 GHz, existem 22 canais operando nos Estados Unidos, portanto a densidade de detecção e a densidade de localização suficiente são menos prováveis. No entanto, se a interferência estiver operando em um canal ocupado por um AP CleanAir, ele o detecta e alerta ou toma medidas para mitigar se esses recursos estão habilitados. A maior parte da interferência observada é limitada à porção de 5,8 GHz da banda. É aí que os dispositivos de consumo vivem e, portanto, onde é mais provável que seja encontrado. Você pode limitar seu plano de canal para forçar mais APs a esse espaço, se desejar. No entanto, não está realmente garantido. Lembre-se, a interferência é apenas um problema se estiver usando o espectro que você precisa. Se o seu AP não estiver nesse canal, é provável que você ainda tenha muito espectro para se mudar. E se a necessidade de monitorar todos os 5 GHz for conduzida por políticas de segurança, veja a definição AP do Modo Monitor abaixo. Modo Monitor AP (opcional) (MMAP) O modo AP de um Monitor CleanAir é dedicado e não serve o tráfego do cliente. Ele fornece varredura em tempo integral de todos os canais usando intervalos de 40 MHz. O CleanAir é suportado no modo monitor, juntamente com todos os outros aplicativos de modo de monitoramento atual, incluindo WIPS Adaptáveis ​​e aprimoramento de localização. Em uma configuração de rádio dupla, isso garante que todos os canais de banda são rotineiramente digitalizados. Os MMAP habilitados para CleanAir podem ser implantados como parte de uma implantação generalizada de LMAPs habilitados para CleanAir para fornecer cobertura adicional em 2,4 e 5 GHz, ou como uma solução de sobreposição autônoma para a funcionalidade CleanAir em uma implantação existente de CleanAir AP. Em um cenário como mencionado acima, onde a segurança é um driver primário, é provável que os WIPS Adaptáveis ​​também sejam um requisito. Isso é suportado simultaneamente com o CleanAir no mesmo MMAP. Existem algumas diferenças distintas em como alguns recursos são suportados ao implantar como uma solução de sobreposição. Isto é abordado na discussão dos modelos de implantação neste documento. Spectrum Expert Connect Mode SE Connect (opcional) Um SE Connect AP é configurado como um Sensor de Espectro dedicado que permite a conexão do aplicativo Cisco Spectrum Expert em execução em um host local para usar o CleanAir AP como sensor de espectro remoto para o aplicativo local. A conexão entre Spectrum Expert e o AP remoto ultrapassa o controlador no plano de dados. O AP permanece em contato com o controlador no plano de controle. Este modo permite a visualização dos dados do espectro bruto, como gráficos FFT e medidas detalhadas. Toda a funcionalidade do sistema CleanAir é suspensa enquanto o AP está neste modo e nenhum cliente é veiculado. Este modo destina-se apenas a resolução remota de problemas. O aplicativo Spectrum Expert é um aplicativo MS Windows que se conecta ao AP via uma sessão TCP. Pode ser suportado no VMWare. No CleanAir, o conceito de qualidade do ar foi introduzido. A qualidade do ar é uma medida da porcentagem de tempo que o espectro em um determinado recipiente observado (rádio, AP, Banda, Piso, Construção) está disponível para o tráfego Wi-Fi. AQ é uma função do índice de gravidade, que é calculado para cada fonte de interferência classificada. O índice de gravidade avalia cada dispositivo não Wi-Fi sobre as características do ar e calcula a porcentagem de tempo que o espectro não está disponível para Wi-Fi com este dispositivo presente. A qualidade do ar é um produto dos índices de severidade de todas as fontes de interferência classificadas. Isso é relatado como a qualidade global do ar por radiochannel, banda ou domínio de propagação de RF (piso, construção) e representa o custo total em relação ao tempo de antena disponível de todas as fontes não-Wi-Fi. Qualquer coisa que seja deixada é teoricamente disponível para a rede Wi-Fi para o tráfego. Isso é teórico porque existe uma ciência inteira atrás de medir a eficiência do tráfego Wi-Fi, e isso está além do escopo deste documento. No entanto, saber que a interferência é ou não está impactando essa ciência é um objetivo fundamental se o seu plano é sucesso na identificação e mitigação de pontos de dor. O que torna a fonte de interferência grave O que determina se é ou não é um problema Como uso essas informações para gerenciar minha rede Estas questões são discutidas neste documento. Nos termos mais simples, a utilização não-Wi-Fi se resume à frequência com que outro rádio está usando o meu espectro de redes (Ciclo de funcionamento) e quanto é alto em relação aos meus rádios (RSSIlocation). A energia no canal que é vista por uma interface 802.11 tentando acessar o canal é percebida como um canal ocupado se estiver acima de um determinado limite de energia. Isso é determinado pela avaliação de canais claros (CCA). O Wi-Fi usa um método de acesso de escuta antes do canal de conversação para acesso PHY livre de contenção. Isto é por CSMA-CA (-Accisão de evitação). O RSSI do interferente determina se pode ser ouvido acima do limite CCA. O ciclo de funcionamento é o horário de um transmissor. Isso determina a persistência de uma energia no canal. Quanto maior o ciclo de trabalho, mais frequentemente o canal é bloqueado. A severidade simples pode ser demonstrada dessa forma, em seguida, usando rigorosamente o RSSI e o Ciclo de Trabalho. Para fins de ilustração, é assumido um dispositivo com 100 ciclo de serviço. Figura 5: À medida que o sinal de interferência diminui - AQI aumenta. No gráfico desta figura, você pode ver isso à medida que o poder do sinal da interferência diminui, o AQI resultante aumenta. Tecnicamente, assim que o sinal cai abaixo de -65 dBm, o AP já não está bloqueado. Você precisa pensar sobre o impacto que isso tem sobre os clientes na célula. O ciclo de trabalho 100 (DC) garante a interrupção constante dos sinais do cliente com SNR insuficiente na presença do ruído. AQ aumenta rapidamente quando a potência do sinal cai abaixo de -78 dBm. Até agora, existem dois dos três principais impactos de interferência definidos na métrica da qualidade do ar com base na gravidade: a interferência é direta ao olhar para 100 DC. Este é o tipo de sinal mais utilizado nas demonstrações do efeito da interferência. É fácil de ver em um espectrograma e tem um efeito muito dramático no canal Wi-Fi. Isso acontece no mundo real também, por exemplo, em câmeras de vídeo analógicas, detectores de movimento, equipamentos de telemetria, sinais TDM e telefones sem fio mais antigos. Há muitos sinais que não são 100 DC. Na verdade, muita interferência encontrada é a interferência desse tipo: variável a mínima. Aqui fica um pouco mais difícil chamar a gravidade. Exemplos de interferências deste tipo são Bluetooth, telefones sem fio, alto-falantes sem fio, dispositivos de telemetria, equipamentos 802.11fh mais antigos e assim por diante. Por exemplo, um único fone de ouvido Bluetooth não causa muito dano em um ambiente Wi-Fi. No entanto, três deles com propagação sobreposta podem desconectar um telefone Wi-Fi se percorreram. Além de CCA, existem disposições nas especificações 802.11, como a janela de contenção, que é necessária para acomodar o tempo de transmissão de diferentes protocolos de base. Então você adiciona a estes vários mecanismos QOS. Todas essas reservas de mídia são usadas por diferentes aplicativos para maximizar a eficiência do tempo de antena e minimizar as colisões. Isso pode ser confuso. No entanto, como todas as interfaces no ar participam e concordam com o mesmo grupo de padrões, isso funciona muito bem. O que ocorre neste caos ordenado quando você introduz uma energia muito específica que não entende os mecanismos de contenção ou, para esse assunto, nem mesmo participa do CSMA-CA Bem, o caos realmente, em maior ou menor grau. Depende de quão ocupado o meio é quando a interferência é experimentada. Figura 6: Ciclos de função do canal semelhantes, mas diferentes Você pode ter dois sinais idênticos em termos do ciclo de trabalho, conforme medido no canal e amplitude, mas tem dois níveis totalmente diferentes de interferência experimentados em uma rede Wi-Fi. Um pulso curto de repetição rápida pode ser mais devastador para Wi-Fi do que uma gordura repetida relativamente lenta. Olhe para um bloqueador de RF, que efetivamente desliga um canal Wi-Fi e registra muito pouco ciclo de trabalho. Para fazer um bom trabalho avaliando, você precisa de uma melhor compreensão do intervalo mínimo de interferência introduzido. O intervalo de interferência mínimo explica o fato de que os impulsos no canal interrompem a atividade do Wi-Fi por um período maior do que a duração real, devido a três efeitos: se já contagem, os dispositivos Wi-Fi devem aguardar um período DIFS adicional após a interferência pulso. Este caso é típico para redes altamente carregadas, onde a interferência começa antes que o contador de back-off Wi-Fis tenha contado a zero. Se um novo pacote chegar a ser transmitido de interferência média, o dispositivo Wi-Fi deve, adicionalmente, desistir usando um valor aleatório entre zero e CWmin. Este caso é típico para redes ligeiramente carregadas, onde a interferência começa antes que o pacote Wi-Fi chegue ao MAC para transmissão. Se o dispositivo Wi-Fi já estiver transmitindo um pacote quando a explosão de interferência chegar, todo o pacote deve ser retransmitido com o próximo valor mais alto de CW, até CWmax. Este caso é típico se a interferência começar em segundo lugar, parcialmente através de um pacote Wi-Fi existente. Se o tempo de atraso expirar sem uma retransmissão bem-sucedida, a próxima volta é o dobro do anterior. Isso continua com a transmissão mal sucedida até CWmax é alcançada ou TTL é excedido para o quadro. Figura 7 - Para 802.11bg CWmin 31, para 802.11a CWmin é 15, ambos possuem CWmax de 1023 Em uma rede Wi-Fi real, é difícil estimar a duração média desses três efeitos porque são funções do número de dispositivos No BSS, BSSs sobrepostos, atividade do dispositivo, comprimentos de pacotes, protocolos de velocidades suportadas, QoS e atividade atual. Portanto, a próxima melhor coisa é criar uma métrica que permaneça constante como um ponto de referência. Isto é o que Severidade faz. Ele mede o impacto de um único interferente contra uma rede teórica e mantém um relatório constante de gravidade, independentemente da utilização subjacente da rede. Isso nos dá um ponto relativo para analisar as infra-estruturas de rede. A resposta à questão de quanto interferência não-Wi-Fi é ruim é subjetiva. Em redes levemente carregadas, é bem possível ter níveis de interferência não-Wi-Fi que passam despercebidos pelos usuários e administradores. Isso é o que leva ao problema no final. A natureza das redes sem fio é tornar-se mais movimentada ao longo do tempo. O sucesso leva a uma adoção organizacional mais rápida e a novas aplicações comprometidas. Se houver interferência presente desde o primeiro dia, é bastante provável que a rede tenha um problema com isso quando estiver ocupado o suficiente. Quando isso acontece, é difícil para as pessoas acreditarem que algo que foi bem aparentemente o tempo todo é o culpado. Como usamos as métricas CleanAirs Air Quality and Severity AQ é usado para desenvolver e monitorar uma medição do espectro de linha de base e alerta sobre mudanças que indicam um impacto no desempenho. Você também pode usá-lo para avaliação de tendências de longo prazo através de relatórios. A gravidade é usada para avaliar o potencial de impacto de interferência e priorizar dispositivos individuais para mitigação. Os transmissores não Wi-Fi são menos amigáveis ​​quando se trata de características únicas que podem ser usadas para identificá-los. Isso é essencialmente o que tornou a solução Cisco Spectrum Expert tão revolucionária. Agora, com o CleanAir existem vários APs que potencialmente todos ouvem a mesma interferência ao mesmo tempo. A correlação desses relatórios para isolar instâncias únicas é um desafio que deve ser resolvido para fornecer recursos avançados, como localização de dispositivos de interferência, bem como uma contagem precisa. Entre no Pseudo MAC ou no PMAC. Uma vez que um dispositivo de vídeo analógico não tem um endereço MAC ou, em vários casos, qualquer outro código digital de identificação, um algoritmo tenha que ser criado para identificar dispositivos únicos que sejam relatados por várias fontes. Um PMAC é calculado como parte da classificação do dispositivo e incluído na gravação do dispositivo de interferência (IDR). Cada AP gera o PMAC de forma independente e, embora não seja idêntico para cada relatório (no mínimo, o RSSI medido do dispositivo provavelmente é diferente em cada AP), é semelhante. A função de comparação e avaliação de PMACs é chamada de fusão. O PMAC não está exposto nas interfaces do cliente. Somente os resultados da fusão estão disponíveis sob a forma de um ID de cluster. Esta fusão é discutida em seguida. Figura 8: Detecção crua de interferências Neste gráfico, você pode ver vários APs todos relatando DECT, como a energia do telefone. No entanto, os APs neste gráfico estão realmente relatando a presença de dois DECT distintos, como fontes do telefone. Antes da atribuição de um PMAC e fusão subsequente, existe apenas a classificação do dispositivo, que pode ser enganosa. O PMAC nos dá uma maneira de identificar fontes de interferência individuais, mesmo que não tenham nenhuma informação lógica que possa ser usada, como um endereço. Existem vários APs todos relatando um dispositivo similar. Para cada AP de relatórios, o PMAC é atribuído ao sinal classificado. O próximo passo é combinar os PMACs que provavelmente são o mesmo dispositivo de origem para um único relatório para o sistema. Isto é o que a fusão faz, consolidando múltiplos relatórios para um único evento. A fusão usa a proximidade espacial dos APs de relatórios. Se houver seis IDRs similares com cinco de APs no mesmo andar, e outro de um edifício a uma milha de distância, é improvável que este seja o mesmo interferente. Uma vez que uma proximidade é estabelecida, um cálculo de probabilidade é executado para igualar os IDRs distintos que pertencem e o resultado é atribuído a um cluster. Um cluster representa a gravação desse dispositivo de interferência e captura os APs individuais que estão relatando sobre ele. 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.